Sample records for airglow emission lines

  1. Effect of severe geomagnetic disturbances on the atomic oxygen airglow emissions

    NASA Astrophysics Data System (ADS)

    Sunil Krishna, M.; Bag, T.

    2013-12-01

    The atomic oxygen greenline (557.7nm) and redline emission (630.0 nm) are the most readily observed and prominent lines in the nightglow. These emissions can be used as precursors for a variety of physical and chemical processes that occur in the upper mesosphere and lower thermosphere. There are a multitude of effects of space weather on the Earth's atmosphere. The decay of ring current is a very important parameter which can induce variation in the densities of few important species in the atmosphere which are of airglow interest. The connection of variation of airglow emissions with the extreme space weather conditions is not very well established. In the present study, severe geomagnetic storms and their effect on the airglow emissions such as 557.7 nm and 630.0 nm emissions is studied. This study is primarily based on photochemical models with the necessary input obtained from a combination of experimental observations and empirical models. We have tried to understand the effect of severe space weather conditions on few very important airglow emissions in terms of volume emission rates, change in the peak emission height. Based on the variation an attempt has been made to understand the cause of the variation and further to link the variations in the ring current to the airglow chemistry. The study presents the results of calculations performed for the most severe geomagnetic storms occurred over the recent past because of variety of causes on Sun.

  2. Enhanced 630nm equatorial airglow emission observed by Limb Viewing Hyper Spectral Imager (LiVHySI) onboard YOUTHSAT-1

    NASA Astrophysics Data System (ADS)

    Bisht, R. S.; Thapa, N.; Babu, P. N.

    2016-04-01

    The Earth's airglow layer, when observed in the limb view mode, appears to be a double layer. LiVHySI onboard YOUTHSAT (inclination 98.730, apogee 817 km, launched by Indian Space Research Organization in April, 2011) is an Earth's limb viewing camera measuring airglow emissions in the spectral window of 550-900 nm. Total altitude coverage is about 500 km with command selectable lowest altitude. During few of the orbits we have observed the double layer structure and obtained absolute spectral intensity and altitude profile for 630 nm airglow emission. Our night time observations of upper atmosphere above dip equator carried out on 3rd May, 2011 show a prominent 630 nm double layer structure. The upper airglow layer consists of the 630 nm atomic oxygen O(1D) emission line and lower layer consists of OH(9-3) meinel band emission at 630 nm. The volume emission rate as a function of altitude is simulated for our observational epoch and the modeled limb intensity distribution is compared with the observations. The observations are in good agreement with the simulated intensity distribution.

  3. OH line selection for nadir airglow gravity wave imaging in the auroral zone

    NASA Astrophysics Data System (ADS)

    Kumer, J. B.; Hecht, J.; Geballe, T. R.; Mergenthaler, J. L.; Rinaldi, M.; Claflin, E. S.; Swenson, G. R.

    2003-04-01

    For satellite borne nadir OH airglow wave imaging in the auroral zone the observed lines must be strong enough to give good signal to noise, coincident with strong atmospheric absorption lines to suppress structure in the image due to reflection of airglow and moonlight from tops of clouds and from high altitude terrain, and in a spectral region coincident with relatively weak aurora that its contribution to the observed structure can be corrected by data obtained in a guard band containing relatively strong auroral emission, and relatively weak, or no airglow. OH airglow spectra observed from high altitude, in our case Mauna Kea by the UKIRT CGS4 grating instrument, (see website http://www.jach.hawaii.edu/JACpublic/UKIRT/instruments/cgs4/maunakea/ohlines.html) provide an opportunity to identify lines that ARE NOT observed at that high altitude. These are most absorbed in the earths atmosphere. These occur in the regions near 1400 and 1900 nm of strong water vapor absorption. Our preliminary determination is that the 7-5 p1(2) line at 1899.01 nm and the p1(3) at 1911.41 nm are the best candidates. These are missing in the observed spectra, and this is confirmed by running FASCODE transmission calculations from top of Mauna Kea to space at .01 cm-1 resolution. Similar calculations for conditions at which the high resolution Kitt peak atlas data were taken confirmed the calculations. OH line positions and relative strengths within the band were derived from the HITRAN data base, and transmitted lines in the 7-5 band were used to determine the strength of these lines. Each are the order 10 kR, and are about four to six times brighter than atmospheric absorbed candidate lines in the 1400 nm region. Also, the aurora in the 1900nm region is considerably weaker than in the 1400nm region. In fact the region 1351 to 1358 contains relatively strong aurora, and practically no airglow, and is candidate for an instrumental auroral guard band. The nadir imaging instrument which

  4. Post sunset behavior of the 6300 A atomic oxygen airglow emission

    NASA Technical Reports Server (NTRS)

    Smith, R. E.

    1976-01-01

    A theoretical model of the 6300 A OI airglow emission was developed based on the assumptions that both the charged and neutral portions of the Earth's upper atmosphere are in steady state conditions of diffusive equilibrium. Intensities of 6300 A OI emission line were calculated using electron density true height profiles from a standard C-4 ionosonde and exospheric temperatures derived from Fabry-Perot interferometer measurements of the Doppler broadened 6300 A emission line shape as inputs to the model. Reaction rate coefficient values, production mechanism efficiencies, solar radiation fluxes, absorption cross sections, and models of the neutral atmosphere were varied parametrically to establish a set of acceptable inputs which will consistently predict 6300 A emission intensities that closely agree with intensities observed during the post-sunset twilight period by an airglow observatory consisting of a Fabry-Perot interferometer and a turret photometer. Emission intensities that can only result from the dissociative recombination of molecular oxygen ions were observed during the latter portion of the observational period. Theoretical calculations indicate that contamination of the 6300 A OI emission should be on the order of or less than 3 percent; however, these results are very sensitive to the wavelengths of the individual lines and their intensities relative to the 6300 A OI intensity. This combination of a model atmosphere, production mechanism efficiencies, and quenching coefficient values was used when the dissociative photoexcitation and direct impact excitation processes were contributing to the intensity to establish best estimates of solar radiation fluxes in the Schumann--Runge continuum and associated absorption cross sections. Results show that the Jacchia 1971 model of the upper atmosphere combined with the Ackerman recommended solar radiation fluxes and associated absorption cross sections produces theoretically calculated intensities that more

  5. Berkeley extreme-ultraviolet airglow rocket spectrometer - BEARS

    NASA Technical Reports Server (NTRS)

    Cotton, D. M.; Chakrabarti, S.

    1992-01-01

    The Berkeley EUV airglow rocket spectrometer (BEARS) instrument is described. The instrument was designed in particular to measure the dominant lines of atomic oxygen in the FUV and EUV dayglow at 1356, 1304, 1027, and 989 A, which is the ultimate source of airglow emissions. The optical and mechanical design of the instrument, the detector, electronics, calibration, flight operations, and results are examined.

  6. HF-enhanced 4278-Å airglow: evidence of accelerated ionosphere electrons?

    NASA Astrophysics Data System (ADS)

    Fallen, C. T.; Watkins, B. J.

    2013-12-01

    We report calculations from a one-dimensional physics-based self-consistent ionosphere model (SCIM) demonstrating that HF-heating of F-region electrons can produce 4278-Å airglow enhancements comparable in magnitude to those reported during ionosphere HF modification experiments at the High-frequency Active Auroral Research Program (HAARP) observatory in Alaska. These artificial 'blue-line' emissions, also observed at the EISCAT ionosphere heating facility in Norway, have been attributed to arise solely from additional production of N2+ ions through impact ionization of N2 molecules by HF-accelerated electrons. Each N2+ ion produced by impact ionization or photoionization has a probability of being created in the N2+(1N) excited state, resulting in a blue-line emission from the allowed transition to its ground state. The ionization potential of N2 exceeds 18 eV, so enhanced impact ionization of N2 implies that significant electron acceleration processes occur in the HF-modified ionosphere. Further, because of the fast N2+ emission time, measurements of 4278-Å intensity during ionosphere HF modification experiments at HAARP have also been used to estimate artificial ionization rates. To the best of our knowledge, all observations of HF-enhanced blue-line emissions have been made during twilight conditions when resonant scattering of sunlight by N2+ ions is a significant source of 4278-Å airglow. Our model calculations show that F-region electron heating by powerful O-mode HF waves transmitted from HAARP is sufficient to increase N2+ ion densities above the shadow height through temperature-enhanced ambipolar diffusion and temperature-suppressed ion recombination. Resonant scattering from the modified sunlit region can cause a 10-20 R increase in 4278-Å airglow intensity, comparable in magnitude to artificial emissions measured during ionosphere HF-modification experiments. This thermally-induced artificial 4278-Å aurora occurs independently of any artificial

  7. Twilight airglow. II - N2/+/ emission at 3914 A

    NASA Technical Reports Server (NTRS)

    Sharp, W. E.

    1974-01-01

    One of the experiments aboard a rocket flight carrying instruments to measure the dawn airglow, the ion and electron densities, and the photoelectron spectrum is reported. For a solar zenith angle of 90 deg the emission at 3914 A from N2(+) peaks at about 260 km. The integrated intensity from model calculations suggests that resonance scattering of 3914-A solar photons off N2(+) produces 90% of the emission, whereas simultaneous photoionization excitation of N2(+) produces less than 10% of the emission. Photoelectron impact excitation is found to contribute about 1%.

  8. Simulations and observations of plasma depletion, ion composition, and airglow emissions in two auroral ionospheric depletion experiments

    NASA Technical Reports Server (NTRS)

    Yau, A. W.; Whalen, B. A.; Harris, F. R.; Gattinger, R. L.; Pongratz, M. B.

    1985-01-01

    Observations of plasma depletion, ion composition modification, and airglow emissions in the Waterhole experiments are presented. The detailed ion chemistry and airglow emission processes related to the ionospheric hole formation in the experiment are examined, and observations are compared with computer simulation results. The latter indicate that the overall depletion rates in different parts of the depletion region are governed by different parameters.

  9. Pluto's Far Ultraviolet Spectrum and Airglow Emissions

    NASA Astrophysics Data System (ADS)

    Steffl, A.; Schindhelm, E.; Kammer, J.; Gladstone, R.; Greathouse, T. K.; Parker, J. W.; Strobel, D. F.; Summers, M. E.; Versteeg, M. H.; Ennico Smith, K.; Hinson, D. P.; Linscott, I.; Olkin, C.; Parker, A. H.; Retherford, K. D.; Singer, K. N.; Tsang, C.; Tyler, G. L.; Weaver, H. A., Jr.; Woods, W. W.; Young, L. A.; Stern, A.

    2015-12-01

    The Alice far ultraviolet spectrograph on the New Horizons spacecraft is the second in a family of six instruments in flight on, or under development for, NASA and ESA missions. Here, we present initial results from the Alice observations of Pluto during the historic flyby. Pluto's far ultraviolet spectrum is dominated by sunlight reflected from the surface with absorption by atmospehric constituents. We tentatively identify C2H2 and C2H4 in Pluto's atmosphere. We also present evidence for weak airglow emissions.

  10. 2D-model of oxygen emissions lines for Europa

    NASA Astrophysics Data System (ADS)

    Cessateur, Gaël; Barthelemy, Mathieu; Lilensten, Jean; Rubin, Martin; Maggiolo, Romain; De Keyser, Johan

    2017-04-01

    The Jovian moon Europa is an interesting case study as an archetype for icy satellites, and will be one of the primary targets of the ESA JUICE mission which should be launched in 2022. Hosting a thin neutral gas atmosphere mainly composed of O2 and H2O, Europa can be studied by its airglow and dayglow emissions. A 1D photochemistry model has first been developed to assess the impact of the solar UV flux on the visible emission, such as the red and green oxygen lines (Cessateur et al. 2016). For limb polar viewing, red line emissions can reach a few hundreds of Rayleigh close to the surface. The impact of the precipitating electrons has also been studied. The density and temperature of the electrons are first derived from the multifluid MHD model from Rubin et al. (2015). A 2D emission model has thus been developed to estimate the airglow emissions. When electrons are the major source of the visible emissions, the solar UV flux can be responsible for up to 15% of those emissions for some specific line of sight. Oxygen emission lines in the UV have also been considered, such as 130.5 and 135.6 nm. For the latter, we did estimate some significant line emissions reaching 700 Rayleigh for a polar limb viewing angle close to the surface. Oxygen emission lines are significant (higher than 10 R) for altitudes lower than 100 km for all lines, except for the red line emissions where emissions are still above 10 R up to 200 km from the surface. A sensitivity study has also been performed in order to assess the impact of the uncertainties relative to the dissociative-excitation cross sections. Cessateur G, Barthelemy M & Peinke I. Photochemistry-emission coupled model for Europa and Ganymede. J. Space Weather Space Clim., 6, A17, 2016 Rubin, M., et al. Self-consistent multifluid MHD simulations of Europa's exospheric interaction with Jupiter's magnetosphere, J. Geophys. Res. Space Physics, 120, 3503-3524, 2015

  11. Temperature estimation from hydroxyl airglow emission in the Venus night side mesosphere

    NASA Astrophysics Data System (ADS)

    Migliorini, A.; Snels, M.; Gérard, J.-C.; Soret, L.; Piccioni, G.; Drossart, P.

    2018-01-01

    The temperature of the night side of Venus at about 95 km has been determined by using spectral features of the hydroxyl airglow emission around 3 μm, recorded from July 2006 to July 2008 by VIRTIS onboard Venus Express. The retrieved temperatures vary from 145.5 to about 198.1 K with an average value of 176.3 ± 14.3 K and are in good agreement with previous ground-based and space observations. The variability with respect to latitude and local time has been studied, showing a minimum of temperature at equatorial latitudes, while temperature values increase toward mid latitudes with a local maximum at about 35°N. The present work provides an independent contribution to the temperature estimation in the transition region between the Venus upper mesosphere and the lower thermosphere, by using the OH emission as a thermometer, following the technique previously applied to the high-resolution O2(a1Δg) airglow emissions observed from ground.

  12. Mesopause region wind, temperature and airglow irradiance above Eureka, Nunavut

    NASA Astrophysics Data System (ADS)

    Kristoffersen, Samuel; Ward, William E.; Vail, Christopher; Shepherd, Marianna

    2016-07-01

    The PEARL All Sky Imager (PASI, airglow images), the Spectral Airglow Temperature Imager (SATI, airglow irradiance and temperature) and the E-Region Wind Interferometer II (ERWIN2, wind, airglow irradiance and temperature) are co-located at the Polar Environment Atmospheric Research Laboratory (PEARL)in Eureka, Nunavut (80 N, 86 W). These instruments view the wind, temperature and airglow irradiance of hydroxyl (all three) O2 (ERWIN2 and SATI), sodium (PASI), and oxygen green line (PASI and ERWIN2). The viewing locations and specific emissions of the various instruments differ. Nevertheless, the co-location of these instruments provides an excellent opportunity for case studies of specific events and for intercomparison between the different techniques. In this paper we discuss the approach we are using to combine observations from the different instruments. Case studies show that at times the various instruments are in good agreement but at other times they differ. Of particular interest are situations where gravity wave signatures are evident for an extended period of time and one such situation is presented. The discussion includes consideration of the filtering effect of viewing through airglow layers and the extent to which wind, airglow and temperature variations can be associated with the same gravity wave.

  13. Further investigations of lightning-induced transient emissions in the OH airglow layer

    NASA Astrophysics Data System (ADS)

    Huang, Tai-Yin; Kuo, C. L.; Chiang, C. Y.; Chen, A. B.; Su, H. T.; Hsu, R. R.

    2010-10-01

    A previous study of lightning-induced transient emissions in and below the OH airglow layer using observations by the Imager of Sprites and Upper Atmospheric Lightning (ISUAL) CCD camera onboard the FORMOSAT-II satellite showed that intensity enhancements occurred more frequently in the OH airglow layer. Here we show the results of new observations made in December 2009 and January 2010 using a narrowband 630 nm filter and spectrophotometer and present further analysis. We estimated the N21P intensity enhancements to be ˜65% and 53% of the total intensity enhancements for the two events we analyzed using ISUAL and the spectrophotometer data in conjunction with a model for emissions of light and VLF perturbations from electromagnetic pulse sources (elves). Our analysis indicates that there is still somewhat considerable intensity enhancement (˜1.25 kR) unaccounted for after the N21P contribution has been removed. Our study suggests that there might be OH emissions in elves and that OH species might also be involved in the lightning-induced process and contribute to the intensity enhancements that we observed.

  14. The equatorial airglow and the ionospheric geomagnetic anomaly

    NASA Technical Reports Server (NTRS)

    Chandra, S.; Reed, E. I.; Troy, B. E., Jr.; Blamont, J. E.

    1972-01-01

    OGO D observations of OI (6300A) emissions reveal a global pattern in the equatorial airglow undetected from the ground-based observations. The post sunset emission rate of OI is generally asymmetrical with respect to the geomagnetic equator and shows no apparent correlation with the ultraviolet airglow (OI 1304 and 1356A) and F region electron density measured simultaneously from the same spacecraft. Both the ultraviolet airglow and the ion density measured in the altitude region of 450 km follow similar latitudinal variations and exhibit properties of the equatorial ionospheric anomaly. The asymmetry in OI emission can be attributed to the asymmetry in the height of the F 2 maximum inferred from the height of the maximum emission. From correlative studies of the airglow and the ionospheric measurements, the mechanisms for the ultraviolet and the 6300A emission are discussed in terms of the processes involving radiative and dissociative recombinations. A relationship between molecular oxygen density and the integrated OI emission rate is derived and the feasibility of using this relationship for estimating O2 density is discussed.

  15. Night Airglow Observations from Orbiting Spacecraft Compared with Measurements from Rockets.

    PubMed

    Koomen, M J; Gulledge, I S; Packer, D M; Tousey, R

    1963-06-07

    A luminous band around the night-time horizon, observed from orbiting capsules by J. H. Glenn and M. S. Carpenter, and identified as the horizon enhancement of the night airglow, is detected regularly in rocket-borne studies of night airglow. Values of luminance and dip angle of this band derived from Carpenter's observations agree remarkably well with values obtained from rocket data. The rocket results, however, do not support Carpenter's observation that the emission which he saw was largely the atomic oxygen line at 5577 A, but assign the principal luminosity to the green continuum.

  16. Satellite-based observations of tsunami-induced mesosphere airglow perturbations

    NASA Astrophysics Data System (ADS)

    Yang, Yu-Ming; Verkhoglyadova, Olga; Mlynczak, Martin G.; Mannucci, Anthony J.; Meng, Xing; Langley, Richard B.; Hunt, Linda A.

    2017-01-01

    Tsunami-induced airglow emission perturbations were retrieved by using space-based measurements made by the Sounding of the Atmosphere using Broad-band Emission Radiometry (SABER) instrument on board the Thermosphere-Ionosphere-Mesosphere Energetics Dynamics spacecraft. At and after the time of the Tohoku-Oki earthquake on 11 March 2011, and the Chile earthquake on 16 September 2015, the spacecraft was performing scans over the Pacific Ocean. Significant ( 10% relative to the ambient emission profiles) and coherent nighttime airglow perturbations were observed in the mesosphere following Sounding of the Atmosphere using Broad-band Emission Radiometry limb scans intercepting tsunami-induced atmospheric gravity waves. Simulations of emission variations are consistent with the physical characteristics of the disturbances at the locations of the corresponding SABER scans. Airglow observations and model simulations suggest that atmospheric neutral density and temperature perturbations can lead to the observed amplitude variations and multipeak structures in the emission profiles. This is the first time that airglow emission rate perturbations associated with tsunamis have been detected with space-based measurements.

  17. Correlation of 1.65 and 2.15 micron airglow emissions

    NASA Technical Reports Server (NTRS)

    Kieffaber, L. M.

    1974-01-01

    The intense infrared airglow is due primarily to vibration-rotation bands of the OH molecule. This airglow has been observed with a 24-in. scanning photometer at two wavelengths. Narrow-band interference filters are used to limit observations to the (9,7) band at 2.15 microns and the (4,2) and (5,3) bands at 1.65 microns. If OH emission results from creation of the excited OH molecule in the v = 9 vibrational state and subsequent cascading through lower vibrational levels, the 1.65 and 2.15 micron radiation will be well correlated in space and time. However, if several mechanisms are involved in producing OH in a variety of initial excitation levels, there is no reason to expect good correlation. Sky maps obtained simultaneously at 1.65 and 2.15 microns show strongly correlated intensity fluctuations. Quantitative analysis of these maps and other investigations of smaller areas of the sky yield correlation coefficients typically in excess of 0.8.

  18. Optimizing hydroxyl airglow retrievals from long-slit astronomical spectroscopic observations

    NASA Astrophysics Data System (ADS)

    Franzen, Christoph; Hibbins, Robert Edward; Espy, Patrick Joseph; Djupvik, Anlaug Amanda

    2017-08-01

    Astronomical spectroscopic observations from ground-based telescopes contain background emission lines from the terrestrial atmosphere's airglow. In the near infrared, this background is composed mainly of emission from Meinel bands of hydroxyl (OH), which is produced in highly excited vibrational states by reduction of ozone near 90 km. This emission contains a wealth of information on the chemical and dynamical state of the Earth's atmosphere. However, observation strategies and data reduction processes are usually optimized to minimize the influence of these features on the astronomical spectrum. Here we discuss a measurement technique to optimize the extraction of the OH airglow signal itself from routine J-, H-, and K-band long-slit astronomical spectroscopic observations. As an example, we use data recorded from a point-source observation by the Nordic Optical Telescope's intermediate-resolution spectrograph, which has a spatial resolution of approximately 100 m at the airglow layer. Emission spectra from the OH vibrational manifold from v' = 9 down to v' = 3, with signal-to-noise ratios up to 280, have been extracted from 10.8 s integrations. Rotational temperatures representative of the background atmospheric temperature near 90 km, the mesosphere and lower thermosphere region, can be fitted to the OH rotational lines with an accuracy of around 0.7 K. Using this measurement and analysis technique, we derive a rotational temperature distribution with v' that agrees with atmospheric model conditions and the preponderance of previous work. We discuss the derived rotational temperatures from the different vibrational bands and highlight the potential for both the archived and future observations, which are at unprecedented spatial and temporal resolutions, to contribute toward the resolution of long-standing problems in atmospheric physics.

  19. Rocket observations of the ultraviolet airglow during morning twilight

    NASA Technical Reports Server (NTRS)

    Cebula, R. P.; Feldman, P. D.

    1984-01-01

    Rocket-borne (Astrobee) UV measurements were made of the terrestrial airglow at morning twilight from 82 and 90 deg zenith angles at altitudes of 90 and 246 km in September 1979. Data were acquired on the NO gamma and delta bands, the 2470 A O II, 1356 A and the 1304 A O I lines, the Lyman-Berge-Hopfield N2 and the Herzberg 02 lines. The zodiacal contribution was substracted to obtain pure airglow data. Spectral analyses supported a larger nighttime decrease of N(4S) than for NO, the latter being in diffusive equilibrium above 190 km altitude. The NO gamma band was directly related to the thermospheric N(4S) contribution, the latter having a density of 2-8 million/cu cm at 200 km. Finally, self-consistent photoionization and photoelectron impact ionization models were derived for the atomic and ionic oxygen emissions.

  20. Heater-induced ionization inferred from spectrometric airglow measurements

    NASA Astrophysics Data System (ADS)

    Hysell, D. L.; Miceli, R. J.; Varney, R. H.; Schlatter, N.; Huba, J. D.

    2013-12-01

    Spectrographic airglow measurements were made during an ionospheric modification experiment at HAARP on March 12, 2013. Artificial airglow enhancements at 427.8, 557.7, 630.0, 777.4, and 844.6 nm were observed. On the basis of these emissions and using a methodology based on the method of Backus and Gilbert [1968, 1970], we estimate the suprathermal electron population and the subsequent equilibrium electron density profile, including contributions from electron impact ionization. We find that the airglow is consistent with significant induced ionization in view of the spatial intermittency of the airglow.

  1. Enhanced airglow at Titan

    NASA Astrophysics Data System (ADS)

    Royer, Emilie; Esposito, Larry; Wahlund, Jan-Erik

    2016-06-01

    The Cassini Ultraviolet Imaging Spectrograph (UVIS) instrument made thousand of observations of Titan since its arrival in the Saturnian system in 2004, but only few of them have been analyzed yet. Using the imaging capability of UVIS combined to a big data analytics approach, we have been able to uncover an unexpected pattern in this observations: on several occasions the Titan airglow exhibits an enhanced brightness by approximately a factor of 2, generally combined with a lower altitude of the airglow emission peak. These events typically last from 10 to 30 minutes and are followed and preceded by an airglow of regular and expected level of brightness and altitude. Observations made by the Cassini Plasma Spectrometer (CAPS) instrument onboard Cassini allowed us to correlate the enhanced airglow observed on T-32 with an electron burst. The timing of the burst and the level of energetic electrons (1 keV) observed by CAPS correspond to a brighter and lower than typical airglow displayed on the UVIS data. Furthermore, during T-32 Titan was inside the Saturn's magnetosheath and thus more subject to bombardment by energetic particles. However, our analysis demonstrates that the presence of Titan inside the magnetosheath is not a necessary condition for the production of an enhanced airglow, as we detected other similar events while Titan was within Saturn's magnetosphere. The study presented here aims to a better understanding of the interactions of Titan's upper atmosphere with its direct environment.

  2. Earth limb views with greenish bands of airglow during STS-99

    NASA Image and Video Library

    2000-04-06

    STS099-356-026 (11-22 February 2000) ---Because of its time exposure, this STS-99 35mm frame provides a view of several stars. The thin greenish band above the horizon is airglow; radiation emitted by the atmosphere from a layer about 30 kilometers thick and about 100 kilometers altitude. The predominant emission in airglow is the green 5577-Angstrom wavelength emission from atomic oxygen atoms. Airglow is always and everywhere present in the atmosphere; it results from the recombination of molecules that have been broken apart by solar radiation during the day. But airglow is so faint that it can only be seen at night by looking "edge on" at the emission layer, such as the view astronauts have in orbit.

  3. Heater-induced ionization inferred from spectrometric airglow measurements

    NASA Astrophysics Data System (ADS)

    Hysell, D. L.; Miceli, R. J.; Kendall, E. A.; Schlatter, N. M.; Varney, R. H.; Watkins, B. J.; Pedersen, T. R.; Bernhardt, P. A.; Huba, J. D.

    2014-03-01

    Spectrographic airglow measurements were made during an ionospheric modification experiment at High Frequency Active Auroral Research Program on 12 March 2013. Artificial airglow enhancements at 427.8, 557.7, 630.0, 777.4, and 844.6 nm were observed. On the basis of these emissions and using a methodology based on the method of Backus and Gilbert (1968, 1970), we estimate the suprathermal electron population and the subsequent equilibrium electron density profile, including contributions from electron impact ionization. We find that the airglow is consistent with heater-induced ionization in view of the spatial intermittency of the airglow.

  4. A rocket-borne airglow photometer

    NASA Technical Reports Server (NTRS)

    Paarmann, L. D.; Smith, L. G.

    1977-01-01

    The design of a rocket-borne photometer to measure the airglow emission of ionized molecular nitrogen in the 391.4 nm band is presented. This airglow is a well known and often observed phenomenon of auroras, where the principal source of ionization is energetic electrons. It is believed that at some midlatitude locations energetic electrons are also a source of nighttime ionization in the E region of the ionosphere. If this is so, then significant levels of 391.4 nm airglow should be present. The intensity of this airglow will be measured in a rocket payload which also contains instrumentation to measured in a rocket payload which also contains instrumentation to measure energetic electron differential flux and the ambient electron density. An intercomparison of the 3 experiments in a nightime launch will allow a test of the importance of energetic electrons as a nighttime source of ionization in the upper E region.

  5. Imaging observations of lower thermospheric O(1S) and O2 airglow emissions from STS 9 - Implications of height variations

    NASA Technical Reports Server (NTRS)

    Swenson, G. R.; Mende, S. B.; Llewellyn, E. J.

    1989-01-01

    The lower thermospheric nightglow in the Southern Hemisphere was observed with the Atmospheric Emissions Photometric Imager during the Spacelab 1 mission in December, 1983. Observations of emission from O(1S) at 2972 and 5577A, O2 at 7620 A, OH near 6300 A, and the combined emission from the three upper states of O2 which lead to the Herzberg I and II and Chamberlain band emissions in B and near UV are discussed. The altitudes of peak emission heights are determined, showing that the peak heights are not constant with latitude. It is found that airglow heights varied with latitude by as much as 8 km. The observed airglow height pattern near the equator is similar to that of Wasser and Donahue (1979).

  6. Pluto's Ultraviolet Airglow and Detection of Ions in the Upper Atmosphere

    NASA Astrophysics Data System (ADS)

    Steffl, A.; Young, L. A.; Kammer, J.; Gladstone, R.; Hinson, D. P.; Summers, M. E.; Strobel, D. F.; Stern, S. A.; Weaver, H. A., Jr.; Olkin, C.; Ennico Smith, K.

    2017-12-01

    In July 2015, the Alice ultraviolet spectrograph aboard the New Horizons spacecraft made numerous observations of Pluto and its atmosphere. We present here the far ultraviolet reflectance spectrum of Pluto and airglow emissions from its atmosphere. At wavelengths greater than 1400Å, Pluto's spectrum is dominated by sunlight reflected from the surface of the planet. Various hydrocarbon species such as C2H4 are detected in absorption of the solar continuum. Below 1400Å, Pluto's atmosphere is opaque and the surface cannot be detected. However, after carefully removing various sources of background light, we see extremely faint airglow emissions (<0.05 Rayleighs/Ångstrom) from Pluto's atmosphere. All of the emissions are produced by nitrogen in various forms: molecular, atomic, and singly ionized. The detection of N+ at 1086Å is the first, and thus far only, direct detection of ions in Pluto's atmosphere. This N+ emission line is produced primarily by dissociative photoionization of molecular N2 by solar EUV photons (energy > 34.7 eV; wavelength < 360Å). Notably absent from Pluto's spectrum are emission lines from argon at 1048 and 1067Å. We place upper limits on the amount of argon in Pluto's atmosphere above the tau=1 level (observed to be at 750km tangent altitude) that are significantly lower than pre-encounter atmospheric models.

  7. Gravity Wave Detection through All-sky Imaging of Airglow

    NASA Astrophysics Data System (ADS)

    Nguyen, T. V.; Martinez, A.; Porat, I.; Hampton, D. L.; Bering, E., III; Wood, L.

    2017-12-01

    Airglow, the faint glow of the atmosphere, is caused by the interaction of air molecules with radiation from the sun. Similarly, the aurora is created by interactions of air molecules with the solar wind. It has been shown that airglow emissions are altered by gravity waves passing through airglow source region (100-110km), making it possible to study gravity waves and their sources through airglow imaging. University of Houston's USIP - Airglow team designed a compact, inexpensive all-sky imager capable of detecting airglow and auroral emissions using a fisheye lens, a simple optical train, a filter wheel with 4 specific filters, and a CMOS camera. This instrument has been used in USIP's scientific campaign in Alaska throughout March 2017. During this period, the imager captured auroral activity in the Fairbanks region. Due to lunar conditions and auroral activity images from the campaign did not yield visible signs of airglow. Currently, the team is trying to detect gravity wave patterns present in the images through numerical analysis. Detected gravity wave patterns will be compared to local weather data, and may be used to make correlations between gravity waves and weather events. Such correlations could provide more data on the relationship between the mesosphere and lower layers of the atmosphere. Practical applications of this research include weather prediction and detection of air turbulence.

  8. NIRAC: Near Infrared Airglow Camera for the International Space Station

    NASA Astrophysics Data System (ADS)

    Gelinas, L. J.; Rudy, R. J.; Hecht, J. H.

    2017-12-01

    NIRAC is a space based infrared airglow imager that will be deployed to the International Space Station in late 2018, under the auspices of the Space Test Program. NIRAC will survey OH airglow emissions in the 1.6 micron wavelength regime, exploring the spatial and temporal variability of emission intensities at latitudes from 51° south to 51° north. Atmospheric perturbations in the 80-100 km altitude range, including those produced by atmospheric gravity waves (AGWs), are observable in the OH airglow. The objective of the NIRAC experiment is to make near global measurement of the OH airglow and airglow perturbations. These emissions also provide a bright source of illumination at night, allowing for nighttime detection of clouds and surface characteristics. The instrument, developed by the Aerospace Space Science Applications Laboratory, employs a space-compatible FPGA for camera control and data collection and a novel, custom optical system to eliminate image smear due to orbital motion. NIRAC utilizes a high-performance, large format infrared focal plane array, transitioning technology used in the existing Aerospace Corporation ground-based airglow imager to a space based platform. The high-sensitivity, four megapixel imager has a native spatial resolution of 100 meters at ISS altitudes. The 23° x 23° FOV sweeps out a 150 km swath of the OH airglow layer as viewed from the ISS, and is sensitive to OH intensity perturbations down to 0.1%. The detector has a 1.7 micron cutoff that precludes the need for cold optics and reduces cooling requirements (to 180 K). Detector cooling is provided by a compact, lightweight cryocooler capable of reaching 120K, providing a great deal of margin.

  9. WINDII atmospheric wave airglow imaging

    NASA Technical Reports Server (NTRS)

    Armstrong, W. T.; Hoppe, U.-P.; Solheim, B. H.; Shepherd, G. G.

    1996-01-01

    Preliminary WINDII nighttime airglow wave-imaging data in the UARS rolldown attitude has been analyzed with the goal to survey gravity waves near the upper boundary of the middle atmosphere. Wave analysis is performed on O[sub 2](0,0) emissions from a selected 1[sup 0] x 1[sup 0] oblique view of the airglow layer at approximately 95 km altitude, which has no direct earth background and only an atmospheric background which is optically thick for the 0[sub 2](0,0) emission. From a small data set, orbital imaging of atmospheric wave structures is demonstrated, with indication of large variations in wave activity across land and sea. Comparison ground-based imagery is discussed with respect to similarity of wave variations across land/sea boundaries and future orbital mosaic image construction.

  10. Spatial and Temporal Stability of Airglow Measured in the Meinel Band Window at 1191.3 nm

    NASA Astrophysics Data System (ADS)

    Nguyen, Hien T.; Zemcov, Michael; Battle, John; Bock, James J.; Hristov, Viktor; Korngut, Phillip; Meek, Andrew

    2016-09-01

    We report on the temporal and spatial fluctuations in the atmospheric brightness in the narrow band between Meinel emission lines at 1191.3 nm using a λ/Δλ = 320 near-infrared instrument. We present the instrument design and implementation, followed by a detailed analysis of data taken over the course of a night from Table Mountain Observatory. At low airmasses, the absolute sky brightness at this wavelength is found to be 5330 ± 30 nW m-2 sr-1, consistent with previous measurements of the inter-band airglow at these wavelengths. This amplitude is larger than simple models of the continuum component of the airglow emission at these wavelengths, confirming that an extra emissive or scattering component is required to explain the observations. We perform a detailed investigation of the noise properties of the data and find no evidence for a noise component associated with temporal instability in the inter-line continuum. This result demonstrates that in several hours of ˜100 s integrations the noise performance of the instrument does not appear to significantly degrade from expectations, giving a proof of concept that near-infrared line intensity mapping may be feasible from ground-based sites.

  11. Estimating the electron energy distribution during ionospheric modification from spectrographic airglow measurements

    NASA Astrophysics Data System (ADS)

    Hysell, D. L.; Varney, R. H.; Vlasov, M. N.; Nossa, E.; Watkins, B.; Pedersen, T.; Huba, J. D.

    2012-02-01

    The electron energy distribution during an F region ionospheric modification experiment at the HAARP facility near Gakona, Alaska, is inferred from spectrographic airglow emission data. Emission lines at 630.0, 557.7, and 844.6 nm are considered along with the absence of detectable emissions at 427.8 nm. Estimating the electron energy distribution function from the airglow data is a problem in classical linear inverse theory. We describe an augmented version of the method of Backus and Gilbert which we use to invert the data. The method optimizes the model resolution, the precision of the mapping between the actual electron energy distribution and its estimate. Here, the method has also been augmented so as to limit the model prediction error. Model estimates of the suprathermal electron energy distribution versus energy and altitude are incorporated in the inverse problem formulation as representer functions. Our methodology indicates a heater-induced electron energy distribution with a broad peak near 5 eV that decreases approximately exponentially by 30 dB between 5-50 eV.

  12. Observations of neutral iron emission in twilight spectra

    NASA Technical Reports Server (NTRS)

    Tepley, C. A.; Meriwether, J. W., Jr.; Walker, J. C. G.; Mathews, J. D.

    1981-01-01

    A method is presented for the analysis of twilight airglow spectra that may be contaminated by atmospheric continuum emission of unknown brightness. The necessity of correcting for this continuum emission when measuring weak airglow features in twilight is illustrated by application of the method to the neutral iron line at 3860 A.

  13. The Visible Airglow Experiment - A review

    NASA Technical Reports Server (NTRS)

    Hays, Paul B.; Abreu, Vincent J.; Solomon, Stanley C.; Yee, Jeng-Hwa

    1988-01-01

    Contributions of the Visible Airglow Experiment (VAE) to the understanding of various airglow and auroral processes are reviewed. The impact of instrumental design and operation on the observations is discussed, and emphasis is placed on the relationship between observations and inversion for optical measurements of light emissions from a diffuse medium. VAE data are used to explain the physical mechanisms responsible for the production and destruction of excited species including O(+)(1P), O(1D), O(1S), N(2D), and Mg(+)2P1/2.

  14. The global characteristics of atmosphere emissions in the lower thermosphere and their aeronomic implications. [OGO-4 airglow photometric observations of oxygen

    NASA Technical Reports Server (NTRS)

    Reed, E. I.; Chandra, S.

    1974-01-01

    The green line of atomic oxygen and the Herzberg bands of molecular oxygen as observed from the OGO-4 airglow photometer are discussed in terms of their spatial and temporal distributions and their relation to the atomic oxygen content in the lower thermosphere. Daily maps of the distribution of emissions show considerable structure (cells, patches, and bands) with appreciable daily changes. When data are averaged over periods of several days in length, the resulting patterns have occasional tendencies to follow geomagnetic parallels. The Seasonal variations are characterized by maxima in both the Northern and Southern Hemispheres in October, with the Northern Hemisphere having substantially higher emission rates. Formulae are derived relating the vertical column emission rates of the green line and the Herzberg bands to the atomic oxygen peak density. Global averages for the time period for these data (August 1967 to January 1968), when converted to maximum atomic oxygen densities near 95 km, have a range of 2.0 x 10 to the 11th power/cu cm 2.7 x 10 to the 11th power/cu cm.

  15. Earth limb views with greenish bands of airglow during STS-99

    NASA Image and Video Library

    2000-04-06

    STS099-355-024 (11-22 February 2000) -- Two separate atmospheric optical phenomena appear in this 35mm photograph captured from the Space Shuttle Endeavour. The thin greenish band above the horizon is airglow; radiation emitted by the atmosphere from a layer about 30-kilometers thick and about 100-kilometers' altitude. The predominant emission in airglow is the green 5577-Angstrom wavelength emission from atomic oxygen atoms, which is also the predominant emission from the aurora. A yellow-orange color is also seen in airglow, which is the emission of the 5800-Angstrom wavelength from sodium atoms. Airglow is always present in the atmosphere; it results from the recombination of molecules that have been broken apart by solar radiation during the day. But airglow is so faint that it can only be seen at night by looking "edge on" at the emission layer, such as the view that astronauts have in Earth orbit. The other phenomenon in the photo appears to be a faint, diffuse red aurora. Red aurora occur from about 200 kilometers to as high as 500 kilometers altitude only in the auroral zones at polar latitudes. They are caused by the emission of 6300- Angstrom wavelength light from oxygen atoms that have been raised to a higher energy level (excited) by collisions with energetic electrons pouring down from the Earth's magnetosphere. The light is emitted when the atoms return to their original unexcited state. With the red light so faint in this picture, scientists are led to believe that the flux density of incoming electrons was small. Also, since there is no green aurora below the red, that indicates that the energy of the incoming electrons was low - higher energy electrons would penetrate deeper into the atmosphere where the green aurora is energized.

  16. Nitrogen airglow sources - Comparison of Triton, Titan, and earth

    NASA Technical Reports Server (NTRS)

    Strobel, Darrell F.; Meier, R. R.; Summers, Michael E.; Strickland, Douglas J.

    1991-01-01

    The individual contributions of direct solar excitation, photoelectron excitation, and magnetospheric electron excitation of Triton and Titan airglow observed by the Voyager Ultraviolet Spectrometer (UVS) are quantified. The principal spectral features of Triton's airglow are shown to be consistent with precipitation of magnetospheric electrons with power dissipation about 500 million W. Solar excitation rates of the dominant N2 and N(+) emission features are factors of 2-7 weaker than magnetospheric electron excitation. On Titan, the calculated disk center and bright limb N(+) 1085 A intensities due to solar excitation agree with observed values, while the 970 A feature is mostly N21 c5 band emission. The calculated LBH intensity by photoelectrons suggests that magnetospheric electrons play a minor role in Titan's UV airglow. On earth, solar/photoelectron excitation explains the observed N(+) 1085 A and LBH intensites and accounts for only 40 percent of the N(+) 916 A intensity.

  17. Equatorial Enhancement of the Nighttime OH Mesospheric Infrared Airglow

    NASA Technical Reports Server (NTRS)

    Baker, D. J.; Mlynczak, M. G.; Russell, J. M.

    2007-01-01

    Global measurements of the hydroxyl mesospheric airglow over an extended period of time have been made possible by the NASA SABER infrared sensor aboard the TIMED satellite which has been functioning since December of 2001. The orbital mission has continued over a significant portion of a solar cycle. Experimental data from SABER for several years have exhibited equatorial enhancements of the nighttime mesospheric OH (delta v = 2) airglow layer consistent with the high average diurnal solar flux. The brightening of the OH airglow typically means more H + O3 is being reacted. At both the spring and autumn seasonal equinoxes when the equatorial solar UV irradiance mean is greatest, the peak volume emission rate (VER) of the nighttime Meinel infrared airglow typically appears to be both significantly brighter plus lower in altitude by several kilometres at low latitudes compared with midlatitude findings.

  18. Cassini UVIS Observations of Titan Ultraviolet Airglow Spectra with Laboratory Modeling from Electron- and Proton-Excited N2 Emission Studies

    NASA Astrophysics Data System (ADS)

    Ajello, J. M.; West, R. A.; Malone, C. P.; Gustin, J.; Esposito, L. W.; McClintock, W. E.; Holsclaw, G. M.; Stevens, M. H.

    2011-12-01

    Joseph M. Ajello, Robert A. West, Rao S. Mangina Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 Charles P. Malone Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 & Department of Physics, California State University, Fullerton, CA 92834 Michael H. Stevens Space Science Division, Naval Research Laboratory, Washington, DC 20375 Jacques Gustin Laboratoire de Physique Atmosphérique et Planétaire, Université de Liège, Liège, Belgium A. Ian F. Stewart, Larry W. Esposito, William E. McClintock, Gregory M. Holsclaw Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, CO 80303 E. Todd Bradley Department of Physics, University of Central Florida, Orlando, FL 32816 The Cassini Ultraviolet Imaging Spectrograph (UVIS) observed photon emissions of Titan's day and night limb-airglow and disk-airglow on multiple occasions, including three eclipse observations from 2009 through 2010. The 77 airglow observations analyzed in this paper show EUV (600-1150 Å) and FUV (1150-1900 Å) atomic multiplet lines and band emissions (lifetimes less than ~100 μs), including the Lyman-Birge-Hopfield (LBH) band system, arising from photoelectron induced fluorescence and solar photo-fragmentation of molecular nitrogen (N2). The altitude of peak UV emission on the limb of Titan during daylight occurred inside the thermosphere/ionosphere (near 1000 km altitude). However, at night on the limb, the same emission features, but much weaker in intensity, arise in the lower atmosphere below 1000 km (lower thermosphere, mesosphere, haze layer) extending downwards to near the surface at ~300 km, possibly resulting from proton- and/or heavier ion-induced emissions as well as secondary-electron-induced emissions. The eclipse observations are unique. UV emissions were observed during only one of the three eclipse events, and no Vegard-Kaplan (VK) or LBH emissions were seen. Through regression analysis using

  19. Thermospheric Airglow Perturbations in the Upper Atmosphere Caused by Hurricane Harvey

    NASA Astrophysics Data System (ADS)

    Bhatt, A.; Kendall, E. A.

    2017-12-01

    The Midlatitude Allsky imaging Network for Geophysical Observations (MANGO) consists of seven allsky imagers distributed across the United States recording observations of large-scale airglow perturbations. The imagers are filtered at 630 nm, a forbidden oxygen line, in order to record the predominant source of airglow at 250 km altitude. While the ubiquitous airglow layer is challenging to observe when under uniform conditions, waves in the upper atmosphere cause ripples in the airglow layer which can easily be imaged by appropriate instrumentation. MANGO is the first network to record perturbations in the airglow layer on a continent-size scale. Large and Mid-scale Traveling Ionospheric Disturbances (LSTIDs and MSTIDs) are recorded that are caused by auroral forcing, mountain turbulence, and tidal variations. On August 25, airglow perturbations centered on the Hurricane Harvey path were observed by MANGO. These images and connections to other complimentary data sets such as GPS will be presented.

  20. Photometer for detection of sodium day airglow.

    NASA Technical Reports Server (NTRS)

    Mcmahon, D. J.; Manring, E. R.; Patty, R. R.

    1973-01-01

    Description of a photometer for daytime ground-based measurements of sodium airglow emission. The photometer described can be characterized by the following principal features: (1) a narrow (4.5-A) interference filter for initial discrimination; (2) cooled photomultiplier detector to reduce noise from dark current fluctuations and chopping to eliminate the average dark current; (3) a sodium vapor resonance cell to provide an effective bandpass comparable to the Doppler line width; (4) separate detection of all light transmitted by the interference filter to evaluate the Rayleigh and Mie components within the Doppler width of the resonance cell; and (5) temperature quenching of the resonance cell to evaluate and account for instrumental imperfections.

  1. The Martian airglow: observations by Mars Express and kinetic modelling

    NASA Astrophysics Data System (ADS)

    Simon, Cyril; Leblanc, François; Gronoff, Guillaume; Witasse, Olivier; Lilensten, Jean; Barthelemy, Mathieu; Bertaux, Jean-Loup

    The photoemissions on Mars are the result of physical chemistry reactions in the upper atmo-sphere that depend on the planet's plasma environment. They arise on the dayside from UV photo-excitation (Barth et al., 1971) and on the nightside from chemical reactions and electron precipitation above regions of strong crustal magnetism (Bertaux et al., 2005). The physics of airglow generation at Mars is discussed both in terms of observations (satellites) and models (especially transport codes). A review of observations made by SPICAM, the UV spectrometer onboard Mars Express, is first presented. The Cameron bands of CO(a - X), the CO+ (A - X) 2 doublet at 289.0 nm and the trans-auroral line of OI (297.2 nm) are mainly seen on the dayside. On the nightside both Cameron emissions and NO(C - X and A - X) emissions are present. In a second step, an updated airglow model has been developed and compared to the latest SPICAM data. Several interesting implications are highlighted regarding neutral atmosphere variations for the dayglow (Simon et al., 2009) and electron precipitation mechanisms at the origin of the auroral intensities measured by SPICAM in conjunction with the particle detector ASPERA and the radar MARSIS.

  2. Influences of CO2 increase, solar cycle variation, and geomagnetic activity on airglow from 1960 to 2015

    NASA Astrophysics Data System (ADS)

    Huang, Tai-Yin

    2018-06-01

    Variations of airglow intensity, Volume Emission Rate (VER), and VER peak height induced by the CO2 increase, and by the F10.7 solar cycle variation and geomagnetic activity were investigated to quantitatively assess their influences on airglow. This study is an extension of a previous study by Huang (2016) covering a time period of 55 years from 1960 to 2015 and includes geomagnetic variability. Two airglow models, OHCD-90 and MACD-90, are used to simulate the induced variations of O(1S) greenline, O2(0,1) atmospheric band, and OH(8,3) airglow for this study. Overall, our results demonstrate that airglow intensity and the peak VER variations of the three airglow emissions are strongly correlated, and in phase, with the F10.7 solar cycle variation. In addition, there is a linear trend, be it increasing or decreasing, existing in the airglow intensities and VERs due to the CO2 increase. On other hand, airglow VER peak heights are strongly correlated, and out of phase, with the Ap index variation of geomagnetic activity. The CO2 increase acts to lower the VER peak heights of OH(8,3) airglow and O(1S) greenline by 0.2 km in 55 years and it has no effect on the VER peak height of O2(0,1) atmospheric band.

  3. Plans of lightning and airglow measurements with LAC/Akatsuki

    NASA Astrophysics Data System (ADS)

    Takahashi, Yukihiro; Hoshino, Naoya; Sato, Mitsuteru; Yair, Yoav; Galand, Marina; Fukuhara, Tetsuya

    Though there are extensive researches on the existence of lightning discharge in Venus over few decades, this issue is still under controversial. Recently it is reported that the magnetometer on board Venus Express detected whistler mode waves whose source could be lightning discharge occurring well below the spacecraft. However, it is too early to determine the origin of these waves. On the other hand, night airglow is expected to provide essential information on the atmospheric circulation in the upper atmosphere of Venus. But the number of consecutive images of airglow obtained by spacecraft is limited and even the variations of most enhanced location is still unknown. In order to identify the discharge phenomena in the atmosphere of Venus separating from noises and to know the daily variation of airglow distribution in night-side disk, we plan to observe the lightning and airglow optical emissions with high-speed and high-sensitivity optical detector with narrow-band filters on board Akatsuki. We are ready to launch the flight model of lightning and airglow detector, LAC (Lightning and Airglow Camera). Main difference from other previous equipments which have provided evidences of lightning existence in Venus is the high-speed sampling rate at 32 us interval for each pixel, enabling us to distinguish the optical lightning flash from other pulsing noises. In this presentation the observation strategies, including ground-based support with optical telescopes, are shown and discussed.

  4. Airglow during ionospheric modifications by the sura facility radiation. experimental results obtained in 2010

    NASA Astrophysics Data System (ADS)

    Grach, S. M.; Klimenko, V. V.; Shindin, A. V.; Nasyrov, I. A.; Sergeev, E. N.; A. Yashnov, V.; A. Pogorelko, N.

    2012-06-01

    We present the results of studying the structure and dynamics of the HF-heated volume above the Sura facility obtained in 2010 by measurements of ionospheric airglow in the red (λ = 630 nm) and green (λ = 557.7 nm) lines of atomic oxygen. Vertical sounding of the ionosphere (followed by modeling of the pump-wave propagation) and measurements of stimulated electromagnetic emission were used for additional diagnostics of ionospheric parameters and the processes occurring in the heated volume.

  5. WINDII airglow observations of wave superposition and the possible association with historical "bright nights"

    NASA Astrophysics Data System (ADS)

    Shepherd, G. G.; Cho, Y.-M.

    2017-07-01

    Longitudinal variations of airglow emission rate are prominent in all midlatitude nighttime O(1S) lower thermospheric data obtained with the Wind Imaging Interferometer (WINDII) on the Upper Atmosphere Research Satellite (UARS). The pattern generally appears as a combination of zonal waves 1, 2, 3, and 4 whose phases propagate at different rates. Sudden localized enhancements of 2 to 4 days duration are sometimes evident, reaching vertically integrated emission rates of 400 R, a factor of 10 higher than minimum values for the same day. These are found to occur when the four wave components come into the same phase at one longitude. It is shown that these highly localized longitudinal maxima are consistent with the historical phenomena known as "bright nights" in which the surroundings of human dark night observers were seen to be illuminated by this enhanced airglow.Plain Language SummaryFor centuries, going back to the Roman era, people have recorded experiences of brightened skies during the night, called "bright nights." Currently, scientists study <span class="hlt">airglow</span>, an <span class="hlt">emission</span> of light from the high atmosphere, 100 km above us. Satellite observations of a green <span class="hlt">airglow</span> have shown that it consists of waves 1, 2, 3, and 4 around the earth. It happens that when the peaks of the different waves coincide there is an <span class="hlt">airglow</span> brightening, and this article demonstrates that this event produces a bright night. The modern data are shown to be entirely consistent with the historical observations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19810043952&hterms=Abreu&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3DAbreu%252C%2Bc.','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19810043952&hterms=Abreu&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3DAbreu%252C%2Bc."><span>The O II /7320-7330 A/ <span class="hlt">airglow</span> - A morphological study</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Yee, J. H.; Abreu, V. J.; Hays, P. B.</p> <p>1981-01-01</p> <p>A statistical study of the 7320-30 A <span class="hlt">airglow</span> arising from the metastable transition between aP and aD states of atomic oxygen ions was conducted by analyzing the data taken from the visible <span class="hlt">airglow</span> experiment on the Atmosphere Explorer satellites C and E during the time periods between 1974 and 1979. Averaged column <span class="hlt">emission</span> rate profiles as a function of solar zenith angle and solar activity variation are presented. The galactic background has been carefully subtracted. The result shows that the rate of decreasing <span class="hlt">emission</span> as a function of solar zenith angle agrees with the theoretical calculation based upon a neutral atmosphere model and the solar spectrum as measured by the EUV spectrometer on the Atmosphere Explorer satellite. Furthermore, an expected increase with solar activity also appeared in a plot of <span class="hlt">emission</span> brightness versus solar 10.7-cm flux.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JASTP.171..260A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JASTP.171..260A"><span>On the importance of an atmospheric reference model: A case study on gravity wave-<span class="hlt">airglow</span> interactions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Amaro-Rivera, Yolián; Huang, Tai-Yin; Urbina, Julio</p> <p>2018-06-01</p> <p>The atmospheric reference model utilized in an <span class="hlt">airglow</span> numerical study is important since <span class="hlt">airglow</span> <span class="hlt">emissions</span> depend on the number density of the light-emitting species. In this study, we employ 2-dimensional, nonlinear, time-dependent numerical models, Multiple <span class="hlt">Airglow</span> Chemistry Dynamics (MACD) and OH Chemistry Dynamics (OHCD), that use the MSISE-90, NRLMSISE-00, and Garcia and Solomon (GS) model data as atmospheric reference models, to investigate gravity wave-induced <span class="hlt">airglow</span> variations for the OH(8,3) <span class="hlt">airglow</span>, O2(0,1) atmospheric band, and O(1S) greenline <span class="hlt">emissions</span> in the Mesosphere and Lower Thermosphere (MLT) region. Our results show that the OHCD-00 produces the largest wave-induced OH(8,3) <span class="hlt">airglow</span> intensity variation (∼34%), followed by the OHCD-90 (∼30%), then by the OHCD (∼22%). For O(1S) greenline, the MACD produces the largest wave-induced variation (∼33%), followed by the MACD-90 (∼28%), then by MACD-00 (∼26%). As for O2(0,1) atmospheric band, the MACD produces the largest wave-induced variation (∼31%), followed by the MACD-90 and MACD-00 (∼29%). Our study illustrates the importance and the need for a good atmospheric reference model that can accurately represent the atmosphere.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016STP.....2c.106M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016STP.....2c.106M"><span>Night <span class="hlt">airglow</span> in RGB mode</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mikhalev, Aleksandr; Podlesny, Stepan; Stoeva, Penka</p> <p>2016-09-01</p> <p>To study dynamics of the upper atmosphere, we consider results of the night sky photometry, using a color CCD camera and taking into account the night <span class="hlt">airglow</span> and features of its spectral composition. We use night <span class="hlt">airglow</span> observations for 2010-2015, which have been obtained at the ISTP SB RAS Geophysical Observatory (52° N, 103° E) by the camera with KODAK KAI-11002 CCD sensor. We estimate the average brightness of the night sky in R, G, B channels of the color camera for eastern Siberia with typical values ranging from ~0.008 to 0.01 erg*cm-2*s-1. Besides, we determine seasonal variations in the night sky luminosities in R, G, B channels of the color camera. In these channels, luminosities decrease in spring, increase in autumn, and have a pronounced summer maximum, which can be explained by scattered light and is associated with the location of the Geophysical Observatory. We consider geophysical phenomena with their optical effects in R, G, B channels of the color camera. For some geophysical phenomena (geomagnetic storms, sudden stratospheric warmings), we demonstrate the possibility of the quantitative relationship between enhanced signals in R and G channels and increases in intensities of discrete 557.7 and 630 nm <span class="hlt">emissions</span>, which are predominant in the <span class="hlt">airglow</span> spectrum.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMSA21A2503F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMSA21A2503F"><span>Estimation of 557.7 nm <span class="hlt">Emission</span> Altitude using Co-located Lidars and Photometers over Arecibo</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Franco, E.; Raizada, S.; Lautenbach, J.; Brum, C. G. M.</p> <p>2017-12-01</p> <p><span class="hlt">Airglow</span> at 557.7 nm (green <span class="hlt">line</span> <span class="hlt">emission</span>) is generated through the Barth mechanism in the E-region altitude and is sometimes associated with red <span class="hlt">line</span> (630.0 nm) originating at F-region altitudes. Photons at 557.7 nm are produced through the quenching of excited atomic oxygen atoms, O(1S), while 630.0 nm results through the de-excitation of O(1D) atoms. Even though, the contribution of the green <span class="hlt">line</span> from F-region is negligible and the significant component comes from the mesosphere, this uncertainty gives rise to a question related to its precise altitude. Previous studies have shown that perturbations generated by atmospheric gravity Waves (GWs) alter the <span class="hlt">airglow</span> intensity and can be used for studying dynamics of the region where it originates. The uncertainty in the <span class="hlt">emission</span> altitude of green <span class="hlt">line</span> can be resolved by using co-located lidars, which provide altitude resolved metal densities. At Arecibo, the resonance lidars tuned to Na and K resonance wavelengths at 589 nm and 770 nm can be used in conjunction with simultaneous measurements from green <span class="hlt">line</span> photometer to resolve this issue. Both photometer and lidars have narrow field of view as compared to <span class="hlt">airglow</span> imagers, and hence provide an added advantage that these instruments sample same GW spectrum. Hence, correlation between density perturbations inferred from lidars and <span class="hlt">airglow</span> intensity perturbations can shed light on the exact altitude of green <span class="hlt">line</span> <span class="hlt">emission</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010DPS....42.3625S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010DPS....42.3625S"><span>The Production of Titan's Ultraviolet Nitrogen <span class="hlt">Airglow</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Stevens, Michael H.; Gustin, J.; Ajello, J. M.; Evans, J. S.; Meier, R. R.; Stewart, A. I. F.; Esposito, L. W.; McClintock, W. E.; Stephan, A. W.</p> <p>2010-10-01</p> <p>The Cassini Ultraviolet Imaging Spectrograph (UVIS) observed Titan's dayside limb on 22 June, 2009, obtaining high quality extreme ultraviolet (EUV) and far ultraviolet (FUV) spectra from a distance of only 60,000 km (23 Titan radii). The observations reveal the same EUV and FUV <span class="hlt">emissions</span> arising from photoelectron excitation and photofragmentation of molecular nitrogen (N2) on Earth but with the altitude of peak <span class="hlt">emission</span> much higher on Titan near 1000 km altitude. In the EUV, <span class="hlt">emission</span> bands from the photoelectron excited N2 Carroll-Yoshino c4'-X system and N I and N II multiplets arising from photofragmentation of N2 dominate, with no detectable c4'(0,0) <span class="hlt">emission</span> near 958 Å, contrary to many interpretations of the lower resolution Voyager 1 Ultraviolet Spectrometer data. The FUV is dominated by <span class="hlt">emission</span> bands from the N2 Lyman-Birge-Hopfield a-X system and additional N I multiplets. We also identify several N2 Vegard-Kaplan A-X bands between 1500-1900 Å, two of which are located near 1561 and 1657 Å where C I multiplets were previously identified from a separate UVIS disk observation. We compare these limb <span class="hlt">emissions</span> to predictions from a terrestrial <span class="hlt">airglow</span> model adapted to Titan that uses a solar spectrum appropriate for these June, 2009 observations. Volume production rates and limb radiances are calculated, including extinction by methane and allowance for multiple scattering within the readily excited c4'(0,v') system, and compared to UVIS observations. We find that for these <span class="hlt">airglow</span> data only <span class="hlt">emissions</span> arising from processes involving N2 are present.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19930005120','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19930005120"><span>Near-infrared oxygen <span class="hlt">airglow</span> from the Venus nightside</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Crisp, D.; Meadows, V. S.; Allen, D. A.; Bezard, B.; Debergh, C.; Maillard, J.-P.</p> <p>1992-01-01</p> <p>Groundbased imaging and spectroscopic observations of Venus reveal intense near-infrared oxygen <span class="hlt">airglow</span> <span class="hlt">emission</span> from the upper atmosphere and provide new constraints on the oxygen photochemistry and dynamics near the mesopause (approximately 100 km). Atomic oxygen is produced by the Photolysis of CO2 on the dayside of Venus. These atoms are transported by the general circulation, and eventually recombine to form molecular oxygen. Because this recombination reaction is exothermic, many of these molecules are created in an excited state known as O2(delta-1). The <span class="hlt">airglow</span> is produced as these molecules emit a photon and return to their ground state. New imaging and spectroscopic observations acquired during the summer and fall of 1991 show unexpected spatial and temporal variations in the O2(delta-1) <span class="hlt">airglow</span>. The implications of these observations for the composition and general circulation of the upper venusian atmosphere are not yet understood but they provide important new constraints on comprehensive dynamical and chemical models of the upper mesosphere and lower thermosphere of Venus.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017DPS....4920902P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017DPS....4920902P"><span>Monitoring Saturn's Upper Atmosphere Density Variations Using Helium 584 <span class="hlt">Airglow</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Parkinson, Chris</p> <p>2017-10-01</p> <p>The study of He 584 Å brightnesses is interesting as the EUV (Extreme UltraViolet) planetary <span class="hlt">airglow</span> have the potential to yield useful information about mixing and other important parameters in its thermosphere. Resonance scattering of sunlight by He atoms is the principal source of the planetary <span class="hlt">emission</span> of He 585 Å. The principal parameter involved in determining the He 584 Å albedo are the He volume mixing ratio, f_He, well below the homopause. Our main science objective is to estimate the helium mixing ratio in the lower atmosphere. Specifically, He <span class="hlt">emissions</span> come from above the homopause where optical depth trau=1 in H2 and therefore the interpretation depends mainly on two parameters: He mixing ratio of the lower atmosphere and K_z. The occultations of Koskinen et al (2015) give K_z with an accuracy that has never been possible before and the combination of occultations and <span class="hlt">airglow</span> therefore provide estimates of the mixing ratio in the lower atmosphere. We make these estimates at several locations that can be reasonably studied with both occultations and <span class="hlt">airglow</span> and then average the results. Our results lead to a greatly improved estimate of the mixing ratio of He in the upper atmosphere and below. The second objective is to constrain the dynamics in the atmosphere by using the estimate of the He mixing ratio from the main objective. Once we have an estimate of the He mixing ratio in the lower atmosphere that agrees with both occultations and <span class="hlt">airglow</span>, helium becomes an effective tracer species as any variations in the Cassini UVIS helium data are direct indicator of changes in K_z i.e., dynamics. Our third objective is to connect this work to our Cassini UVIS data He 584 Å <span class="hlt">airglow</span> analyses as they both cover the time span of the observations and allow us to monitor changes in the <span class="hlt">airglow</span> observations that may correlate with changes in the state of the atmosphere as revealed by the occultations Saturn's upper thermosphere. This work helps to determine the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..19.8154K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..19.8154K"><span>16 years of <span class="hlt">airglow</span> measurement with astronomical facilities</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kausch, Wolfgang; Noll, Stefan; Kimeswenger, Stefan; Unterguggenberger, Stefanie; Jones, Amy; Proxauf, Bastian</p> <p>2017-04-01</p> <p>Observations taken with ground-based astronomical telescopes are affected by various <span class="hlt">airglow</span> <span class="hlt">emission</span> processes in the Earth's upper atmosphere. This chemiluminescent <span class="hlt">emission</span> can be used to investigate the physical state of the meso- and the thermosphere. By applying a modified approach of techniques originally developed to characterise and remove these features from the astronomical spectra, which are not primarily taken for <span class="hlt">airglow</span> studies, these spectra are suitable for <span class="hlt">airglow</span> research. For our studies, we currently use data from two observing sites on both hemispheres for our studies: The European Southern Observatory operates four 8m telescopes at the Very Large Telescope (VLT) in the Chilean Atacama desert (24.6°S, 70.4°W). The 2.5m Sloan Digital Sky Survey telescope (SDSS) located in New Mexico/USA (32.8°N, 105.8°W) provides observations from the northern hemisphere. Each of these telescopes is equipped with several astronomical instruments. Among them are several spectrographs operating in the optical and near-IR regime with medium to high spectral resolution. Currently, we work on data from the following three spectrographs (1) UVES@VLT (Ultraviolet and Visual Echelle Spectrograph): This instrument provides spectra in the wavelength regime from 0.3 to 1.1μm in small spectral ranges. Its high resolving power (up to R˜110 000) allows a detailed study of oxygen (OI@557nm, OI@630nm), sodium (NaD@589nm), nitrogen (NI@520nm), and many OH bands. UVES has been in operation since 1999 providing the longest time series. (2) X-Shooter@VLT: This spectrograph is unique as it provides the whole wavelength range from 0.3 to 2.5μm at once with medium resolving power (R˜3 300 to 18 000, depending on the setup). This enables us to study the dependency of optical and near-IR <span class="hlt">airglow</span> processes simultaneously, e.g. the OH bands. In addition, weak <span class="hlt">airglow</span> continuum <span class="hlt">emission</span>, e.g. arising from FeO and NiO can be studied. In operation since 2009, the data cover half a</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018ACP....18.6691D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018ACP....18.6691D"><span>The <span class="hlt">airglow</span> layer <span class="hlt">emission</span> altitude cannot be determined unambiguously from temperature comparison with lidars</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dunker, Tim</p> <p>2018-05-01</p> <p>I investigate the nightly mean <span class="hlt">emission</span> height and width of the OH* (3-1) layer by comparing nightly mean temperatures measured by the ground-based spectrometer GRIPS 9 and the Na lidar at ALOMAR. The data set contains 42 coincident measurements taken between November 2010 and February 2014, when GRIPS 9 was in operation at the ALOMAR observatory (69.3° N, 16.0° E) in northern Norway. To closely resemble the mean temperature measured by GRIPS 9, I weight each nightly mean temperature profile measured by the lidar using Gaussian distributions with 40 different centre altitudes and 40 different full widths at half maximum. In principle, one can thus determine the altitude and width of an <span class="hlt">airglow</span> layer by finding the minimum temperature difference between the two instruments. On most nights, several combinations of centre altitude and width yield a temperature difference of ±2 K. The generally assumed altitude of 87 km and width of 8 km is never an unambiguous, good solution for any of the measurements. Even for a fixed width of ˜ 8.4 km, one can sometimes find several centre altitudes that yield equally good temperature agreement. Weighted temperatures measured by lidar are not suitable to unambiguously determine the <span class="hlt">emission</span> height and width of an <span class="hlt">airglow</span> layer. However, when actual altitude and width data are lacking, a comparison with lidars can provide an estimate of how representative a measured rotational temperature is of an assumed altitude and width. I found the rotational temperature to represent the temperature at the commonly assumed altitude of 87.4 km and width of 8.4 km to within ±16 K, on average. This is not a measurement uncertainty.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMNH51A1922G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMNH51A1922G"><span>Methods for analyzing optical observations of tsunami-induced signatures in <span class="hlt">airglow</span> <span class="hlt">emissions</span> from ground-based and space-based platforms</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Grawe, M.; Makela, J. J.</p> <p>2016-12-01</p> <p><span class="hlt">Airglow</span> imaging of the 630.0-nm redline <span class="hlt">emission</span> has emerged as a useful tool for studying the properties of tsunami-ionospheric coupling in recent years, offering spatially continuous coverage of the sky with a single instrument. Past studies have shown that <span class="hlt">airglow</span> signatures induced by tsunamis are inherently anisotropic due to the observation geometry and effects from the geomagnetic field. Here, we present details behind the techniques used to determine the parameters of the signature (orientation, wavelength, etc) with potential extensions to real or quasi-real time and a tool for interpreting the location and strength of the signatures in the field of view. We demonstrate application of the techniques to ground-based optical measurements of several tsunami-induced signatures taking place over the past five years from an imaging system in Hawaii. Additionally, these methods are extended for use on space-based observation platforms, offering advantages over ground-based installations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19940022877','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19940022877"><span>Solar and <span class="hlt">airglow</span> measurements aboard the two suborbital flights NASA 36.098 and 36.107</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Woods, Thomas N.</p> <p>1994-01-01</p> <p>This suborbital program, involving the University of Colorado (CU), National Center for Atmospheric Research (NCAR), University of California at Berkeley (UCB), and Boston University (BU), has resulted in two rocket flights from the White Sands Missile Range, one in 1992 and one in 1993 as NASA 36.098 and 36.107 respectively. The rocket payload includes five solar instruments and one <span class="hlt">airglow</span> instrument from CU/NCAR and one solar instrument and two <span class="hlt">airglow</span> instruments from UCB/BU. This report discusses results on solar radiation measurements and the study of thermospheric <span class="hlt">airglow</span>, namely the photoelectron excited <span class="hlt">emissions</span> from N2 and O, for the CU/NCAR program.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JGRA..122.7834S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JGRA..122.7834S"><span>Global modeling of thermospheric <span class="hlt">airglow</span> in the far ultraviolet</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Solomon, Stanley C.</p> <p>2017-07-01</p> <p>The Global <span class="hlt">Airglow</span> (GLOW) model has been updated and extended to calculate thermospheric <span class="hlt">emissions</span> in the far ultraviolet, including sources from daytime photoelectron-driven processes, nighttime recombination radiation, and auroral excitation. It can be run using inputs from empirical models of the neutral atmosphere and ionosphere or from numerical general circulation models of the coupled ionosphere-thermosphere system. It uses a solar flux module, photoelectron generation routine, and the Nagy-Banks two-stream electron transport algorithm to simultaneously handle energetic electron distributions from photon and auroral electron sources. It contains an ion-neutral chemistry module that calculates excited and ionized species densities and the resulting <span class="hlt">airglow</span> volume <span class="hlt">emission</span> rates. This paper describes the inputs, algorithms, and code structure of the model and demonstrates example outputs for daytime and auroral cases. Simulations of far ultraviolet <span class="hlt">emissions</span> by the atomic oxygen doublet at 135.6 nm and the molecular nitrogen Lyman-Birge-Hopfield bands, as viewed from geostationary orbit, are shown, and model calculations are compared to limb-scan observations by the Global Ultraviolet Imager on the TIMED satellite. The GLOW model code is provided to the community through an open-source academic research license.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.P31B2808B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.P31B2808B"><span>Energy balance in Saturn's upper atmosphere: Joint Lyman-α <span class="hlt">airglow</span> observations with HST and Cassini</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ben-Jaffel, L.; Baines, K. H.; Ballester, G.; Holberg, H. B.; Koskinen, T.; Moses, J. I.; West, R. A.; Yelle, R. V.</p> <p>2017-12-01</p> <p>We are conducting Hubble Space Telescope UV spectroscopy of Saturn's disk-reflected Lyman-α <span class="hlt">line</span> (Ly-α) at the same time as Cassini <span class="hlt">airglow</span> measurements. Saturn's Ly-α <span class="hlt">emission</span> is composed of solar and interplanetary (IPH) Ly-α photons scattered by its upper atmosphere. The H I Ly-a <span class="hlt">line</span> probes different upper atmospheric layers down to the homopause, providing an independent way to investigate the H I abundance and energy balance. However, this is a degenerate, multi-parameter, radiative-transfer problem that depends on: H I column density, scattering process by thermal and superthermal hydrogen, time-variable solar and IPH sources, and instrument calibration. Our joint HST-Cassini campaign should break the degeneracy in the Saturn <span class="hlt">airglow</span> problem. First, <span class="hlt">line</span> integrated fluxes simultaneously measured by HST/STIS (dayside) and Cassini/UVIS (nightside), avoiding solar variability, should resolve the solar and IPH sources. Second, high-resolution spectroscopy with STIS will reveal superthermal <span class="hlt">line</span> broadening not accessible with a low-resolution spectrometer like UVIS. Third, a second visit observing the same limb of Saturn will cross-calibrate the instruments and, with the STIS linewidth information, will yield the H I abundance, a key photochemical parameter not measured by Cassini. Finally, the STIS latitudinal mapping of the Ly-α linewidth will be correlated with Cassini's latitudinal temperature profile of the thermosphere, to provide an independent constraint on the thermospheric energy budget, a fundamental outstanding problem for giant planets. Here, we report the first results from the HST-Cassini campaign.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMSA21B2025K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMSA21B2025K"><span>HF-induced <span class="hlt">airglow</span> structure as a proxy for ionospheric irregularity detection</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kendall, E. A.</p> <p>2013-12-01</p> <p>The High Frequency Active Auroral Research Program (HAARP) heating facility allows scientists to test current theories of plasma physics to gain a better understanding of the underlying mechanisms at work in the lower ionosphere. One powerful technique for diagnosing radio frequency interactions in the ionosphere is to use ground-based optical instrumentation. High-frequency (HF), heater-induced artificial <span class="hlt">airglow</span> observations can be used to diagnose electron energies and distributions in the heated region, illuminate natural and/or artificially induced ionospheric irregularities, determine ExB plasma drifts, and measure quenching rates by neutral species. Artificial <span class="hlt">airglow</span> is caused by HF-accelerated electrons colliding with various atmospheric constituents, which in turn emit a photon. The most common <span class="hlt">emissions</span> are 630.0 nm O(1D), 557.7 nm O(1S), and 427.8 nm N2+(1NG). Because more photons will be emitted in regions of higher electron energization, it may be possible to use <span class="hlt">airglow</span> imaging to map artificial field-aligned irregularities at a particular altitude range in the ionosphere. Since fairly wide field-of-view imagers are typically deployed in <span class="hlt">airglow</span> campaigns, it is not well-known what meter-scale features exist in the artificial <span class="hlt">airglow</span> <span class="hlt">emissions</span>. Rocket data show that heater-induced electron density variations, or irregularities, consist of bundles of ~10-m-wide magnetic field-aligned filaments with a mean depletion depth of 6% [Kelley et al., 1995]. These bundles themselves constitute small-scale structures with widths of 1.5 to 6 km. Telescopic imaging provides high resolution spatial coverage of ionospheric irregularities and goes hand in hand with other observing techniques such as GPS scintillation, radar, and ionosonde. Since <span class="hlt">airglow</span> observations can presumably image ionospheric irregularities (electron density variations), they can be used to determine the spatial scale variation, the fill factor, and the lifetime characteristics of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19990069911&hterms=quantitative+data+analysis&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dquantitative%2Bdata%2Banalysis','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19990069911&hterms=quantitative+data+analysis&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dquantitative%2Bdata%2Banalysis"><span>Issues in Quantitative Analysis of Ultraviolet Imager (UV) Data: <span class="hlt">Airglow</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Germany, G. A.; Richards, P. G.; Spann, J. F.; Brittnacher, M. J.; Parks, G. K.</p> <p>1999-01-01</p> <p>The GGS Ultraviolet Imager (UVI) has proven to be especially valuable in correlative substorm, auroral morphology, and extended statistical studies of the auroral regions. Such studies are based on knowledge of the location, spatial, and temporal behavior of auroral <span class="hlt">emissions</span>. More quantitative studies, based on absolute radiometric intensities from UVI images, require a more intimate knowledge of the instrument behavior and data processing requirements and are inherently more difficult than studies based on relative knowledge of the oval location. In this study, UVI <span class="hlt">airglow</span> observations are analyzed and compared with model predictions to illustrate issues that arise in quantitative analysis of UVI images. These issues include instrument calibration, long term changes in sensitivity, and imager flat field response as well as proper background correction. <span class="hlt">Airglow</span> <span class="hlt">emissions</span> are chosen for this study because of their relatively straightforward modeling requirements and because of their implications for thermospheric compositional studies. The analysis issues discussed here, however, are identical to those faced in quantitative auroral studies.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_1");'>1</a></li> <li><a href="#" onclick='return showDiv("page_2");'>2</a></li> <li class="active"><span>3</span></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_3 --> <div id="page_4" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_2");'>2</a></li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li class="active"><span>4</span></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="61"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19800026554&hterms=day+night&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dday%2Bnight','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19800026554&hterms=day+night&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dday%2Bnight"><span>O2/1 Delta/ <span class="hlt">emission</span> in the day and night <span class="hlt">airglow</span> of Venus</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Connes, P.; Noxon, J. F.; Traub, W. A.; Carleton, N. P.</p> <p>1979-01-01</p> <p>An intense <span class="hlt">airglow</span> from O2(1 Delta) at 1.27 microns on both the light and the dark sides of Venus has been detected by using a ground-based high-resolution Fourier-transform spectrometer. Both dayglow and nightglow are roughly 1,000 times brighter than the visible O2 nightglow found by Veneras 9 and 10 in 1975. The column <span class="hlt">emission</span> rate of O2(1 Delta) from Venus is close to the rate at which fresh O atoms are produced from photolysis of CO2 on the day side. Formation of O2(1 Delta) is thus a major step in the removal of O atoms from the atmosphere, and dynamical processes must carry these atoms to the night side fast enough to yield a maximum density near 90 km, which is almost constant over the planet.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012JASTP..78...62T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012JASTP..78...62T"><span>Simultaneous Rayleigh lidar and <span class="hlt">airglow</span> measurements of middle atmospheric waves over low latitudes in India</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Taori, A.; Kamalakar, V.; Raghunath, K.; Rao, S. V. B.; Russell, J. M.</p> <p>2012-04-01</p> <p>We utilize simultaneous Rayleigh lidar and mesospheric OH and O2 <span class="hlt">airglow</span> measurements to identify the dominant and propagating waves within 40-95 km altitude regions over a low latitude station Gadanki (13.8° N, 79.2 °E). It is found that waves with 0.4-0.6 h periodicity are common throughout the altitude range of 40-95 km with significant amplitudes. The ground based temperature measurements with lidar and <span class="hlt">airglow</span> monitoring are found to compare well with SABER data. With simultaneous Rayleigh lidar (temperature) and mesospheric <span class="hlt">airglow</span> (<span class="hlt">emission</span> intensity and temperature) measurements, we estimate the amplitude growth and Krassovsky parameters to characterize the propagation and dissipation of these upward propagating waves.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19800065052&hterms=Dissociative&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3DDissociative','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19800065052&hterms=Dissociative&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3DDissociative"><span><span class="hlt">Emission</span> <span class="hlt">line</span> shapes produced by dissociative excitation of atmospheric gases</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Zipf, E. C.; Wells, W. C.</p> <p>1980-01-01</p> <p>The spectral <span class="hlt">line</span> shapes of the radiation emitted from O atoms produced by the dissociative excitation of O2, CO, CO2 and NO are investigated. Doppler <span class="hlt">line</span> shapes are derived from time-of-flight spectra of O (5S0) atoms decaying by the <span class="hlt">emission</span> of 1356-A radiation after being produced in electron impact experiments at incident electron energies from 25 to 300 eV. It is shown that the effective <span class="hlt">line</span> width of the radiation is large compared with the Doppler absorption widths of ambient O atoms in both photoelectron and auroral excitation, and thus the dissociatively excited component of the O I 1304-A <span class="hlt">airglow</span> will behave as though it were optically thin, exhibiting pronounced limb brightening effects and a scale height characteristic of the initial, local source function. It is found that the average kinetic energy of the dissociation fragments inferred from O I (5S) time-of-flight spectra is in good agreement with that of O I (3S) atoms in the electron impact dissociation of CO2, although not for O2. Finally, it is suggested that although electron impact dissociation of CO and CO2 contributes to the 1304-A <span class="hlt">emission</span> in the upper atmosphere of Venus, it cannot be the dominant source of this radiation since the absolute cross sections for the reaction are too small.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006AGUSMSA43A..03W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006AGUSMSA43A..03W"><span>First Light from Triple-Etalon Fabry-Perot Interferometer for Atmospheric OI <span class="hlt">Airglow</span> (6300 A)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Watchorn, S.; Noto, J.; Pedersen, T.; Betremieux, Y.; Migliozzi, M.; Kerr, R. B.</p> <p>2006-05-01</p> <p>Scientific Solutions, Inc. (SSI) has developed a triple-etalon Fabry-Perot interferometer (FPI) to observe neutral winds in the ionosphere by measuring neutral oxygen (O I) <span class="hlt">emission</span> at 630.0 nm during the day. This instrument is to be deployed in the SSI <span class="hlt">airglow</span> building at the Cerro Tololo observatory (30.17S 70.81W) in Chile, in support of the Comm/Nav Outage Forecast System (C/NOFS) project. Post-deployment observation will be made in conjunction with two other Clemson University Fabry-Perots in Peru, creating a longitudinal chain of interferometers for thermospheric observations. These instruments will make autonomous day and night observations of thermospheric dynamics. Instruments of this type can be constructed for a global chain of autonomous <span class="hlt">airglow</span> observatories. The FPI presented in this talk consists of three independently pressure-controlled etalons, fed collimated light by a front optical train headed by an all-sky lens with a 160-degree field of view. It can be controlled remotely via a web-based service which allows any internet-connected computer to mimic the control computer at the instrument site. In fall 2005, the SSI system was first assembled at the Millstone Hill Observatory in Westford, Massachusetts, and made day and evening observations. It was then moved to the High-frequency Active Auroral Research Project (HAARP) site in Gakona, Alaska, to participate in joint optical/ionospheric heating campaigns. Additionally, natural <span class="hlt">airglow</span> observations were made, both locally and remotely via the internet from Massachusetts. The Millstone and HAARP observations with two etalons yielded strong 630-nm atmospheric Fraunhofer absorption <span class="hlt">lines</span>, with some suggestion of the Ring effect. By modeling the atmospheric absorption <span class="hlt">line</span> as the constant times the corresponding solar absorption -- itself modeled as a Gaussian plus a polynomial -- the absorption feature is subtracted, leaving only the <span class="hlt">emission</span> feature. Software ring-summing tools developed at the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007AGUSMSA53A..01B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007AGUSMSA53A..01B"><span>Important Considerations When Using Hydroxyl <span class="hlt">Airglow</span> Measurements to Determine Climate Trends of the Mesopause Region.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Burns, G.; French, J.</p> <p>2007-05-01</p> <p>Spectral calibrations, <span class="hlt">airglow</span> and possibly auroral contaminations, solar and telluric absorption features and the selection of transition probabilities can all influence rotational temperatures derived from measurements of hydroxyl <span class="hlt">airglow</span> intensities. Consideration and examples are given of these influences. Measurements and analyses are outlined for data checking that should be undertaken if a hydroxyl <span class="hlt">airglow</span> data set is to be used to determine climate trends. Multiple spectral calibrations should be conducted throughout the observing period, with regular inter- comparisons to other calibration sources also required. Uncertainties in spectral calibrations should be expressed as a temperature equivalent. Sufficient spectral scans at maximum resolution should be obtained under all extreme observing conditions (at the lowest solar depression angle operated both morning and night, moon and cloud both separately and combined, aurora and under conditions of enhanced atomic oxygen <span class="hlt">airglow</span>, and under clear sky conditions but with high atmospheric water vapour content) so that an uncertainty for the derived rotational temperatures can be determined for the established data selection criteria. Once the varying <span class="hlt">emission</span> and absorption features for the hydroxyl region of interest at your site are understood for the observing site, then the spectral resolution of the observing instrument can be reduced to increase temporal resolution with reasonable confidence. This confidence should be tested by investigating the average rotational temperatures derived from all possible <span class="hlt">line</span> intensity ratios under the extreme observing conditions noted. If a spectral-fitting rotational temperature determination is used, the residuals from the fit should be summed and similarly examined. Hydroxyl measurements provide a cost effective means of monitoring the temperature of the climate-sensitive mesopause region on an almost nightly basis. If care is taken, they provide a valuable data set</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19720018659','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19720018659"><span>An atlas of low latitude 6300A (01) night <span class="hlt">airglow</span> from OGO-4 observations</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Reed, E. I.; Fowler, W. B.; Blamont, J. E.</p> <p>1972-01-01</p> <p>The atomic oxygen <span class="hlt">emission</span> <span class="hlt">line</span> at 6300 A, measured in the nadir direction by a photometer on the polar orbiting satellite OGO-4, was plotted between 40 deg N and 40 deg S latitude on a series of maps for the moon-free periods between 30 August 1967 and 10 January 1968 The longitudinal and local time variations which occur during the northern fall-winter season are indicated. The northern tropical arc is more widespread while the southern arc is not present at all longitudes. The conditions under which the observations were made are described, and four <span class="hlt">airglow</span> maps were selected to show the local time variations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19730021619','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19730021619"><span>Measurements of the Michigan <span class="hlt">Airglow</span> Observatory from 1971 to 1973 at Ester Dome Alaska</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Mcwatters, K. D.; Meriwether, J. W.; Hays, P. B.; Nagy, A. F.</p> <p>1973-01-01</p> <p>The Michigan <span class="hlt">Airglow</span> Observatory (MAO) was located at Ester Dome Observatory, College, Alaska (latitude: 64 deg 53'N, longitude: 148 deg 03'W) since October, 1971. The MAO houses a 6-inch Fabry-Perot interferometer, a 2-channel monitoring photometer and a 4-channel tilting filter photometer. The Fabry-Perot interferometer was used extensively during the winter observing seasons of 1971-72 and 1972-73 to measure temperature and mass motions of the neutral atmosphere above approximately 90 kilometers altitude. Neutral wind data from the 1971-72 observing season as measured by observing the Doppler shift of the gamma 6300 A atomic oxygen <span class="hlt">emission</span> <span class="hlt">line</span> are presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMSA33A2422S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMSA33A2422S"><span>Performance evaluation of low-cost <span class="hlt">airglow</span> cameras for mesospheric gravity wave measurements</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Suzuki, S.; Shiokawa, K.</p> <p>2016-12-01</p> <p>Atmospheric gravity waves significantly contribute to the wind/thermal balances in the mesosphere and lower thermosphere (MLT) through their vertical transport of horizontal momentum. It has been reported that the gravity wave momentum flux preferentially associated with the scale of the waves; the momentum fluxes of the waves with a horizontal scale of 10-100 km are particularly significant. <span class="hlt">Airglow</span> imaging is a useful technique to observe two-dimensional structure of small-scale (<100 km) gravity waves in the MLT region and has been used to investigate global behaviour of the waves. Recent studies with simultaneous/multiple <span class="hlt">airglow</span> cameras have derived spatial extent of the MLT waves. Such network imaging observations are advantageous to ever better understanding of coupling between the lower and upper atmosphere via gravity waves. In this study, we newly developed low-cost <span class="hlt">airglow</span> cameras to enlarge the <span class="hlt">airglow</span> imaging network. Each of the cameras has a fish-eye lens with a 185-deg field-of-view and equipped with a CCD video camera (WATEC WAT-910HX) ; the camera is small (W35.5 x H36.0 x D63.5 mm) and inexpensive, much more than the <span class="hlt">airglow</span> camera used for the existing ground-based network (Optical Mesosphere Thermosphere Imagers (OMTI) operated by Solar-Terrestrial Environmental Laboratory, Nagoya University), and has a CCD sensor with 768 x 494 pixels that is highly sensitive enough to detect the mesospheric OH <span class="hlt">airglow</span> <span class="hlt">emission</span> perturbations. In this presentation, we will report some results of performance evaluation of this camera made at Shigaraki (35-deg N, 136-deg E), Japan, where is one of the OMTI station. By summing 15-images (i.e., 1-min composition of the images) we recognised clear gravity wave patterns in the images with comparable quality to the OMTI's image. Outreach and educational activities based on this research will be also reported.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..19.3465X','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..19.3465X"><span>The advances in <span class="hlt">airglow</span> study and observation by the ground-based <span class="hlt">airglow</span> observation network over China</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Xu, Jiyao; Li, Qinzeng; Yuan, Wei; Liu, Xiao; Liu, Weijun; Sun, Longchang</p> <p>2017-04-01</p> <p>Ground-based <span class="hlt">airglow</span> observation networks over China used to study <span class="hlt">airglow</span> have been established, which contains 15 stations. Some new results were obtained using the networks. For OH <span class="hlt">airglow</span> observations, firstly, an unusual outbreak of Concentric Gravity Wave (CGW) events were observed by the first no-gap network nearly every night during the first half of August 2013. Combination of the ground imager network with satellites provides multilevel observations of the CGWs from the troposphere to the mesopause region. Secondly, three-year OH <span class="hlt">airglow</span> images (2012-2014) from Qujing (25.6°N, 103.7°E) were used to study how orographic features of the Tibetan Plateau (TP) affect the geographical distributions of gravity wave (GW) sources. We find the orographic forcings have a significant impact on the gravity wave propagation features. Thirdly, ground-based observations of the OH (9-4, 8-3, 6-2, 5-1, 3-0) band <span class="hlt">airglow</span> over Xinglong (40°2N, 117°4E) in northern China from 2012 to 2014 are used to calculate rotational temperatures. By comparing the ground-based OH rotational temperature with SABER's observations, five Einstein coefficient datasets are evaluated. We find rotational temperatures determined using any of the available Einstein coefficient datasets have systematic errors. We have obtained a set of optimal Einstein coefficients ratios for rotational temperature derivation using three years data from ground-based OH spectra and SABER temperatures. For the OI 630.0 nm <span class="hlt">airglow</span> observations, we used three-year (2011-2013) observations of thermospheric winds (at 250 km) by Fabry-Perot interferometers at Xinglong to study the climatology of atmospheric planetary wave-type oscillations (PWTOs) with periods of 4-19 days. We found these PWTOs occur more frequently in the months from May to October. They are consistent with the summertime preference of middle-latitude ionospheric electron density oscillations noted in other studies. By using an all-sky <span class="hlt">airglow</span> imager</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JGRA..122.4628Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JGRA..122.4628Y"><span>Peak height of OH <span class="hlt">airglow</span> derived from simultaneous observations a Fabry-Perot interferometer and a meteor radar</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yu, Tao; Zuo, Xiaomin; Xia, Chunliang; Li, Mingyuan; Huang, Cong; Mao, Tian; Zhang, Xiaoxin; Zhao, Biqiang; Liu, Libo</p> <p>2017-04-01</p> <p>A new method for estimating daily averaged peak height of the OH <span class="hlt">airglow</span> layer from a ground-based meteor radar (MR) and a Fabry-Perot interferometer (FPI) is presented. The first results are derived from 4 year simultaneous measurements of winds by a MR and a FPI at two adjacent stations over center China and are compared with observations from the Thermosphere Ionosphere Mesosphere Energetics and Dynamics/Sounding of the Atmosphere using Broadband <span class="hlt">Emission</span> Radiometry (SABER) instrument. The OH <span class="hlt">airglow</span> peak heights, which are derived by using correlation analysis between winds of the FPI and MR, are found to generally peak at an altitude of 87 km and frequently varied between 80 km and 90 km day to day. In comparison with SABER OH 1.6 μm observations, reasonable similarity of <span class="hlt">airglow</span> peak heights is found, and rapid day-to-day variations are also pronounced. Lomb-Scargle analysis is used to determine cycles of temporal variations of <span class="hlt">airglow</span> peak heights, and there are obvious periodic variations both in our <span class="hlt">airglow</span> peak heights and in the satellite observations. In addition to the annual, semiannual, monthly, and three monthly variations, the shorter time variations, e.g., day-to-day and several days' variations, are also conspicuous. The day-to-day variations of <span class="hlt">airglow</span> height obviously could reduce observation accuracy and lead to some deviations in FPI measurements. These FPI wind deviations arising from <span class="hlt">airglow</span> height variations are also estimated to be about 3-5 m/s from 2011 to 2015, with strong positive correlation with <span class="hlt">airglow</span> peak height variation. More attention should be paid to the wind deviations associated with <span class="hlt">airglow</span> height variation when using and interpreting winds measured by FPI.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19880066225&hterms=Abreu&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DAbreu%252C%2Bc.','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19880066225&hterms=Abreu&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DAbreu%252C%2Bc."><span>The auroral 6300 A <span class="hlt">emission</span> - Observations and modeling</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Solomon, Stanley C.; Hays, Paul B.; Abreu, Vincent J.</p> <p>1988-01-01</p> <p>A tomographic inversion is used to analyze measurements of the auroral atomic oxygen <span class="hlt">emission</span> <span class="hlt">line</span> at 6300 A made by the atmosphere explorer visible <span class="hlt">airglow</span> experiment. A comparison is made between <span class="hlt">emission</span> altitude profiles and the results from an electron transport and chemical reaction model. Measurements of the energetic electron flux, neutral composition, ion composition, and electron density are incorporated in the model.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006ihy..workE.135S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006ihy..workE.135S"><span>OI 630.0 nm Night <span class="hlt">Airglow</span> Observations during the Geomagnetic Storm on November 20, 2003 at Kolhapur (P43)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sharma, A. K.; et al.</p> <p>2006-11-01</p> <p>sharma_ashokkumar@yahoo.com The ground based photometric observations of OI 630 nm <span class="hlt">emission</span> <span class="hlt">line</span> have been carried out from Kolhapur station (Geog. Lat.16.8˚N, Geo. Long 74.2˚E), India during the period of the largest geomagnetic storm of the solar cycle 23 which occurred on 20 November 2003, with minimum Dst index 472 nT occurring around mid-night hours. We observed that on 19 November 2003 which was geomagnetically quiet day, the <span class="hlt">airglow</span> activity of OI 630 nm <span class="hlt">emission</span> was subdued and it was decreasing monotonically. However, on the night of November 20, 2003 the enhancement is observed during geomagnetic storm due to the increased electron density at the altitude of the F region which is related to the downward transport of electron from the plasmasphere to the F-region. <span class="hlt">Airglow</span> intensity at OI 630.0 nm showed increase around midnight on November 21, 2003 but comparatively on a smaller scale. On this night the DST index was about 100 nT. This implies that the effect of the geomagnetic storm persisted on that night also. These observations have been explained by the penetration magnetospheric electric field to the low latitude region and the subsequent modulation of meridional wind during the magnetic disturbance at night.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018Icar..307..207N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018Icar..307..207N"><span>Extreme ultraviolet spectra of Venusian <span class="hlt">airglow</span> observed by EXCEED</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nara, Yusuke; Yoshikawa, Ichiro; Yoshioka, Kazuo; Murakami, Go; Kimura, Tomoki; Yamazaki, Atsushi; Tsuchiya, Fuminori; Kuwabara, Masaki; Iwagami, Naomoto</p> <p>2018-06-01</p> <p>Extreme ultraviolet (EUV) spectra of Venus in the wavelength range 520 - 1480 Å with 3 - 4 Å resolutions were obtained in March 2014 by an EUV imaging spectrometer EXCEED (Extreme Ultraviolet Spectroscope for Exospheric Dynamics) on the HISAKI spacecraft. Due to its high sensitivity and long exposure time, many new <span class="hlt">emission</span> <span class="hlt">lines</span> and bands were identified. Already known <span class="hlt">emissions</span> such as the O II 834 Å, O I 989 Å, H ILy - β 1026 Å, and the C I 1277 Å <span class="hlt">lines</span> (Broadfoot et al., 1974; Bertaux et al., 1980; Feldman et al., 2000) are also detected in the EXCEED spectrum. In addition, N2 band systems such as the Lyman-Birge-Hopfield (a 1Πg - X 1Σg+) (2, 0), (2, 1), (3, 1), (3, 2) and (5, 3) bands, the Birge-Hopfield (b1Πu - X 1 Σg+) (1, 3) band, and the Carroll-Yoshino (c 4‧ 1 Σu+ - X 1Σg+) (0, 0) and (0, 1) bands together are identified for the first time in the Venusian <span class="hlt">airglow</span>. We also identified the CO Hopfield-Birge (B 1Σ+ - X 1Σ+) (1, 0) band in addition to the already known (0, 0) band, and the CO Hopfield-Birge (C 1Σ+ - X 1Σ+) (0, 1), (0, 2) bands in addition to the already known (0, 0) band (Feldman et al., 2000; Gérard et al., 2011).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-GSFC_20171208_Archive_e001596.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-GSFC_20171208_Archive_e001596.html"><span>Waves in <span class="hlt">Airglow</span></span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>2017-12-08</p> <p>In April 2012, waves in Earth’s “airglow” spread across the nighttime skies of northern Texas like ripples in a pond. In this case, the waves were provoked by a massive thunderstorm. <span class="hlt">Airglow</span> is a layer of nighttime light <span class="hlt">emissions</span> caused by chemical reactions high in Earth’s atmosphere. A variety of reactions involving oxygen, sodium, ozone and nitrogen result in the production of a very faint amount of light. In fact, it’s approximately one billion times fainter than sunlight (~10-11 to 10-9 W·cm-2· sr-1). This chemiluminescence is similar to the chemical reactions that light up a glow stick or glow-in-the-dark silly putty. The “day-night band,” of the Visible Infrared Imaging Radiometer Suite (VIIRS) on the Suomi NPP satellite captured these glowing ripples in the night sky on April 15, 2012 (top image). The day-night band detects lights over a range of wavelengths from green to near-infrared and uses highly sensitive electronics to observe low light signals. (The absolute minimum signals detectable are at the levels of nightglow <span class="hlt">emission</span>.) The lower image shows the thunderstorm as observed by a thermal infrared band on VIIRS. This thermal band, which is sensitive only to heat <span class="hlt">emissions</span> (cold clouds appear white), is not sensitive to the subtle visible-light wave structures seen by the day-night band. Technically speaking, <span class="hlt">airglow</span> occurs at all times. During the day it is called “dayglow,” at twilight “twilightglow,” and at night “nightglow.” There are slightly different processes taking place in each case, but in the image above the source of light is nightglow. The strongest nightglow <span class="hlt">emissions</span> are mostly constrained to a relatively thin layer of atmosphere between 85 and 95 kilometers (53 and 60 miles) above the Earth’s surface. Little <span class="hlt">emission</span> occurs below this layer since there’s a higher concentration of molecules, allowing for dissipation of chemical energy via collisions rather than light production. Likewise, little</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA460185','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA460185"><span>Telescopic Imaging of Heater-Induced <span class="hlt">Airglow</span> at HAARP</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2007-01-01</p> <p>03-01-2007 Final1 10-09-2003 - 10-09-2006 4. TITLE AND SUBTITLE Ba. CONTRACT NUMBER Telescopic Imaging of Heater-Induced <span class="hlt">Airglow</span> at HAARP N00014-03-1... HAARP to optically measure fine structure in the ionosphere and to study <span class="hlt">airglow</span> sources. In the presence of aurora and a strong blanketing E layer... HAARP was modulated at intervals of several seconds. For several cycles, small bright <span class="hlt">airglow</span> spots were observed whenever HAARP was on. These spots</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..19.8423K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..19.8423K"><span>Investigating the Concept of Using <span class="hlt">Airglow</span> Measurements to Detect Seismicity on Venus</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kenda, Balthasar; Lognonné, Philippe; Komjathy, Attila; Banerdt, Bruce; Cutts, Jim; Soret, Lauriane; Jackson, Jennifer</p> <p>2017-04-01</p> <p>The internal structure and dynamics of Venus are poorly constrained by observations. Seismology is among the best candidates for probing the interior of the planet, and it would also provide indispensable information about the present-day tectonic activity of Venus. However, due to the extreme surface temperatures, a long-duration seismic station seems to be beyond the technical capabilities achievable today. Nonetheless, the thick and dense atmosphere, which strongly couples with the ground, gives rise to the attractive option of detecting seismic waves from quakes within the atmosphere itself (Garcia et al., 2005, Lognonné and Johnson, 2007, 2015) using in-situ or remote-sensing measurements (Cutts et al., 2015). Here, we consider the bright <span class="hlt">airglow</span> <span class="hlt">emission</span> of O2 at 1.27 μm on the nightside of Venus and we model the intensity fluctuations induced by Venus quakes. Synthetic seismograms in the <span class="hlt">airglow</span> layer, at 90-120 km altitude, are computed using normal-mode summation for a fully coupled solid planet-atmosphere system, including the effects of molecular relaxation of CO2 and a radiative boundary condition at the top of the atmosphere (Lognonné et al., 2016). The corresponding variations in the volumetric <span class="hlt">emission</span> rate, calculated for realistic background intensities of the <span class="hlt">airglow</span> (Soret et al., 2012), are then vertically integrated to reproduce the signals that would be seen from orbit. The noise level of existing <span class="hlt">airglow</span> cameras suggests that the Rayleigh waves generated by quakes of magnitude 5 and above occurring on the nightside of the planet may be detectable up to about 60° in epicentral distance. A significant advantage of this technique is that a single orbiting camera may be sufficient to serve the role of a seismic network. By identifying and tracking the waves it is indeed possible to locate the source, estimate the magnitude and measure the horizontal surface-wave propagation velocities on Venus. In particular, it is expected that this would</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19870038348&hterms=Abreu&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DAbreu%252C%2Bc.','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19870038348&hterms=Abreu&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DAbreu%252C%2Bc."><span>The quenching rate of O(1D) by O(3P). [with data from Visible <span class="hlt">Airglow</span> experiment on AE satellites</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Abreu, V. J.; Yee, J. H.; Solomon, S. C.; Dalgarno, A.</p> <p>1986-01-01</p> <p>The rate coefficient for the quenching of O(1D) by O(3P) has recently been calculated by Yee et al. (1985). Their results indicate that quenching by atomic oxygen should not be ignored in the analysis of the 6300 A <span class="hlt">emission</span> <span class="hlt">airglow</span>. Data obtained by the Visible <span class="hlt">Airglow</span> Experiment on board the AE satellites have been reanalyzed to determine the quenching rate of O(1D) by atomic oxygen. The results of this analysis are presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JASTP.164..116L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JASTP.164..116L"><span>Semidiurnal tidal activity of the middle atmosphere at mid-latitudes derived from O2 atmospheric and OH(6-2) <span class="hlt">airglow</span> SATI observations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>López-González, M. J.; Rodríguez, E.; García-Comas, M.; López-Puertas, M.; Olivares, I.; Ruiz-Bueno, J. A.; Shepherd, M. G.; Shepherd, G. G.; Sargoytchev, S.</p> <p>2017-11-01</p> <p>In this paper, we investigate the tidal activity in the mesosphere and lower thermosphere region at 370N using OH Meinel and O2 atmospheric <span class="hlt">airglow</span> observations from 1998 to 2015. The observations were taken with a Spectral <span class="hlt">Airglow</span> Temperature Imager (SATI) installed at Sierra Nevada Observatory (SNO) (37.060N, 3.380W) at 2900 m height. From these observations a seasonal dependence of the amplitudes of the semidiurnal tide is inferred. The maximum tidal amplitude occurs in winter and the minimum in summer. The vertically averaged rotational temperatures and vertically integrated volume <span class="hlt">emission</span> rate (rotational temperatures and intensities here in after), from the O2 atmospheric band measurements and the rotational temperature derived from OH Meinel band measurements reach the maximum amplitude about 1-4 h after midnight during almost all the year except in August-September where the maximum is found 2-4 h earlier. The amplitude of the tide in the OH intensity reaches the minimum near midnight in midwinter, then it is progressively delayed until 4:00 LT in August-September, and from there on it moves again forward towards midnight. The mean Krassovsky numbers for OH and O2 <span class="hlt">emissions</span> are 5.9 ±1.8 and 5.6 ±1.0, respectively, with negative Krassovsky phases for almost all the year, indicating an upward energy transport. The mean vertical wavelengths for the vertical tidal propagation derived from OH and O2 <span class="hlt">emissions</span> are 35 ±20 km and 33 ±18 km, respectively. The vertical wavelengths together with the phase shift in the temperature derived from both <span class="hlt">airglow</span> <span class="hlt">emissions</span> indicate that these <span class="hlt">airglow</span> <span class="hlt">emission</span> layers are separated by 7 ±3 km, on average.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMSA33A2576A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMSA33A2576A"><span>Model simulations of <span class="hlt">line</span>-of-sight effects in <span class="hlt">airglow</span> imaging of acoustic and fast gravity waves from ground and space</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Aguilar Guerrero, J.; Snively, J. B.</p> <p>2017-12-01</p> <p>Acoustic waves (AWs) have been predicted to be detectable by imaging systems for the OH <span class="hlt">airglow</span> layer [Snively, GRL, 40, 2013], and have been identified in spectrometer data [Pilger et al., JASP, 104, 2013]. AWs are weak in the mesopause region, but can attain large amplitudes in the F region [Garcia et al., GRL, 40, 2013] and have local impacts on the thermosphere and ionosphere. Similarly, fast GWs, with phase speeds over 100 m/s, may propagate to the thermosphere and impart significant local body forcing [Vadas and Fritts, JASTP, 66, 2004]. Both have been clearly identified in ionospheric total electron content (TEC), such as following the 2013 Moore, OK, EF5 tornado [Nishioka et al., GRL, 40, 2013] and following the 2011 Tohoku-Oki tsunami [e.g., Galvan et al., RS, 47, 2012, and references therein], but AWs have yet to be unambiguously imaged in MLT data and fast GWs have low amplitudes near the threshold of detection; nevertheless, recent imaging systems have sufficient spatial and temporal resolution and sensitivity to detect both AWs and fast GWs with short periods [e.g., Pautet et al., AO, 53, 2014]. The associated detectability challenges are related to the transient nature of their signatures and to systematic challenges due to <span class="hlt">line</span>-of-sight (LOS) effects such as enhancements and cancelations due to integration along aligned or oblique wavefronts and geometric intensity enhancements. We employ a simulated <span class="hlt">airglow</span> imager framework that incorporates 2D and 3D <span class="hlt">emission</span> rate data and performs the necessary LOS integrations for synthetic imaging from ground- and space-based platforms to assess relative intensity and temperature perturbations. We simulate acoustic and fast gravity wave perturbations to the hydroxyl layer from a nonlinear, compressible model [e.g., Snively, 2013] for different idealized and realistic test cases. The results show clear signal enhancements when acoustic waves are imaged off-zenith or off-nadir and the temporal evolution of these</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017SPIE10562E..0WL','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017SPIE10562E..0WL"><span>Atise: a miniature Fourier-transform spectro-imaging concept for surveying auroras and <span class="hlt">airglow</span> monitoring from a 6/12u cubesat</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Le Courer, E.; Barthelemy, M.; Vialatte, A.; Prugniaux, M.; Bourdarot, G.; Sequies, T.; Monsinjon, P.; Puget, R.; Guerineau, N.</p> <p>2017-09-01</p> <p>The nanosatellite ATISE is a mission dedicated to the observation of the <span class="hlt">emission</span> spectra of the upper atmosphere (i.e. <span class="hlt">Airglow</span> and Auroras) mainly related to both the solar UV flux and the precipitation of suprathermal particles coming from the solar wind through the magnetosphere. ATISE will measure specifically the auroral <span class="hlt">emissions</span>, and the <span class="hlt">airglow</span> (day- and night) in the spectral range between 380 and 900 nm at altitudes between 100 and 350 km. The exposure time will be 1 second in auroral region and 20 s at low latitude regions. The 5 year expected lifetime of this mission should cover almost a half of solar cycle (2 years nominal). This instrument concept is based on an innovative miniaturized Fourier-transform spectrometer (FTS) allowing simultaneous 1 Rayleigh sensitivity detection along six 1.5°x1° limb <span class="hlt">lines</span> of sight. This 1-2kg payload instrument is hosted in a 12U cubeSat where 6U are allocated to the payload and 6U to the plateform subsystems. This represents a miniaturisation by a factor of 500 on weight and volume compared to previous Arizona-GLO instrument for equivalent performances in the visible. The instrument is based on microSPOC concept developed by ONERA and IPAG using one Fizeau interferometer per <span class="hlt">line</span> of sight directly glued on top of the half of a very sensitive CMOS Pyxalis HDPYX detector. Three detectors are necessary with a total electrical consumption compatible with a 6U nanoSat. Each interferometer occupies a 1.4 M pixel part of detector, each is placed on an image of the entrance pupil corresponding to a unique direction of the six <span class="hlt">lines</span> of sight, this in order to have a uniform illumination permitting good spectral Fourier reconstruction from fringes created between the Fizeau plate and the detector itself. Despite a limited 8x6 cm telescope, this configuration takes advantage of FTS multiplex effect and permits us to maximize the throughput and to integrate very faint <span class="hlt">emission</span> <span class="hlt">lines</span> over a wide field of view even if the 1</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_2");'>2</a></li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li class="active"><span>4</span></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_4 --> <div id="page_5" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li class="active"><span>5</span></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="81"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMSA51C2409K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMSA51C2409K"><span>MANGO Imager Network Observations of Geomagnetic Storm Impact on Midlatitude 630 nm <span class="hlt">Airglow</span> <span class="hlt">Emissions</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kendall, E. A.; Bhatt, A.</p> <p>2017-12-01</p> <p>The Midlatitude Allsky-imaging Network for GeoSpace Observations (MANGO) is a network of imagers filtered at 630 nm spread across the continental United States. MANGO is used to image large-scale <span class="hlt">airglow</span> and aurora features and observes the generation, propagation, and dissipation of medium and large-scale wave activity in the subauroral, mid and low-latitude thermosphere. This network consists of seven all-sky imagers providing continuous coverage over the United States and extending south into Mexico. This network sees high levels of medium and large scale wave activity due to both neutral and geomagnetic storm forcing. The geomagnetic storm observations largely fall into two categories: Stable Auroral Red (SAR) arcs and Large-scale traveling ionospheric disturbances (LSTIDs). In addition, less-often observed effects include anomalous <span class="hlt">airglow</span> brightening, bright swirls, and frozen-in traveling structures. We will present an analysis of multiple events observed over four years of MANGO network operation. We will provide both statistics on the cumulative observations and a case study of the "Memorial Day Storm" on May 27, 2017.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1994AdSpR..14..177K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1994AdSpR..14..177K"><span>Moon based global field <span class="hlt">airglow</span>: For Artemis or any common Lunar Lander</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kozlowski, R. W. H.; Sprague, A. L.; Sandel, B. R.; Hunten, D. M.; Broadfoot, A. L.</p> <p>1994-06-01</p> <p>An inexpensive, small mass, <span class="hlt">airglow</span> experiment consisting of a suite of <span class="hlt">airglow</span> detectors is planned for one or more lunar landers. Solid state detectors measuring light through narrow band filters or concave gratings can integrate <span class="hlt">emissions</span> from lunar atmospheric constituents and store the information for relay to earth when convenient. The proposed instrument is a simplified version of the Shuttle-borne Arizona Imager-Spectrograph. These zenith and near horizon viewing detectors may allow us to monitor fluctuations in atomic species of oxygen, calcium, sodium, potassium, argon, and neon and OH, if present. This choice of observations would monitor outgassing from the interior (Ar), meteoritic dust flux (Na, K) solar wind sputtering (O, Ca), and outgassing from the surface (implanted Ne, Na, K). A global network could be inexpensively deployed aboard landers carrying a variety of other selenographic instrumentation. Powered by solar cells such a field network will return data applicable to a wide variety of interplanetary medium and solar-lunar interaction problems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19720029859&hterms=twilight&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dtwilight','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19720029859&hterms=twilight&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dtwilight"><span>Vacuum ultraviolet spectra of the late twilight <span class="hlt">airglow</span>.</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Buckley, J. L.; Moos, H. W.</p> <p>1971-01-01</p> <p>Evaluation of sounding rocket spectra of the late twilight (solar-zenith angle of 120 deg) ultraviolet <span class="hlt">airglow</span> between 1260 and 1900 A. The only observed features are O I 1304 and 1356. When the instrument looked at an elevation of 17 deg above the western horizon, the brightnesses were 70 and 33 rayleighs, respectively. The upper limits on the total intensity of the Lyman-Birge-Hopfield and Vegard-Kaplan systems of N2 were 26 plus or minus 26 and 55 plus or minus 55 rayleighs, respectively. An estimate shows that a large part of the O I <span class="hlt">emissions</span> may be due to excitation by conjugate-point electrons.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014cosp...40E3040S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014cosp...40E3040S"><span><span class="hlt">Airglow</span> at 630 and 557.7 nm during HF pumping of the Ionosphere near the 4th Gyroharmonic at the ``Sura'' Facility in September 2012</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shindin, Alexey; Nasyrov, Igor; Grach, Savely; Sergeev, Evgeny; Klimenko, Vladimir; Beletsky, Alexandr</p> <p></p> <p>We present results of artificial optical <span class="hlt">emission</span> observations in the red (630 nm) and green (557.7 nm) <span class="hlt">lines</span> of the atomic oxygen during ionosphere HF pumping at the Sura facility (56.1°N, 46.1°E, magnetic field dip angle 71.5°) in Sep. 2012. Pump wave (PW) of O-polarization at frequencies f0 = 4.74 - 5.64 MHz was used in the experiment according to ionospheric conditions after sunset. Two CCD cameras (S1C/079-FP(FU) and KEO Sentinel with fields of view 20° and 145°, respectively, and 3 photometers were used for the <span class="hlt">emission</span> registration. For estimation of a relation between the PW frequency f0 and 4th electron gyroharmonic 4fce Stimulated Electromagnetic <span class="hlt">Emission</span> (SEE) registration was applied (for details see [1]). On September 11 the pump beam was inclined by 12° to the South, the PW frequencies f0 = 5.40 and 5.42 MHz were slightly above 4fce. On September 13, for vertical pumping, f0 was 5.64 MHz (well above 4fce), 5.32 - 5.42 MHz (around 4fce) and 4.74 MHz (well below 4fce). On September 14 the vertical pumping at f0 = 5.30 - 5.36 MHz and 4.74 MHz was used. In the latter day due to natural motion of the ionosphere and concurrent SEE measurements we were able to obtain a fine dependence of the optical brightness on the proximity f0 and 4fce. For the red <span class="hlt">line</span> no essential dependence, as well of the shape and position of the <span class="hlt">airglow</span> spot on the proximity was obtained with one exception: on Sep. 14 when, according to the SEE spectra, f0 was just below 4fce (by 15-20 kHz), the brightness essentially increased, by 1.25-1.5 times. For the green <span class="hlt">line</span>, the brightest <span class="hlt">emission</span> occurred when f0 was passing through 4fce (Sep. 14) and when f0 = 5.64 MHz (Sep. 13, well above 4fce). Also, on Sep. 14 the <span class="hlt">airglow</span> enhancement in the red <span class="hlt">line</span> during the pumping was replaced by the suppression of the background <span class="hlt">emission</span> when the ionosphere critical frequency approached to f0 by less than 500 kHz. Similar effect was obtained on Sep. 11 and in [2] for south-inclined pump beam</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMNH21C1828O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMNH21C1828O"><span>Internal Gravity Wave Induced by the Queen Charlotte Event (27 October 2012, Mw 7.8): <span class="hlt">Airglow</span> Observation and Modeling.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Occhipinti, G.; Bablet, A.; Makela, J. J.</p> <p>2015-12-01</p> <p>The detection of the tsunami related internal gravity waves (IGWtsuna) by <span class="hlt">airglow</span> camera has been recently validated by observation (Makela et al., 2011) and modeling (Occhipinti et al., 2011) in the case of the Tohoku event (11 March 2011, Mw 9.0). The <span class="hlt">airglow</span> is measuring the photon <span class="hlt">emission</span> at 630 nm, indirectly linked to the plasma density of O2+ (Link & Cogger, 1988) and it is commonly used to detect transient event in the ionosphere (Kelley et al., 2002, Makela et al., 2009, Miller et al., 2009). The modeling of the IGWtsuna clearly reproduced the pattern of the <span class="hlt">airglow</span> measurement observed over Hawaii and the comparison between the observation and the modeling allows to recognize the wave form and allow to explain the IGWtsuna arriving before the tsunami wavefront at the sea level (Occhipinti et al., 2011). Approaching the Hawaiian archipelagos the tsunami propagation is slowed down (reduction of the sea depth), instead, the IGWtsuna, propagating in the atmosphere/ionosphere, conserves its speed. In this work, we present the modeling of the new <span class="hlt">airglow</span> observation following the Queen Charlotte event (27 October 2012, Mw 7.8) that has been recently detected, proving that the technique can be generalized for smaller events. Additionally, the effect of the wind on the IGWtsuna, already evocated in the past, is included in the modeling to better reproduce the <span class="hlt">airglow</span> observations. All ref. here @ www.ipgp.fr/~ninto</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018R%26QE..tmp...26S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018R%26QE..tmp...26S"><span>Spatial Characteristics of the 630-nm Artificial Ionospheric <span class="hlt">Airglow</span> Generation Region During the Sura Facility Pumping</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shindin, A. V.; Klimenko, V. V.; Kogogin, D. A.; Beletsky, A. B.; Grach, S. M.; Nasyrov, I. A.; Sergeev, E. N.</p> <p>2018-05-01</p> <p>We describe the method and the results of modeling and retrieval of the spatial distribution of excited oxygen atoms in the HF-pumped ionospheric region based on two-station records of artificial <span class="hlt">airglow</span> in the red <span class="hlt">line</span> (λ = 630 nm). The HF ionospheric pumping was provided by the Sura facility. The red-<span class="hlt">line</span> records of the night-sky portraits were obtained at two reception points—directly at the heating facility and 170 km east of it. The results were compared with the vertical ionospheric sounding data. It was found that in the course of the experiments the <span class="hlt">airglow</span> region was about 250 km high and did not depend on the altitude of the pump-wave resonance. The characteristic size of the region was 35 km, and the shape of the distribution isosurfaces was well described by oblique spheroids or a drop-shaped form. The average value of the maximum concentration of excited atoms during the experiment was about 1000 cm-3.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006PhDT.......206C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006PhDT.......206C"><span>Studies of the polar MLT region using SATI <span class="hlt">airglow</span> measurements</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cho, Youngmin</p> <p></p> <p>To investigate atmospheric dynamics of the MLT (Mesosphere and Lower Thermosphere) region, a ground-based instrument called SATI (Spectral <span class="hlt">Airglow</span> Temperature Imager) was developed at York University. The rotational temperatures and <span class="hlt">emission</span> rates of the OH (6-2) Meinel band and the O2 (0-1) Atmospheric band have been measured in the MLT region by the SATI instrument at Resolute Bay (74.68°N, 94.90°W) since November, 2001, and at the King Sejong station (62.22°S, 58.75°W) since February, 2002. The MLT measurements are examined for periodic oscillations in the ambient temperature and <span class="hlt">airglow</span> <span class="hlt">emission</span> rate. A dominant and coherent 4-hr oscillation is seen in both the OH and O2 temperature and <span class="hlt">emission</span> rate at Resolute Bay in November, 2001. Tidal variation with a 12 hour period is shown in hourly averaged temperatures of the season 2001--2002 and the season 2003--2004. In addition, planetary waves with periods of 3 and 4.5 days are also seen in a longer interval. The observations at high latitudes have revealed that temperatures and <span class="hlt">emission</span> rates are higher around the winter solstice. MLT cooling events were found at Resolute Bay in December, 2001 and February, 2002. They are compared with the UKMO (UK Meteorological Office) stratospheric assimilated data, and the MLT coolings coincide in time with the stratospheric warmings. A consistent inverse relationship of the OH temperatures and temperatures at 0.316 hPa is presented in the comparison. In previous studies of wave perturbations, the background (mean) values were normally subtracted from the instantaneous signal, but in the present investigation this was not done, allowing the long-term relationship to be examined. A positive relationship of the temperature and <span class="hlt">emission</span> rate is seen from the SATI measurements for both short and long-term variations, suggesting that similar dynamical processes are responsible for both. This relationship is supported by satellite data from the SABER (Sounding of the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20000038366','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20000038366"><span>Gravity Wave Energetics Determined From Coincident Space-Based and Ground-Based Observations of <span class="hlt">Airglow</span> <span class="hlt">Emissions</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>2000-01-01</p> <p>Significant progress was made toward the goals of this proposal in a number of areas during the covered period. Section 5.1 contains a copy of the originally proposed schedule. The tasks listed below have been accomplished: (1) Construction of space-based observing geometry gravity wave model. This model has been described in detail in the paper accompanying this report (Section 5.2). It can simulate the observing geometry of both ground-based, and orbital instruments allowing comparisons to be made between them. (2) Comparisons of relative <span class="hlt">emission</span> intensity, temperatures, and Krassovsky's ratio for space- and ground-based observing geometries. These quantities are used in gravity wave literature to describe the effects of the waves on the <span class="hlt">airglow</span>. (3) Rejection of Bates [1992], and Copeland [1994] chemistries for gravity wave modeling purposes. Excessive 02(A(sup 13)(Delta)) production led to overproduction of O2(b(sup 1)(Sigma)), the state responsible for the <span class="hlt">emission</span> of O2. Atmospheric band. Attempts were made to correct for this behavior, but could not adequately compensate for this. (4) Rejection of MSX dataset due to lack of coincident data, and resolution necessary to characterize the waves. A careful search to identify coincident data revealed only four instances, with only one of those providing usable data. Two high latitude overpasses and were contaminated by auroral <span class="hlt">emissions</span>. Of the remaining two mid-latitude coincidences, one overflight was obscured by cloud, leaving only one ten minute segment of usable data. Aside from the statistical difficulties involved in comparing measurements taken in this short period, the instrument lacks the necessary resolution to determine the vertical wavelength of the gravity wave. This means that the wave cannot be uniquely characterized from space with this dataset. Since no observed wave can be uniquely identified, model comparisons are not possible.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19950058911&hterms=twilight&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dtwilight','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19950058911&hterms=twilight&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dtwilight"><span>Sensitivity of the 6300 A twilight <span class="hlt">airglow</span> to neutral composition</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Melendez-Alvira, D. J.; Torr, D. G.; Richards, P. G.; Swift, W. R.; Torr, M. R.; Baldridge, T.; Rassoul, H.</p> <p>1995-01-01</p> <p>The field <span class="hlt">line</span> interhemispheric plasma (FLIP) model is used to study the 6300 A <span class="hlt">line</span> intensity measured during three morning twilights from the McDonald Observatory in Texas. The Imaging Spectrometric Observatory (ISO) measured the 6300 A intensity during the winter of 1987 and the spring and summer of 1988. The FLIP model reproduces the measured intensity and its variation through the twilight well on each day using neutral densities from the MSIS-86 empirical model. This is in spite of the fact that different component sources dominate the integrated volume <span class="hlt">emission</span> rate on each of the days analyzed. The sensitivity of the intensity to neutral composition is computed by varying the N2, O2, and O densities in the FLIP model and comparing to the intensity computed with the unmodified MSIS-86 densities. The ion densities change self-consistently. Thus the change in neutral composition also changes the electron density. The F2 peak height is unchanged in the model runs for a given day. The intensity changes near 100 deg SZA are comparable to within 10% when either (O2), (N2), or (O) is changed, regardless of which component source is dominant. There is strong sensitivity to changes in (N2) when dissociative recombination is dominant, virtually no change in the nighttime (SZA greater than or equal to 108 deg) intensity with (O2) doubled, and sensitivity of over 50% to doubling or halving (O) at night. When excitation by conjugate photoelectrons is the dominant nighttime component source, the relative intensity change with (O) doubled or halved is very small. This study shows the strong need for simultaneous measurements of electron density and of <span class="hlt">emissions</span> proportional to photoelectron fluxes if the 6300 A twilight <span class="hlt">airglow</span> is to be used to retrieve neutral densities.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19940010211','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19940010211"><span>Vacuum ultraviolet instrumentation for solar irradiance and thermospheric <span class="hlt">airglow</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Woods, Thomas N.; Rottman, Gary J.; Bailey, Scott M.; Solomon, Stanley C.</p> <p>1993-01-01</p> <p>A NASA sounding rocket experiment was developed to study the solar extreme ultraviolet (EUV) spectral irradiance and its effect on the upper atmosphere. Both the solar flux and the terrestrial molecular nitrogen via the Lyman-Birge-Hopfield bands in the far ultraviolet (FUV) were measured remotely from a sounding rocket on October 27, 1992. The rocket experiment also includes EUV instruments from Boston University (Supriya Chakrabarti), but only the National Center for Atmospheric Research (NCAR)/University of Colorado (CU) four solar instruments and one <span class="hlt">airglow</span> instrument are discussed here. The primary solar EUV instrument is a 1/4 meter Rowland circle EUV spectrograph which has flown on three rockets since 1988 measuring the solar spectral irradiance from 30 to 110 nm with 0.2 nm resolution. Another solar irradiance instrument is an array of six silicon XUV photodiodes, each having different metallic filters coated directly on the photodiodes. This photodiode system provides a spectral coverage from 0.1 to 80 nm with about 15 nm resolution. The other solar irradiance instrument is a silicon avalanche photodiode coupled with pulse height analyzer electronics. This avalanche photodiode package measures the XUV photon energy providing a solar spectrum from 50 to 12,400 eV (25 to 0.1 nm) with an energy resolution of about 50 eV. The fourth solar instrument is an XUV imager that images the sun at 17.5 nm with a spatial resolution of 20 arc-seconds. The <span class="hlt">airglow</span> spectrograph measures the terrestrial FUV <span class="hlt">airglow</span> <span class="hlt">emissions</span> along the horizon from 125 to 160 nm with 0.2 nm spectral resolution. The photon-counting CODACON detectors are used for three of these instruments and consist of coded arrays of anodes behind microchannel plates. The one-dimensional and two-dimensional CODACON detectors were developed at CU by Dr. George Lawrence. The pre-flight and post-flight photometric calibrations were performed at our calibration laboratory and at the Synchrotron Ultraviolet</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..19.1919F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..19.1919F"><span>Very high resolution observations of waves in the OH <span class="hlt">airglow</span> at low latitudes.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Franzen, Christoph; Espy, Patrick J.; Hibbins, Robert E.; Djupvik, Amanda A.</p> <p>2017-04-01</p> <p>Vibrationally excited hydroxyl (OH) is produced in the mesosphere by the reaction of atomic hydrogen and ozone. This excited OH radiates a strong, near-infrared <span class="hlt">airglow</span> <span class="hlt">emission</span> in a thin ( 8 km thick) layer near 87 km. In the past, remote sensing of perturbations in the OH Meinel <span class="hlt">airglow</span> has often been used to observe gravity, tidal and planetary waves travelling through this region. However, information on the highest frequency gravity waves is often limited by the temporal and spatial resolution of the available observations. In an effort to expand the wave scales present near the mesopause, we present a series of observations of the OH Meinel (9,7) transition that were executed with the Nordic Optical Telescope on La Palma (18°W, 29°N). These measurements are taken with a 10 s integration time (24 s repetition rate), and the spatial resolution at 87 km is as small as 10 m, allowing us to quantify the transition between the gravity and acoustic wave domains in the mesosphere.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.P43D2916C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.P43D2916C"><span>3D model of auroral <span class="hlt">emissions</span> for Europa</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cessateur, G.; Barthelemy, M.; Rubin, M.; Lilensten, J.; Maggiolo, R.; De Keyser, J.; Gunell, H.; Loreau, J.</p> <p>2017-12-01</p> <p>As archetype of icy satellites, Europa will be one of the primary targets of the ESA JUICE and NASA Europa Clipper missions. Through surface sputtering, Europa does possess a thin neutral gas atmosphere, mainly composed of O2 and H2O. Valuable information can therefore be retrieved from auroral and <span class="hlt">airglow</span> measurements. We present here a 3D electron-excitation-transport-<span class="hlt">emission</span> coupled model of oxygen <span class="hlt">line</span> <span class="hlt">emissions</span> produced through precipitating electrons. The density and temperature of the electrons are first derived from the multifluid MHD model from Rubin et al. (2015). Oxygen <span class="hlt">emission</span> <span class="hlt">lines</span> in the UV have first been modelled, such as those at 130.5 and 135.6 nm, and there is a nonhomogenous distribution of the <span class="hlt">emission</span>. For 135.6 nm, the <span class="hlt">line</span> <span class="hlt">emission</span> can be significant and reach 700 Rayleigh close to the surface for a polar limb viewing angle. Visible <span class="hlt">emissions</span> with the red-doublet (630-636.4 nm) and green (577.7 nm) oxygen <span class="hlt">lines</span> are also considered with <span class="hlt">emission</span> intensities reaching 7150 R and 200 R, respectively, for limb polar viewing. Using different cross section data, a sensitivity study has also been performed to assess the impact of the uncertainties on the auroral <span class="hlt">emissions</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-S39-342-026.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-S39-342-026.html"><span>Aurora Australis, Spiked and Sinuous Red and Green <span class="hlt">Airglow</span></span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>1991-05-06</p> <p>STS039-342-026 (28 April-6 May 1991) --- This view of the Aurora Australis, or Southern Lights, shows a band of <span class="hlt">airglow</span> above the limb of Earth. Photo experts at NASA studying the mission photography identify the <span class="hlt">airglow</span> as being in the 80-120 kilometer altitude region and attribute its existence to atomic oxygen (wavelength of 5,577 Angstroms), although other atoms can also contribute. The atomic oxygen <span class="hlt">airglow</span> is usually most intense at altitudes around 65 degrees north and south latitude, and is most intense in the spring and fall of the year. The aurora phenomena is due to atmospheric oxygen and nitrogen being excited by the particles from the Van Allen Radiation belts which extend between the two geomagnetic poles. The red and green rays appear to extend upward to 200-300 kilometers, much higher than the usual upper limits of about 110 kilometers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19532147','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19532147"><span>The generalization of upper atmospheric wind and temperature based on the Voigt <span class="hlt">line</span> shape profile.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhang, Chunmin; He, Jian</p> <p>2006-12-25</p> <p>The principle of probing the upper atmospheric wind field, which is the Voigt profile spectral <span class="hlt">line</span> shape, is presented for the first time. By the Fourier Transform of Voigt profile, with the Imaging Spectroscope and the Doppler effect of electromagnetic wave, the distribution and calculation formulae of the velocity field, temperature field, and pressure field of the upper atmosphere wind field are given. The probed source is the two major aurora <span class="hlt">emission</span> <span class="hlt">lines</span> originated from the metastable O(1S) and O(1D) at 557.7nm and 630.0nm. From computer simulation and error analysis, the Voigt profile, which is the correlation of the Gaussian profile and Lorentzian profile, is closest to the actual <span class="hlt">airglow</span> <span class="hlt">emission</span> <span class="hlt">lines</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AdSpR..54..554B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AdSpR..54..554B"><span>Limb Viewing Hyper Spectral Imager (LiVHySI) for <span class="hlt">airglow</span> measurements onboard YOUTHSAT-1</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bisht, R. S.; Hait, A. K.; Babu, P. N.; Sarkar, S. S.; Benerji, A.; Biswas, A.; Saji, A. K.; Samudraiah, D. R. M.; Kirankumar, A. S.; Pant, T. K.; Parimalarangan, T.</p> <p>2014-08-01</p> <p>The Limb Viewing Hyper Spectral Imager (LiVHySI) is one of the Indian payloads onboard YOUTHSAT (inclination 98.73°, apogee 817 km) launched in April, 2011. The Hyper-spectral imager has been operated in Earth’s limb viewing mode to measure <span class="hlt">airglow</span> <span class="hlt">emissions</span> in the spectral range 550-900 nm, from terrestrial upper atmosphere (i.e. 80 km altitude and above) with a <span class="hlt">line</span>-of-sight range of about 3200 km. The altitude coverage is about 500 km with command selectable lowest altitude. This imaging spectrometer employs a Linearly Variable Filter (LVF) to generate the spectrum and an Active Pixel Sensor (APS) area array of 256 × 512 pixels, placed in close proximity of the LVF as detector. The spectral sampling is done at 1.06 nm interval. The optics used is an eight element f/2 telecentric lens system with 80 mm effective focal length. The detector is aligned with respect to the LVF such that its 512 pixel dimension covers the spectral range. The radiometric sensitivity of the imager is about 20 Rayleigh at noise floor through the signal integration for 10 s at wavelength 630 nm. The imager is being operated during the eclipsed portion of satellite orbits. The integration in the time/spatial domain could be chosen depending upon the season, solar and geomagnetic activity and/or specific target area. This paper primarily aims at describing LiVHySI, its in-orbit operations, quality, potential of the data and its first observations. The images reveal the thermospheric <span class="hlt">airglow</span> at 630 nm to be the most prominent. These first LiVHySI observations carried out on the night of 21st April, 2011 are presented here, while the variability exhibited by the thermospheric nightglow at O(1D) 630 nm has been described in detail.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1998larm.confE.176B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1998larm.confE.176B"><span>Database of <span class="hlt">emission</span> <span class="hlt">lines</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Binette, L.; Ortiz, P.; Joguet, B.; Rola, C.</p> <p>1998-11-01</p> <p>A widely accessible data bank (available through Netscape) and consiting of all (or most) of the <span class="hlt">emission</span> <span class="hlt">lines</span> reported in the litterature is being built. It will comprise objects as diverse as HII regions, PN, AGN, HHO. One of its use will be to define/refine existing diagnostic <span class="hlt">emission</span> <span class="hlt">line</span> diagrams.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19980007988','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19980007988"><span>Consistency Between SC#21REF Solar XUV Energy Input and the 1973 Pioneer 10 Observations of the Jovian Photoelectron Excited H2 <span class="hlt">Airglow</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gangopadhyay, P.; Ogawa, H. S.; Judge, D. L.</p> <p>1988-01-01</p> <p>It has been suggested in the literature that the F74113 solar spectrum for the solar minimum condition needs to be modified to explain the production of photoelectrons in the Earth's atmosphere. We have studied here the effect of another solar minimum spectrum, SC#21REF, on the Jovian upper atmosphere <span class="hlt">emissions</span> and we have compared the predicted photoelectron excited H2 <span class="hlt">airglow</span> with the 1973 Pioneer 10 observations, analyzed according to the methodology of Shemansky and Judge (1988). In this model calculation we find that in 1973, the Jovian H2 band <span class="hlt">emissions</span> can be accounted for almost entirely by photoelectron excitation, if the preflight calibration of the Pioneer 10 ultraviolet photometer is adopted. If the SC#21REF flux shortward of 250 A is multiplied by 2 as proposed by Richards and Torr (1988) then the Pioneer 10 calibration and/or the <span class="hlt">airglow</span> model used must be modified in order to have a self consistent set of observations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19720027233&hterms=May+13th+1969&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DMay%2B13th%2B1969','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19720027233&hterms=May+13th+1969&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DMay%2B13th%2B1969"><span>Simultaneous measurements of the hydrogen <span class="hlt">airglow</span> <span class="hlt">emissions</span> of Lyman alpha, Lyman beta, and Balmer alpha.</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Weller, C. S.; Meier, R. R.; Tinsley, B. A.</p> <p>1971-01-01</p> <p>Comparison of Lyman-alpha, 740- to 1050-A, and Balmer-alpha <span class="hlt">airglow</span> measurements made at 134 deg solar-zenith angle on Oct. 13, 1969, with resonance-scattering models of solar radiation. Model comparison with Lyman-alpha data fixes the hydrogen column abundance over 215 km to 2 x 10 to the 13th per cu cm within a factor of 2. Differences between the Lyman-alpha model and data indicate a polar-equatorial departure from spherical symmetry in the hydrogen distribution. A Lyman-beta model based on the hydrogen distribution found to fit the Lyman-alpha data fits the spatial variation of the 740- to 1050-A data well from 100 to 130 km, but it does not fit the data well at higher altitudes; thus the presence of more rapidly absorbed shorter-wavelength radiation is indicated. This same resonance-scattering model yields Balmer-alpha intensities that result in good spatial agreement with the Balmer-alpha measurements, but a fivefold increase in the measured solar <span class="hlt">line</span> center Lyman-beta flux is required (as required for the Lyman-beta measurement). The intensity ratio of Lyman-beta and Balmer-alpha at night is found to be a simple measure of the hydrogen optical depth if measurements with good accuracy can be made in the visible and ultraviolet spectrum.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/227151-analysis-lyman-alpha-he-angstrom-airglow-measurements-using-spherical-radiative-transfer-model','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/227151-analysis-lyman-alpha-he-angstrom-airglow-measurements-using-spherical-radiative-transfer-model"><span>Analysis of Lyman {alpha} and He I 584-{Angstrom} <span class="hlt">airglow</span> measurements using a spherical radiative transfer model</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Bush, B.C.; Chakrabarti, S.</p> <p>1995-10-01</p> <p>The authors report on the scattering and excitation mechanisms of the terrestrial exospheric H I 1216-{Angstrom} <span class="hlt">airglow</span> <span class="hlt">emissions</span> by comparing simulations from a radiative transfer model with spectroscopic measurements from an Earth-orbiting satellite. The purpose of these comparisons are twofold: to assess the sensitivity of the input parameters to the model results and to test the applicability of the model to <span class="hlt">airglow</span> analysis. The model incorporates a spherically oriented atmosphere to account for the extended scale heights of the exospheric scatterers as well as to properly mimic scattering across the terminator region from the dayside to the nightside hemispheres. Spectroscopicmore » Lyman {alpha} and He I 584 {Angstrom} data were obtained by the STP78-1 satellite that circumnavigated the Earth in a noon/midnight orbit at an altitude of 600 km. The {open_quotes}best fit{close_quotes} analysis of the Lyman {alpha} data acquired on March 25, 1979, requires scaling the hydrogen density distribution obtained from the MSIS-90 (Hedin) atmospheric model by 45-50%, the exospheric temperature by 90-100%, and the Lyman {alpha} solar flux predicted by EUV91 model (Tobiska) by 1.9-2.0. Similar analysis of the He I 584 {Angstrom} data acquired on March 5, 1979, requires scaling the helium density distribution obtained from the MSIS-90 (Hedin) atmospheric model by 60-80% and the exospheric temperature by 105-115% while using a <span class="hlt">line</span> center 584-{Angstrom} solar flux of 1.44x10{sup 10} photons cm{sup {minus}2}s{sup {minus}1} {Angstrom}{sup {minus}1}. 46 refs., 22 figs., 5 tabs.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010JGRA..115.9315A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010JGRA..115.9315A"><span>Midnight latitude-altitude distribution of 630 nm <span class="hlt">airglow</span> in the Asian sector measured with FORMOSAT-2/ISUAL</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Adachi, Toru; Yamaoka, Masashi; Yamamoto, Mamoru; Otsuka, Yuichi; Liu, Huixin; Hsiao, Chun-Chieh; Chen, Alfred B.; Hsu, Rue-Ron</p> <p>2010-09-01</p> <p>The Imager for Sprites and Upper Atmospheric Lightning (ISUAL) payload on board the FORMOSAT-2 satellite carried out the first limb imaging observation of 630 nm <span class="hlt">airglow</span> for the purpose of studying physical processes in the F region ionosphere. For a total of 14 nights in 2006-2008, ISUAL scanned the midnight latitude-altitude distribution of 630 nm <span class="hlt">airglow</span> in the Asian sector. On two nights of relatively active conditions (ΣKp = 26, 30+) we found several bright <span class="hlt">airglow</span> regions, which were highly variable each night in terms of luminosity and location. In relatively quiet conditions (ΣKp = 4-20) near May/June we found two bright regions which were stably located in the midlatitude region of 40°S-10°S (50°S-20°S magnetic latitude (MLAT)) and in the equatorial region of 0°-10°N (10°S-0° MLAT). On one of the quiet nights, FORMOSAT-3/COSMIC and CHAMP simultaneously measured the plasma density in the same region where ISUAL observed <span class="hlt">airglow</span>. The plasma density data generally show good agreement, suggesting that plasma enhancements were the primary source of these two bright <span class="hlt">airglow</span> regions. From detailed comparison with past studies we explain that the <span class="hlt">airglow</span> in the equatorial region was due to the midnight brightness wave produced in association with the midnight temperature maximum, while that in the midlatitude region was due to the typical plasma distribution usually formed in the midnight sector. The fact that the equatorial <span class="hlt">airglow</span> was much brighter than the midlatitude <span class="hlt">airglow</span> and was observed on most nights during the campaign period strongly suggests the importance of further studies on the MTM/MBW phenomenology, which is not well reproduced in the current general circulation model.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li class="active"><span>5</span></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_5 --> <div id="page_6" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li class="active"><span>6</span></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="101"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19930018294','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19930018294"><span>An assessment of twilight <span class="hlt">airglow</span> inversion procedures using atmosphere explorer observations</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Mcdade, I. C.; Sharp, W. E.</p> <p>1993-01-01</p> <p>The aim of this research project was to test and truth some recently developed methods for recovering thermospheric oxygen atom densities and thermospheric temperatures from ground-based observations of the 7320 A O(+)((sup 2)D - (sup 2)P) twilight air glow <span class="hlt">emission</span>. The research plan was to use twilight observations made by the Visible <span class="hlt">Airglow</span> Experiment (VAE) on the Atmosphere Explorer 'E' satellite as proxy ground based twilight observations. These observations were to be processed using the twilight inversion procedures, and the recovered oxygen atom densities and thermospheric temperatures were then to be examined to see how they compared with the densities and temperatures that were measured by the Open Source Mass Spectrometer and the Neutral Atmosphere Temperature Experiment on the satellite.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20733778','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20733778"><span>Berkeley extreme-ultraviolet <span class="hlt">airglow</span> rocket spectrometer: BEARS.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Cotton, D M; Chakrabarti, S</p> <p>1992-09-20</p> <p>We describe the Berkeley extreme-UV <span class="hlt">airglow</span> rocket spectrometer, which is a payload designed to test several thermospheric remote-sensing concepts by measuring the terrestrial O I far-UV and extreme-UV dayglow and the solar extreme-UV spectrum simultaneously. The instrument consisted of two near-normal Rowland mount spectrometers and a Lyman-alpha photometer. The dayglow spectrometer covered two spectral regions from 980 to 1040 A and from 1300 to 1360 A with 1.5-A resolution. The solar spectrometer had a bandpass of 250-1150 A with an ~ 10-A resolution. All three spectra were accumulated by using a icrochannel-plate-intensified, two-dimensional imaging detector with three separate wedge-and strip anode readouts. The hydrogen Lyman-alpha photometer was included to monitor the solar Lyman-alpha irradiance and geocoronal Lyman-alpha <span class="hlt">emissions</span>. The instrument was designed, fabricated, and calibrated at the University of California, Berkeley and was successfully launched on 30 September 1988 aboard the first test flight of a four-stage sounding rocket, Black Brant XII.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19930009172','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19930009172"><span>Visible <span class="hlt">Airglow</span> Experiment data analysis</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Abreu, Vincent J.</p> <p>1990-01-01</p> <p>The Visible <span class="hlt">Airglow</span> Experiment (VAE) was designed to provide detailed profiles of the distribution of excited states of atoms and molecules in the upper atmosphere. The studies supported during the funding period (1983 - 1989) have made significant contributions in the area of thermospheric aeronomy, and the progress during the first four years of this period has been reviewed by Hays et al. (1988). The investigations carried out have resulted in more than 20 publications, and these are summarized.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009PhDT........82A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009PhDT........82A"><span><span class="hlt">Airglow</span> studies using observations made with the GLO instrument on the Space Shuttle</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Alfaro Suzan, Ana Luisa</p> <p>2009-12-01</p> <p>Our understanding of Earth's upper atmosphere has advanced tremendously over the last few decades due to our enhanced capacity for making remote observations from space. Space based observations of Earth's daytime and nighttime <span class="hlt">airglow</span> <span class="hlt">emissions</span> are very good examples of such enhancements to our knowledge. The terrestrial nighttime <span class="hlt">airglow</span>, or nightglow, is barely discernible to the naked eye as viewed from Earth's surface. However, it is clearly visible from space - as most astronauts have been amazed to report. The nightglow consists of <span class="hlt">emissions</span> of ultraviolet, visible and near-infrared radiation from electronically excited oxygen molecules and atoms and vibrationally excited OH molecules. It mostly emanates from a 10 km thick layer located about 100 km above Earth's surface. Various photochemical models have been proposed to explain the production of the emitting species. In this study some unique observations of Earth's nightglow made with the GLO instrument on NASA's Space Shuttle, are analyzed to assess the proposed excitation models. Previous analyses of these observations by Broadfoot and Gardner (2001), performed using a 1-D inversion technique, have indicated significant spatial structures and have raised serious questions about the proposed nightglow excitation models. However, the observation of such strong spatial structures calls into serious question the appropriateness of the adopted 1-D inversion technique and, therefore, the validity of the conclusions. In this study a more rigorous 2-D tomographic inversion technique is developed and applied to the available GLO data to determine if some of the apparent discrepancies can be explained by the limitations of the previously applied 1-D inversion approach. The results of this study still reveal some potentially serious inadequacies in the proposed photochemical models. However, alternative explanations for the discrepancies between the GLO observations and the model expectations are suggested. These</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016SPIE.9910E..1BR','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016SPIE.9910E..1BR"><span>Measurements of <span class="hlt">airglow</span> on Maunakea at Gemini Observatory</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Roth, Katherine C.; Smith, Adam; Stephens, Andrew; Smirnova, Olesja</p> <p>2016-07-01</p> <p>Gemini Observatory on Maunakea has been collecting optical and infrared science data for almost 15 years. We have begun a program to analyze imaging data from two of the original facility instruments, GMOS and NIRI, in order to measure sky brightness levels in multiple infrared and optical broad-band filters. The present work includes data from mid-2016 back through late-2008. We present measured background levels as a function of several operational quantities (e.g. moon phase, hours from twilight, season). We find that <span class="hlt">airglow</span> is a significant contributor to background levels in several filters. Gemini is primarily a queue scheduled telescope, with observations being optimally executed in order to provide the most efficient use of telescope time. We find that while most parameters are well-understood, the atmospheric <span class="hlt">airglow</span> remains challenging to predict. This makes it difficult to schedule observations which require dark skies in these filters, and we suggest improvements to ensure data quality.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22167707-microlensing-quasar-broad-emission-lines-constraints-broad-line-region-size','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22167707-microlensing-quasar-broad-emission-lines-constraints-broad-line-region-size"><span>MICROLENSING OF QUASAR BROAD <span class="hlt">EMISSION</span> <span class="hlt">LINES</span>: CONSTRAINTS ON BROAD <span class="hlt">LINE</span> REGION SIZE</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Guerras, E.; Mediavilla, E.; Jimenez-Vicente, J.</p> <p>2013-02-20</p> <p>We measure the differential microlensing of the broad <span class="hlt">emission</span> <span class="hlt">lines</span> between 18 quasar image pairs in 16 gravitational lenses. We find that the broad <span class="hlt">emission</span> <span class="hlt">lines</span> are in general weakly microlensed. The results show, at a modest level of confidence (1.8{sigma}), that high ionization <span class="hlt">lines</span> such as C IV are more strongly microlensed than low ionization <span class="hlt">lines</span> such as H{beta}, indicating that the high ionization <span class="hlt">line</span> <span class="hlt">emission</span> regions are more compact. If we statistically model the distribution of microlensing magnifications, we obtain estimates for the broad <span class="hlt">line</span> region size of r{sub s} = 24{sup +22} {sub -15} and r{sub s}more » = 55{sup +150} {sub -35} lt-day (90% confidence) for the high and low ionization <span class="hlt">lines</span>, respectively. When the samples are divided into higher and lower luminosity quasars, we find that the <span class="hlt">line</span> <span class="hlt">emission</span> regions of more luminous quasars are larger, with a slope consistent with the expected scaling from photoionization models. Our estimates also agree well with the results from local reveberation mapping studies.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20170003090&hterms=plasma&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dplasma','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20170003090&hterms=plasma&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dplasma"><span>Hemispheric Asymmetry in Transition from Equatorial Plasma Bubble to Blob as Deduced from 630.0 nm <span class="hlt">Airglow</span> Observations at Low Latitudes</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Park, Jaeheung; Martinis, Carlos R.; Luehr, Hermann; Pfaff, Robert F.; Kwak, Young-Sil</p> <p>2016-01-01</p> <p>Transitions from depletions to enhancements of 630.0 nm nighttime <span class="hlt">airglow</span> have been observed at Arecibo. Numerical simulations by Krall et al. (2009) predicted that they should occur only in one hemisphere, which has not yet been confirmed observationally. In this study we investigate the hemispheric conjugacy of the depletion-to-enhancement transition using multiple instruments. We focus on one event observed in the American longitude sector on 22 December 2014: 630.0 nm <span class="hlt">airglow</span> depletions evolved into enhancements in the Northern Hemisphere while the evolution did not occur in the conjugate location in the Southern Hemisphere. Concurrent plasma density measured by low Earth orbit (LEO) satellites and 777.4 nm <span class="hlt">airglow</span> images support that the depletions and enhancements of 630.0 nm night time <span class="hlt">airglow</span> reflect plasma density decreases and increases (blobs), respectively. Characteristics of the <span class="hlt">airglow</span> depletions, in the context of the LEO satellite data, further suggest that the plasma density depletion deduced from the <span class="hlt">airglow</span> data represents equatorial plasma bubbles (EPBs) rather than medium-scale traveling ionospheric disturbances from midlatitudes. Hence, the event in this study can be interpreted as EPB-to-blob transition.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JGRA..123.2168L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JGRA..123.2168L"><span>First OH <span class="hlt">Airglow</span> Observation of Mesospheric Gravity Waves Over European Russia Region</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Li, Qinzeng; Yusupov, Kamil; Akchurin, Adel; Yuan, Wei; Liu, Xiao; Xu, Jiyao</p> <p>2018-03-01</p> <p>For the first time, we perform a study of mesospheric gravity waves (GWs) for four different seasons of 1 year in the latitudinal band from 45°N to 75°N using an OH all-sky <span class="hlt">airglow</span> imager over Kazan (55.8°N, 49.2°E), Russia, during the period of August 2015 to July 2016. Our observational study fills a huge <span class="hlt">airglow</span> imaging observation gap in Europe and Russia region. In total, 125 GW events and 28 ripple events were determined by OH <span class="hlt">airglow</span> images in 98 clear nights. The observed GWs showed a strong preference of propagation toward northeast in all seasons, which was significantly different from <span class="hlt">airglow</span> imager observations at other latitudes that the propagation directions were seasonal dependent. The middle atmosphere wind field is used to explain the lack of low phase speed GWs since these GWs were falling into the blocking region due to the filtering effects. Deep tropospheric convections derived from the European Centre for Medium-Range Weather Forecasts reanalysis data are determined near Caucasus Mountains region, which suggests that the convections are the dominant source of the GWs in spring, summer, and autumn seasons. This finding extends our knowledge that convection might also be an important source of GWs in the higher latitudes. In winter the generation mechanism of the GWs are considered to be jet stream systems. In addition, the occurrence frequency of ripple is much lower than other stations. This study provides some constraints on the range of GW parameters in GW parameterization in general circulation models in Europe and Russia region.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19950029567&hterms=university+college&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Duniversity%2Bcollege','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19950029567&hterms=university+college&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Duniversity%2Bcollege"><span>Interpretation of satellite <span class="hlt">airglow</span> observations during the March 22, 1979, magnetic storm, using the coupled ionosphere-thermosphere model developed at University College, London</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Parish, H. F.; Gladstone, G. R.; Chakrabarti, S.</p> <p>1994-01-01</p> <p>The University of California, Berkeley, extreme ultraviolet spectrometer aboard the U.S. Air Force STP 78-1 satellite measured <span class="hlt">emission</span> features in the Earth's dayglow due to neutral and ionized species in the atmosphere, in the 35 to 140-nm range. The spectrometer was operating between March 1979 and March 1980, including the period of the magnetic storm on March 22, 1979. Some of these measurements are interpreted using the predictions of the three-dimensional time-dependent coupled ionosphere-thermosphere model developed at University College, London. The observations show a reduction in the atomic oxygen 130.4-nm <span class="hlt">airglow</span> <span class="hlt">emission</span> at high northern latitudes following the storm. Model simulations show that this reduction in 130.4-nm <span class="hlt">emission</span> is associated with an increase in the O2/O ratio. Analysis of model results using electron transport and radiative transport codes show that the brightness of 130.4-nm <span class="hlt">emission</span> at high latitudes due to resonantly scattered sunlight is approximately twice that due to photoelectron impact excitation. However, the observed decrease in the brightness at high northern latitudes is mainly due to a change in the photoelectron impact source, which contributes approximately 75% of the total, as well as its multiple scattering component; for the photoelectron impact source at 70 deg latitude and 200 km altitude, the reduction in multiple scattering is 1.5 times greater than the reduction in the initial excitation. The reduction in the <span class="hlt">airglow</span> <span class="hlt">emission</span> is visible only in the norther n hemisphere because the south pole was not sunlit over the storm period. The comparison of model results with observations suggests that 130.4-nm <span class="hlt">emission</span> may be useful as a tracer for global changes in the concentration of atomic energy.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19910066084&hterms=LHS&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DLHS','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19910066084&hterms=LHS&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DLHS"><span>Spectroscopy of an unusual <span class="hlt">emission</span> <span class="hlt">line</span> M star</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Schneider, Donald P.; Greenstein, Jesse L.; Schmidt, Maarten; Gunn, James E.</p> <p>1991-01-01</p> <p>Moderate-resolution spectroscopy of an unusual late-type faint <span class="hlt">emission-line</span> star, PC 0025 + 0047, is reported. A very strong (greater than 250 A equivalent width) an H-alpha <span class="hlt">emission</span> <span class="hlt">line</span> was detected by the present automated <span class="hlt">line</span> search algorithm. The spectrum was found to have two unresolved <span class="hlt">emission</span> <span class="hlt">lines</span> (H-alpha and H-beta) near zero velocity, superposed on the absorption spectrum of a very red M dwarf which has strong K I, and relatively weak bands of TiO. From the weakness of the subordinate <span class="hlt">lines</span> of Na I (8192 A) and other spectral features, it is inferred that it is definitely a cooler, and probably fainter, analog of LHS 2924. The strength of the <span class="hlt">emission</span> <span class="hlt">lines</span> indicates that PC 0025 + 0447 is very young and may be a fading predecessor brown drawf at an estimated M(bol) approaching 14m at a distance of about 60 pc.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19920024816','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19920024816"><span><span class="hlt">Emission</span> <span class="hlt">lines</span> in the long period Cepheid l Carinae</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Boehm-Vitense, Erika; Love, Stanley G.</p> <p>1991-01-01</p> <p>For the Cepheid (l) Carinae with a pulsation period of 35.5 days we have studied the <span class="hlt">emission</span> <span class="hlt">line</span> fluxes as a function of pulsational phase in order to find out whether we see chromosphere and transition layer <span class="hlt">emission</span> or whether we see <span class="hlt">emission</span> due to an outward moving shock. All <span class="hlt">emission</span> <span class="hlt">lines</span> show a steep increase in flux shortly before maximum light suggestive of a shock moving through the surface layers. The large ratio of the C IV to C II <span class="hlt">line</span> fluxes shows that these are not transition layer <span class="hlt">lines</span>. During maximum light the large ratio of the C IV to C II <span class="hlt">line</span> fluxes also suggests that we see <span class="hlt">emission</span> from a shock with velocities greater than 100 km/sec such that C IV <span class="hlt">emission</span> can be excited. With such velocities mass outflow appears possible. The variations seen in the Mg II <span class="hlt">line</span> profiles show that there is an internal absorption over a broad velocity band independent of the pulsational phase. We attribute this absorption to a circumstellar 'shell'. This 'shell' appears to be seen also as spatially extended <span class="hlt">emission</span> in the O I <span class="hlt">line</span> at 1300 angstrom, which is probably excited by resonance with Ly beta.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20040015180&hterms=quasar&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dquasar','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20040015180&hterms=quasar&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dquasar"><span>Far-Infrared <span class="hlt">Line</span> <span class="hlt">Emission</span> from High Redshift Quasars</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Benford, D. J.; Cox, P.; Hunter, T. R.; Malhotra, S.; Phillips, T. G.; Yun, M. S.</p> <p>2002-01-01</p> <p>Recent millimeter and submillimeter detections of <span class="hlt">line</span> <span class="hlt">emission</span> in high redshift objects have yielded new information and constraints on star formation at early epochs. Only CO transitions and atomic carbon transitions have been detected from these objects, yet bright far-infrared <span class="hlt">lines</span> such as C+ at 158 microns and N+ at 205 microns should be fairly readily detectable when redshifted into a submillimeter atmospheric window. We have obtained upper limits for C+ <span class="hlt">emission</span> &om two high redshift quasars, BR1202-0725 at z=4.69 and BRI1335-0415 at z=4.41. These limits show that the ratio of the C+ <span class="hlt">line</span> luminosity to the total far-infrared luminosity is less than 0.0l%, ten times smaller than has been observed locally. Additionally, we have searched for <span class="hlt">emission</span> in the N+ 205 micron <span class="hlt">line</span> from the Cloverleaf quasar, H1413+117, and detected <span class="hlt">emission</span> in CO J=7-6. The N+ <span class="hlt">emission</span> is found to be below the amount predicted based on comparison to the only previous detection of this <span class="hlt">line</span>, in the starburst galaxy M82.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.epa.gov/healthresearch/community-line-source-model-c-line-estimate-roadway-emissions','PESTICIDES'); return false;" href="https://www.epa.gov/healthresearch/community-line-source-model-c-line-estimate-roadway-emissions"><span>Community-<span class="hlt">LINE</span> Source Model (C-<span class="hlt">LINE</span>) to estimate roadway <span class="hlt">emissions</span></span></a></p> <p><a target="_blank" href="http://www.epa.gov/pesticides/search.htm">EPA Pesticide Factsheets</a></p> <p></p> <p></p> <p>C-<span class="hlt">LINE</span> is a web-based model that estimates <span class="hlt">emissions</span> and dispersion of toxic air pollutants for roadways in the U.S. This reduced-form air quality model examines what-if scenarios for changes in <span class="hlt">emissions</span> such as traffic volume fleet mix and vehicle speed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/5412546','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/biblio/5412546"><span>Optical <span class="hlt">emission</span> <span class="hlt">line</span> monitor with background observation and cancellation</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Goff, D.R.; Notestein, J.E.</p> <p>1985-01-04</p> <p>A fiber optics based optical <span class="hlt">emission</span> <span class="hlt">line</span> monitoring system is provided in which selected spectral <span class="hlt">emission</span> <span class="hlt">lines</span>, such as the sodium D-<span class="hlt">line</span> <span class="hlt">emission</span> in coal combustion, may be detected in the presence of interferring background or blackbody radiation with <span class="hlt">emissions</span> much greater in intensity than that of the <span class="hlt">emission</span> <span class="hlt">line</span> being detected. A bifurcated fiber optic light guide is adapted at the end of one branch to view the combustion light which is guided to a first bandpass filter, adapted to the common trunk end of the fiber. A portion of the light is reflected back through the common trunk portion of the fiber to a second bandpass filter adapted to the end of the other branch of the fiber. The first filter bandpass is centered at a wavelength corresponding to the <span class="hlt">emission</span> <span class="hlt">line</span> to be detected with a bandwidth of about three nanometers (nm). The second filter is centered at the same wavelength but having a width of about 10 nm. First and second light detectors are located to view the light passing through the first and second filters respectively. Thus, the second detector is blind to the light corresponding to the <span class="hlt">emission</span> <span class="hlt">line</span> of interest detected by the first detector and the difference between the two detector outputs is uniquely indicative of the intensity of only the combustion flame <span class="hlt">emission</span> of interest. This instrument can reduce the effects of interfering blackbody radiation by greater than 20 dB.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/866008','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/866008"><span>Optical <span class="hlt">emission</span> <span class="hlt">line</span> monitor with background observation and cancellation</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Goff, David R.; Notestein, John E.</p> <p>1986-01-01</p> <p>A fiber optics based optical <span class="hlt">emission</span> <span class="hlt">line</span> monitoring system is provided in which selected spectral <span class="hlt">emission</span> <span class="hlt">lines</span>, such as the sodium D-<span class="hlt">line</span> <span class="hlt">emission</span> in coal combustion, may be detected in the presence of interferring background or blackbody radiation with <span class="hlt">emissions</span> much greater in intensity than that of the <span class="hlt">emission</span> <span class="hlt">line</span> being detected. A bifurcated fiber optic light guide is adapted at the end of one branch to view the combustion light which is guided to a first bandpass filter, adapted to the common trunk end of the fiber. A portion of the light is reflected back through the common trunk portion of the fiber to a second bandpass filter adapted to the end of the other branch of the fiber. The first filter bandpass is centered at a wavelength corresponding to the <span class="hlt">emission</span> <span class="hlt">line</span> to be detected with a bandwidth of about three nanometers (nm). The second filter is centered at the same wavelength but having a width of about 10 nm. First and second light detectors are located to view the light passing through the first and second filters respectively. Thus, the second detector is blind to the light corresponding to the <span class="hlt">emission</span> <span class="hlt">line</span> of interest detected by the first detector and the difference between the two detector outputs is uniquely indicative of the intensity of only the combustion flame <span class="hlt">emission</span> of interest. This instrument can reduce the effects of interferring blackbody radiation by greater than 20 dB.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19800019770','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19800019770"><span>Observations of <span class="hlt">emission</span> <span class="hlt">lines</span> in M supergiants</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lambert, D. L.</p> <p>1979-01-01</p> <p>Copernicus observations of Mg 2 h and k <span class="hlt">emission</span> <span class="hlt">lines</span> from M giants and supergiants are described. Supergiants with extensive circumstellar gas shells show an asymmetric k <span class="hlt">line</span>. The asymmetry is ascribed to superimposed <span class="hlt">lines</span> of Fe 1 and Mn 1. The Mg 2 <span class="hlt">line</span> width fit the Wilson-Bappu relation derived from observations of G and K Stars. Results of correlated ground-based observations include (1) the discovery of K 1 fluorescent <span class="hlt">emission</span> from the Betelgeuse shell; (2) extimates of the mass-loss rates; and (3) the proposal that silicate dust grains must account for the major fraction of the Si atoms in the Betelgeuse shell.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1997JGR...10219949Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1997JGR...10219949Y"><span>Global simulations and observations of O(1S), O2(1Σ) and OH mesospheric nightglow <span class="hlt">emissions</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yee, Jeng-Hwa; Crowley, G.; Roble, R. G.; Skinner, W. R.; Burrage, M. D.; Hays, P. B.</p> <p>1997-09-01</p> <p>Despite a large number of observations of mesospheric nightglow <span class="hlt">emissions</span> in the past, the quantitative comparison between theoretical and experimental brightnesses is rather poor, owing primarily to the short duration of the observations, the strong variability of the tides, and the influence of short-timescale gravity waves. The high-resolution Doppler imager (HRDI) instrument onboard the upper atmosphere research satellite (UARS) provides nearly simultaneous, near-global observations of O(1S) green <span class="hlt">line</span>, O2(0-1) atmospheric band, and OH Meinel band nightglow <span class="hlt">emissions</span>. Three days of these observations near the September equinox of 1993 are presented to show the general characteristics of the three <span class="hlt">emissions</span>, including the <span class="hlt">emission</span> brightness, peak <span class="hlt">emission</span> altitude, and their temporal and spatial variabilities. The global distribution of these <span class="hlt">emissions</span> is simulated on the basis of atmospheric parameters from the recently developed National Center for Atmospheric Research (NCAR) thermosphere-ionosphere-mesosphere-electrodynamics general circulation model (TIME-GCM). The most striking features revealed by the global simulation are the structuring of the mesospheric nightglow by the diurnal tides and enhancements of the <span class="hlt">airglow</span> at high latitudes. The model reproduces the inverse relationship observed by HRDI between the nightglow brightness and peak <span class="hlt">emission</span> altitude. Analysis of our model results shows that the large-scale latitudinal/tidal nightglow brightness variations are a direct result of a complex interplay between mesospheric and lower thermospheric diffusive and advective processes, acting mainly on the atomic oxygen concentrations. The inclination of the UARS spacecraft precluded observations of high latitude nightglow <span class="hlt">emissions</span> by HRDI. However, our predicted high-latitude brightness enhancements confirm previous limited groundbased observations in the polar region. This work provides an initial validation of the NCAR-TIMEGCM using <span class="hlt">airglow</span> data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018MNRAS.477.1484U','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018MNRAS.477.1484U"><span>GAME: GAlaxy Machine learning for <span class="hlt">Emission</span> <span class="hlt">lines</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ucci, G.; Ferrara, A.; Pallottini, A.; Gallerani, S.</p> <p>2018-06-01</p> <p>We present an updated, optimized version of GAME (GAlaxy Machine learning for <span class="hlt">Emission</span> <span class="hlt">lines</span>), a code designed to infer key interstellar medium physical properties from <span class="hlt">emission</span> <span class="hlt">line</span> intensities of ultraviolet /optical/far-infrared galaxy spectra. The improvements concern (a) an enlarged spectral library including Pop III stars, (b) the inclusion of spectral noise in the training procedure, and (c) an accurate evaluation of uncertainties. We extensively validate the optimized code and compare its performance against empirical methods and other available <span class="hlt">emission</span> <span class="hlt">line</span> codes (PYQZ and HII-CHI-MISTRY) on a sample of 62 SDSS stacked galaxy spectra and 75 observed HII regions. Very good agreement is found for metallicity. However, ionization parameters derived by GAME tend to be higher. We show that this is due to the use of too limited libraries in the other codes. The main advantages of GAME are the simultaneous use of all the measured spectral <span class="hlt">lines</span> and the extremely short computational times. We finally discuss the code potential and limitations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JASTP.171..269L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JASTP.171..269L"><span>Detection of large-scale concentric gravity waves from a Chinese <span class="hlt">airglow</span> imager network</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lai, Chang; Yue, Jia; Xu, Jiyao; Yuan, Wei; Li, Qinzeng; Liu, Xiao</p> <p>2018-06-01</p> <p>Concentric gravity waves (CGWs) contain a broad spectrum of horizontal wavelengths and periods due to their instantaneous localized sources (e.g., deep convection, volcanic eruptions, or earthquake, etc.). However, it is difficult to observe large-scale gravity waves of >100 km wavelength from the ground for the limited field of view of a single camera and local bad weather. Previously, complete large-scale CGW imagery could only be captured by satellite observations. In the present study, we developed a novel method that uses assembling separate images and applying low-pass filtering to obtain temporal and spatial information about complete large-scale CGWs from a network of all-sky <span class="hlt">airglow</span> imagers. Coordinated observations from five all-sky <span class="hlt">airglow</span> imagers in Northern China were assembled and processed to study large-scale CGWs over a wide area (1800 km × 1 400 km), focusing on the same two CGW events as Xu et al. (2015). Our algorithms yielded images of large-scale CGWs by filtering out the small-scale CGWs. The wavelengths, wave speeds, and periods of CGWs were measured from a sequence of consecutive assembled images. Overall, the assembling and low-pass filtering algorithms can expand the <span class="hlt">airglow</span> imager network to its full capacity regarding the detection of large-scale gravity waves.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017A%26A...599A..83M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017A%26A...599A..83M"><span><span class="hlt">Emission</span> <span class="hlt">line</span> galaxies and active galactic nuclei in WINGS clusters</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Marziani, P.; D'Onofrio, M.; Bettoni, D.; Poggianti, B. M.; Moretti, A.; Fasano, G.; Fritz, J.; Cava, A.; Varela, J.; Omizzolo, A.</p> <p>2017-03-01</p> <p>We present the analysis of the <span class="hlt">emission</span> <span class="hlt">line</span> galaxies members of 46 low-redshift (0.04 < z < 0.07) clusters observed by WINGS (WIde-field Nearby Galaxy cluster Survey). <span class="hlt">Emission</span> <span class="hlt">line</span> galaxies were identified following criteria that are meant to minimize biases against non-star-forming galaxies and classified employing diagnostic diagrams. We examined the <span class="hlt">emission</span> <span class="hlt">line</span> properties and frequencies of star-forming galaxies, transition objects, and active galactic nuclei (AGNs: LINERs and Seyferts), unclassified galaxies with <span class="hlt">emission</span> <span class="hlt">lines</span>, and quiescent galaxies with no detectable <span class="hlt">line</span> <span class="hlt">emission</span>. A deficit of <span class="hlt">emission</span> <span class="hlt">line</span> galaxies in the cluster environment is indicated by both a lower frequency, and a systematically lower Balmer <span class="hlt">emission</span> <span class="hlt">line</span> equivalent width and luminosity with respect to control samples; this implies a lower amount of ionized gas per unit mass and a lower star formation rate if the source is classified as Hii region. A sizable population of transition objects and of low-luminosity LINERs (≈ 10-20% of all <span class="hlt">emission</span> <span class="hlt">line</span> galaxies) are detected among WINGS cluster galaxies. These sources are a factor of ≈1.5 more frequent, or at least as frequent, as in control samples with respect to Hii sources. Transition objects and LINERs in clusters are most affected in terms ofline equivalent width by the environment and appear predominantly consistent with so-called retired galaxies. Shock heating can be a possible gas excitation mechanism that is able to account for observed <span class="hlt">line</span> ratios. Specific to the cluster environment, we suggest interaction between atomic and molecular gas and the intracluster medium as a possible physical cause of <span class="hlt">line</span>-emitting shocks. The data whose description is provided in Table B.1, and <span class="hlt">emission</span> <span class="hlt">line</span> catalog of the WINGS database are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/599/A83</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li class="active"><span>6</span></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_6 --> <div id="page_7" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li class="active"><span>7</span></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="121"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013JASTP..93...70P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013JASTP..93...70P"><span>Statistical analysis of infrasound signatures in <span class="hlt">airglow</span> observations: Indications for acoustic resonance</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pilger, Christoph; Schmidt, Carsten; Bittner, Michael</p> <p>2013-02-01</p> <p>The detection of infrasonic signals in temperature time series of the mesopause altitude region (at about 80-100 km) is performed at the German Remote Sensing Data Center of the German Aerospace Center (DLR-DFD) using GRIPS instrumentation (GRound-based Infrared P-branch Spectrometers). Mesopause temperature values with a temporal resolution of up to 10 s are derived from the observation of nocturnal <span class="hlt">airglow</span> <span class="hlt">emissions</span> and permit the identification of signals within the long-period infrasound range.Spectral intensities of wave signatures with periods between 2.5 and 10 min are estimated applying the wavelet analysis technique to one minute mean temperature values. Selected events as well as the statistical distribution of 40 months of observation are presented and discussed with respect to resonant modes of the atmosphere. The mechanism of acoustic resonance generated by strong infrasonic sources is a potential explanation of distinct features with periods between 3 and 5 min observed in the dataset.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22348304-significant-contribution-cerenkov-line-like-radiation-broad-emission-lines-quasars','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22348304-significant-contribution-cerenkov-line-like-radiation-broad-emission-lines-quasars"><span>Significant contribution of the Cerenkov <span class="hlt">line</span>-like radiation to the broad <span class="hlt">emission</span> <span class="hlt">lines</span> of quasars</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Liu, D. B.; You, J. H.; Chen, W. P.</p> <p>2014-01-01</p> <p>The Cerenkov <span class="hlt">line</span>-like radiation in a dense gas (N {sub H} > 10{sup 13} cm{sup –3}) is potentially important in the exploration of the optical broad <span class="hlt">emission</span> <span class="hlt">lines</span> of quasars and Seyfert 1 galaxies. With this quasi-<span class="hlt">line</span> <span class="hlt">emission</span> mechanism, some long standing puzzles in the study of quasars could be resolved. In this paper, we calculate the power of the Cerenkov <span class="hlt">line</span>-like radiation in dense gas and compare with the powers of other radiation mechanisms by a fast electron to confirm its importance. From the observed gamma-ray luminosity of 3C 279, we show that the total number of fast electronsmore » is sufficiently high to allow effective operation of the quasi-<span class="hlt">line</span> <span class="hlt">emission</span>. We present a model calculation for the luminosity of the Cerenkov Lyα <span class="hlt">line</span> of 3C 279, which is high enough to compare with observations. We therefore conclude that the broad <span class="hlt">line</span> of quasars may be a blend of the Cerenkov <span class="hlt">emission</span> <span class="hlt">line</span> with the real <span class="hlt">line</span> produced by the bound-bound transition. A new approach to the absorption of the Cerenkov <span class="hlt">line</span> is presented with the method of escape probability, which markedly simplifies the computation in the optically thick case. The revised set of formulae for the Cerenkov <span class="hlt">line</span>-like radiation is more convenient in applications.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMSA33A2575F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMSA33A2575F"><span>Small-Scale Dynamical Structures Using OH <span class="hlt">Airglow</span> From Astronomical Observations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Franzen, C.; Espy, P. J.; Hibbins, R. E.; Djupvik, A. A.</p> <p>2017-12-01</p> <p>Remote sensing of perturbations in the hydroxyl (OH) Meinel <span class="hlt">airglow</span> has often been used to observe gravity, tidal and planetary waves travelling through the 80-90 km region. While large scale (>1 km) gravity waves and the winds caused by their breaking are widely documented, information on the highest frequency waves and instabilities occurring during the breaking process is often limited by the temporal and spatial resolution of the available observations. In an effort to better quantify the full range of wave scales present near the mesopause, we present a series of observations of the OH Meinel (9,7) transition that were executed with the Nordic Optical Telescope on La Palma (18°W, 29°N). These measurements have a 24 s repetition rate and horizontal spatial resolutions at 87 km as small as 10 cm, allowing us to quantify the transition in the mesospheric wave domains as the gravity waves break. Temporal scales from hours to minutes, as well as sub-100 m coherent structures in the OH <span class="hlt">airglow</span> have been observed and will be presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2011-title40-vol33/pdf/CFR-2011-title40-vol33-sec1060-510.pdf','CFR2011'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2011-title40-vol33/pdf/CFR-2011-title40-vol33-sec1060-510.pdf"><span>40 CFR 1060.510 - How do I test EPA Low-<span class="hlt">Emission</span> Fuel <span class="hlt">Lines</span> for permeation <span class="hlt">emissions</span>?</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2011&page.go=Go">Code of Federal Regulations, 2011 CFR</a></p> <p></p> <p>2011-07-01</p> <p>... 40 Protection of Environment 33 2011-07-01 2011-07-01 false How do I test EPA Low-<span class="hlt">Emission</span> Fuel... NONROAD AND STATIONARY EQUIPMENT Test Procedures § 1060.510 How do I test EPA Low-<span class="hlt">Emission</span> Fuel <span class="hlt">Lines</span> for permeation <span class="hlt">emissions</span>? For EPA Low-<span class="hlt">Emission</span> Fuel <span class="hlt">Lines</span>, measure <span class="hlt">emissions</span> according to SAE J2260, which is...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2012-title40-vol34/pdf/CFR-2012-title40-vol34-sec1060-510.pdf','CFR2012'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2012-title40-vol34/pdf/CFR-2012-title40-vol34-sec1060-510.pdf"><span>40 CFR 1060.510 - How do I test EPA Low-<span class="hlt">Emission</span> Fuel <span class="hlt">Lines</span> for permeation <span class="hlt">emissions</span>?</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2012&page.go=Go">Code of Federal Regulations, 2012 CFR</a></p> <p></p> <p>2012-07-01</p> <p>... 40 Protection of Environment 34 2012-07-01 2012-07-01 false How do I test EPA Low-<span class="hlt">Emission</span> Fuel... NONROAD AND STATIONARY EQUIPMENT Test Procedures § 1060.510 How do I test EPA Low-<span class="hlt">Emission</span> Fuel <span class="hlt">Lines</span> for permeation <span class="hlt">emissions</span>? For EPA Low-<span class="hlt">Emission</span> Fuel <span class="hlt">Lines</span>, measure <span class="hlt">emissions</span> according to SAE J2260, which is...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2013-title40-vol34/pdf/CFR-2013-title40-vol34-sec1060-510.pdf','CFR2013'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2013-title40-vol34/pdf/CFR-2013-title40-vol34-sec1060-510.pdf"><span>40 CFR 1060.510 - How do I test EPA Low-<span class="hlt">Emission</span> Fuel <span class="hlt">Lines</span> for permeation <span class="hlt">emissions</span>?</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2013&page.go=Go">Code of Federal Regulations, 2013 CFR</a></p> <p></p> <p>2013-07-01</p> <p>... 40 Protection of Environment 34 2013-07-01 2013-07-01 false How do I test EPA Low-<span class="hlt">Emission</span> Fuel... NONROAD AND STATIONARY EQUIPMENT Test Procedures § 1060.510 How do I test EPA Low-<span class="hlt">Emission</span> Fuel <span class="hlt">Lines</span> for permeation <span class="hlt">emissions</span>? For EPA Low-<span class="hlt">Emission</span> Fuel <span class="hlt">Lines</span>, measure <span class="hlt">emissions</span> according to SAE J2260, which is...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2014-title40-vol33/pdf/CFR-2014-title40-vol33-sec1060-510.pdf','CFR2014'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2014-title40-vol33/pdf/CFR-2014-title40-vol33-sec1060-510.pdf"><span>40 CFR 1060.510 - How do I test EPA Low-<span class="hlt">Emission</span> Fuel <span class="hlt">Lines</span> for permeation <span class="hlt">emissions</span>?</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2014&page.go=Go">Code of Federal Regulations, 2014 CFR</a></p> <p></p> <p>2014-07-01</p> <p>... 40 Protection of Environment 33 2014-07-01 2014-07-01 false How do I test EPA Low-<span class="hlt">Emission</span> Fuel... NONROAD AND STATIONARY EQUIPMENT Test Procedures § 1060.510 How do I test EPA Low-<span class="hlt">Emission</span> Fuel <span class="hlt">Lines</span> for permeation <span class="hlt">emissions</span>? For EPA Low-<span class="hlt">Emission</span> Fuel <span class="hlt">Lines</span>, measure <span class="hlt">emissions</span> according to SAE J2260, which is...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2010-title40-vol32/pdf/CFR-2010-title40-vol32-sec1060-510.pdf','CFR'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2010-title40-vol32/pdf/CFR-2010-title40-vol32-sec1060-510.pdf"><span>40 CFR 1060.510 - How do I test EPA Low-<span class="hlt">Emission</span> Fuel <span class="hlt">Lines</span> for permeation <span class="hlt">emissions</span>?</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2010&page.go=Go">Code of Federal Regulations, 2010 CFR</a></p> <p></p> <p>2010-07-01</p> <p>... 40 Protection of Environment 32 2010-07-01 2010-07-01 false How do I test EPA Low-<span class="hlt">Emission</span> Fuel... NONROAD AND STATIONARY EQUIPMENT Test Procedures § 1060.510 How do I test EPA Low-<span class="hlt">Emission</span> Fuel <span class="hlt">Lines</span> for permeation <span class="hlt">emissions</span>? For EPA Low-<span class="hlt">Emission</span> Fuel <span class="hlt">Lines</span>, measure <span class="hlt">emissions</span> according to SAE J2260, which is...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1997ApJS..108..401K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1997ApJS..108..401K"><span>An Atlas of Computed Equivalent Widths of Quasar Broad <span class="hlt">Emission</span> <span class="hlt">Lines</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Korista, Kirk; Baldwin, Jack; Ferland, Gary; Verner, Dima</p> <p></p> <p>We present graphically the results of several thousand photoionization calculations of broad <span class="hlt">emission-line</span> clouds in quasars, spanning 7 orders of magnitude in hydrogen ionizing flux and particle density. The equivalent widths of 42 quasar <span class="hlt">emission</span> <span class="hlt">lines</span> are presented as contours in the particle density-ionizing flux plane for a typical incident continuum shape, solar chemical abundances, and cloud column density of N(H) = 1023 cm-2. Results are similarly given for a small subset of <span class="hlt">emission</span> <span class="hlt">lines</span> for two other column densities (1022 and 1024 cm-2), five other incident continuum shapes, and a gas metallicity of 5 Z⊙. These graphs should prove useful in the analysis of quasar <span class="hlt">emission-line</span> data and in the detailed modeling of quasar broad <span class="hlt">emission-line</span> regions. The digital results of these <span class="hlt">emission-line</span> grids and many more are available over the Internet.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19910058277&hterms=optics+interference&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Doptics%2Binterference','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19910058277&hterms=optics+interference&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Doptics%2Binterference"><span>Thin film interference optics for imaging the O II 834-A <span class="hlt">airglow</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Seely, John F.; Hunter, William R.</p> <p>1991-01-01</p> <p>Normal incidence thin film interference mirrors and filters have been designed to image the O II 834-A <span class="hlt">airglow</span>. It is shown that MgF2 is a useful spacer material for this wavelength region. The mirrors consist of thin layers of MgF2 in combination with other materials that are chosen to reflect efficiently in a narrow band centered at 834 A. Peak reflectance of 60 percent can be obtained with a passband 200 A wide. Al/MgF2/Si and Al/MgF2/SiC interference coatings have been designed to reflect 834 A and to absorb the intense H I 1216 A <span class="hlt">airglow</span>. An In/MgF2/In interference filter is designed to transmit 834 A and attenuate 1216 A radiation. Interference photocathode coatings for rejecting 1216 A radiation are also discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMSA31A2387B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMSA31A2387B"><span>Mid-latitude response to geomagnetic storms observed in 630nm <span class="hlt">airglow</span> over continental United States</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bhatt, A.; Kendall, E. A.</p> <p>2016-12-01</p> <p>We present analysis of mid-latitude response observed to geomagnetic storms using the MANGO network consisting of all-sky cameras imaging 630nm <span class="hlt">emission</span> over the continental United States. The response largely falls in two categories: Stable Auroral Red (SAR) arc and Large-scale traveling ionospheric disturbances (LSTIDs). However, outside of these phenomena, less often observed response include anomalous <span class="hlt">airglow</span> brightening, bright swirls, and frozen in traveling structures. We will present an analysis of various events observed over 3 years of MANGO network operation, which started with two imagers in the western US with addition of new imagers in the last year. We will also present unusual north and northeastward propagating waves often observed in conjunction with diffuse aurora. Wherever possible, we will compare with observations from Boston University imagers located in Massachusetts and Texas.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014cosp...40E.968G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014cosp...40E.968G"><span>Mars dayside temperature from <span class="hlt">airglow</span> limb profiles : comparison with in situ measurements and models</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gérard, Jean-Claude; Bougher, Stephen; Montmessin, Franck; Bertaux, Jean-Loup; Stiepen, A.</p> <p></p> <p>The thermal structure of the Mars upper atmosphere is the result of the thermal balance between heating by EUV solar radiation, infrared heating and cooling, conduction and dynamic influences such as gravity waves, planetary waves, and tides. It has been derived from observations performed from different spacecraft. These include in situ measurements of orbital drag whose strength depends on the local gas density. Atmospheric temperatures were determined from the altitude variation of the density measured in situ by the Viking landers and orbital drag measurements. Another method is based on remote sensing measurements of ultraviolet <span class="hlt">airglow</span> limb profiles obtained over 40 years ago with spectrometers during the Mariner 6 and 7 flybys and from the Mariner 9 orbiter. Comparisons with model calculations indicate that they both reflect the CO_2 scale height from which atmospheric temperatures have been deduced. Upper atmospheric temperatures varying over the wide range 270-445 K, with a mean value of 325 K were deduced from the topside scale height of the <span class="hlt">airglow</span> vertical profile. We present an analysis of limb profiles of the CO Cameron (a(3) Pi-X(1) Sigma(+) ) and CO_2(+) doublet (B(2) Sigma_u(+) - X(2) PiΠ_g) <span class="hlt">airglows</span> observed with the SPICAM instrument on board Mars Express. We show that the temperature in the Mars thermosphere is very variable with a mean value of 270 K, but values ranging between 150 and 400 K have been observed. These values are compared to earlier determinations and model predictions. No clear dependence on solar zenith angle, latitude or season is apparent. Similarly, exospheric variations with F10.7 in the SPICAM <span class="hlt">airglow</span> dataset are small over the solar minimum to moderate conditions sampled by Mars Express since 2005. We conclude that an unidentified process is the cause of the large observed temperature variability, which dominates the other sources of temperature variations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017yCat..74482900R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017yCat..74482900R"><span>VizieR Online Data Catalog: <span class="hlt">Emission</span> <span class="hlt">lines</span> for SDSS Coronal-<span class="hlt">Line</span> Forest AGNs (Rose+, 2015)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rose, M.; Elvis, M.; Tadhunter, C. N.</p> <p>2017-11-01</p> <p>In this paper, we make use of SDSS spectra. The basic properties of the CLiF AGN sample studied in this paper are given in Table 1. Note that the outputs of the SDSS pipeline are used only for the sample selection. Detailed measurements of <span class="hlt">emission</span> <span class="hlt">line</span> parameters such as the flux and velocity widths are measured using our own methods (Section 4). The redshifts were determined using single Gaussian fits to the [O III] λ5007 <span class="hlt">emission</span> <span class="hlt">line</span>. This <span class="hlt">line</span> was chosen because it is the most prominent <span class="hlt">emission</span> <span class="hlt">line</span> in the optical spectra of these and most other AGN. (5 data files).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19850005393','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19850005393"><span>Far-infrared <span class="hlt">line</span> <span class="hlt">emission</span> from the galaxy. Ph.D. Thesis</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Stacey, G. J.</p> <p>1985-01-01</p> <p>The diffuse 157.74 micron (CII) <span class="hlt">emission</span> from the Galaxy was sampled at several galactic longitudes near the galactic plane including complete scan across the plane at (II) = 2.16 deg and (II) = 7.28 deg. The observed (CII) <span class="hlt">emission</span> profiles follow closely the nearby (12)CO (J=1to0) <span class="hlt">emission</span> profiles. The (CII) <span class="hlt">emission</span> probably arises in neutral photodissociation regions near the edges of giant moleclar clouds (GMC's). These regions have densities of approximately 350 cm(-3) and temperatures of approximately 300 K, and amount to 4x10(8) solar mass of hydrogen in the inner Galaxy. The total 157.74 micron luminosity of the Galaxy is estimated to be 6x10(7) solar luminosity. Estimates were also made of the galactic <span class="hlt">emission</span> in other far-infrared (FIR) cooling <span class="hlt">lines</span>. The (CII) <span class="hlt">line</span> was found to be the dominant FIR <span class="hlt">emission</span> <span class="hlt">line</span> from the galaxy and the primary coolant for the warm neutral gas near the galactic plane. Other cooling <span class="hlt">lines</span> predicted to be prominent in the galactic spectrum are discussed. The 145.53 micron (OI) <span class="hlt">emission</span> <span class="hlt">line</span> from the Orion nebula was also measured.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19760048306&hterms=lupus&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dlupus','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19760048306&hterms=lupus&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dlupus"><span>Observations of southern <span class="hlt">emission-line</span> stars</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Henize, K. G.</p> <p>1976-01-01</p> <p>A catalog of 1929 stars showing H-alpha <span class="hlt">emission</span> on photographic plates is presented which covers the entire southern sky south of declination -25 deg to a red limiting magnitude of about 11.0. The catalog provides previous designations of known <span class="hlt">emission-line</span> stars equatorial (1900) and galactic coordinates, visual and photographic magnitudes, H-alpha <span class="hlt">emission</span> parameters, spectral types, and notes on unusual spectral features. The objects listed include 16 M stars, 25 S stars, 37 carbon stars, 20 symbiotic stars, 40 confirmed or suspected T Tauri stars, 16 novae, 14 planetary nebulae, 11 P Cygni stars, 9 Bep stars, 87 confirmed or suspected Wolf-Rayet stars, and 26 'peculiar' stars. Two new T associations are discovered, one in Lupus and one in Chamaeleon. Objects with variations in continuum or H-alpha intensity are noted, and the distribution by spectral type is analyzed. It is found that the sky distribution of these <span class="hlt">emission-line</span> stars shows significant concentrations in the region of the small Sagittarius cloud and in the Carina region.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFMSA21B..07W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFMSA21B..07W"><span>An Intense Traveling <span class="hlt">Airglow</span> Front in the Upper Mesosphere-Lower Thermosphere with Characteristic of a Turbulent Bore Observed over Alice Springs, Australia</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Walterscheid, R. L.; Hecht, J. H.; Hickey, M. P.; Gelinas, L. J.; Vincent, R. A.; Reid, I. M.; Woithe, J.</p> <p>2010-12-01</p> <p>The Aerospace Corporation’s Nightglow Imager observed a large step-function change in <span class="hlt">airglow</span> in the form of a traveling front in the OH and O2 <span class="hlt">airglow</span> <span class="hlt">emissions</span> over Alice Springs Australia on February 2, 2003. The front exhibited a stepwise increase of nearly a factor two in the OH brightness and a stepwise decrease in the O2 brightness. The change in brightness in each layer was associated with a strong leading disturbance followed by a train of weak barely visible waves. The OH <span class="hlt">airglow</span> brightness behind the front was the brightness night for 02 at Alice Springs that we have measured in seven years of observations. The OH brightness was among the five brightest. The event was associated with a strong phase-locked two-day wave (TDW).We have analyzed the stability conditions for the upper mesosphere and lower thermosphere and found that the <span class="hlt">airglow</span> layers were found in a region of strong ducting. The thermal structure was obtained from combining data from the SABER instrument on the TIMED satellite and the NRLMSISE-00 model. The wind profile was obtained by combining the HWM07 model and MF radar winds from Buckland Park Australia. We found that the TDW-disturbed profile was significantly more effective in supporting a high degree of ducting than a profile based only on HWM07 winds. Dramatic wall events have been interpreted as manifestations of undular bores (e.g., Smith et al. [2003]). Undular bores are nonlinear high Froude number events that must generate an ever increasing train of waves to carry the excess energy away from the bore front. Only a very weak wave train behind the initial disturbance was seen for the Alice Springs event. The form of the amplitude ordering was not typical of a nonlinear wave train. Therefore a bore interpretation requires another means of energy dissipation, namely turbulent dissipation. We suggest that a reasonable interpretation of the observed event is a turbulent bore. We are unaware of any previous event having</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20165509','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20165509"><span>Silicon photodiode as a detector in the rocket-borne photometry of the near infrared <span class="hlt">airglow</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Schaeffer, R C</p> <p>1976-11-01</p> <p>The application of a silicon P-I-N photodiode to the dc measurement of low levels of near ir radiation is described. It is shown that the threshold of signal detection is set by the current amplifier voltage noise, the effect of which at the output is determined by the value of source resistance of the photodiode. The photodiode was used as the detector in a compact interference filter photometer designed for rocket-borne studies of the <span class="hlt">airglow</span>. Flight results have proved the instrument's capability to provide measurements sufficiently precise to yield an accurate height profile of the (0-0) atmospheric band of O(2) night <span class="hlt">airglow</span> at lambda762 nm.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AnGeo..35..567R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AnGeo..35..567R"><span>Seasonal MLT-region nightglow intensities, temperatures, and <span class="hlt">emission</span> heights at a Southern Hemisphere midlatitude site</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Reid, Iain M.; Spargo, Andrew J.; Woithe, Jonathan M.; Klekociuk, Andrew R.; Younger, Joel P.; Sivjee, Gulamabas G.</p> <p>2017-04-01</p> <p>We consider 5 years of spectrometer measurements of OH(6-2) and O2(0-1) <span class="hlt">airglow</span> <span class="hlt">emission</span> intensities and temperatures made near Adelaide, Australia (35° S, 138° E), between September 2001 and August 2006 and compare them with measurements of the same parameters from at the same site using an <span class="hlt">airglow</span> imager, with the intensities of the OH(8-3) and O(1S) <span class="hlt">emissions</span> made with a filter photometer, and with 2 years of Aura MLS (Microwave Limb Sounder) v3.3 temperatures and 4.5 years of TIMED SABER (Thermosphere Ionosphere Mesosphere Energetics and Dynamics Sounding of the Atmosphere using Broadband <span class="hlt">Emission</span> Radiometry) v2.0 temperatures for the same site. We also consider whether we can recover the actual <span class="hlt">emission</span> heights from the intercomparison of the ground-based and satellite observations. We find a significant improvement in the correlation between the spectrometer OH and SABER temperatures by interpolating the latter to constant density surfaces determined using a meteor radar.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014cosp...40E2035M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014cosp...40E2035M"><span>Statistical analysis of gravity waves characteristics observed by <span class="hlt">airglow</span> imaging at Syowa Station (69S, 39E), Antarctica</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Matsuda, Takashi S.; Nakamura, Takuji; Shiokawa, Kazuo; Tsutsumi, Masaki; Suzuki, Hidehiko; Ejiri, Mitsumu K.; Taguchi, Makoto</p> <p></p> <p>Atmospheric gravity waves (AGWs), which are generated in the lower atmosphere, transport significant amount of energy and momentum into the mesosphere and lower thermosphere and cause the mean wind accelerations in the mesosphere. This momentum deposit drives the general circulation and affects the temperature structure. Among many parameters to characterize AGWs, horizontal phase velocity is very important to discuss the vertical propagation. <span class="hlt">Airglow</span> imaging is a useful technique for investigating the horizontal structures of AGWs at around 90 km altitude. Recently, there are many reports about statistical characteristics of AGWs observed by <span class="hlt">airglow</span> imaging. However, comparison of these results obtained at various locations is difficult because each research group uses its own method for extracting and analyzing AGW events. We have developed a new statistical analysis method for obtaining the power spectrum in the horizontal phase velocity domain from <span class="hlt">airglow</span> image data, so as to deal with huge amounts of imaging data obtained on different years and at various observation sites, without bias caused by different event extraction criteria for the observer. This method was applied to the data obtained at Syowa Station, Antarctica, in 2011 and compared with a conventional event analysis in which the phase fronts were traced manually in order to estimate horizontal characteristics. This comparison shows that our new method is adequate to deriving the horizontal phase velocity characteristics of AGWs observed by <span class="hlt">airglow</span> imaging technique. We plan to apply this method to <span class="hlt">airglow</span> imaging data observed at Syowa Station in 2002 and between 2008 and 2013, and also to the data observed at other stations in Antarctica (e.g. Rothera Station (67S, 68W) and Halley Station (75S, 26W)), in order to investigate the behavior of AGWs propagation direction and source distribution in the MLT region over Antarctica. In this presentation, we will report interim analysis result of the data</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMSA31B4097M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMSA31B4097M"><span>Comparison with the horizontal phase velocity distribution of gravity waves observed <span class="hlt">airglow</span> imaging data of different sampling periods</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Matsuda, T. S.; Nakamura, T.; Ejiri, M. K.; Tsutsumi, M.; Shiokawa, K.</p> <p>2014-12-01</p> <p>Atmospheric gravity waves (AGWs), which are generated in the lower atmosphere, transport significant amount of energy and momentum into the mesosphere and lower thermosphere. Among many parameters to characterize AGWs, horizontal phase velocity is very important to discuss the vertical propagation. <span class="hlt">Airglow</span> imaging is a useful technique for investigating the horizontal structures of AGWs around mesopause. There are many <span class="hlt">airglow</span> imagers operated all over the world, and a large amount of data which could improve our understanding of AGWs propagation direction and source distribution in the MLT region. We have developed a new statistical analysis method for obtaining the power spectrum in the horizontal phase velocity domain (phase velocity spectrum), from <span class="hlt">airglow</span> image data, so as to deal with huge amounts of imaging data obtained on different years and at various observation sites, without bias caused by different event extraction criteria for the observer. From a series of images projected onto the geographic coordinates, 3-D Fourier transform is applied and 3-D power spectrum in horizontal wavenumber and frequency domain is obtained. Then, it is converted into phase velocity and frequency domain. Finally, the spectrum is integrated along the frequency for the range of interest and 2-D spectrum in horizontal phase velocity is calculated. This method was applied to the data obtained at Syowa Station (69ºS, 40ºE), Antarctica, in 2011 and compared with a conventional event analysis in which the phase fronts were traced manually in order to estimate horizontal propagation characteristics. This comparison shows that our new method is adequate to deriving the horizontal phase velocity characteristics of AGWs observed by <span class="hlt">airglow</span> imaging technique. <span class="hlt">Airglow</span> imaging observation has been operated with various sampling intervals. We also presents how the images with different sample interval should be treated.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li class="active"><span>7</span></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_7 --> <div id="page_8" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li class="active"><span>8</span></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="141"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMSM43A2474Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMSM43A2474Z"><span>Mesoscale Magnetosphere-Ionosphere Coupling along Open Magnetic Field <span class="hlt">Lines</span> Associated with <span class="hlt">Airglow</span> Patches: Field-aligned Currents and Precipitation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zou, Y.; Nishimura, Y.; Lyons, L. R.; Shiokawa, K.; Burchill, J. K.; Knudsen, D. J.; Buchert, S. C.; Chen, S.; Nicolls, M. J.; Ruohoniemi, J. M.; McWilliams, K. A.; Nishitani, N.</p> <p>2016-12-01</p> <p>Although <span class="hlt">airglow</span> patches are traditionally regarded as high-density plasma unrelated to local field-aligned currents (FACs) and precipitation, past observations were limited to storm-time conditions. Recent non-storm time observations show patches to be associated with azimuthally narrow ionospheric fast flow channels that substantially contribute to plasma transportation across the polar cap and connect dayside and nightside explosive disturbances. We examine whether non-storm time patches are related also to localized polar cap FACs and precipitation using Swarm- and FAST-imager-radar conjunctions. In Swarm data, we commonly (66%) identify substantial magnetic perturbations indicating FAC enhancements around patches. These FACs have substantial densities (0.1-0.2 μA/m-2) and can be approximated as infinite current sheets (typically 75 km wide) orientated roughly parallel to patches. They usually exhibit a Region-1 sense, i.e. a downward FAC lying eastward of an upward FAC, and can close through Pedersen currents in the ionosphere, implying that the locally enhanced dawn-dusk electric field across the patch is imposed by processes in the magnetosphere. In FAST data, we identify localized precipitation that is enhanced within patches in comparison to weak polar rain outside patches. The precipitation consists of structured or diffuse soft electron fluxes. While the latter resembles polar rain only with higher fluxes, the former consists of discrete fluxes enhanced by 1-2 orders of magnitude from several to several hundred eV. Although the precipitation is not a major contributor to patch ionization, it implies that newly reconnected flux tubes that retain electrons of magnetosheath origin can rapidly traverse the polar cap from the dayside. Therefore non-storm time patches should be regarded as part of a localized magnetosphere-ionosphere coupling system along open magnetic field <span class="hlt">lines</span>, and their transpolar evolution as a reflection of reconnected flux tubes</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017ACP....17.4177U','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017ACP....17.4177U"><span>Measuring FeO variation using astronomical spectroscopic observations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Unterguggenberger, Stefanie; Noll, Stefan; Feng, Wuhu; Plane, John M. C.; Kausch, Wolfgang; Kimeswenger, Stefan; Jones, Amy; Moehler, Sabine</p> <p>2017-03-01</p> <p><span class="hlt">Airglow</span> <span class="hlt">emission</span> <span class="hlt">lines</span> of OH, O2, O and Na are commonly used to probe the MLT (mesosphere-lower thermosphere) region of the atmosphere. Furthermore, molecules like electronically excited NO, NiO and FeO emit a (pseudo-) continuum. These continua are harder to investigate than atomic <span class="hlt">emission</span> <span class="hlt">lines</span>. So far, limb-sounding from space and a small number of ground-based low-to-medium resolution spectra have been used to measure FeO <span class="hlt">emission</span> in the MLT. In this study the medium-to-high resolution echelle spectrograph X-shooter at the Very Large Telescope (VLT) in the Chilean Atacama Desert (24°37' S, 70°24' W; 2635 m) is used to study the FeO pseudo-continuum in the range from 0.5 to 0.72 µm based on 3662 spectra. Variations of the FeO spectrum itself, as well as the diurnal and seasonal behaviour of the FeO and Na <span class="hlt">emission</span> intensities, are reported. These <span class="hlt">airglow</span> <span class="hlt">emissions</span> are linked by their common origin, meteoric ablation, and they share O3 as a common reactant. Major differences are found in the main <span class="hlt">emission</span> peak of the FeO <span class="hlt">airglow</span> spectrum between 0.58 and 0.61 µm, compared with a theoretical spectrum. The FeO and Na <span class="hlt">airglow</span> intensities exhibit a similar nocturnal variation and a semi-annual seasonal variation with equinoctial maxima. This is satisfactorily reproduced by a whole atmosphere chemistry climate model, if the quantum yields for the reactions of Fe and Na with O3 are 13 ± 3 and 11 ± 2 % respectively. However, a comparison between the modelled O3 in the upper mesosphere and measurements of O3 made with the SABER satellite instrument suggests that these quantum yields may be a factor of ˜ 2 smaller.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22663643-nebular-continuum-line-emission-stellar-population-synthesis-models','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22663643-nebular-continuum-line-emission-stellar-population-synthesis-models"><span>Nebular Continuum and <span class="hlt">Line</span> <span class="hlt">Emission</span> in Stellar Population Synthesis Models</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Byler, Nell; Dalcanton, Julianne J.; Conroy, Charlie</p> <p></p> <p>Accounting for nebular <span class="hlt">emission</span> when modeling galaxy spectral energy distributions (SEDs) is important, as both <span class="hlt">line</span> and continuum <span class="hlt">emissions</span> can contribute significantly to the total observed flux. In this work, we present a new nebular <span class="hlt">emission</span> model integrated within the Flexible Stellar Population Synthesis code that computes the <span class="hlt">line</span> and continuum <span class="hlt">emission</span> for complex stellar populations using the photoionization code Cloudy. The self-consistent coupling of the nebular <span class="hlt">emission</span> to the matched ionizing spectrum produces <span class="hlt">emission</span> <span class="hlt">line</span> intensities that correctly scale with the stellar population as a function of age and metallicity. This more complete model of galaxy SEDs will improvemore » estimates of global gas properties derived with diagnostic diagrams, star formation rates based on H α , and physical properties derived from broadband photometry. Our models agree well with results from other photoionization models and are able to reproduce observed <span class="hlt">emission</span> from H ii regions and star-forming galaxies. Our models show improved agreement with the observed H ii regions in the Ne iii/O ii plane and show satisfactory agreement with He ii <span class="hlt">emission</span> from z = 2 galaxies, when including rotating stellar models. Models including post-asymptotic giant branch stars are able to reproduce <span class="hlt">line</span> ratios consistent with low-ionization <span class="hlt">emission</span> regions. The models are integrated into current versions of FSPS and include self-consistent nebular <span class="hlt">emission</span> predictions for MIST and Padova+Geneva evolutionary tracks.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-iss029e007455.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-iss029e007455.html"><span>"Aurora Australis, <span class="hlt">Airglow</span>, Terminator view taken by the Expedition 29 crew"</span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>2011-09-18</p> <p>ISS029-E-007455 (18 Sept. 2011) --- This is one of a series of night time images photographed by one of the Expedition 29 crew members from the International Space Station. It features Aurora Australis, <span class="hlt">airglow</span>, Earth?s Terminator and the southeastern Indian Ocean. Nadir coordinates are 51.78 degrees south latitude and 124.41 degrees east longitude.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-iss029e007500.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-iss029e007500.html"><span>"Aurora Australis, <span class="hlt">Airglow</span>, Terminator view taken by the Expedition 29 crew"</span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>2011-09-18</p> <p>ISS029-E-007500 (18 Sept. 2011) --- This is one of a series of night time images photographed by one of the Expedition 29 crew members from the International Space Station. It features the Aurora Australis, <span class="hlt">airglow</span> and parts of the southeastern Indian Ocean. Nadir coordinates are 50.66 degrees south latitude and 137.70 degrees east longitude.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-iss029e007502.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-iss029e007502.html"><span>"Aurora Australis, <span class="hlt">Airglow</span>, Terminator view taken by the Expedition 29 crew"</span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>2011-09-18</p> <p>ISS029-E-007502 (18 Sept. 2011) --- This is one of a series of night time images photographed by one of the Expedition 29 crew members from the International Space Station. It features Aurora Australis, <span class="hlt">airglow</span>, and parts of the southeast Indian Ocean. Nadir coordinates are 50.58 degrees south latitude and 138.28 degrees east longitude.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007ASPC..376..281G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007ASPC..376..281G"><span>The VIRUS <span class="hlt">Emission</span> <span class="hlt">Line</span> Detection Recipe</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gössl, C. A.; Hopp, U.; Köhler, R.; Grupp, F.; Relke, H.; Drory, N.; Gebhardt, K.; Hill, G.; MacQueen, P.</p> <p>2007-10-01</p> <p>HETDEX, the Hobby-Eberly Telescope Dark Energy Experiment, will measure the imprint of the baryonic acoustic oscillations on the galaxy population at redshifts of 1.8 < z < 3.7 to constrain the nature of dark energy. The survey will be performed over at least 200 deg^2. The tracer population for this blind search will be Ly-α emitting galaxies through their most prominent <span class="hlt">emission</span> <span class="hlt">line</span>. The data reduction pipeline will extract these <span class="hlt">emission</span> <span class="hlt">line</span> objects from ˜35,000 spectra per exposure (5 million per night, i.e. 500 million in total) while performing astrometric, photometric, and wavelength calibration fully automatically. Here we will present our ideas how to find and classify objects even at low signal-to-noise ratios.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19930072471&hterms=molecular+diagnostic&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dmolecular%2Bdiagnostic','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19930072471&hterms=molecular+diagnostic&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dmolecular%2Bdiagnostic"><span>Molecular <span class="hlt">line</span> <span class="hlt">emission</span> models of Herbig-Haro objects. II - HCO(+) <span class="hlt">emission</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wolfire, Mark G.; Koenigl, Arieh</p> <p>1993-01-01</p> <p>We present time-dependent models of the chemistry and temperature of interstellar molecular gas clumps that are exposed to the radiation from propagating stellar-jet shocks. The X-ray, EUV, and FUV radiation from the shock initiates ion chemistry and also heats the gas in the clumps. Using representative parameters, we show that, on the shock transit time between the clumps, the abundances of the ionized molecular species that are produced in the clumps can exceed the values determined from steady state models by several orders of magnitude. Collisional excitation by the heated gas can lead to measurable <span class="hlt">line</span> <span class="hlt">emission</span> from several ionized species; as in previous investigations of X-ray-irradiated molecular gas, we find that electron impacts contribute significantly to this process. We apply these results to the interpretation of the HCO(+) <span class="hlt">line</span> <span class="hlt">emission</span> that has already been detected in several Herbig-Haro objects. We demonstrate that this picture provides a natural explanation of the fact that the <span class="hlt">line</span> intensity typically peaks ahead of the associated shock, as well as of the reported low <span class="hlt">line</span>-center velocities and narrow <span class="hlt">line</span> widths. We tabulate several diagnostic <span class="hlt">line</span> intensities of HCO(+) and other molecular species that may be used to infer the physical conditions in the emitting gas.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18360466','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18360466"><span>Three-channel imaging fabry-perot interferometer for measurement of mid-latitude <span class="hlt">airglow</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Shiokawa, K; Kadota, T; Ejiri, M K; Otsuka, Y; Katoh, Y; Satoh, M; Ogawa, T</p> <p>2001-08-20</p> <p>We have developed a three-channel imaging Fabry-Perot interferometer with which to measure atmospheric wind and temperature in the mesosphere and thermosphere through nocturnal <span class="hlt">airglow</span> <span class="hlt">emissions</span>. The interferometer measures two-dimensional wind and temperature for wavelengths of 630.0 nm (OI, altitude, 200-300 km), 557.7 nm (OI, 96 km), and 839.9 nm (OH, 86 km) simultaneously with a time resolution of 20 min, using three cooled CCD detectors with liquid-N(2) Dewars. Because we found that the CCD sensor moves as a result of changes in the level of liquid N(2) in the Dewars, the cooling system has been replaced by thermoelectric coolers. The fringe drift that is due to changes in temperature of the etalon is monitored with a frequency-stabilized He-Ne laser. We also describe a data-reduction scheme for calculating wind and temperature from the observed fringes. The system is fully automated and has been in operation since June 1999 at the Shigaraki Observatory (34.8N, 136.1E), Shiga, Japan.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017A%26A...599A..75W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017A%26A...599A..75W"><span>First detection of hydrogen in the β Pictoris gas disk</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wilson, P. A.; Lecavelier des Etangs, A.; Vidal-Madjar, A.; Bourrier, V.; Hébrard, G.; Kiefer, F.; Beust, H.; Ferlet, R.; Lagrange, A.-M.</p> <p>2017-03-01</p> <p>The young and nearby star β Pictoris (β Pic) is surrounded by a debris disk composed of dust and gas known to host a myriad evaporating exocomets, planetesimals and at least one planet. At an edge-on inclination, as seen from Earth, this system is ideal for debris disk studies providing an excellent opportunity to use absorption spectroscopy to study the planet forming environment. Using the Cosmic Origins Spectrograph (COS) instrument on the Hubble Space Telescope (HST) we observe the most abundant element in the disk, hydrogen, through the H I Lyman α (Ly-α) <span class="hlt">line</span>. We present a new technique to decrease the contamination of the Ly-α <span class="hlt">line</span> by geocoronal <span class="hlt">airglow</span> in COS spectra. This <span class="hlt">Airglow</span> Virtual Motion (AVM) technique allows us to shift the Ly-α <span class="hlt">line</span> of the astrophysical target away from the contaminating <span class="hlt">airglow</span> <span class="hlt">emission</span> revealing more of the astrophysical <span class="hlt">line</span> profile. This new AVM technique, together with subtraction of an <span class="hlt">airglow</span> <span class="hlt">emission</span> map, allows us to analyse the shape of the β Pic Ly-α <span class="hlt">emission</span> <span class="hlt">line</span> profile and from it, calculate the column density of neutral hydrogen surrounding β Pic. The column density of hydrogen in the β Pic stable gas disk at the stellar radial velocity is measured to be log (NH/ 1 cm2) ≪ 18.5. The Ly-α <span class="hlt">emission</span> <span class="hlt">line</span> profile is found to be asymmetric and we propose that this is caused by H I falling in towards the star with a bulk radial velocity of 41 ± 6 km s-1 relative to β Pic and a column density of log (NH/ 1 cm2) = 18.6 ± 0.1. The high column density of hydrogen relative to the hydrogen content of CI chondrite meteorites indicates that the bulk of the hydrogen gas does not come from the dust in the disk. This column density reveals a hydrogen abundance much lower than solar, which excludes the possibility that the detected hydrogen could be a remnant of the protoplanetary disk or gas expelled by the star. We hypothesise that the hydrogen gas observed falling towards the star arises from the dissociation of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/5733714-double-emission-line-radio-galaxy','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/5733714-double-emission-line-radio-galaxy"><span>3C 159 - a double <span class="hlt">emission-line</span> radio galaxy</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Tytler, D.; Browne, I.</p> <p>1985-09-01</p> <p>An optical identification for 3C 159 is reported with a 19-mag <span class="hlt">emission-line</span> radio galaxy at z = 0.482. Photometric measurements show it to be unusually bright and blue. The <span class="hlt">emission</span> <span class="hlt">lines</span> are of exceptionally high luminosity, and are split into two components separated by 598 + or - 13 km/s and 3 kpc along the spectrograph slit. A VLA may show that one of the radio lobes has two hot spots with tails of <span class="hlt">emission</span> leading to both. 21 references.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EP%26S...68..155H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EP%26S...68..155H"><span>Calibration of imaging parameters for space-borne <span class="hlt">airglow</span> photography using city light positions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hozumi, Yuta; Saito, Akinori; Ejiri, Mitsumu K.</p> <p>2016-09-01</p> <p>A new method for calibrating imaging parameters of photographs taken from the International Space Station (ISS) is presented in this report. <span class="hlt">Airglow</span> in the mesosphere and the F-region ionosphere was captured on the limb of the Earth with a digital single-lens reflex camera from the ISS by astronauts. To utilize the photographs as scientific data, imaging parameters, such as the angle of view, exact position, and orientation of the camera, should be determined because they are not measured at the time of imaging. A new calibration method using city light positions shown in the photographs was developed to determine these imaging parameters with high accuracy suitable for <span class="hlt">airglow</span> study. Applying the pinhole camera model, the apparent city light positions on the photograph are matched with the actual city light locations on Earth, which are derived from the global nighttime stable light map data obtained by the Defense Meteorological Satellite Program satellite. The correct imaging parameters are determined in an iterative process by matching the apparent positions on the image with the actual city light locations. We applied this calibration method to photographs taken on August 26, 2014, and confirmed that the result is correct. The precision of the calibration was evaluated by comparing the results from six different photographs with the same imaging parameters. The precisions in determining the camera position and orientation are estimated to be ±2.2 km and ±0.08°, respectively. The 0.08° difference in the orientation yields a 2.9-km difference at a tangential point of 90 km in altitude. The <span class="hlt">airglow</span> structures in the photographs were mapped to geographical points using the calibrated imaging parameters and compared with a simultaneous observation by the Visible and near-Infrared Spectral Imager of the Ionosphere, Mesosphere, Upper Atmosphere, and Plasmasphere mapping mission installed on the ISS. The comparison shows good agreements and supports the validity</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2011-title40-vol33/pdf/CFR-2011-title40-vol33-sec1060-515.pdf','CFR2011'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2011-title40-vol33/pdf/CFR-2011-title40-vol33-sec1060-515.pdf"><span>40 CFR 1060.515 - How do I test EPA Nonroad Fuel <span class="hlt">Lines</span> and EPA Cold-Weather Fuel <span class="hlt">Lines</span> for permeation <span class="hlt">emissions</span>?</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2011&page.go=Go">Code of Federal Regulations, 2011 CFR</a></p> <p></p> <p>2011-07-01</p> <p>... and EPA Cold-Weather Fuel <span class="hlt">Lines</span> for permeation <span class="hlt">emissions</span>? 1060.515 Section 1060.515 Protection of... Nonroad Fuel <span class="hlt">Lines</span> and EPA Cold-Weather Fuel <span class="hlt">Lines</span> for permeation <span class="hlt">emissions</span>? Measure <span class="hlt">emission</span> as follows for EPA Nonroad Fuel <span class="hlt">Lines</span> and EPA Cold-Weather Fuel <span class="hlt">Lines</span>: (a) Prior to permeation testing, use good...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2013-title40-vol34/pdf/CFR-2013-title40-vol34-sec1060-515.pdf','CFR2013'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2013-title40-vol34/pdf/CFR-2013-title40-vol34-sec1060-515.pdf"><span>40 CFR 1060.515 - How do I test EPA Nonroad Fuel <span class="hlt">Lines</span> and EPA Cold-Weather Fuel <span class="hlt">Lines</span> for permeation <span class="hlt">emissions</span>?</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2013&page.go=Go">Code of Federal Regulations, 2013 CFR</a></p> <p></p> <p>2013-07-01</p> <p>... and EPA Cold-Weather Fuel <span class="hlt">Lines</span> for permeation <span class="hlt">emissions</span>? 1060.515 Section 1060.515 Protection of... Nonroad Fuel <span class="hlt">Lines</span> and EPA Cold-Weather Fuel <span class="hlt">Lines</span> for permeation <span class="hlt">emissions</span>? Measure <span class="hlt">emission</span> as follows for EPA Nonroad Fuel <span class="hlt">Lines</span> and EPA Cold-Weather Fuel <span class="hlt">Lines</span>: (a) Prior to permeation testing, use good...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2012-title40-vol34/pdf/CFR-2012-title40-vol34-sec1060-515.pdf','CFR2012'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2012-title40-vol34/pdf/CFR-2012-title40-vol34-sec1060-515.pdf"><span>40 CFR 1060.515 - How do I test EPA Nonroad Fuel <span class="hlt">Lines</span> and EPA Cold-Weather Fuel <span class="hlt">Lines</span> for permeation <span class="hlt">emissions</span>?</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2012&page.go=Go">Code of Federal Regulations, 2012 CFR</a></p> <p></p> <p>2012-07-01</p> <p>... and EPA Cold-Weather Fuel <span class="hlt">Lines</span> for permeation <span class="hlt">emissions</span>? 1060.515 Section 1060.515 Protection of... Nonroad Fuel <span class="hlt">Lines</span> and EPA Cold-Weather Fuel <span class="hlt">Lines</span> for permeation <span class="hlt">emissions</span>? Measure <span class="hlt">emission</span> as follows for EPA Nonroad Fuel <span class="hlt">Lines</span> and EPA Cold-Weather Fuel <span class="hlt">Lines</span>: (a) Prior to permeation testing, use good...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2010-title40-vol32/pdf/CFR-2010-title40-vol32-sec1060-515.pdf','CFR'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2010-title40-vol32/pdf/CFR-2010-title40-vol32-sec1060-515.pdf"><span>40 CFR 1060.515 - How do I test EPA Nonroad Fuel <span class="hlt">Lines</span> and EPA Cold-Weather Fuel <span class="hlt">Lines</span> for permeation <span class="hlt">emissions</span>?</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2010&page.go=Go">Code of Federal Regulations, 2010 CFR</a></p> <p></p> <p>2010-07-01</p> <p>... and EPA Cold-Weather Fuel <span class="hlt">Lines</span> for permeation <span class="hlt">emissions</span>? 1060.515 Section 1060.515 Protection of... Nonroad Fuel <span class="hlt">Lines</span> and EPA Cold-Weather Fuel <span class="hlt">Lines</span> for permeation <span class="hlt">emissions</span>? Measure <span class="hlt">emission</span> as follows for EPA Nonroad Fuel <span class="hlt">Lines</span> and EPA Cold-Weather Fuel <span class="hlt">Lines</span>: (a) Prior to permeation testing, use good...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2014-title40-vol33/pdf/CFR-2014-title40-vol33-sec1060-515.pdf','CFR2014'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2014-title40-vol33/pdf/CFR-2014-title40-vol33-sec1060-515.pdf"><span>40 CFR 1060.515 - How do I test EPA Nonroad Fuel <span class="hlt">Lines</span> and EPA Cold-Weather Fuel <span class="hlt">Lines</span> for permeation <span class="hlt">emissions</span>?</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2014&page.go=Go">Code of Federal Regulations, 2014 CFR</a></p> <p></p> <p>2014-07-01</p> <p>... and EPA Cold-Weather Fuel <span class="hlt">Lines</span> for permeation <span class="hlt">emissions</span>? 1060.515 Section 1060.515 Protection of... Nonroad Fuel <span class="hlt">Lines</span> and EPA Cold-Weather Fuel <span class="hlt">Lines</span> for permeation <span class="hlt">emissions</span>? Measure <span class="hlt">emission</span> as follows for EPA Nonroad Fuel <span class="hlt">Lines</span> and EPA Cold-Weather Fuel <span class="hlt">Lines</span>: (a) Prior to permeation testing, use good...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFM.P53B2186H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFM.P53B2186H"><span>What generates Callisto's atmosphere? - Indications from calculations of ionospheric electron densities and <span class="hlt">airglow</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hartkorn, O. A.; Saur, J.; Strobel, D. F.</p> <p>2016-12-01</p> <p>Callisto's atmosphere has been probed by the Galileo spacecraft and the Hubble Space Telescope (HST) and is expected to be composed of O2 and minor components CO2 and H2O. We use an ionosphere model coupled with a parametrized atmosphere model to calculate ionospheric electron densities and <span class="hlt">airglow</span>. By varying a prescribed neutral atmosphere and comparing the model results to Galileo radio occultation and HST-Cosmic Origin Spectrograph observations we find that Callisto's atmosphere likely possesses a day/night asymmetry driven by solar illumination. We see two possible explanation for this asymmetry: 1) If sublimation dominates the atmosphere formation, a day/night asymmetry will be generated since the sublimation production rate is naturally much stronger at the day side than at the night side. 2) If surface sputtering dominates the atmosphere formation, a day/night asymmetry is likely generated as well since the sputtering yield increases with increasing surface temperature and, therefore, with decreasing solar zenith angle. The main difference between both processes is given by the fact that surface sputtering, in contrast to sublimation, is also a function of Callisto's orbital position since sputtering projectiles predominately co-rotate with the Jovian magnetosphere. On this basis, we develop a method that can discriminate between both explanations by comparing <span class="hlt">airglow</span> observations at different orbital positions with <span class="hlt">airglow</span> predictions. Our predictions are based on our ionosphere model and an orbital position dependent atmosphere model originally developed for the O2 atmosphere of Europa by Plainaki et al. (2013).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-iss029e007473.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-iss029e007473.html"><span>"Aurora Australis, <span class="hlt">Airglow</span>, Terminator view taken by the Expedition 29 crew"</span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>2011-09-18</p> <p>ISS029-E-007473 (18 Sept. 2011) --- This is one of a series of night time images photographed by one of the Expedition 29 crew members from the International Space Station. It features Aurora Australis, <span class="hlt">airglow</span>, Earth?s Terminator and parts of the southeast Indian Ocean. Nadir coordinates are 51.53 degrees south latitude and 129.80 degrees east longitude.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018EP%26S...70...88T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018EP%26S...70...88T"><span>Initiation of a lightning search using the lightning and <span class="hlt">airglow</span> camera onboard the Venus orbiter Akatsuki</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Takahashi, Yukihiro; Sato, Mitsuteru; Imai, Masataka; Lorenz, Ralph; Yair, Yoav; Aplin, Karen; Fischer, Georg; Nakamura, Masato; Ishii, Nobuaki; Abe, Takumi; Satoh, Takehiko; Imamura, Takeshi; Hirose, Chikako; Suzuki, Makoto; Hashimoto, George L.; Hirata, Naru; Yamazaki, Atsushi; Sato, Takao M.; Yamada, Manabu; Murakami, Shin-ya; Yamamoto, Yukio; Fukuhara, Tetsuya; Ogohara, Kazunori; Ando, Hiroki; Sugiyama, Ko-ichiro; Kashimura, Hiroki; Ohtsuki, Shoko</p> <p>2018-05-01</p> <p>The existence of lightning discharges in the Venus atmosphere has been controversial for more than 30 years, with many positive and negative reports published. The lightning and <span class="hlt">airglow</span> camera (LAC) onboard the Venus orbiter, Akatsuki, was designed to observe the light curve of possible flashes at a sufficiently high sampling rate to discriminate lightning from other sources and can thereby perform a more definitive search for optical <span class="hlt">emissions</span>. Akatsuki arrived at Venus during December 2016, 5 years following its launch. The initial operations of LAC through November 2016 have included a progressive increase in the high voltage applied to the avalanche photodiode detector. LAC began lightning survey observations in December 2016. It was confirmed that the operational high voltage was achieved and that the triggering system functions correctly. LAC lightning search observations are planned to continue for several years.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li class="active"><span>8</span></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_8 --> <div id="page_9" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li class="active"><span>9</span></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="161"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19910066714&hterms=red+giants&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dred%2Bgiants','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19910066714&hterms=red+giants&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dred%2Bgiants"><span>Fe II <span class="hlt">emission</span> <span class="hlt">lines</span>. I - Chromospheric spectra of red giants</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Judge, P. G.; Jordan, C.</p> <p>1991-01-01</p> <p>A 'difference filtering' algorithm developed by Ayers (1979) is used to construct high-quality high-dispersion long-wavelength IUE spectra of three giant stars. Measurements of all the <span class="hlt">emission</span> <span class="hlt">lines</span> seen between 2230 and 3100 A are tabulated. The <span class="hlt">emission</span> spectrum of Fe II is discussed in comparison with other <span class="hlt">lines</span> whose formation mechanisms are well understood. Systematic changes in the Fe II spectrum are related to the different physical conditions in the three stars, and examples are given of <span class="hlt">line</span> profiles and ratios which can be used to determine conditions in the outer atomspheres of giants. It is concluded that most of the Fe II <span class="hlt">emission</span> results from collisional excitation and/or absorption of photospheric photons at optical wavelengths, but some <span class="hlt">lines</span> are formed by fluorescence, being photoexcited by other strong chromospheric <span class="hlt">lines</span>. Between 10 and 20 percent of the radiative losses of Fe II arise from 10 eV levels radiatively excited by the strong chromospheric H Ly-alpha <span class="hlt">line</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014GeoRL..41.6943A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014GeoRL..41.6943A"><span>First spaceborne observation of the entire concentric <span class="hlt">airglow</span> structure caused by tropospheric disturbance</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Akiya, Y.; Saito, A.; Sakanoi, T.; Hozumi, Y.; Yamazaki, A.; Otsuka, Y.; Nishioka, M.; Tsugawa, T.</p> <p>2014-10-01</p> <p>Spaceborne imagers are able to observe the <span class="hlt">airglow</span> structures with wide field of views regardless of the tropospheric condition that limits the observational time of the ground-based imagers. Concentric wave structures of the O2 <span class="hlt">airglow</span> in 762 nm wavelength were observed over North America on 1 June 2013 from the International Space Station. This was the first observation in which the entire image of the structure was captured from space, and its spatial scale size was determined to be 1200 km radius without assumptions. The apparent horizontal wavelength was 80 km, and the amplitude in the intensity was approximately 20% of the background intensity. The propagation velocity of the structure was derived as 125 ± 62 m/s and atmospheric gravity waves were estimated to be generated for 3.5 ± 1.7 h. Concentric structures observed in this event were interpreted to be generated by super cells that caused a tornado in its early phase.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMSA42A..04H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMSA42A..04H"><span>Optical imaging of <span class="hlt">airglow</span> structure in equatorial plasma bubbles at radio scintillation scales</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Holmes, J. M.; Pedersen, T.; Parris, R. T.; Stephens, B.; Caton, R. G.; Dao, E. V.; Kratochvil, S.; Morton, Y.; Xu, D.; Jiao, Y.; Taylor, S.; Carrano, C. S.</p> <p>2015-12-01</p> <p>Imagery of optical <span class="hlt">emissions</span> from F-region plasma is one of the few means available todetermine plasma density structure in two dimensions. However, the smallest spatial scalesobservable with this technique are typically limited not by magnification of the lens or resolutionof the detector but rather by the optical throughput of the system, which drives the integrationtime, which in turn causes smearing of the features that are typically moving at speeds of 100m/s or more. In this paper we present high spatio-temporal imagery of equatorial plasma bubbles(EPBs) from an imaging system called the Large Aperture Ionospheric Structure Imager(LAISI), which was specifically designed to capture short-integration, high-resolution images ofF-region recombination <span class="hlt">airglow</span> at λ557.7 nm. The imager features 8-inch diameter entranceoptics comprised of a unique F/0.87 lens, combined with a monolithic 8-inch diameterinterference filter and a 2x2-inch CCD detector. The LAISI field of view is approximately 30degrees. Filtered all-sky images at common <span class="hlt">airglow</span> wavelengths are combined with magneticfield-aligned LAISI images, GNSS scintillation, and VHF scintillation data obtained atAscension Island (7.98S, 14.41W geographic). A custom-built, multi-constellation GNSS datacollection system was employed that sampled GPS L1, L2C, L5, GLONASS L1 and L2, BeidouB1, and Galileo E1 and E5a signals. Sophisticated processing software was able to maintainlock of all signals during strong scintillation, providing unprecedented spatial observability ofL band scintillation. The smallest-resolvable scale sizes above the noise floor in the EPBs, as viewed byLAISI, are illustrated for integration times of 1, 5 and 10 seconds, with concurrentzonal irregularity drift speeds from both spaced-receiver VHF measurements and single-stationGNSS measurements of S4 and σφ. These observable optical scale sizes are placed in thecontext of those that give rise to radio scintillation in VHF and L band signals.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120015659','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120015659"><span>PEARS <span class="hlt">Emission</span> <span class="hlt">Line</span> Galaxies</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Pirzkal, Nor; Rothberg, Barry; Ly, Chun; Rhoads, James E.; Malhotra, Sangeeta; Grogin, Norman A.; Dahlen, Tomas; Meurer, Gerhardt R.; Walsh, Jeremy; Hathi, Nimish P.; <a style="text-decoration: none; " href="javascript:void(0); " onClick="displayelement('author_20120015659'); toggleEditAbsImage('author_20120015659_show'); toggleEditAbsImage('author_20120015659_hide'); "> <img style="display:inline; width:12px; height:12px; " src="images/arrow-up.gif" width="12" height="12" border="0" alt="hide" id="author_20120015659_show"> <img style="width:12px; height:12px; display:none; " src="images/arrow-down.gif" width="12" height="12" border="0" alt="hide" id="author_20120015659_hide"></p> <p>2012-01-01</p> <p>We present a full analysis of the Probing Evolution And Reionization Spectroscopically (PEARS) slitless grism spectroscopic data obtained vl'ith the Advanced Camera for Surveys on HST. PEARS covers fields within both the Great Observatories Origins Deep Survey (GOODS) North and South fields, making it ideal as a random surveY of galaxies, as well as the availability of a wide variety of ancillary observations to support the spectroscopic results. Using the PEARS data we are able to identify star forming galaxies within the redshift volume 0 < z < 1.5. Star forming regions in the PEARS survey are pinpointed independently of the host galaxy. This method allOW8 us to detect the presence of multiple <span class="hlt">emission</span> <span class="hlt">line</span> regions (ELRs) within a single galaxy. 1162 [OII], [OIII] and/or H-alpha <span class="hlt">emission</span> <span class="hlt">lines</span> have been identified in the PEARS sample of approx 906 galaxies down to a limiting flux of approx 10 - 18 erg/s/sq cm . The ELRs have also been compared to the properties of the host galaxy, including morphology, luminosity, and mass. From this analysis we find three key results: 1) The computed <span class="hlt">line</span> luminosities show evidence of a flattening in the luminosity function with increasing redshift; 2) The star forming systems show evidence of disturbed morphologies, with star formation occurring predominantly within one effective (half-light) radius. However, the morphologies show no correlation with host stellar mass; and 3) The number density of star forming galaxies with M(*) >= 10(exp 9) Solar M decreases by an order of magnitude at z<=0.5 relative to the number at 0.5 < z < 0.9 in support of the argument for galaxy downsizing.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19920003658','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19920003658"><span>Ethylene <span class="hlt">line</span> <span class="hlt">emission</span> from the North Pole of Jupiter</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kostiuk, Theodor; Espenak, F.; Romani, P.; Goldstein, J.</p> <p>1991-01-01</p> <p>A significant enhancement in infrared <span class="hlt">emission</span> from hydrocarbon constituents of Jupiter's stratosphere was observed at a north polar hot spot (60 degrees latitude, 180 degrees longitude). A unique probe of this phenomena is ethylene (C2H4), which has not been observed previously from the ground. The profile of the <span class="hlt">emission</span> <span class="hlt">line</span> from ethylene at 951.742 cm-1, measured near the north pole of Jupiter, was analyzed to determine the morphology of the enhancement, the increase in C2H4 abundance and local temperature, as well as possible information on the altitude (pressure regions) where the increased <span class="hlt">emission</span> is formed. Measurements were made using infrared heterodyne spectroscopy at the NASA Infrared Telescope Facility on Mauna Kea, Hawaii in December 1989. At 181 degrees longitude a very strong <span class="hlt">emission</span> <span class="hlt">line</span> was seen, which corresponds to a 13-fold increase in C2H4 abundance or a 115K increase in temperature in the upper stratosphere, compared to values outside the hot spot. The hot spot was found to be localized to approx. 10 degrees in longitude; the <span class="hlt">line</span> shape (width) implied that the enhanced <span class="hlt">emission</span> originated very high in the stratosphere.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011adap.prop..188W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011adap.prop..188W"><span>X-ray <span class="hlt">Emission</span> <span class="hlt">Line</span> Spectroscopy of Nearby Galaxies</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, Daniel</p> <p></p> <p>What are the origins of the diffuse soft X-ray <span class="hlt">emission</span> from non-AGN galaxies? Preliminary analysis of XMM-Newton RGS spectra shows that a substantial fraction of the <span class="hlt">emission</span> cannot arise from optically-thin thermal plasma, as commonly assumed, and may originate in charge exchange at the interface with neutral gas. We request the support for a comprehensive observing, data analysis, and modeling program to spectroscopically determine the origins of the <span class="hlt">emission</span>. First, we will use our scheduled XMM-Newton AO-10 368 ks observations of the nearest compact elliptical galaxy M32 to obtain the first spectroscopic calibration of the cumulative soft X-ray <span class="hlt">emission</span> from the old stellar population and will develop a spectral model for the charge exchange, as well as analysis tools to measure the spatial and kinematic properties of the X-ray <span class="hlt">line</span>- emitting plasma. Second, we will characterize the truly diffuse <span class="hlt">emission</span> from the hot plasma and/or its interplay with the neutral gas in a sample of galactic spheroids and active star forming/starburst regions in nearby galaxies observed by XMM-Newton. In particular, we will map out the spatial distributions of key <span class="hlt">emission</span> <span class="hlt">lines</span> and measure (or tightly constrain) the kinematics of hot plasma outflows for a few X-ray-emitting regions with high-quality RGS data. For galaxies with insufficient counting statistics in individual <span class="hlt">emission</span> <span class="hlt">lines</span>, we will conduct a spectral stacking analysis to constrain the average properties of the X-ray-emitting plasma. We will use the results of these X-ray spectroscopic analyses, together with complementary X-ray CCD imaging/spectral data and observations in other wavelength bands, to test the models of the <span class="hlt">emission</span>. In addition to the charge exchange, alternative scenarios such as resonance scattering and relic AGN photo-ionization will also be examined for suitable regions. These studies are important to the understanding of the relationship between the diffuse soft X-ray <span class="hlt">emission</span> and various</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/4314019-interferometric-investigation-emission-lines-from-solar-corona','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/4314019-interferometric-investigation-emission-lines-from-solar-corona"><span>Interferometric investigation of <span class="hlt">emission</span> <span class="hlt">lines</span> from the solar corona</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Marshall, P.M.; Henderson, G.</p> <p>1973-11-01</p> <p>The profiles of the Fe XN, lambda 5303, and Fe X, lambda 6374, <span class="hlt">emission</span> <span class="hlt">lines</span> of the solar corona were observed at different posttions using a photoelectric scanning Fabry -- Perot interferometer. These profiles were obtained during the eclipse of 7th March 1970, in Mexico and at the Pic-du-Midi coronagraph in October, 1970. The half-widths of these profiles were determined for both the coronal <span class="hlt">lines</span> and temperatures were derived from these widths. No systematic temperature variation was discovered, however there was some suggestion of the existence of a fluctuation with time in the width of the <span class="hlt">emission</span> <span class="hlt">lines</span>. (auth)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMAE31B3408W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMAE31B3408W"><span>The D-Region Ledge at Nighttime: Why are Elves Collocated with the OH Meinel Band <span class="hlt">Airglow</span> Layer?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wu, Y. J.; Williams, E. R.; Hsu, R. R.</p> <p>2014-12-01</p> <p>The Imager of Sprite and Upper Atmosphere Lightning (ISUAL) onboard the Taiwanese satellite Formosat-2 has continuously observed transient luminous events (TLEs) within the +/-60 degree range of latitude for a decade since May 2004. The lightning electromagnetic pulse is responsible for Elves , the dominate TLE type which accounts for approximately 80% of the total TLE count according to the ISUAL global survey. By analyzing the limb-viewed images with a wavelength filter of 622.8-754nm, 72% of elves are found to be 'glued' to the OH Meinel band (~630nm) nightglow layer within its thickness of 8km, with the OH layer normally at an altitude of 87 km (Huang et al., 2010).This collocation of elves and <span class="hlt">airglow</span> layer is frequently dismissed as coincidence, since the physical mechanisms for the formation of the two optical phenomena are macroscopically quite different. However, a common ingredient in the atmospheric chemistry is monatomic oxygen. O is needed to make O3 and ultimately hydroxyl OH, the main radiative species of the <span class="hlt">airglow</span> layer. O is also needed to form nitric oxide NO, the species with the lowest known ionization potential (9.26 eV) in the D-region. Thomas (1990) has documented steep increases in O concentration in the 83-85 km altitude range and Hale (1985) has found steep increases in electrical conductivity in the 84-85 km range, both with rocket measurements. A great simplification of the nighttime ionosphere is the presence of a single photon energy—10.2 eV—Lyman-α, originating in monatomic H in the Earth's geocorona. A simple Chapman layer calculation for the altitude of maximum photo-dissociation of O2, using the measured absorption cross-section of O2 at the Lyman-α energy, shows an altitude of maximum O production at 85 km. Elve <span class="hlt">emission</span> in the nitrogen first positive band is enhanced by the presence of free electrons from ionized NO, but too large a conductivity will lead to the exclusion of the radiation field from the lightning return</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2000AAS...197.0907R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2000AAS...197.0907R"><span>Near-Infrared <span class="hlt">Emission</span> <span class="hlt">Lines</span> of Nova Cassiopeiae 1995</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rudy, R. J.; Lynch, D. K.; Mazuk, S. M.; Venturini, C. C.; Puetter, R. C.</p> <p>2000-12-01</p> <p>The slow nova V 723 Cas (Nova Cas 1995) exhibits comparatively narrow <span class="hlt">emission</span> features (FWHM 500 km sec-1) that make it ideal for classifying weak <span class="hlt">lines</span> and <span class="hlt">lines</span> blended with stronger features. We present spectra from 0.8-2.5 microns that track the gradual incrase in excitation of Nova Cas and discuss the <span class="hlt">emission</span> <span class="hlt">lines</span> that were present. During the period encompassed by these observations Nova Cas reached only moderate excitation-the most energetic coronal <span class="hlt">lines</span> were [S VIII] 9913 and [Al IX] 20444; <span class="hlt">lines</span> such as [S IX] 12523 that are prominent in some novae were not detected. Additional coronal <span class="hlt">lines</span> present include [Si VI] 19641, [Ca VIII] 23205, and [Si VII] 24807. New <span class="hlt">lines</span> identified include features of [Fe V], [Fe VI]. These iron features are not coronal <span class="hlt">lines</span>, arising from transitions among low-lying terms rather than within the ground term itself. Also detected was [Ti VI] 17151 that was first identified in V1974 Cygni (Nova Cyg 1992), and possibly [Ti VII] 22050. Accurate wavelengths for a number of unidentified <span class="hlt">lines</span> are also presented. These unidentified features are discussed with regard to their likely level of excitation and their presence in other novae. This work was supported by the IR&D program of the Aerospace Corporation. RCP acknowledges support from NASA.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20070016569','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20070016569"><span>A Suzaku Observation of the Neutral Fe-<span class="hlt">line</span> <span class="hlt">Emission</span> from RCW 86</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ueno, Masaru; Sato, Rie; Kataoka, Jun; Bamba, Aya; Harrus, Ilana; Hiraga, Junko; Hughes, John P.; Kilbourne, Caroline A.; Koyama, Katsuji; Kokubun, Motohide; <a style="text-decoration: none; " href="javascript:void(0); " onClick="displayelement('author_20070016569'); toggleEditAbsImage('author_20070016569_show'); toggleEditAbsImage('author_20070016569_hide'); "> <img style="display:inline; width:12px; height:12px; " src="images/arrow-up.gif" width="12" height="12" border="0" alt="hide" id="author_20070016569_show"> <img style="width:12px; height:12px; display:none; " src="images/arrow-down.gif" width="12" height="12" border="0" alt="hide" id="author_20070016569_hide"></p> <p>2007-01-01</p> <p>The newly operational X-ray satellite Suzaku observed the supernova remnant (SNR) RCW 86 in February 2006 to study the nature of the 6.4 keV <span class="hlt">emission</span> <span class="hlt">line</span> first detected with the Advanced Satellite for Cosmology and Astronomy (ASCA). The new data confirms the existence of the <span class="hlt">line</span>, localizing it for the first time inside a low temperature <span class="hlt">emission</span> region and not at the locus of the continuum hard X-ray <span class="hlt">emission</span>. We also report the first detection of a 7.1 keV <span class="hlt">line</span> that we interpret as the K(beta) <span class="hlt">emission</span> from neutral or low-ionized iron. The Fe-K <span class="hlt">line</span> features are consistent with a non-equilibrium plasma of Fe-rich ejecta with n(sub e) less than or approx. equal to 10(exp 9)/cu cm s and kT(sub e) > 1 keV. We found a sign that Fe K(alpha) <span class="hlt">line</span> is intrinsically broadened 47 (35-57) eV (99% error region). Cr-K <span class="hlt">line</span> is also marginally detected, which is supporting the ejecta origin for the Fe-K <span class="hlt">line</span>. By showing that the hard continuum above 3 keV has different spatial distribution from the Fe-K <span class="hlt">line</span>, we confirmed it to be synchrotron X-ray <span class="hlt">emission</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMSA33A2424C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMSA33A2424C"><span>Relationship between Ripples and Gravity Waves Observed in OH <span class="hlt">Airglow</span> over the Andes Lidar Observatory</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cao, B.; Gelinas, L. J.; Liu, A. Z.; Hecht, J. H.</p> <p>2016-12-01</p> <p>Instabilities generated by large amplitude gravity waves are ubiquitous in the mesopause region, and contribute to the strong forcing on the background atmosphere. Gravity waves and ripples generated by instability are commonly detected by high resolution <span class="hlt">airglow</span> imagers that measure the hydroxyl <span class="hlt">emissions</span> near the mesopause ( 87 km). Recently, a method based on 2D wavelet is developed by Gelinas et al. to characterize the statistics of ripple parameters from the Aerospace Infrared Camera at Andes Lidar Observatory located at Cerro Pachón, Chile (70.74°W, 30.25°S). In the meantime, data from a collocated all-sky imager is used to derive gravity wave parameters and their statistics. In this study, the relationship between the ripples and gravity waves that appeared at the same time and location are investigated in terms of their orientations, magnitudes and scales, to examine the statistical properties of the gravity wave induced instabilities and the ripples they generate.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018GeoRL..45...31H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018GeoRL..45...31H"><span>Nighttime Medium-Scale Traveling Ionospheric Disturbances From <span class="hlt">Airglow</span> Imager and Global Navigation Satellite Systems Observations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Huang, Fuqing; Lei, Jiuhou; Dou, Xiankang; Luan, Xiaoli; Zhong, Jiahao</p> <p>2018-01-01</p> <p>In this study, coordinated <span class="hlt">airglow</span> imager, GPS total electron content (TEC), and Beidou geostationary orbit (GEO) TEC observations for the first time are used to investigate the characteristics of nighttime medium-scale traveling ionospheric disturbances (MSTIDs) over central China. The results indicated that the features of nighttime MSTIDs from three types of observations are generally consistent, whereas the nighttime MSTID features from the Beidou GEO TEC are in better agreement with those from <span class="hlt">airglow</span> images as compared with the GPS TEC, given that the nighttime MSTID characteristics from GPS TEC are significantly affected by Doppler effect due to satellite movement. It is also found that there are three peaks in the seasonal variations of the occurrence rate of nighttime MSTIDs in 2016. Our study revealed that the Beidou GEO satellites provided fidelity TEC observations to study the ionospheric variability.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20000090625&hterms=applications+thermodynamic&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dapplications%2Bthermodynamic','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20000090625&hterms=applications+thermodynamic&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dapplications%2Bthermodynamic"><span>Cloudy 94 and Applications to Quasar <span class="hlt">Emission</span> <span class="hlt">Line</span> Regions</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ferland, Gary J.</p> <p>2000-01-01</p> <p>This review discusses the most recent developments of the plasma simulation code Cloudy and its application to the, <span class="hlt">emission-line</span> regions of quasars. The longterm goal is to develop the tools needed to determine the chemical composition of the emitting gas and the luminosity of the central engine for any <span class="hlt">emission</span> <span class="hlt">line</span> source. <span class="hlt">Emission</span> <span class="hlt">lines</span> and the underlying thermal continuum are formed in plasmas that are far from thermodynamic equilibrium. Their thermal and ionization states are the result of a balance of a vast set of microphysical processes. Once produced, radiation must, propagate out of the (usually) optically thick source. No analytic solutions are possible, and recourse to numerical simulations is necessary. I am developing the large-scale plasma simulation code Cloudy as an investigative tool for this work, much as an observer might build a spectrometer. This review describes the current version of Cloudy, version 94. It describes improvements made since the, release of the previous version, C90. The major recent, application has been the development of the "Locally Optimally-Emitting Cloud" (LOC) model of AGN <span class="hlt">emission</span> <span class="hlt">line</span> regions. Powerful selection effects, introduced by the atomic physics and <span class="hlt">line</span> formation process, permit individual <span class="hlt">lines</span> to form most efficiently only near certain selected parameters. These selection effects, together with the presence of gas with a wide range of conditions, are enough to reproduce the spectrum of a typical quasar with little dependence on details. The spectrum actually carries little information to the identity of the emitters. I view this as a major step forward since it provides a method to handle accidental details at the source, so that we can concentrate on essential information such as the luminosity or chemical composition of the quasar.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AAS...22211510H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AAS...22211510H"><span>A Calibrated H-alpha Index to Monitor <span class="hlt">Emission</span> <span class="hlt">Line</span> Objects</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hintz, Eric G.; Joner, M. D.</p> <p>2013-06-01</p> <p>Over an 8 year period we have developed a calibrated H-alpha index, similar to the more traditional H-beta index, based on spectrophotometric observations (Joner & Hintz, 2013) from the DAO 1.2-m Telescope. While developing the calibration for this filter set we also obtained spectra of a number of <span class="hlt">emission</span> <span class="hlt">line</span> systems such as high mass x-ray binaries (HMXB), Be stars, and young stellar objects. From this work we find that the main sequence stars fill a very tight relation in the H-alpha/H-beta plane and that the <span class="hlt">emission</span> <span class="hlt">line</span> objects are easily detected. We will present the overall location of these <span class="hlt">emission</span> <span class="hlt">line</span> objects. We will also present the changes experiences by these objects over the course of the years of the project.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19950035282&hterms=twilight&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dtwilight','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19950035282&hterms=twilight&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dtwilight"><span>Recent observations of the OI 8446 A <span class="hlt">emission</span> over Millstone Hill</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lancaster, R. S.; Kerr, R. B.; Ng, K.; Noto, J.; Franco, M.; Solomon, Stanley C.</p> <p>1994-01-01</p> <p>Evening twilight spectra of the OI 8446 A <span class="hlt">emission</span> were obtained during May and June of 1993 using a single-etalon, pressure scanning, Fabry-Perot interferometer located in the Millstone Hill Optical Facility. The goals of this work are to positively identify the 8446 A <span class="hlt">emission</span> in the twilight <span class="hlt">airglow</span> and to determine the intensity decay as a function of solar depression angle. Also, a study of the relative triplet <span class="hlt">line</span> strengths is performed in hopes of establishing the importance of the primary excitation mechanisms (photoelectron impact or Bowen fluorescence) during the twilight period. Although absent in most of the data, a distinct auroral influence is also found to contribute considerably, on occasion, to the <span class="hlt">emission</span> over Millstone Hill. The ratio of the combined 8446.26 A and 8446.38 A intensities to the 8446.76 A intensity varies as 0.13 +/- 0.03 per degree of solar depression angle, indicating that secondary excitation mechanisms are becoming increasingly important as evening twilight progresses. Bowen fluorescence is not found to be the primary excitation mechanism at any time during twilight, contributing just a few Rayleighs at most. These observations are an important first step toward a better characterization of highly variable thermospheric oxygen concentrations through ground-based measurements of the OI 8446 A <span class="hlt">emission</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20050160227&hterms=hELIOSTAT&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DhELIOSTAT','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20050160227&hterms=hELIOSTAT&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DhELIOSTAT"><span>Linear Polarization Measurements of Chromospheric <span class="hlt">Emission</span> <span class="hlt">Lines</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Sheeley, N. R., Jr.; Keller, C. U.</p> <p>2003-01-01</p> <p>We have used the Zurich Imaging Stokes Polarimeter (ZIMPOL I) with the McMath-Pierce 1.5 m main telescope on Kitt Peak to obtain linear polarization measurements of the off-limb chromosphere with a sensitivity better than 1 x 10(exp -5). We found that the off-disk observations require a combination of good seeing (to show the <span class="hlt">emission</span> <span class="hlt">lines</span>) and a clean heliostat (to avoid contamination by scattered light from the Sun's disk). When these conditions were met, we obtained the following principal results: 1. Sometimes self-reversed <span class="hlt">emission</span> <span class="hlt">lines</span> of neutral and singly ionized metals showed linear polarization caused by the transverse Zeeman effect or by instrumental cross talk from the longitudinal Zeeman effect in chromospheric magnetic fields. Otherwise, these <span class="hlt">lines</span> tended to depolarize the scattered continuum radiation by amounts that ranged up to 0.2%. 2. <span class="hlt">Lines</span> previously known to show scattering polarization just inside the limb (such as the Na I lambda5889 D2 and the He I lambda5876 D3 <span class="hlt">lines</span>) showed even more polarization above the Sun's limb, with values approaching 0.7%. 3. The O I triplet at lambda7772, lambda7774, and lambda7775 showed a range of polarizations. The lambda7775 <span class="hlt">line</span>, whose maximum intrinsic polarizability, P(sub max), is less than 1%, revealed mainly Zeeman contributions from chromospheric magnetic fields. However, the more sensitive lambda7772 (P(sub max) = 19%) and lambda7774 (P(sub max) = 29%) <span class="hlt">lines</span> had relatively strong scattering polarizations of approximately 0.3% in addition to their Zeeman polarizations. At times of good seeing, the polarization spectra resolve into fine structures that seem to be chromospheric spicules.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013RMxAC..42...20M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013RMxAC..42...20M"><span><span class="hlt">Emission-line</span> maps with OSIRIS-TF: The case of M101</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Méndez-Abreu, J.</p> <p>2013-05-01</p> <p>We investigate the suitability of GTC/OSIRIS Tunable Filters (TFs) for obtaining <span class="hlt">emission-line</span> maps of extended objects. We developed a technique to reconstruct an <span class="hlt">emission-line</span> image from a set of images taken at consecutive central wavelengths. We demonstrate the feasibility of the reconstruction method by generating a flux calibrated Hα image of the well-known spiral galaxy M101. We tested our <span class="hlt">emission-line</span> fluxes and ratios by using data present in the literature. We found that the differences in both Hα fluxes and N II/Hα <span class="hlt">line</span> ratios are ~15% and ~50%, respectively. These results are fully in agreement with the expected values for our observational setup. The proposed methodology will allow us to use OSIRIS/GTC to perform accurate spectrophotometric studies of extended galaxies in the local Universe.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004cosp...35..231A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004cosp...35..231A"><span>Zonal drift velocities of the ionospheric plasma bubbles over brazilian region using oi630nm <span class="hlt">airglow</span> digital images</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Arruda, D. C. S.; Sobral, J. H. A.; Abdu, M. A.; Castilho, V. M.; Takahashi, H.</p> <p></p> <p>The zonal drift velocities of the ionospheric plasma bubbles over the Brazilian region are analyzed in this study that is based on OI630nm <span class="hlt">airglow</span> digital images. These digital images were obtained by an all-sky imager system between October 1998 and August 2000, at Cachoeira Paulista (22.5°S, 45°W), a low latitude region. In this period, 138 nights of OI 630 nm <span class="hlt">airglow</span> experiments were carried out of which 30 nights detected the ionospheric plasma bubbles. These 30 nights correspond to magnetically quiet days (ΣK_P<24+) and were grouped according approximately to their season. KEY WORDS: Imager System, Ionospheric Plasma Bubbles, Zonal drift velocities, OI630nm.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19920033871&hterms=molecular+diagnostic&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dmolecular%2Bdiagnostic','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19920033871&hterms=molecular+diagnostic&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dmolecular%2Bdiagnostic"><span>Molecular <span class="hlt">line</span> <span class="hlt">emission</span> models of Herbig-Haro objects. I - H2 <span class="hlt">emission</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wolfire, Mark G.; Konigl, Arieh</p> <p>1991-01-01</p> <p>A comprehensive model for molecular hydrogen emssion in Herbig-Haro objects that are associated with the heads of radiative stellar jets is presented by using a simple representation of the jet head as a comprising a leading bow shock and a trailing jet shock, separated by a dense layer of cool shocked gas. Attention is given to collisional excitation in a nondissociative shock and formation pumping in the molecular reformation zone behind a dissociative shock, employing detailed shock and photodissociation-region <span class="hlt">emission</span> models that incorporate most of the relevant atomic physics and chemistry. The conditions under which each of these excitation mechanisms may be expected to contribute to the observed <span class="hlt">emission</span> are discussed, and a general diagnostic scheme for discriminating among them is constructed. Applying this scheme to the HH 1-2 system, strong evidence for excitation by the radiation field of a fast shock is found. It is inferred that FUV pumping contributes a significant fraction of the H2 <span class="hlt">line</span> <span class="hlt">emission</span>, and it is shown that this can occur only if the UV pump <span class="hlt">lines</span> are not strongly self-shielded.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AAS...22734417H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AAS...22734417H"><span>Calibration of H-alpha/H-beta Indexes for <span class="hlt">Emission</span> <span class="hlt">Line</span> Objects</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hintz, Eric G.; Joner, Michael D.</p> <p>2016-01-01</p> <p>In Joner and Hintz (2015) they report on a standard star system for calibration of H-alpha and H-beta observations. This work was based on data obtained with the Dominion Astrophysical Observatory 1.2-m telescope. As part of the data acquisition for that project, a large number of <span class="hlt">emission</span> <span class="hlt">line</span> objects were also observed. We will report on the preliminary results for the <span class="hlt">emission</span> <span class="hlt">line</span> data set. This will include a comparison of equivalent width measurements of each <span class="hlt">line</span> with the matching index. We will also examine the relation between the absorption <span class="hlt">line</span> objects previously published and the <span class="hlt">emission</span> <span class="hlt">line</span> objects, along with a discussion of the transition point. Object types included are Be stars, high mass x-ray binaries, one low mass x-ray binary, Herbig Ae/Be stars, pre-main sequence stars, T Tauri stars, young stellar objects, and one BY Draconis star. Some of these objects come from Cygnus OB-2, NGC 659, NGC 663, NGC 869 and NGC 884.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li class="active"><span>9</span></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_9 --> <div id="page_10" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li class="active"><span>10</span></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="181"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19980236655','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19980236655"><span>Continuing Studies in Support of Ultraviolet Observations of Planetary Atmospheres</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Clark, John</p> <p>1997-01-01</p> <p>This program was a one-year extension of an earlier Planetary Atmospheres program grant, covering the period 1 August 1996 through 30 September 1997. The grant was for supporting work to complement an active program observing planetary atmospheres with Earth-orbital telescopes, principally the Hubble Space Telescope (HST). The recent concentration of this work has been on HST observations of Jupiter's upper atmosphere and aurora, but it has also included observations of Io, serendipitous observations of asteroids, and observations of the velocity structure in the interplanetary medium. The observations of Jupiter have been at vacuum ultraviolet wavelengths, including imaging and spectroscopy of the auroral and <span class="hlt">airglow</span> <span class="hlt">emissions</span>. The most recent HST observations have been at the same time as in situ measurements made by the Galileo orbiter instruments, as reflected in the meeting presentations listed below. Concentrated efforts have been applied in this year to the following projects: The analysis of HST WFPC 2 images of Jupiter's aurora, including the Io footprint <span class="hlt">emissions</span>. We have performed a comparative analysis of the lo footprint locations with two magnetic field models, studied the statistical properties of the apparent dawn auroral storms on Jupiter, and found various other repeated patterns in Jupiter's aurora. Analysis and modeling of <span class="hlt">airglow</span> and auroral Ly alpha <span class="hlt">emission</span> <span class="hlt">line</span> profiles from Jupiter. This has included modeling the aurora] <span class="hlt">line</span> profiles, including the energy degradation of precipitating charged particles and radiative transfer of the emerging <span class="hlt">emissions</span>. Jupiter's auroral <span class="hlt">emission</span> <span class="hlt">line</span> profile is self-absorbed, since it is produced by an internal source, and the resulting <span class="hlt">emission</span> with a deep central absorption from the overlying atmosphere permits modeling of the depth of the <span class="hlt">emissions</span>, plus the motion of the emitting layer with respect to the overlying atmospheric column from the observed Doppler shift of the central absorption. By contrast</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AAS...22943706M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AAS...22943706M"><span>Economical <span class="hlt">Emission-Line</span> Mapping: ISM Properties of Nearby Protogalaxy Analogs</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Monkiewicz, Jacqueline A.</p> <p>2017-01-01</p> <p>Optical <span class="hlt">emission</span> <span class="hlt">line</span> imaging can produce a wealth of information about the conditions of the interstellar medium, but a full set of custom <span class="hlt">emission-line</span> filters for a professional-grade telescope camera can cost many thousands of dollars. A cheaper alternative is to use commercially-produced 2-inch narrow-band astrophotography filters. In order to use these standardized filters with professional-grade telescope cameras, custom filter mounts must be manufactured for each individual filter wheel. These custom filter adaptors are produced by 3-D printing rather than standard machining, which further lowers the total cost.I demonstrate the feasibility of this technique with H-alpha, H-beta, and [OIII] <span class="hlt">emission</span> <span class="hlt">line</span> mapping of the low metallicity star-forming galaxies IC10 and NGC 1569, taken with my astrophotography filter set on three different 2-meter class telescopes in Southern Arizona.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22663192-double-peaked-emission-lines-due-radio-outflow-kissr','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22663192-double-peaked-emission-lines-due-radio-outflow-kissr"><span>Double-peaked <span class="hlt">Emission</span> <span class="hlt">Lines</span> Due to a Radio Outflow in KISSR 1219</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Kharb, P.; Vaddi, S.; Subramanian, S.</p> <p></p> <p>We present the results from 1.5 and 5 GHz phase-referenced VLBA and 1.5 GHz Karl G. Jansky Very Large Array (VLA) observations of the Seyfert 2 galaxy KISSR 1219, which exhibits double-peaked <span class="hlt">emission</span> <span class="hlt">lines</span> in its optical spectrum. The VLA and VLBA data reveal a one-sided core-jet structure at roughly the same position angles, providing evidence of an active galactic nucleus outflow. The absence of dual parsec-scale radio cores puts the binary black-hole picture in doubt for the case of KISSR 1219. The high brightness temperatures of the parsec-scale core and jet components (>10{sup 6} K) are consistent with thismore » interpretation. Doppler boosting with jet speeds of ≳0.55 c to ≳0.25 c , going from parsec to kiloparsec scales, at a jet inclination ≳50° can explain the jet one-sidedness in this Seyfert 2 galaxy. A blueshifted broad <span class="hlt">emission</span> <span class="hlt">line</span> component in [O iii] is also indicative of an outflow in the <span class="hlt">emission</span> <span class="hlt">line</span> gas at a velocity of ∼350 km s{sup −1}, while the [O i] doublet <span class="hlt">lines</span> suggest the presence of shock-heated gas. A detailed <span class="hlt">line</span> ratio study using the MAPPINGS III code further suggests that a shock+precursor model can explain the <span class="hlt">line</span> ionization data well. Overall, our data suggest that the radio outflow in KISSR 1219 is pushing the <span class="hlt">emission</span> <span class="hlt">line</span> clouds, both ahead of the jet and in a lateral direction, giving rise to the double peak <span class="hlt">emission</span> <span class="hlt">line</span> spectra.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1995ApJ...447..496C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1995ApJ...447..496C"><span>QSO Broad <span class="hlt">Emission</span> <span class="hlt">Line</span> Asymmetries: Evidence of Gravitational Redshift?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Corbin, Michael R.</p> <p>1995-07-01</p> <p>The broad optical and ultraviolet <span class="hlt">emission</span> <span class="hlt">lines</span> of QSOs and active galactic nuclei (AGNs) display both redward and blueward asymmetries. This result is particularly well established for Hβ and C IV λ1549, and it has been found that Hβ becomes increasingly redward asymmetric with increasing soft X-ray luminosity. Two models for the origin of these asymmetries are investigated: (1) Anisotropic <span class="hlt">line</span> <span class="hlt">emission</span> from an ensemble of radially moving clouds, and (2) Two-component profiles consisting of a core of intermediate (˜1000-4000 km s-1) velocity width and a very broad (˜5000-20,000 km s-1) base, in which the asymmetries arise due to a velocity difference between the centroids of the components. The second model is motivated by the evidence that the traditional broad-<span class="hlt">line</span> region is actually composed of an intermediate-<span class="hlt">line</span> region (ILR) of optically thick clouds and a very broad <span class="hlt">line</span> region (VBLR) of optically thin clouds lying closer to the central continuum source. <span class="hlt">Line</span> profiles produced by model (1) are found to be inconsistent with those observed, being asymmetric mainly in their cores, whereas the asymmetries of actual profiles arise mainly from excess <span class="hlt">emission</span> in their wings. By contrast, numerical fitting to actual Hβ and C IV λ1549 <span class="hlt">line</span> profiles reveals that the majority can be accurately modeled by two components, either two Gaussians or the combination of a Gaussian base and a logarithmic core. The profile asymmetries in Hβ can be interpreted as arising from a shift of the base component over a range ˜6300 km s-1 relative to systemic velocity as defined by the position of the [O III] λ5007 <span class="hlt">line</span>. A similar model appears to apply to C IV λ1549. The correlation between Hβ asymmetry and X-ray luminosity may thus be interpreted as a progressive red- shift of the VBLR velocity centroid relative to systemic velocity with increasing X-ray luminosity. This in turn suggests that the underlying effect is gravitational red shift, as soft X-ray <span class="hlt">emission</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20040027570&hterms=thermodynamics&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dthermodynamics','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20040027570&hterms=thermodynamics&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dthermodynamics"><span>Ground Based Remote Sensing of Upper Atmosphere Dynamics, Thermodynamics and Composition in Support of TIMED Satellites Scientific Mission</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>2004-01-01</p> <p>The following research work was accomplished: 1. We operated high throughput spectrophotometers and interferometers at eight observatories in the Arctic, Antarctic and mid-latitude regions to record relatively high-resolution spectra of very low light level <span class="hlt">airglow</span> and auroral <span class="hlt">line</span> as well as band <span class="hlt">emissions</span>. 2. Our Polar observations of auroral <span class="hlt">emissions</span> from N2 and O <span class="hlt">emissions</span> have been analyzed to derive the O/N2 ratios around 110 km height in the Polar thermosphere during different auroral events triggered by the precipitation of auroral electrons with average energy of about 10 keV. These results have been compared with similar ratios derived from TIMED satellite s GUVI measurements of N2 LBH and 01 1356A <span class="hlt">emissions</span>. 3. Our <span class="hlt">airglow</span> measurements show MLT density and temperature modulations by Planetary, Tidal and Gravity Waves. They also indicate Mesopause cooling preceding a Stratospheric Warming Event (SWE).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA626079','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA626079"><span>Electron Gyro-Harmonic Effects on Ionospheric Stimulated Brillouin Scatter</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2014-08-21</p> <p>27709-2211 Brillouin, SBS, <span class="hlt">emission</span> <span class="hlt">lines</span>, pump frequency stepping, cyclotron , EIC, <span class="hlt">airglow</span>, upper hybrid REPORT DOCUMENTATION PAGE 11. SPONSOR...direction and the background magnetic field vector, the excited electrostatic wave could be either ion acoustic (IA) or electrostatic ion cyclotron (EIC...A. Hedberg, B. Lundborg, P. Stubbe, H. Kopka, and M. T. Rietveld (1989), Stimulated electromagnetic <span class="hlt">emission</span> near electron cyclotron harmonics in</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19930061209&hterms=atmosphere+wind+profile&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Datmosphere%2Bwind%2Bprofile','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19930061209&hterms=atmosphere+wind+profile&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Datmosphere%2Bwind%2Bprofile"><span>WINDII, the wind imaging interferometer on the Upper Atmosphere Research Satellite</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Shepherd, G. G.; Thuillier, G.; Gault, W. A.; Solheim, B. H.; Hersom, C.; Alunni, J. M.; Brun, J.-F.; Brune, S.; Charlot, P.; Cogger, L. L.</p> <p>1993-01-01</p> <p>The WIND imaging interferometer (WINDII) was launched on the Upper Atmosphere Research Satellite (UARS) on September 12, 1991. This joint project, sponsored by the Canadian Space Agency and the French Centre National d'Etudes Spatiales, in collaboration with NASA, has the responsibility of measuring the global wind pattern at the top of the altitude range covered by UARS. WINDII measures wind, temperature, and <span class="hlt">emission</span> rate over the altitude range 80 to 300 km by using the visible region <span class="hlt">airglow</span> <span class="hlt">emission</span> from these altitudes as a target and employing optical Doppler interferometry to measure the small wavelength shifts of the narrow atomic and molecular <span class="hlt">airglow</span> <span class="hlt">emission</span> <span class="hlt">lines</span> induced by the bulk velocity of the atmosphere carrying the emitting species. The instrument used is an all-glass field-widened achromatically and thermally compensated phase-stepping Michelson interferometer, along with a bare CCD detector that images the <span class="hlt">airglow</span> limb through the interferometer. A sequence of phase-stepped images is processed to derive the wind velocity for two orthogonal view directions, yielding the vector horizontal wind. The process of data analysis, including the inversion of apparent quantities to vertical profiles, is described.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22667351-nature-active-galactic-nuclei-velocity-offset-emission-lines','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22667351-nature-active-galactic-nuclei-velocity-offset-emission-lines"><span>THE NATURE OF ACTIVE GALACTIC NUCLEI WITH VELOCITY OFFSET <span class="hlt">EMISSION</span> <span class="hlt">LINES</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Müller-Sánchez, F.; Comerford, J.; Stern, D.</p> <p></p> <p>We obtained Keck/OSIRIS near-IR adaptive optics-assisted integral-field spectroscopy to probe the morphology and kinematics of the ionized gas in four velocity-offset active galactic nuclei (AGNs) from the Sloan Digital Sky Survey. These objects possess optical <span class="hlt">emission</span> <span class="hlt">lines</span> that are offset in velocity from systemic as measured from stellar absorption features. At a resolution of ∼0.″18, OSIRIS allows us to distinguish which velocity offset <span class="hlt">emission</span> <span class="hlt">lines</span> are produced by the motion of an AGN in a dual supermassive black hole system, and which are produced by outflows or other kinematic structures. In three galaxies, J1018+2941, J1055+1520, and J1346+5228, the spectral offsetmore » of the <span class="hlt">emission</span> <span class="hlt">lines</span> is caused by AGN-driven outflows. In the remaining galaxy, J1117+6140, a counterrotating nuclear disk is observed that contains the peak of Pa α <span class="hlt">emission</span> 0.″2 from the center of the galaxy. The most plausible explanation for the origin of this spatially and kinematically offset peak is that it is a region of enhanced Pa α <span class="hlt">emission</span> located at the intersection zone between the nuclear disk and the bar of the galaxy. In all four objects, the peak of ionized gas <span class="hlt">emission</span> is not spatially coincident with the center of the galaxy as traced by the peak of the near-IR continuum <span class="hlt">emission</span>. The peaks of ionized gas <span class="hlt">emission</span> are spatially offset from the galaxy centers by 0.″1–0.″4 (0.1–0.7 kpc). We find that the velocity offset originates at the location of this peak of <span class="hlt">emission</span>, and the value of the offset can be directly measured in the velocity maps. The <span class="hlt">emission-line</span> ratios of these four velocity-offset AGNs can be reproduced only with a mixture of shocks and AGN photoionization. Shocks provide a natural explanation for the origin of the spatially and spectrally offset peaks of ionized gas <span class="hlt">emission</span> in these galaxies.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-STS099-349-002.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-STS099-349-002.html"><span>Views of a sunrise and an aurora taken from OV-105 during STS-99</span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>2000-04-06</p> <p>STS099-349-002 (11-22 February 2000) ---The Space Shuttle Endeavour's vertical stabilizer is visible in the foreground of this 35mm frame featuring <span class="hlt">airglow</span>, the thin greenish band above the horizon. <span class="hlt">Airglow</span> is radiation emitted by the atmosphere from a layer about 30 kilometers thick and about 100 kilometers altitude. The predominant <span class="hlt">emission</span> in <span class="hlt">airglow</span> is the green 5577-Angstrom wavelength <span class="hlt">emission</span> from atomic oxygen atoms. <span class="hlt">Airglow</span> is always and everywhere present in the atmosphere; it results from the recombination of molecules that have been broken apart by solar radiation during the day. But <span class="hlt">airglow</span> is so faint that it can only be seen at night by looking "edge on" at the <span class="hlt">emission</span> layer, such as the view astronauts have in orbit.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016APS..DPPBO4012P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016APS..DPPBO4012P"><span><span class="hlt">Line</span> <span class="hlt">Emission</span> and X-ray <span class="hlt">Line</span> Polarization of Multiply Ionized Mo Ions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Petkov, E. E.; Safronova, A. S.; Kantsyrev, V. L.; Shlyaptseva, V. V.; Stafford, A.; Safronova, U. I.; Shrestha, I. K.; Schultz, K. A.; Childers, R.; Cooper, M. C.; Beiersdorfer, P.; Hell, N.; Brown, G. V.</p> <p>2016-10-01</p> <p>We present a comprehensive experimental and theoretical study of the <span class="hlt">line</span> <span class="hlt">emission</span> from multiply ionized Mo ions produced by two different sets of experiments: at LLNL EBIT and the pulsed power generator Zebra at UNR. Mo <span class="hlt">line</span> <span class="hlt">emission</span> and polarization measurements were accomplished at EBIT for the first time. In particular, benchmarking experiments at the LLNL EBIT with Mo ions produced at electron beam energies from 2.75 keV up to 15 keV allowed us to break down these very complicated spectra into spectra with only few ionization stages and to select processes that influence them as well as to measure <span class="hlt">line</span> polarization. The EBIT data were recorded using the EBIT Calorimeter Spectrometer and a crystal spectrometer with a Ge crystal. X-ray Mo spectra and pinhole images were collected from Z-pinch plasmas produced from various wire loads. Non-LTE modeling, high-precision relativistic atomic and polarization data were used to analyze L-shell Mo spectra. The influence of different plasma processes including electron beams on Mo <span class="hlt">line</span> radiation is summarized. This work was supported by NNSA under DOE Grant DE-NA0002954. Experiments at the NTF/UNR were funded in part by DE-NA0002075. Work at LLNL was performed under the auspices of the U.S. DOE under contract DE-AC52-07NA27344.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMSA51A2384L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMSA51A2384L"><span>A new method of derived equatorial plasma bubbles motion by tracing OI 630 nm <span class="hlt">emission</span> all-sky images</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Li, M.; Yu, T.; Chunliang, X.; Zuo, X.; Liu, Z.</p> <p>2017-12-01</p> <p>A new method for estimating the equatorial plasma bubbles (EPBs) motions from <span class="hlt">airglow</span> <span class="hlt">emission</span> all-sky images is presented in this paper. This method, which is called 'cloud-derived wind technology' and widely used in satellite observation of wind, could reasonable derive zonal and meridional velocity vectors of EPBs drifts by tracking a series of successive <span class="hlt">airglow</span> 630.0 nm <span class="hlt">emission</span> images. <span class="hlt">Airglow</span> <span class="hlt">emission</span> images data are available from an all sky <span class="hlt">airglow</span> camera in Hainan Fuke (19.5°N, 109.2°E) supported by China Meridional Project, which can receive the 630.0nm <span class="hlt">emission</span> from the ionosphere F region at low-latitudes to observe plasma bubbles. A series of pretreatment technology, e.g. image enhancement, orientation correction, image projection are utilized to preprocess the raw observation. Then the regions of plasma bubble extracted from the images are divided into several small tracing windows and each tracing window can find a target window in the searching area in following image, which is considered as the position tracing window moved to. According to this, velocities in each window are calculated by using the technology of cloud-derived wind. When applying the cloud-derived wind technology, the maximum correlation coefficient (MCC) and the histogram of gradient (HOG) methods to find the target window, which mean to find the maximum correlation and the minimum euclidean distance between two gradient histograms in respectively, are investigated and compared in detail. The maximum correlation method is fianlly adopted in this study to analyze the velocity of plasma bubbles because of its better performance than HOG. All-sky images from Hainan Fuke, between August 2014 and October 2014, are analyzed to investigate the plasma bubble drift velocities using MCC method. The data at different local time at 9 nights are studied and find that zonal drift velocity in different latitude at different local time ranges from 50 m/s to 180 m/s and there is a peak value at</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19930017664','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19930017664"><span>Infrared coronal <span class="hlt">emission</span> <span class="hlt">lines</span> and the possibility of their maser <span class="hlt">emission</span> in Seyfert nuclei</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Greenhouse, Matthew A.; Feldman, Uri; Smith, Howard A.; Klapisch, Marcel; Bhatia, Anand K.; Bar-Shalom, Abi</p> <p>1993-01-01</p> <p>Energetic emitting regions have traditionally been studied via x-ray, UV and optical <span class="hlt">emission</span> <span class="hlt">lines</span> of highly ionized intermediate mass elements. Such <span class="hlt">lines</span> are often referred to as 'coronal <span class="hlt">lines</span>' since the ions, when produced by collisional ionization, reach maximum abundance at electron temperatures of approx. 10(exp 5) - 10(exp 6) K typical of the sun's upper atmosphere. However, optical and UV coronal <span class="hlt">lines</span> are also observed in a wide variety of Galactic and extragalactic sources including the Galactic interstellar medium, nova shells, supernova remnants, galaxies and QSOs. Infrared coronal <span class="hlt">lines</span> are providing a new window for observation of energetic emitting regions in heavily dust obscured sources such as infrared bright merging galaxies and Seyfert nuclei and new opportunities for model constraints on physical conditions in these sources. Unlike their UV and optical counterparts, infrared coronal <span class="hlt">lines</span> can be primary coolants of collisionally ionized plasmas with 10(exp 4) less than T(sub e)(K) less than 10(exp 6) which produce little or no optical or shorter wavelength coronal <span class="hlt">line</span> <span class="hlt">emission</span>. In addition, they provide a means to probe heavily dust obscured emitting regions which are often inaccessible to optical or UV <span class="hlt">line</span> studies. In this poster, we provide results from new model calculations to support upcoming Infrared Space Observatory (ISO) and current ground-based observing programs involving infrared coronal <span class="hlt">emission</span> <span class="hlt">lines</span> in AGN. We present a complete list of infrared (lambda greater than 1 micron) <span class="hlt">lines</span> due to transitions within the ground configurations 2s(2)2p(k) and 3s(2)3p(k) (k = 1 to 5) or the first excited configurations 2s2p and 3s3p of highly ionized (x greater than or equal to 100 eV) astrophysically abundant (n(X)/n(H) greater than or equal to 10(exp -6)) elements. Included are approximately 74 <span class="hlt">lines</span> in ions of O, Ne, Na, Mg, Al, Si, S, Ar, Ca, Fe, and Ni spanning a wavelength range of approximately 1 - 280 microns. We present new</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015IAUGA..2246421I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015IAUGA..2246421I"><span>Prediction of <span class="hlt">emission</span> <span class="hlt">line</span> fluxes of gravitationally lensed very high-z galaxies</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Inoue, Akio; Shimizu, Ikkoh; Okamoto, Takashi; Yoshida, Naoki; Matsuo, Hiroshi; Tamura, Yoichi</p> <p>2015-08-01</p> <p>Spectroscopic confirmation of very high-z galaxy candidates is extremely valuable because this is a direct proof of the existence of galaxies in the early Universe and put a strong constraint on the structure formation theory to produce such galaxies during the limited age of the Universe. Before the completion of the cosmic reionization, hydrogen Ly-alpha <span class="hlt">emission</span> <span class="hlt">line</span> is hard to be observed and we need other <span class="hlt">emission</span> <span class="hlt">lines</span> to confirm the redshift of galaxies. By using a state-of-the-art cosmological hydrodynamics simulation of galaxy formation and evolution with an <span class="hlt">emission</span> <span class="hlt">line</span> model based on Cloudy, we predict the <span class="hlt">line</span> fluxes of some gravitationally-lensed very high-z galaxy candidates. We also discuss their detectability with the current and future telescopes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AAS...22420405N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AAS...22420405N"><span>A Link Between X-ray <span class="hlt">Emission</span> <span class="hlt">Lines</span> and Radio Jets in 4U 1630-47?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Neilsen, Joseph; Coriat, Mickaël; Fender, Rob; Lee, Julia C.; Ponti, Gabriele; Tzioumis, A.; Edwards, Phillip; Broderick, Jess</p> <p>2014-06-01</p> <p>Recently, Díaz Trigo et al. reported an XMM-Newton detection of relativistically Doppler-shifted <span class="hlt">emission</span> <span class="hlt">lines</span> associated with steep-spectrum radio <span class="hlt">emission</span> in the stellar-mass black hole candidate 4U 1630-47 during its 2012 outburst. They interpreted these <span class="hlt">lines</span> as indicative of a baryonic jet launched by the accretion disk. We present a search for the same <span class="hlt">lines</span> earlier in the same outburst using high-resolution X-ray spectra from the Chandra HETGS. While our observations (eight months prior to the XMM-Newton campaign) also coincide with detections of steep spectrum radio <span class="hlt">emission</span> by the Australia Telescope Compact Array, we find a strong disk wind but no evidence for any relativistic X-ray <span class="hlt">emission</span> <span class="hlt">lines</span>. Indeed, despite ˜5× brighter radio <span class="hlt">emission</span>, our Chandra spectra allow us to place an upper limit on the flux in the blueshifted Fe XXVI <span class="hlt">line</span> that is ˜20× weaker than the <span class="hlt">line</span> observed by Díaz Trigo et al. Thus we can conclusively say that radio <span class="hlt">emission</span> is not universally associated with relativistically Doppler-shifted <span class="hlt">emission</span> <span class="hlt">lines</span> in 4U 1630-47. We explore several scenarios that could explain our differing results, including variations in the geometry of the jet or a mass-loading process or jet baryon content that evolves with the accretion state of the black hole. We also consider the possibility that the radio <span class="hlt">emission</span> arises in an interaction between a jet and the nearby ISM, in which case the X-ray <span class="hlt">emission</span> <span class="hlt">lines</span> might be unrelated to the radio <span class="hlt">emission</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014JGRD..119.9707M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014JGRD..119.9707M"><span>New statistical analysis of the horizontal phase velocity distribution of gravity waves observed by <span class="hlt">airglow</span> imaging</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Matsuda, Takashi S.; Nakamura, Takuji; Ejiri, Mitsumu K.; Tsutsumi, Masaki; Shiokawa, Kazuo</p> <p>2014-08-01</p> <p>We have developed a new analysis method for obtaining the power spectrum in the horizontal phase velocity domain from <span class="hlt">airglow</span> intensity image data to study atmospheric gravity waves. This method can deal with extensive amounts of imaging data obtained on different years and at various observation sites without bias caused by different event extraction criteria for the person processing the data. The new method was applied to sodium <span class="hlt">airglow</span> data obtained in 2011 at Syowa Station (69°S, 40°E), Antarctica. The results were compared with those obtained from a conventional event analysis in which the phase fronts were traced manually in order to estimate horizontal characteristics, such as wavelengths, phase velocities, and wave periods. The horizontal phase velocity of each wave event in the <span class="hlt">airglow</span> images corresponded closely to a peak in the spectrum. The statistical results of spectral analysis showed an eastward offset of the horizontal phase velocity distribution. This could be interpreted as the existence of wave sources around the stratospheric eastward jet. Similar zonal anisotropy was also seen in the horizontal phase velocity distribution of the gravity waves by the event analysis. Both methods produce similar statistical results about directionality of atmospheric gravity waves. Galactic contamination of the spectrum was examined by calculating the apparent velocity of the stars and found to be limited for phase speeds lower than 30 m/s. In conclusion, our new method is suitable for deriving the horizontal phase velocity characteristics of atmospheric gravity waves from an extensive amount of imaging data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19770026443','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19770026443"><span>Electromagnetic plasma wave <span class="hlt">emissions</span> from the auroral field <span class="hlt">lines</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gurnett, D. A.</p> <p>1977-01-01</p> <p>The most important types of auroral radio <span class="hlt">emissions</span> are reviewed, both from a historical perspective as well as considering the latest results. Particular emphasis is placed on four types of electromagnetic <span class="hlt">emissions</span> which are directly associated with the plasma on the auroral field <span class="hlt">lines</span>. These <span class="hlt">emissions</span> are (1) auroral hiss, (2) saucers, (3) ELF noise bands, and (4) auroral kilometric radiation. Ray tracing and radio direction finding measurements indicate that both the auroral hiss and auroral kilometric radiation are generated along the auroral field <span class="hlt">lines</span> relatively close to the earth, at radial distances from about 2.5 to 5 R sub e. For the auroral hiss the favored mechanism appears to be amplified Cerenkov radiation. For the auroral kilometric radiation several mechanisms have been proposed, usually involving the intermediate generation of electrostatic waves by the precipitating electrons.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20000082009&hterms=solar+energy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dsolar%2Benergy','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20000082009&hterms=solar+energy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dsolar%2Benergy"><span>Solar Energy Deposition Rates in the Mesosphere Derived from <span class="hlt">Airglow</span> Measurements: Implications for the Ozone Model Deficit Problem</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Mlynczak, Martin G.; Garcia, Rolando R.; Roble, Raymond G.; Hagan, Maura</p> <p>2000-01-01</p> <p>We derive rates of energy deposition in the mesosphere due to the absorption of solar ultraviolet radiation by ozone. The rates are derived directly from measurements of the 1.27-microns oxygen dayglow <span class="hlt">emission</span>, independent of knowledge of the ozone abundance, the ozone absorption cross sections, and the ultraviolet solar irradiance in the ozone Hartley band. Fifty-six months of <span class="hlt">airglow</span> data taken between 1982 and 1986 by the near-infrared spectrometer on the Solar-Mesosphere Explorer satellite are analyzed. The energy deposition rates exhibit altitude-dependent annual and semi-annual variations. We also find a positive correlation between temperatures and energy deposition rates near 90 km at low latitudes. This correlation is largely due to the semiannual oscillation in temperature and ozone and is consistent with model calculations. There is also a suggestion of possible tidal enhancement of this correlation based on recent theoretical and observational analyses. The <span class="hlt">airglow</span>-derived rates of energy deposition are then compared with those computed by multidimensional numerical models. The observed and modeled deposition rates typically agree to within 20%. This agreement in energy deposition rates implies the same agreement exists between measured and modeled ozone volume mixing ratios in the mesosphere. Only in the upper mesosphere at midlatitudes during winter do we derive energy deposition rates (and hence ozone mixing ratios) consistently and significantly larger than the model calculations. This result is contrary to previous studies that have shown a large model deficit in the ozone abundance throughout the mesosphere. The climatology of solar energy deposition and heating presented in this paper is available to the community at the Middle Atmosphere Energy Budget Project web site at http://heat-budget.gats-inc.com.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMSA33A2573T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMSA33A2573T"><span>Statistical analysis of 16-year phase velocity distribution of mesospheric and ionospheric waves in <span class="hlt">airglow</span> images: Comparison between Rikubetsu and Shigaraki, Japan</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tsuchiya, S.; Shiokawa, K.; Fujinami, H.; Otsuka, Y.; Nakamura, T.; Yamamoto, M.</p> <p>2017-12-01</p> <p>A new spectral analysis technique has been developed to obtain power spectra in the horizontal phase velocity by using the 3-D Fast Fourier Transform [Matsuda et al., JGR, 2014]. Takeo et al. (JGR, 2017) studied spectral parameters of atmospheric gravity waves (AGWs) in the mesopause region and medium-scale traveling ionospheric disturbances (MSTIDs) in the thermosphere over 16 years by using <span class="hlt">airglow</span> images at wavelengths of 557.7 nm (<span class="hlt">emission</span> altitudes: 90-100 km) and 630.0 nm (200-300 km) obtained at Shigaraki (34.8N, 136.1E), Japan. In this study, we have applied the same spectral analysis technique to the 557.7 nm and 630.0-nm <span class="hlt">airglow</span> images obtained at Rikubetsu (43.5N, 143.8E), Japan, for 16 years from 1999 to 2014. We compared spectral features of AGWs and MSTIDs over 16 years observed at Shigaraki and Rikubetsu, which are separated by 1,174 km. The propagation direction of mesospheric AGWs seen in 557.7-nm <span class="hlt">airglow</span> images is northeastward in summer and southwestward in winter at both Shigaraki and Rikubetsu, probably due to wind filtering of these waves by the mesospheric jet. In winter, the propagation direction of AGWs gradually shifted from southwestward to northwestward as time progresses from evening to morning at both stations. We suggest that this local-time shift of propagation direction can also be explained by the wind filtering effect. The propagation direction of AGWs changed from southwestward to northeastward at Rikubetsu on the day of the reversal of eastward zonal wind at 60N and 10 hPa (about 35 km in altitude) by the stratospheric sudden warming (SSW), while such a SSW-associated change was not identified at Shigaraki, indicating that the effect of SSW wind reversal reached only to the Rikubetsu latitudes. For MSTIDs, there is a negative correlation between yearly variation of powers spectral density and F10.7 flux and propagation direction is southwestward in all season at both Shigaraki and Rikubetsu. This negative correlation can be</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19940014952','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19940014952"><span>Spectrophotometry of <span class="hlt">emission-line</span> stars in the magellanic clouds</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Bohannan, Bruce</p> <p>1990-01-01</p> <p>The strong <span class="hlt">emission</span> <span class="hlt">lines</span> in the most luminous stars in the Magellanic Clouds indicate that these stars have such strong stellar winds that their photospheres are so masked that optical absorption <span class="hlt">lines</span> do not provide an accurate measure of photospheric conditions. In the research funded by this grant, temperatures and gravities of <span class="hlt">emission-line</span> stars both in the Large (LMC) and Small Magellanic Clouds (SMC) have been measured by fitting of continuum ultraviolet-optical fluxes observed with IUE with theoretical model atmospheres. Preliminary results from this work formed a major part of an invited review 'The Distribution of Types of Luminous Blue Variables'. Interpretation of the IUE observations obtained in this grant and archive data were also included in a talk at the First Boulder-Munich Hot Stars Workshop. Final results of these studies are now being completed for publication in refereed journals.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014ApJ...784L...5N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014ApJ...784L...5N"><span>A Link between X-Ray <span class="hlt">Emission</span> <span class="hlt">Lines</span> and Radio Jets in 4U 1630-47?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Neilsen, Joseph; Coriat, Mickaël; Fender, Rob; Lee, Julia C.; Ponti, Gabriele; Tzioumis, Anastasios K.; Edwards, Philip G.; Broderick, Jess W.</p> <p>2014-03-01</p> <p>Recently, Díaz Trigo et al. reported an XMM-Newton detection of relativistically Doppler-shifted <span class="hlt">emission</span> <span class="hlt">lines</span> associated with steep-spectrum radio <span class="hlt">emission</span> in the stellar-mass black hole candidate 4U 1630-47 during its 2012 outburst. They interpreted these <span class="hlt">lines</span> as indicative of a baryonic jet launched by the accretion disk. Here we present a search for the same <span class="hlt">lines</span> earlier in the same outburst using high-resolution X-ray spectra from the Chandra HETGS. While our observations (eight months prior to the XMM-Newton campaign) also coincide with detections of steep spectrum radio <span class="hlt">emission</span> by the Australia Telescope Compact Array, we find no evidence for any relativistic X-ray <span class="hlt">emission</span> <span class="hlt">lines</span>. Indeed, despite ~5 × brighter radio <span class="hlt">emission</span>, our Chandra spectra allow us to place an upper limit on the flux in the blueshifted Fe XXVI <span class="hlt">line</span> that is >~ 20 × weaker than the <span class="hlt">line</span> observed by Díaz Trigo et al. We explore several scenarios that could explain our differing results, including variations in the geometry of the jet or a mass-loading process or jet baryon content that evolves with the accretion state of the black hole. We also consider the possibility that the radio <span class="hlt">emission</span> arises in an interaction between a jet and the nearby interstellar medium, in which case the X-ray <span class="hlt">emission</span> <span class="hlt">lines</span> might be unrelated to the radio <span class="hlt">emission</span>.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li class="active"><span>10</span></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_10 --> <div id="page_11" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li class="active"><span>11</span></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="201"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017MNRAS.465.1144U','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017MNRAS.465.1144U"><span>Inferring physical properties of galaxies from their <span class="hlt">emission-line</span> spectra</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ucci, G.; Ferrara, A.; Gallerani, S.; Pallottini, A.</p> <p>2017-02-01</p> <p>We present a new approach based on Supervised Machine Learning algorithms to infer key physical properties of galaxies (density, metallicity, column density and ionization parameter) from their <span class="hlt">emission-line</span> spectra. We introduce a numerical code (called GAME, GAlaxy Machine learning for <span class="hlt">Emission</span> <span class="hlt">lines</span>) implementing this method and test it extensively. GAME delivers excellent predictive performances, especially for estimates of metallicity and column densities. We compare GAME with the most widely used diagnostics (e.g. R23, [N II] λ6584/Hα indicators) showing that it provides much better accuracy and wider applicability range. GAME is particularly suitable for use in combination with Integral Field Unit spectroscopy, both for rest-frame optical/UV nebular <span class="hlt">lines</span> and far-infrared/sub-millimeter <span class="hlt">lines</span> arising from photodissociation regions. Finally, GAME can also be applied to the analysis of synthetic galaxy maps built from numerical simulations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ApJ...830...50M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ApJ...830...50M"><span>The Nature of Active Galactic Nuclei with Velocity Offset <span class="hlt">Emission</span> <span class="hlt">Lines</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Müller-Sánchez, F.; Comerford, J.; Stern, D.; Harrison, F. A.</p> <p>2016-10-01</p> <p>We obtained Keck/OSIRIS near-IR adaptive optics-assisted integral-field spectroscopy to probe the morphology and kinematics of the ionized gas in four velocity-offset active galactic nuclei (AGNs) from the Sloan Digital Sky Survey. These objects possess optical <span class="hlt">emission</span> <span class="hlt">lines</span> that are offset in velocity from systemic as measured from stellar absorption features. At a resolution of ˜0.″18, OSIRIS allows us to distinguish which velocity offset <span class="hlt">emission</span> <span class="hlt">lines</span> are produced by the motion of an AGN in a dual supermassive black hole system, and which are produced by outflows or other kinematic structures. In three galaxies, J1018+2941, J1055+1520, and J1346+5228, the spectral offset of the <span class="hlt">emission</span> <span class="hlt">lines</span> is caused by AGN-driven outflows. In the remaining galaxy, J1117+6140, a counterrotating nuclear disk is observed that contains the peak of Paα <span class="hlt">emission</span> 0.″2 from the center of the galaxy. The most plausible explanation for the origin of this spatially and kinematically offset peak is that it is a region of enhanced Paα <span class="hlt">emission</span> located at the intersection zone between the nuclear disk and the bar of the galaxy. In all four objects, the peak of ionized gas <span class="hlt">emission</span> is not spatially coincident with the center of the galaxy as traced by the peak of the near-IR continuum <span class="hlt">emission</span>. The peaks of ionized gas <span class="hlt">emission</span> are spatially offset from the galaxy centers by 0.″1-0.″4 (0.1-0.7 kpc). We find that the velocity offset originates at the location of this peak of <span class="hlt">emission</span>, and the value of the offset can be directly measured in the velocity maps. The <span class="hlt">emission-line</span> ratios of these four velocity-offset AGNs can be reproduced only with a mixture of shocks and AGN photoionization. Shocks provide a natural explanation for the origin of the spatially and spectrally offset peaks of ionized gas <span class="hlt">emission</span> in these galaxies. Based on observations at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22034590-ray-emission-line-profiles-from-wind-clump-bow-shocks-massive-stars','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22034590-ray-emission-line-profiles-from-wind-clump-bow-shocks-massive-stars"><span>X-RAY <span class="hlt">EMISSION</span> <span class="hlt">LINE</span> PROFILES FROM WIND CLUMP BOW SHOCKS IN MASSIVE STARS</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Ignace, R.; Waldron, W. L.; Cassinelli, J. P.</p> <p>2012-05-01</p> <p>The consequences of structured flows continue to be a pressing topic in relating spectral data to physical processes occurring in massive star winds. In a preceding paper, our group reported on hydrodynamic simulations of hypersonic flow past a rigid spherical clump to explore the structure of bow shocks that can form around wind clumps. Here we report on profiles of <span class="hlt">emission</span> <span class="hlt">lines</span> that arise from such bow shock morphologies. To compute <span class="hlt">emission</span> <span class="hlt">line</span> profiles, we adopt a two-component flow structure of wind and clumps using two 'beta' velocity laws. While individual bow shocks tend to generate double-horned <span class="hlt">emission</span> <span class="hlt">line</span> profiles,more » a group of bow shocks can lead to <span class="hlt">line</span> profiles with a range of shapes with blueshifted peak <span class="hlt">emission</span> that depends on the degree of X-ray photoabsorption by the interclump wind medium, the number of clump structures in the flow, and the radial distribution of the clumps. Using the two beta law prescription, the theoretical <span class="hlt">emission</span> measure and temperature distribution throughout the wind can be derived. The <span class="hlt">emission</span> measure tends to be power law, and the temperature distribution is broad in terms of wind velocity. Although restricted to the case of adiabatic cooling, our models highlight the influence of bow shock effects for hot plasma temperature and <span class="hlt">emission</span> measure distributions in stellar winds and their impact on X-ray <span class="hlt">line</span> profile shapes. Previous models have focused on geometrical considerations of the clumps and their distribution in the wind. Our results represent the first time that the temperature distribution of wind clump structures are explicitly and self-consistently accounted for in modeling X-ray <span class="hlt">line</span> profile shapes for massive stars.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018AAS...23232203B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018AAS...23232203B"><span>Investigating the Fraction of Radio-Loud Quasars with High Velocity Broad <span class="hlt">Emission</span> <span class="hlt">LInes</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bhattacharjee, Anirban; Gilbert, Miranda; Brotherton, Michael S.</p> <p>2018-06-01</p> <p>Quasars show a bimodal distribution in their radio <span class="hlt">emission</span>, with some having powerful radio-emitting jets (radio-loud), and most having weak or no jets (radio-quiet). Surveys have shown around 10% of of quasars have detectable radio <span class="hlt">emissions</span>. These quasars are called radio-loud. Several multiwavelength studies have shown that radio-loud quasars have different properties than radio-quiet quasars. This fraction of radio-loud quasars to radio-quiet quasars has been assumed to be constant across all parameter space. In this study, we breakdown the parameter space with respect to the increasing velocity dispersion of broad <span class="hlt">emission</span> <span class="hlt">lines</span>. Our sample has been drawn from 2011 Shen et al. catalog of more than 100,000 quasars. In this study, we demonstrate that this fraction varies with respect to the increasing velocity dispersion (FWHM) of broad <span class="hlt">emission</span> <span class="hlt">lines</span>. We compare three different <span class="hlt">emission</span> <span class="hlt">lines</span>: H-Beta, MgII, and CIV. We observe with increasing FWHM of these three <span class="hlt">emission</span> <span class="hlt">lines</span>, fraction of radio-loud quasars within the subset increases. This poster presents our initial results into investigating whether the fraction of RL quasars remains 10% in different parameter space.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017ApJ...843..130L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017ApJ...843..130L"><span>Bayesian Redshift Classification of <span class="hlt">Emission-line</span> Galaxies with Photometric Equivalent Widths</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Leung, Andrew S.; Acquaviva, Viviana; Gawiser, Eric; Ciardullo, Robin; Komatsu, Eiichiro; Malz, A. I.; Zeimann, Gregory R.; Bridge, Joanna S.; Drory, Niv; Feldmeier, John J.; Finkelstein, Steven L.; Gebhardt, Karl; Gronwall, Caryl; Hagen, Alex; Hill, Gary J.; Schneider, Donald P.</p> <p>2017-07-01</p> <p>We present a Bayesian approach to the redshift classification of <span class="hlt">emission-line</span> galaxies when only a single <span class="hlt">emission</span> <span class="hlt">line</span> is detected spectroscopically. We consider the case of surveys for high-redshift Lyα-emitting galaxies (LAEs), which have traditionally been classified via an inferred rest-frame equivalent width (EW {W}{Lyα }) greater than 20 Å. Our Bayesian method relies on known prior probabilities in measured <span class="hlt">emission-line</span> luminosity functions and EW distributions for the galaxy populations, and returns the probability that an object in question is an LAE given the characteristics observed. This approach will be directly relevant for the Hobby-Eberly Telescope Dark Energy Experiment (HETDEX), which seeks to classify ˜106 <span class="hlt">emission-line</span> galaxies into LAEs and low-redshift [{{O}} {{II}}] emitters. For a simulated HETDEX catalog with realistic measurement noise, our Bayesian method recovers 86% of LAEs missed by the traditional {W}{Lyα } > 20 Å cutoff over 2 < z < 3, outperforming the EW cut in both contamination and incompleteness. This is due to the method’s ability to trade off between the two types of binary classification error by adjusting the stringency of the probability requirement for classifying an observed object as an LAE. In our simulations of HETDEX, this method reduces the uncertainty in cosmological distance measurements by 14% with respect to the EW cut, equivalent to recovering 29% more cosmological information. Rather than using binary object labels, this method enables the use of classification probabilities in large-scale structure analyses. It can be applied to narrowband <span class="hlt">emission-line</span> surveys as well as upcoming large spectroscopic surveys including Euclid and WFIRST.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016cosp...41E2022V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016cosp...41E2022V"><span>First retrievals of MLT sodium profiles based on satellite sodium nightglow observations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Von Savigny, Christian; Zilker, Bianca; Langowski, Martin</p> <p>2016-07-01</p> <p>The Na D <span class="hlt">lines</span> are a well known feature of the terrestrial <span class="hlt">airglow</span> and have been identified for the first time in 1929. During the daytime the Na <span class="hlt">airglow</span> <span class="hlt">emission</span> is caused by resonance fluorescence, while during the night the excitation occurs by chemiluminescent reactions. Knowledge of Na in the mesopause region is of interest, because the Na layer is thought to be maintained by meteoric ablation and Na measurements allow constraining the meteoric mass influx into the Earth system. In this contribution we employ SCIAMACHY/Envisat nighttime limb measurements of the Na D-<span class="hlt">line</span> <span class="hlt">airglow</span> from fall 2002 to spring 2012 - in combination with photochemical models - in order to retrieve Na concentration profiles in the 75 - 100 km altitude range. The Na profiles show realistic peak altitudes, number densities and seasonal variations. The retrieval scheme, sample results and comparisons to ground-based LIDAR measurements of Na as well as SCIAMACHY daytime retrievals will be presented. Moreover, uncertainties in the assumed photochemical scheme and their impact on the Na retrievals will be discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19800060823&hterms=carbon+emissions&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dcarbon%2Bemissions','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19800060823&hterms=carbon+emissions&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dcarbon%2Bemissions"><span>An optical <span class="hlt">emission-line</span> phase of the extreme carbon star IRC +30219</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Cohen, M.</p> <p>1980-01-01</p> <p>Optical spectroscopic monitoring of the extreme carbon star IRC +30219 has revealed striking changes between 1977 and 1980. The stellar photosphere was barely visible in early 1979. There was an <span class="hlt">emission</span> <span class="hlt">line</span> spectrum consisting of H, forbidden O I, forbidden O II, forbidden N I, forbidden N II, forbidden S II, and He I. It is likely that these <span class="hlt">lines</span> arose in a shocked region where recent stellar mass loss encountered the extensive circumstellar envelope. By late 1979, this <span class="hlt">emission-line</span> spectrum had vanished, and the photosphere had reappeared. The weakening of the photospheric features in early 1979 was caused by increased attenuation of starlight and overlying thermal <span class="hlt">emission</span>, both due to recently condensed hot dust grains.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMSA34A..07K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMSA34A..07K"><span>Effect of equatorial electrodynamics on low-latitude thermosphere as inferred from neutral optical dayglow <span class="hlt">emission</span> observations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Karan, D. K.; Duggirala, P. R.</p> <p>2017-12-01</p> <p>The diurnal variations in daytime <span class="hlt">airglow</span> <span class="hlt">emission</span> intensity measurements at three wavelengths OI 777.4 nm, OI 630.0 nm, and OI 557.7 nm made from a low-latitude location, Hyderabad (Geographic 17.50 N, 78.40 E; 8.90 N Mag. Lat) in India have been investigated. The intensity patterns showed both symmetric and asymmetric behavior in their respective diurnal <span class="hlt">emission</span> variability with respect to local noon. The asymmetric diurnal behavior is not expected considering the photochemical nature of the production mechanisms. The reason for this observed asymmetric diurnal behavior has been found to be predominantly the temporal variation in the equatorial electrodynamics. The plasma that is transported across latitudes due to the action of varying electric field strength over the magnetic equator in the daytime contributes to the asymmetric diurnal behavior in the neutral daytime <span class="hlt">airglow</span> <span class="hlt">emissions</span>. Independent magnetic and radio measurements support this finding. It is also noted that this asymmetric diurnal behavior in the neutral <span class="hlt">emission</span> intensities has a solar cycle dependence with more number of days during high solar activity period showing asymmetric diurnal behavior compared to those during low-solar activity epoch. These intensity variations over long time scale demonstrate that the daytime neutral optical <span class="hlt">emissions</span> are extremely sensitive to the changes in the eastward electric field over low- and equatorial-latitudes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013HEAD...1312204L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013HEAD...1312204L"><span>Extreme Ultraviolet <span class="hlt">Emission</span> <span class="hlt">Lines</span> of Iron Fe XI-XIII</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lepson, Jaan; Beiersdorfer, P.; Brown, G. V.; Liedahl, D. A.; Brickhouse, N. S.; Dupree, A. K.</p> <p>2013-04-01</p> <p>The extreme ultraviolet (EUV) spectral region (ca. 20--300 Å) is rich in <span class="hlt">emission</span> <span class="hlt">lines</span> from low- to mid-Z ions, particularly from the middle charge states of iron. Many of these <span class="hlt">emission</span> <span class="hlt">lines</span> are important diagnostics for astrophysical plasmas, providing information on properties such as elemental abundance, temperature, density, and even magnetic field strength. In recent years, strides have been made to understand the complexity of the atomic levels of the ions that emit the <span class="hlt">lines</span> that contribute to the richness of the EUV region. Laboratory measurements have been made to verify and benchmark the <span class="hlt">lines</span>. Here, we present laboratory measurements of Fe XI, Fe XII, and Fe XIII between 40-140 Å. The measurements were made at the Lawrence Livermore electron beam ion trap (EBIT) facility, which has been optimized for laboratory astrophysics, and which allows us to select specific charge states of iron to help <span class="hlt">line</span> identification. We also present new calculations by the Hebrew University - Lawrence Livermore Atomic Code (HULLAC), which we also utilized for <span class="hlt">line</span> identification. We found that HULLAC does a creditable job of reproducing the forest of <span class="hlt">lines</span> we observed in the EBIT spectra, although <span class="hlt">line</span> positions are in need of adjustment, and <span class="hlt">line</span> intensities often differed from those observed. We identify or confirm a number of new <span class="hlt">lines</span> for these charge states. This work was supported by the NASA Solar and Heliospheric Program under Contract NNH10AN31I and the DOE General Plasma Science program. Work was performed in part under the auspices of the Department of Energy by Lawrence Livermore National Laboratory under Contract DEAC52-07NA27344.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JGRA..123.3078W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JGRA..123.3078W"><span>Evidence for Radiative Recombination of O+ Ions as a Significant Source of O 844.6 nm <span class="hlt">Emission</span> Excitation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Waldrop, L.; Kerr, R. B.; Huang, Y.</p> <p>2018-04-01</p> <p>Photoelectron (PE) impact on ground-state O(3P) atoms is well known as a major source of twilight 844.6 nm <span class="hlt">emission</span> in the midlatitude thermosphere. Knowledge of the PE flux can be used to infer thermospheric oxygen density, [O], from photometric measurements of 844.6 nm <span class="hlt">airglow</span>, provided that PE impact is the dominant process generating the observed <span class="hlt">emission</span>. During several spring observational campaigns at Arecibo Observatory, however, we have observed significant 844.6 nm <span class="hlt">emission</span> throughout the night, which is unlikely to arise from PE impact excitation which requires solar illumination of either the local or geomagnetically conjugate thermosphere. Here we show that radiative recombination (RR) of O+ ions is likely responsible for the observed nighttime <span class="hlt">emission</span>, based on model predictions of electron and O+ ion density and temperature by the Incoherent Scatter Radar Ionosphere Model. The calculated <span class="hlt">emission</span> brightness produced by O + RR exhibits good agreement with the <span class="hlt">airglow</span> data, in that both decay approximately monotonically throughout the night at similar rates. We conclude that the conventional assumption of a pure PE impact source is most likely to be invalid during dusk twilight, when RR-generated <span class="hlt">emission</span> is most significant. Estimation of [O] from measurements of 844.6 nm <span class="hlt">emission</span> demands isolation of the PE impact source via coincident estimation of the RR source, and the effective cross section for RR-generated <span class="hlt">emission</span> is found here to be consistent with optically thin conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018AAS...23231707H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018AAS...23231707H"><span>Classification of Hot Stars by Disk Variability using Hα <span class="hlt">Line</span> <span class="hlt">Emission</span> Characteristics</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hoyt Hannah, Christian; Glennon Fagan, W.; Tycner, Christopher</p> <p>2018-06-01</p> <p>The variability associated with circumstellar disks around hot and massive stars has been observed on time scales ranging from less than a day to decades. Variations detected in <span class="hlt">line</span> <span class="hlt">emission</span> from circumstellar disks on long time scales are typically attributed to disk-growth and disk-loss events. However, in order to fully describe and model such phenomena, adequate spectroscopic observations over long time scales are needed. In this project, we conduct a comprehensive study that is based on spectra recorded over a 14-year period (2005 to 2018) of roughly 100 B-type stars. Using results from a representative sample of over 20 targets, we illustrate how the Hα <span class="hlt">emission</span> <span class="hlt">line</span>, one of the most prominent <span class="hlt">emission</span> features from circumstellar disks, can be used to monitor the variability associated with these systems. Using high-resolution spectra, we utilize <span class="hlt">line</span> <span class="hlt">emission</span> characteristics such as equivalent width, peak strength(s), and <span class="hlt">line</span>-width to setup a classification scheme that describes different types of variabilities. This in turn can be used to divide the systems in disk-growth, disk-loss, variable and stable categories. With additional numerical disk modeling, the recorded variations based on <span class="hlt">emission</span> <span class="hlt">line</span> characteristics can also be used to describe changes in disk temperature and density structure. The aim is to develop a tool to help further our understanding of the processes behind the production and eventual dissipation of the circumstellar disks found in hot stars. This work has been supported by NSF grant AST-1614983.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20000086188&hterms=imprint&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dimprint','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20000086188&hterms=imprint&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dimprint"><span>The Wardle Instability in Interstellar Shocks. 2; Gas Temperture and <span class="hlt">Line</span> <span class="hlt">Emission</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Neufeld, David A.; Stone, James M.</p> <p>1997-01-01</p> <p>We have modeled the gas temperature structure in unstable C-type shocks and obtained predictions for the resultant CO and H2 rotational <span class="hlt">line</span> <span class="hlt">emissions</span>, using numerical simulations of the Wardle instability. Our model for the thermal balance of the gas includes ion-neutral frictional heating; compressional heating; radiative cooling due to rotational and ro-vibrational transitions of the molecules CO, H2O, and H2; and gas-grain collisional cooling. We obtained results for the gas temperature distribution in-and H2 and CO <span class="hlt">line</span> <span class="hlt">emission</span> from-shocks of neutral Alfvenic Mach number 10 and velocity 20 or 40 km/ s in which the Wardle instability has saturated. Both two- and three-dimensional simulations were carried out for shocks in which the preshock magnetic field is perpendicular to the shock propagation direction, and a two-dimensional simulation was carried out for the case in which the magnetic field is obliquely oriented with respect to the shock propagation direction. Although the Wardle instability profoundly affects the density structure behind C-type shocks, most of the shock-excited molecular <span class="hlt">line</span> <span class="hlt">emission</span> is generated upstream of the region where the strongest effects of the instability are felt. Thus the Wardle instability has a relatively small effect on the overall gas temperature distribution in-and the <span class="hlt">emission-line</span> spectrum from-C-type shocks, at least for the cases that we have considered. In none of the cases that we have considered thus far did any of the predicted <span class="hlt">emission-line</span> luminosities change by more than a factor of 2.5, and in most cases the effects of instability were significantly smaller than that. Slightly larger changes in the <span class="hlt">line</span> luminosities seem likely for three-dimensional simulations of oblique shocks, although such simulations have yet to be carried out and lie beyond the scope of this study. Given the typical uncertainties that are always present when model predictions are compared with real astronomical data, we conclude that</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017hst..prop15077J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017hst..prop15077J"><span>Accurate <span class="hlt">Emission</span> <span class="hlt">Line</span> Diagnostics at High Redshift</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jones, Tucker</p> <p>2017-08-01</p> <p>How do the physical conditions of high redshift galaxies differ from those seen locally? Spectroscopic surveys have invested hundreds of nights of 8- and 10-meter telescope time as well as hundreds of Hubble orbits to study evolution in the galaxy population at redshifts z 0.5-4 using rest-frame optical strong <span class="hlt">emission</span> <span class="hlt">line</span> diagnostics. These surveys reveal evolution in the gas excitation with redshift but the physical cause is not yet understood. Consequently there are large systematic errors in derived quantities such as metallicity.We have used direct measurements of gas density, temperature, and metallicity in a unique sample at z=0.8 to determine reliable diagnostics for high redshift galaxies. Our measurements suggest that offsets in <span class="hlt">emission</span> <span class="hlt">line</span> ratios at high redshift are primarily caused by high N/O abundance ratios. However, our ground-based data cannot rule out other interpretations. Spatially resolved Hubble grism spectra are needed to distinguish between the remaining plausible causes such as active nuclei, shocks, diffuse ionized gas <span class="hlt">emission</span>, and HII regions with escaping ionizing flux. Identifying the physical origin of evolving excitation will allow us to build the necessary foundation for accurate measurements of metallicity and other properties of high redshift galaxies. Only then can we expoit the wealth of data from current surveys and near-future JWST spectroscopy to understand how galaxies evolve over time.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1912782S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1912782S"><span>High resolution observations of small-scale gravity waves and turbulence features in the OH <span class="hlt">airglow</span> layer</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sedlak, René; Hannawald, Patrick; Schmidt, Carsten; Wüst, Sabine; Bittner, Michael</p> <p>2017-04-01</p> <p>A new version of the Fast <span class="hlt">Airglow</span> Imager (FAIM) for the detection of atmospheric waves in the OH <span class="hlt">airglow</span> layer has been set up at the German Remote Sensing Data Centre (DFD) of the German Aerospace Centre (DLR) at Oberpfaffenhofen (48.09 ° N, 11.28 ° E), Germany. The spatial resolution of the instrument is 17 m/pixel in zenith direction with a field of view (FOV) of 11.1 km x 9.0 km at the OH layer height of ca. 87 km. Since November 2015, the system has been in operation in two different setups (zenith angles 46 ° and 0 °) with a temporal resolution of 2.5 to 2.8 s. In a first case study we present observations of two small wave-like features that might be attributed to gravity wave instabilities. In order to spectrally analyse harmonic structures even on small spatial scales down to 550 m horizontal wavelength, we made use of the Maximum Entropy Method (MEM) since this method exhibits an excellent wavelength resolution. MEM further allows analysing relatively short data series, which considerably helps to reduce problems such as stationarity of the underlying data series from a statistical point of view. We present an observation of the subsequent decay of well-organized wave fronts into eddies, which we tentatively interpret in terms of an indication for the onset of turbulence. Another remarkable event which demonstrates the technical capabilities of the instrument was observed during the night of 4th to 5th April 2016. It reveals the disintegration of a rather homogenous brightness variation into several filaments moving in different directions and with different speeds. It resembles the formation of a vortex with a horizontal axis of rotation likely related to a vertical wind shear. This case shows a notable similarity to what is expected from theoretical modelling of Kelvin-Helmholtz instabilities (KHIs). The comparatively high spatial resolution of the presented new version of the FAIM <span class="hlt">airglow</span> imager provides new insights into the structure of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014MNRAS.439.1051L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014MNRAS.439.1051L"><span>Constraints on the outer radius of the broad <span class="hlt">emission</span> <span class="hlt">line</span> region of active galactic nuclei</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Landt, Hermine; Ward, Martin J.; Elvis, Martin; Karovska, Margarita</p> <p>2014-03-01</p> <p>Here we present observational evidence that the broad <span class="hlt">emission</span> <span class="hlt">line</span> region (BELR) of active galactic nuclei (AGN) generally has an outer boundary. This was already clear for sources with an obvious transition between the broad and narrow components of their <span class="hlt">emission</span> <span class="hlt">lines</span>. We show that the narrow component of the higher-order Paschen <span class="hlt">lines</span> is absent in all sources, revealing a broad <span class="hlt">emission</span> <span class="hlt">line</span> profile with a broad, flat top. This indicates that the BELR is kinematically separate from the narrow <span class="hlt">emission</span> <span class="hlt">line</span> region. We use the virial theorem to estimate the BELR outer radius from the flat top width of the unblended profiles of the strongest Paschen <span class="hlt">lines</span>, Paα and Paβ, and find that it scales with the ionizing continuum luminosity roughly as expected from photoionization theory. The value of the incident continuum photon flux resulting from this relationship corresponds to that required for dust sublimation. A flat-topped broad <span class="hlt">emission</span> <span class="hlt">line</span> profile is produced by both a spherical gas distribution in orbital motion and an accretion disc wind if the ratio between the BELR outer and inner radius is assumed to be less than ˜100-200. On the other hand, a pure Keplerian disc can be largely excluded, since for most orientations and radial extents of the disc the <span class="hlt">emission</span> <span class="hlt">line</span> profile is double-horned.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1326854-dark-matter-line-emission-constraints-from-nustar-observations-bullet-cluster','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1326854-dark-matter-line-emission-constraints-from-nustar-observations-bullet-cluster"><span>Dark matter <span class="hlt">line</span> <span class="hlt">emission</span> constraints from NuSTAR observations of the bullet cluster</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Riemer-Sørensen, S.; Wik, D.; Madejski, G.; ...</p> <p>2015-08-27</p> <p>Some dark matter candidates, e.g., sterile neutrinos, provide observable signatures in the form of mono-energetic <span class="hlt">line</span> <span class="hlt">emission</span>. Here, we present the first search for dark matter <span class="hlt">line</span> <span class="hlt">emission</span> in themore » $$3-80\\;\\mathrm{keV}$$ range in a pointed observation of the Bullet Cluster with NuSTAR. We do not detect any significant <span class="hlt">line</span> <span class="hlt">emission</span> and instead we derive upper limits (95% CL) on the flux, and interpret these constraints in the context of sterile neutrinos and more generic dark matter candidates. NuSTAR does not have the sensitivity to constrain the recently claimed <span class="hlt">line</span> detection at $$3.5\\;\\mathrm{keV}$$, but improves on the constraints for energies of $$10-25\\;\\mathrm{keV}$$.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19850048727&hterms=transfer+slab&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dtransfer%2Bslab','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19850048727&hterms=transfer+slab&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dtransfer%2Bslab"><span>Theoretical quasar <span class="hlt">emission-line</span> ratios. VII - Energy-balance models for finite hydrogen slabs</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hubbard, E. N.; Puetter, R. C.</p> <p>1985-01-01</p> <p>The present energy balance calculations for finite, isobaric, hydrogen-slab quasar <span class="hlt">emission</span> <span class="hlt">line</span> clouds incorporate probabilistic radiative transfer (RT) in all <span class="hlt">lines</span> and bound-free continua of a five-level continuum model hydrogen atom. Attention is given to the <span class="hlt">line</span> ratios, <span class="hlt">line</span> formation regions, level populations and model applicability results obtained. H <span class="hlt">lines</span> and a variety of other considerations suggest the possibility of <span class="hlt">emission</span> <span class="hlt">line</span> cloud densities in excess of 10 to the 10th/cu cm. Lyman-beta/Lyman-alpha <span class="hlt">line</span> ratios that are in agreement with observed values are obtained by the models. The observed Lyman/Balmer ratios can be achieved with clouds whose column depths are about 10 to the 22nd/sq cm.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JPhCS.846a2020I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JPhCS.846a2020I"><span>Study on <span class="hlt">Emission</span> Spectral <span class="hlt">Lines</span> of Iron, Fe in Laser-Induced Breakdown Spectroscopy (LIBS) on Soil Samples</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Idris, Nasrullah; Lahna, Kurnia; Fadhli; Ramli, Muliadi</p> <p>2017-05-01</p> <p>In this work, LIBS technique has been used for detection of heavy metal especially iron, Fe in soil sample. As there are a large number of <span class="hlt">emission</span> spectral <span class="hlt">lines</span> due to Fe and other constituents in soil, this study is intended to identify <span class="hlt">emission</span> spectral <span class="hlt">lines</span> of Fe and finally to find best fit <span class="hlt">emission</span> spectral <span class="hlt">lines</span> for carrying out a qualitative and quantitative analysis. LIBS apparatus used in this work consists of a laser system (Neodymium Yttrium Aluminum Garnet, Nd-YAG: Quanta Ray; LAB SERIES; 1,064 nm; 500 mJ; 8 ns) and an optical multichannel analyzer (OMA) system consisting of a spectrograph (McPherson model 2061; 1,000 mm focal length; f/8.6 Czerny- Turner) and an intensified charge coupled device (ICCD) 1024x256 pixels (Andor I*Star). The soil sample was collected from Banda Aceh city, Aceh, Indonesia. For spectral data acquisition, the soil sample has been prepared by a pressing machine in the form of pellet. The laser beam was focused using a high density lens (f=+150 mm) and irradiated on the surface of the pellet for generating luminous plasma under 1 atmosphere of air surrounding. The plasma <span class="hlt">emission</span> was collected by an optical fiber and then sent to the optical multichannel analyzer (OMA) system for acquisition of the <span class="hlt">emission</span> spectra. It was found that there are many Fe <span class="hlt">emission</span> <span class="hlt">lines</span> both atomic <span class="hlt">lines</span> (Fe I) and ionic <span class="hlt">lines</span> (Fe II) appeared in all detection windows in the wavelength regions, ranging from 200 nm to 1000 nm. The <span class="hlt">emission</span> <span class="hlt">lines</span> of Fe with strong intensities occurs together with <span class="hlt">emission</span> <span class="hlt">lines</span> due to other atoms such as Mg, Ca, and Si. Thus, the identification of <span class="hlt">emission</span> <span class="hlt">lines</span> from Fe is complicated by presence of many other <span class="hlt">lines</span> due to other major and minor elements in soil. Considering the features of the detected <span class="hlt">emission</span> <span class="hlt">lines</span>, several <span class="hlt">emission</span> spectral <span class="hlt">lines</span> of Fe I (atomic <span class="hlt">emission</span> <span class="hlt">line</span>), especially Fe I 404.58 nm occurring at visible range are potential to be good candidate of analytical <span class="hlt">lines</span> in relation to detection</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22667454-emission-signatures-from-sub-parsec-binary-supermassive-black-holes-diagnostic-power-broad-emission-lines','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22667454-emission-signatures-from-sub-parsec-binary-supermassive-black-holes-diagnostic-power-broad-emission-lines"><span><span class="hlt">EMISSION</span> SIGNATURES FROM SUB-PARSEC BINARY SUPERMASSIVE BLACK HOLES. I. DIAGNOSTIC POWER OF BROAD <span class="hlt">EMISSION</span> <span class="hlt">LINES</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Nguyen, Khai; Bogdanović, Tamara</p> <p></p> <p>Motivated by advances in observational searches for sub-parsec supermassive black hole binaries (SBHBs) made in the past few years, we develop a semi-analytic model to describe spectral <span class="hlt">emission-line</span> signatures of these systems. The goal of this study is to aid the interpretation of spectroscopic searches for binaries and to help test one of the leading models of binary accretion flows in the literature: SBHB in a circumbinary disk. In this work, we present the methodology and a comparison of the preliminary model with the data. We model SBHB accretion flows as a set of three accretion disks: two mini-disks thatmore » are gravitationally bound to the individual black holes and a circumbinary disk. Given a physically motivated parameter space occupied by sub-parsec SBHBs, we calculate a synthetic database of nearly 15 million broad optical <span class="hlt">emission-line</span> profiles and explore the dependence of the profile shapes on characteristic properties of SBHBs. We find that the modeled profiles show distinct statistical properties as a function of the semimajor axis, mass ratio, eccentricity of the binary, and the degree of alignment of the triple disk system. This suggests that the broad <span class="hlt">emission-line</span> profiles from SBHB systems can in principle be used to infer the distribution of these parameters and as such merit further investigation. Calculated profiles are more morphologically heterogeneous than the broad <span class="hlt">emission</span> <span class="hlt">lines</span> in observed SBHB candidates and we discuss improved treatment of radiative transfer effects, which will allow a direct statistical comparison of the two groups.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19780061652&hterms=1082&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3D%2526%25231082','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19780061652&hterms=1082&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3D%2526%25231082"><span>Sodium D-<span class="hlt">line</span> <span class="hlt">emission</span> from Io - Comparison of observed and theoretical <span class="hlt">line</span> profiles</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Carlson, R. W.; Matson, D. L.; Johnson, T. V.; Bergstralh, J. T.</p> <p>1978-01-01</p> <p>High-resolution spectra of the D-<span class="hlt">line</span> profiles have been obtained for Io's sodium <span class="hlt">emission</span> cloud. These <span class="hlt">lines</span>, which are produced through resonance scattering of sunlight, are broad and asymmetric and can be used to infer source and dynamical properties of the sodium cloud. In this paper we compare <span class="hlt">line</span> profile data with theoretical <span class="hlt">line</span> shapes computed for several assumed initial velocity distributions corresponding to various source mechanisms. We also examine the consequences of source distributions which are nonuniform over the surface of Io. It is found that the experimental data are compatible with escape of sodium atoms from the leading hemisphere of Io and with velocity distributions characteristic of sputtering processes. Thermal escape and simple models of plasma sweeping are found to be incompatible with the observations.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li class="active"><span>11</span></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_11 --> <div id="page_12" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="221"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20050040863','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20050040863"><span>The Far-Infrared <span class="hlt">Emission</span> <span class="hlt">Line</span> and Continuum Spectrum of the Seyfert Galaxy NGC 1068</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Spinoglio, Luigi; Smith, Howard A.; Gonzalez-Alfonso, Eduardo; Fisher, Jacqueline</p> <p>2005-01-01</p> <p>We report on the analysis of the first complete far-infrared spectrum (43-197 microns) of the Seyfert 2 galaxy NGC 1068 as observed with the Long Wavelength Spectrometer (LWS) onboard the Infrared Space Observatory (ISO). In addition to the 7 expected ionic fine structure <span class="hlt">emission</span> <span class="hlt">lines</span>, the OH rotational <span class="hlt">lines</span> at 79, 119 and 163 microns were all detected in <span class="hlt">emission</span>, which is unique among galaxies with full LWS spectra, where the 119 micron <span class="hlt">line</span>, where detected, is always in absorption. The observed <span class="hlt">line</span> intensities were modelled together with IS0 Short Wavelength Spectrometer (SWS) and optical and ultraviolet <span class="hlt">line</span> intensities from the literature, considering two independent <span class="hlt">emission</span> components: the AGN component and the starburst component in the circumnuclear ring of approximately 3kpc in size. Using the UV to mid-IR <span class="hlt">emission</span> <span class="hlt">line</span> spectrum to constrain the nuclear ionizing continuum, we have confirmed previous results: a canonical power-law ionizing spectrum is a poorer fit than one with a deep absorption trough, while the presence of a big blue bump is ruled out. Based on the instantaneous starburst age of 5 Myr constrained by the Br gamma equivalent width in the starburst ring, and starburst synthesis models of the mid- and far-infrared fine-structure <span class="hlt">line</span> <span class="hlt">emission</span>, a low ionization parameter (U=10(exp -3.5)) and low densities (n=100 cm (exp -3)) are derived. Combining the AGN and starburst components, we succeed in modeling the overall UV to far-IR atomic spectrum of SGC 1068, reproducing the <span class="hlt">line</span> fluxes to within a factor 2.0 on average with a standard deviation of 1.4. The OH 119 micron <span class="hlt">emission</span> indicates that the <span class="hlt">line</span> is collisionally excited, and arises in a warm and dense region. The OH <span class="hlt">emission</span> has been modeled using spherically symmetric, non-local, non-LTE radiative transfer models. The models indicate that the bulk of the <span class="hlt">emission</span> arises from the nuclear region, although some extended contribution from the starburst is not ruled out. The OH abundance</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19950029592&hterms=twilight&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dtwilight','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19950029592&hterms=twilight&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dtwilight"><span>Simultaneous retrieval of the solar EUV flux and neutral thermospheric O, O2, N2, and temperature from twilight <span class="hlt">airglow</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Fennelly, J. A.; Torr, D. G.; Richards, P. G.; Torr, M. R.</p> <p>1994-01-01</p> <p>We present a method to retrieve neutral thermospheric composition and the solar EUV flux from ground-based twilight optical measurements of the O(+) ((exp 2)P) 7320 A and O((exp 1)D) 6300 A <span class="hlt">airglow</span> <span class="hlt">emissions</span>. The parameters retrieved are the neutral temperature, the O, O2, N2 density profiles, and a scaling factor for the solar EUV flux spectrum. The temperature, solar EUV flux scaling factor, and atomic oxygen density are first retrieved from the 7320-A <span class="hlt">emission</span>, which are then used with the 6300-A <span class="hlt">emission</span> to retrieve the O2 and N2 densities. The retrieval techniques have been verified by computer simulations. We have shown that the retrieval technique is able to statistically retrieve values, between 200 and 400 km, within an average error of 3.1 + or - 0.6% for thermospheric temperature, 3.3 + or - 2.0% for atomic oxygen, 2.3 + or - 1.3% for molecular oxygen, and 2.4 + or - 1.3% for molecular nitrogen. The solar EUV flux scaling factor was found to have a retrieval error of 5.1 + or - 2.3%. All the above errors have a confidence level of 95%. The purpose of this paper is to prove the viability and usefulness of the retrieval technique by demonstrating the ability to retrieve known quantities under a realistic simulation of the measurement process, excluding systematic effects.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1369231-sdss-iv-eboss-emission-line-galaxy-pilot-survey','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1369231-sdss-iv-eboss-emission-line-galaxy-pilot-survey"><span>SDSS-IV eBOSS <span class="hlt">emission-line</span> galaxy pilot survey</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Comparat, J.; Delubac, T.; Jouvel, S.; ...</p> <p>2016-08-09</p> <p>The Sloan Digital Sky Survey IV extended Baryonic Oscillation Spectroscopic Survey (SDSS-IV/eBOSS) will observe 195,000 <span class="hlt">emission-line</span> galaxies (ELGs) to measure the Baryonic Acoustic Oscillation standard ruler (BAO) at redshift 0.9. To test different ELG selection algorithms, 9,000 spectra were observed with the SDSS spectrograph as a pilot survey based on data from several imaging surveys. First, using visual inspection and redshift quality flags, we show that the automated spectroscopic redshifts assigned by the pipeline meet the quality requirements for a reliable BAO measurement. We also show the correlations between sky <span class="hlt">emission</span>, signal-to-noise ratio in the <span class="hlt">emission</span> <span class="hlt">lines</span>, and redshift error.more » Then we provide a detailed description of each target selection algorithm we tested and compare them with the requirements of the eBOSS experiment. As a result, we provide reliable redshift distributions for the different target selection schemes we tested. Lastly, we determine an target selection algorithms that is best suited to be applied on DECam photometry because they fulfill the eBOSS survey efficiency requirements.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/15327709','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/15327709"><span>Measurement of X-ray <span class="hlt">emission</span> efficiency for K-<span class="hlt">lines</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Procop, M</p> <p>2004-08-01</p> <p>Results for the X-ray <span class="hlt">emission</span> efficiency (counts per C per sr) of K-<span class="hlt">lines</span> for selected elements (C, Al, Si, Ti, Cu, Ge) and for the first time also for compounds and alloys (SiC, GaP, AlCu, TiAlC) are presented. An energy dispersive X-ray spectrometer (EDS) of known detection efficiency (counts per photon) has been used to record the spectra at a takeoff angle of 25 degrees determined by the geometry of the secondary electron microscope's specimen chamber. Overall uncertainty in measurement could be reduced to 5 to 10% in dependence on the <span class="hlt">line</span> intensity and energy. Measured <span class="hlt">emission</span> efficiencies have been compared with calculated efficiencies based on models applied in standardless analysis. The widespread XPP and PROZA models give somewhat too low <span class="hlt">emission</span> efficiencies. The best agreement between measured and calculated efficiencies could be achieved by replacing in the modular PROZA96 model the original expression for the ionization cross section by the formula given by Casnati et al. (1982) A discrepancy remains for carbon, probably due to the high overvoltage ratio.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014MNRAS.439..771B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014MNRAS.439..771B"><span>The metallicities of the broad <span class="hlt">emission</span> <span class="hlt">line</span> regions in the nitrogen-loudest quasars</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Batra, Neelam Dhanda; Baldwin, Jack A.</p> <p>2014-03-01</p> <p>We measured the metallicity Z in the broad <span class="hlt">emission-line</span> regions (BELRs) of 43 Sloan Digital Sky Survey (SDSS) quasars with the strongest N IV] and N III] <span class="hlt">emission</span> <span class="hlt">lines</span>. These N-loud quasi-stellar objects (QSOs) have unusually low-black-hole masses. We used the intensity ratio of N <span class="hlt">lines</span> to collisionally excited <span class="hlt">emission</span> <span class="hlt">lines</span> of other heavy elements to find metallicities in their BELR regions. We found that seven of the eight <span class="hlt">line</span>-intensity ratios that we employed give roughly consistent metallicities as measured, but that for each individual QSO their differences from the mean of all metallicity measurements depend on the ionization potential of the ions that form the <span class="hlt">emission</span> <span class="hlt">lines</span>. After correcting for this effect, the different <span class="hlt">line</span>-intensity ratios give metallicities that generally agree to within the 0.24 dex uncertainty in the measurements of the <span class="hlt">line</span>-intensity ratios. The metallicities are very high, with mean log Z for the whole sample of 5.5 Z⊙ and a maximum of 18 Z⊙. Our results argue against the possibility that the strong N <span class="hlt">lines</span> represent an overabundance only of N but not of all heavy elements. They are compatible with either that (1) the BELR gas has been chemically enriched by the general stellar population in the central bulge of the host galaxy, but the locally optimally emitting cloud model used in the analysis needs some fine tuning or (2) that instead this gas has been enriched by intense star formation on the very local scale of the active nucleus that has resulted in an abundance gradient within the BELR.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22597079-design-portable-optical-emission-tomography-system-microwave-induced-compact-plasma-visible-near-infrared-emission-lines','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22597079-design-portable-optical-emission-tomography-system-microwave-induced-compact-plasma-visible-near-infrared-emission-lines"><span>Design of a portable optical <span class="hlt">emission</span> tomography system for microwave induced compact plasma for visible to near-infrared <span class="hlt">emission</span> <span class="hlt">lines</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Rathore, Kavita, E-mail: kavira@iitk.ac.in, E-mail: pmunshi@iitk.ac.in, E-mail: sudeepb@iitk.ac.in; Munshi, Prabhat, E-mail: kavira@iitk.ac.in, E-mail: pmunshi@iitk.ac.in, E-mail: sudeepb@iitk.ac.in; Bhattacharjee, Sudeep, E-mail: kavira@iitk.ac.in, E-mail: pmunshi@iitk.ac.in, E-mail: sudeepb@iitk.ac.in</p> <p></p> <p>A new non-invasive diagnostic system is developed for Microwave Induced Plasma (MIP) to reconstruct tomographic images of a 2D <span class="hlt">emission</span> profile. A compact MIP system has wide application in industry as well as research application such as thrusters for space propulsion, high current ion beams, and creation of negative ions for heating of fusion plasma. <span class="hlt">Emission</span> profile depends on two crucial parameters, namely, the electron temperature and density (over the entire spatial extent) of the plasma system. <span class="hlt">Emission</span> tomography provides basic understanding of plasmas and it is very useful to monitor internal structure of plasma phenomena without disturbing its actualmore » processes. This paper presents development of a compact, modular, and versatile Optical <span class="hlt">Emission</span> Tomography (OET) tool for a cylindrical, magnetically confined MIP system. It has eight slit-hole cameras and each consisting of a complementary metal–oxide–semiconductor linear image sensor for light detection. The optical noise is reduced by using aspheric lens and interference band-pass filters in each camera. The entire cylindrical plasma can be scanned with automated sliding ring mechanism arranged in fan-beam data collection geometry. The design of the camera includes a unique possibility to incorporate different filters to get the particular wavelength light from the plasma. This OET system includes selected band-pass filters for particular argon <span class="hlt">emission</span> 750 nm, 772 nm, and 811 nm <span class="hlt">lines</span> and hydrogen <span class="hlt">emission</span> H{sub α} (656 nm) and H{sub β} (486 nm) <span class="hlt">lines</span>. Convolution back projection algorithm is used to obtain the tomographic images of plasma <span class="hlt">emission</span> <span class="hlt">line</span>. The paper mainly focuses on (a) design of OET system in detail and (b) study of <span class="hlt">emission</span> profile for 750 nm argon <span class="hlt">emission</span> <span class="hlt">lines</span> to validate the system design.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19870060961&hterms=Evidence+atomic+theory&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DEvidence%2Batomic%2Btheory','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19870060961&hterms=Evidence+atomic+theory&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DEvidence%2Batomic%2Btheory"><span>Hydrogen Balmer alpha intensity distributions and <span class="hlt">line</span> profiles from multiple scattering theory using realistic geocoronal models</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Anderson, D. E., Jr.; Meier, R. R.; Hodges, R. R., Jr.; Tinsley, B. A.</p> <p>1987-01-01</p> <p>The H Balmer alpha nightglow is investigated by using Monte Carlo models of asymmetric geocoronal atomic hydrogen distributions as input to a radiative transfer model of solar Lyman-beta radiation in the thermosphere and atmosphere. It is shown that it is essential to include multiple scattering of Lyman-beta radiation in the interpretation of Balmer alpha <span class="hlt">airglow</span> data. Observations of diurnal variation in the Balmer alpha <span class="hlt">airglow</span> showing slightly greater intensities in the morning relative to evening are consistent with theory. No evidence is found for anything other than a single sinusoidal diurnal variation of exobase density. Dramatic changes in effective temperature derived from the observed Balmer alpha <span class="hlt">line</span> profiles are expected on the basis of changing illumination conditions in the thermosphere and exosphere as different regions of the sky are scanned.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1992ApJ...399..563B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1992ApJ...399..563B"><span>Mid-infrared rotational <span class="hlt">line</span> <span class="hlt">emission</span> from interstellar molecular hydrogen</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Burton, Michael G.; Hollenbach, D. J.; Tielens, A. G. G.</p> <p>1992-11-01</p> <p>The <span class="hlt">line</span> <span class="hlt">emission</span> from the v = 0-0 S(0), S(2), and S(3), and the v = 1-0 and v = 2-1 S(1) transitions of molecular hydrogen in clouds exposed to high FUV fluxes and in shocks is modeled. Particular attention is given to the lowest pure rotational H2 transitions at 20 and 17 microns, respectively. It is found that, in photodissociation regions (PDRs), the <span class="hlt">emission</span> comes from warm (greater than about 100 k) molecular gas, situated at optical depths greater than about 1, beyond the hot atomic surface layer of the clouds. For FUV fields, G0 = 1000 to 100,000 times the average interstellar field densities n = 10 exp 3 - 10 exp 7/cu cm, the typical <span class="hlt">line</span> intensities are in the range 10 exp -6 to 10 exp -4 ergs/s sq cm sr. The predictions for the <span class="hlt">line</span> intensities from both C-type and J-type shock models are compared. The results are applied to recent observations of the 0-0 S(1) transition in both the PDR and the shocked gas in Orion.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AAS...22920303B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AAS...22920303B"><span>Excitation Mechanisms of Near-Infrared <span class="hlt">Emission</span> <span class="hlt">Lines</span> in LINER Galaxies</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Boehle, Anna</p> <p>2017-01-01</p> <p>I will present high spatial resolution, integral field spectroscopic observations of the nearby LINER (low ionization nuclear <span class="hlt">emission</span> <span class="hlt">line</span> region) galaxy NGC 404. LINERs are found at the centers of ~1/3 of galaxies within 40 Mpc, but their physical nature is not well understood. Although NGC 404 is thought to host a intermediate mass black hole at its center, it is unclear whether accretion onto the black hole or another mechanism such as shock excitation drives its LINER <span class="hlt">emission</span>. We use the OSIRIS near-infrared integral field spectrograph at Keck Observatory behind laser guide star adaptive optics to map the strength and kinematics of [FeII], H2, and hydrogen recombination <span class="hlt">lines</span> in the nucleus of NGC 404. These observations have a spatial pixel sampling of 0.5 pc and span the central 30 pc of the galaxy. We find that the ionized and molecular gas show differences in their morphology and kinematics on parsec scales. In particular, there are regions with <span class="hlt">line</span> ratios of [FeII]/Pa-β that are much higher than previously seen in spatially integrated spectra, significantly restricting the possible excitation mechanisms of the near-infrared <span class="hlt">emission</span> <span class="hlt">lines</span> in this source. We are also applying these analysis techniques to 10 additional nearby LINERs, a part of a larger sample of 14 sources, to understand what drives the <span class="hlt">emission</span> <span class="hlt">lines</span> in these active galaxies. As a part of this program, I worked on the upgrade of the detector in the OSIRIS spectrograph, which has allowed observations for this survey obtained since January 2016 to be taken with increased instrument sensitivity of a factor of ~2 at J-band wavelengths (1.2 - 1.4 microns) and ~1.6 at H- and K-band wavelengths (1.5 - 2.4 microns). I will present results from the LINER survey, the OSIRIS detector upgrade, and also touch on related work using stellar orbits around the Milky Way supermassive black hole Sgr A* to constrain the mass and distance to our own Galactic Center.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19920030078&hterms=magnetic+cooling&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dmagnetic%2Bcooling','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19920030078&hterms=magnetic+cooling&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dmagnetic%2Bcooling"><span>A photoionization model for the optical <span class="hlt">line</span> <span class="hlt">emission</span> from cooling flows</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Donahue, Megan; Voit, G. M.</p> <p>1991-01-01</p> <p>The detailed predictions of a photoionization model previously outlined in Voit and Donahue (1990) to explain the optical <span class="hlt">line</span> <span class="hlt">emission</span> associated with cooling flows in X-ray emitting clusters of galaxies are presented. In this model, EUV/soft X-ray radiation from condensing gas photoionizes clouds that have already cooled. The energetics and specific consequences of such a model, as compared to other models put forth in the literature is discussed. Also discussed are the consequences of magnetic fields and cloud-cloud shielding. The results illustrate how varying the individual column densities of the ionized clouds can reproduce the range of <span class="hlt">line</span> ratios observed and strongly suggest that the <span class="hlt">emission-line</span> nebulae are self-irradiated condensing regions at the centers of cooling flows.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22518802-detection-intermediate-width-emission-line-region-quasar-oi-broad-emission-line-region-obscured-dusty-torus','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22518802-detection-intermediate-width-emission-line-region-quasar-oi-broad-emission-line-region-obscured-dusty-torus"><span>DETECTION OF THE INTERMEDIATE-WIDTH <span class="hlt">EMISSION</span> <span class="hlt">LINE</span> REGION IN QUASAR OI 287 WITH THE BROAD <span class="hlt">EMISSION</span> <span class="hlt">LINE</span> REGION OBSCURED BY THE DUSTY TORUS</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Li, Zhenzhen; Zhou, Hongyan; Wang, Huiyuan</p> <p>2015-10-20</p> <p>The existence of intermediate-width <span class="hlt">emission</span> <span class="hlt">line</span> regions (IELRs) in active galactic nuclei has been discussed for over two decades. A consensus, however, is yet to be arrived at due to the lack of convincing evidence for their detection. We present a detailed analysis of the broadband spectrophotometry of the partially obscured quasar OI 287. The ultraviolet intermediate-width <span class="hlt">emission</span> <span class="hlt">lines</span> (IELs) are very prominent, in high contrast to the corresponding broad <span class="hlt">emission</span> <span class="hlt">lines</span> (BELs) which are heavily suppressed by dust reddening. Assuming that the IELR is virialized, we estimated its distance to the central black hole to be ∼2.9 pc, similarmore » to the dust sublimation radius of ∼1.3 pc. Photo-ionization calculations suggest that the IELR has a hydrogen density of ∼10{sup 8.8}–10{sup 9.4} cm{sup −3}, within the range of values quoted for the dusty torus near the sublimation radius. Both its inferred location and physical conditions suggest that the IELR originates from the inner surface of the dusty torus. In the spectrum of this quasar, we identified only one narrow absorption-<span class="hlt">line</span> system associated with the dusty material. With the aid of photo-ionization model calculations, we found that the obscuring material might originate from an outer region of the dusty torus. We speculate that the dusty torus, which is exposed to the central ionizing source, may produce IELs through photo-ionization processes, as well as obscure BELs as a natural “coronagraph.” Such a “coronagraph” could be found in a large number of partially obscured quasars and may be a useful tool to study IELRs.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20119327','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20119327"><span>Tilting-filter measurements in dayglow rocket photometry.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Schaeffer, R C; Fastie, W G</p> <p>1972-10-01</p> <p>A rocket-borne photometer containing two tilting-filter channels for the measurement of the [OI] lambdalambda6300-A and 5577A <span class="hlt">emission</span> <span class="hlt">lines</span> in the day <span class="hlt">airglow</span> is described. The results of one flight substantiate the employment of tilting filters to determine accurate corrections for background continuum and provide reliable height profiles of <span class="hlt">emission</span> intensity down to approximately 90 km. Discussions on the calibration of the instrument and its baffling against sunlight are also presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014cosp...40E3297T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014cosp...40E3297T"><span>Capability of simultaneous Rayleigh LiDAR and O2 <span class="hlt">airglow</span> measurements in exploring the short period wave characteristics</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Taori, Alok; Raghunath, Karnam; Jayaraman, Achuthan</p> <p></p> <p>We use combination of simultaneous measurements made with Rayleigh lidar and O2 <span class="hlt">airglow</span> monitoring to improve lidar investigation capability to cover a higher altitude range. We feed instantaneous O2 <span class="hlt">airglow</span> temperatures instead the model values at the top altitude for subsequent integration method of temperature retrieval using Rayleigh lidar back scattered signals. Using this method, errors in the lidar temperature estimates converges at higher altitudes indicating better altitude coverage compared to regular methods where model temperatures are used instead of real-time measurements. This improvement enables the measurements of short period waves at upper mesospheric altitudes (~90 km). With two case studies, we show that above 60 km the few short period wave amplitude drastically increases while, some of the short period wave show either damping or saturation. We claim that by using such combined measurements, a significant and cost effective progress can be made in the understanding of short period wave processes which are important for the coupling across the different atmospheric regions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19950041628&hterms=conocimiento&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dconocimiento','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19950041628&hterms=conocimiento&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dconocimiento"><span>Survey of <span class="hlt">emission-line</span> galaxies: Universidad Complutense de Madrid list</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Zamorano, J.; Rego, Gallego, J.; Gallego, J. G.; Vitores, A. G.RA, R.; Gonzalez-Riestra, R..; Rodriguez-Caderot, G.</p> <p>1994-01-01</p> <p>A low-dispersion objective-prism survey for low-redshift <span class="hlt">emission-line</span> galaxies (ELGs) is being carried out by the University Complutense de Madrid with the Schmidt telescope at the German-Spanish Observatory of Calar Alto (Almeria, Spain). A 4 deg full aperture prism, which provides a dispersion of 1950 A/mm, and IIIaF emulsion combination has been used to search for ELGs selected by the presence of H-alpha <span class="hlt">emission</span> in their spectra. Our survey has proved to be able to recover objects already found by similar surveys with different techniques and, what is more important, to discover new objects not previously cataloged. A compilation of descriptions and positions, along with finding charts when necessary, is presented for 160 extragalactic <span class="hlt">emission-line</span> objects. This is the first list, which contains objects located in a region of the sky covering 270 sq deg in 10 fields near alpha = 0(sup h) and delta = 20 deg.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19980006526','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19980006526"><span>Mid Infrared Hydrogen Recombination <span class="hlt">Line</span> <span class="hlt">Emission</span> from the Maser Star MWC 349A</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Smith, Howard A.; Strelnitski, V.; Miles, J. W.; Kelly, D. M.; Lacy, J. H.</p> <p>1997-01-01</p> <p>We have detected and spectrally resolved the mid-IR hydrogen recombination <span class="hlt">lines</span> H6(alpha)(12.372 micrometers), H7(alpha)(19.062 micrometers), H7(beta)(l1.309 micrometers) and H8(gamma)(12.385 micrometers) from the star MWC349A. This object has strong hydrogen maser <span class="hlt">emission</span> (reported in the millimeter and submillimeter hydrogen recombination <span class="hlt">lines</span> from H36(alpha) to H21(alpha)) and laser <span class="hlt">emission</span> (reported in the H15(alpha), H12(alpha) and H10(alpha) <span class="hlt">lines</span>). The lasers/masers are thought to arise predominantly in a Keplerian disk around the star. The mid-IR <span class="hlt">lines</span> do not show evident signs of lasing, and can be well modeled as arising from the strong stellar wind, with a component arising from a quasi-static atmosphere around the disk, similar to what is hypothesized for the near IR (less than or equal to 4 micrometers) recombination <span class="hlt">lines</span>. Since populations inversions in the levels producing these mid-IR transitions are expected at densities up to approximately 10(exp 11)/cu cm, these results imply either that the disk does not contain high-density ionized gas over long enough path lengths to produce a gain approximately 1, and/or that any laser <span class="hlt">emission</span> from such regions is small compared to the spontaneous background <span class="hlt">emission</span> from the rest of the source as observed with a large beam. The results reinforce the interpretation of the far-IR <span class="hlt">lines</span> as true lasers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2010-title40-vol12/pdf/CFR-2010-title40-vol12-sec63-1569.pdf','CFR'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2010-title40-vol12/pdf/CFR-2010-title40-vol12-sec63-1569.pdf"><span>40 CFR 63.1569 - What are my requirements for HAP <span class="hlt">emissions</span> from bypass <span class="hlt">lines</span>?</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2010&page.go=Go">Code of Federal Regulations, 2010 CFR</a></p> <p></p> <p>2010-07-01</p> <p>... 40 Protection of Environment 12 2010-07-01 2010-07-01 true What are my requirements for HAP <span class="hlt">emissions</span> from bypass <span class="hlt">lines</span>? 63.1569 Section 63.1569 Protection of Environment ENVIRONMENTAL PROTECTION... HAP <span class="hlt">emissions</span> from bypass <span class="hlt">lines</span>? (a) What work practice standards must I meet? (1) You must meet each...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19790034893&hterms=1085&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3D%2526%25231085','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19790034893&hterms=1085&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3D%2526%25231085"><span>Search with Copernicus for ultraviolet <span class="hlt">emission</span> <span class="hlt">lines</span> in the planetary nebula NGC 3242</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Schwartz, R. D.; Snow, T. P., Jr.; Upson, W. L., II</p> <p>1978-01-01</p> <p>The high-excitation planetary nebula NGC 3242 has been observed with the ultraviolet telescope-spectrometer aboard Copernicus. Wavelength intervals corresponding to the <span class="hlt">emission</span> <span class="hlt">lines</span> of O VI at 1032 A, He II at 1085 A, Si III at 1206 A, and N V at 1239 A have been scanned. Upper limits to the observed fluxes are reported and compared with predicted <span class="hlt">emission-line</span> fluxes from this object.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20100015625','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20100015625"><span>Mid-IR Properties of an Unbiased AGN Sample of the Local Universe. 1; <span class="hlt">Emission-Line</span> Diagnostics</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Weaver, K. A.; Melendez, M.; Muhotzky, R. F.; Kraemer, S.; Engle, K.; Malumuth. E.; Tueller, J.; Markwardt, C.; Berghea, C. T.; Dudik, R. P.; <a style="text-decoration: none; " href="javascript:void(0); " onClick="displayelement('author_20100015625'); toggleEditAbsImage('author_20100015625_show'); toggleEditAbsImage('author_20100015625_hide'); "> <img style="display:inline; width:12px; height:12px; " src="images/arrow-up.gif" width="12" height="12" border="0" alt="hide" id="author_20100015625_show"> <img style="width:12px; height:12px; display:none; " src="images/arrow-down.gif" width="12" height="12" border="0" alt="hide" id="author_20100015625_hide"></p> <p>2010-01-01</p> <p>\\Ve compare mid-IR <span class="hlt">emission-lines</span> properties, from high-resolution Spitzer IRS spectra of a statistically-complete hard X-ray (14-195 keV) selected sample of nearby (z < 0.05) AGN detected by the Burst Alert Telescope (BAT) aboard Swift. The luminosity distribution for the mid-infrared <span class="hlt">emission-lines</span>, [O IV] 25.89 microns, [Ne II] 12.81 microns, [Ne III] 15.56 microns and [Ne V] 14.32 microns, and hard X-ray continuum show no differences between Seyfert 1 and Seyfert 2 populations, although six newly discovered BAT AGNs are shown to be under-luminous in [O IV], most likely the result of dust extinction in the host galaxy. The overall tightness of the mid-infrared correlations and BAT luminosities suggests that the <span class="hlt">emission</span> <span class="hlt">lines</span> primarily arise in gas ionized by the AGN. We also compared the mid-IR <span class="hlt">emission-lines</span> in the BAT AGNs with those from published studies of star-forming galaxies and LINERs. We found that the BAT AGN fall into a distinctive region when comparing the [Ne III]/[Ne II] and the [O IV]/[Ne III] quantities. From this we found that sources that have been previously classified in the mid-infrared/optical as AGN have smaller <span class="hlt">emission</span> <span class="hlt">line</span> ratios than those found for the BAT AGNs, suggesting that, in our X-ray selected sample, the AGN represents the main contribution to the observed <span class="hlt">line</span> <span class="hlt">emission</span>. Overall, we present a different set of <span class="hlt">emission</span> <span class="hlt">line</span> diagnostics to distinguish between AGN and star forming galaxies that can be used as a tool to find new AGN.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22596394-measurement-deuterium-balmer-series-line-emission-east','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22596394-measurement-deuterium-balmer-series-line-emission-east"><span>Measurement of the deuterium Balmer series <span class="hlt">line</span> <span class="hlt">emission</span> on EAST</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Wu, C. R.; Xu, Z.; Jin, Z.</p> <p></p> <p>Volume recombination plays an important role towards plasma detachment for magnetically confined fusion devices. High quantum number states of the Balmer series of deuterium are used to study recombination. On EAST (Experimental Advanced Superconducting Tokamak), two visible spectroscopic measurements are applied for the upper/lower divertor with 13 channels, respectively. Both systems are coupled with Princeton Instruments ProEM EMCCD 1024B camera: one is equipped on an Acton SP2750 spectrometer, which has a high spectral resolution ∼0.0049 nm with 2400 gr/mm grating to measure the D{sub α}(H{sub α}) spectral <span class="hlt">line</span> and with 1200 gr/mm grating to measure deuterium molecular Fulcher band emissionsmore » and another is equipped on IsoPlane SCT320 using 600 gr/mm to measure high-n Balmer series <span class="hlt">emission</span> <span class="hlt">lines</span>, allowing us to study volume recombination on EAST and to obtain the related <span class="hlt">line</span> averaged plasma parameters (T{sub e}, n{sub e}) during EAST detached phases. This paper will present the details of the measurements and the characteristics of deuterium Balmer series <span class="hlt">line</span> <span class="hlt">emissions</span> during density ramp-up L-mode USN plasma on EAST.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19930056188&hterms=effectiveness+surveys&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Deffectiveness%2Bof%2Bsurveys','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19930056188&hterms=effectiveness+surveys&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Deffectiveness%2Bof%2Bsurveys"><span>Twenty-two <span class="hlt">emission-line</span> AGNs from the HEAO-1 X-ray survey</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Remillard, R. A.; Bradt, H. V. D.; Brissenden, R. J. V.; Buckley, D. A. H.; Roberts, W.; Schwartz, D. A.; Stroozas, B. A.; Tuohy, I. R.</p> <p>1993-01-01</p> <p>We report 22 <span class="hlt">emission-line</span> AGN as bright, hard X-ray sources. All of them appear to be new classifications with the exception of one peculiar IRAS source which is a known quasar and has no published spectrum. This sample exhibits a rich diversity in optical spectral properties and luminosities, ranging from a powerful broad-absorption-<span class="hlt">line</span> quasar to a weak nucleus embedded in a nearby NGC galaxy. Two cases confer X-ray luminosities in excess of 10 exp 47 erg/s. However, there is a degree of uncertainty in the X-ray identification for the AGN fainter than V about 16.5. Optically, several AGN exhibit very strong Fe II <span class="hlt">emission</span>. One Seyfert galaxy with substantial radio flux is an exception to the common association of strong Fe II <span class="hlt">emission</span> and radio-quiet AGN. The previously recognized IRAS quasar shows extreme velocities in the profiles of the forbidden <span class="hlt">lines</span>; the 0 III pair is broadened to the point that the <span class="hlt">lines</span> are blended. Several of these AGN show evidence of intrinsic obscuration, illustrating the effectiveness of hard X-ray surveys in locating AGN through high column density.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_12 --> <div id="page_13" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="241"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19930071280&hterms=negev+radiation&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dnegev%2Bradiation','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19930071280&hterms=negev+radiation&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dnegev%2Bradiation"><span>Infrared coronal <span class="hlt">emission</span> <span class="hlt">lines</span> and the possibility of their laser <span class="hlt">emission</span> in Seyfert nuclei</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Greenhouse, Matthew A.; Feldman, Uri; Smith, Howard A.; Klapisch, Marcel; Bhatia, Anand K.; Bar-Shalom, Avi</p> <p>1993-01-01</p> <p>Results are presented from detailed balance calculations, and a compilation of atomic data and other model calculations designed to support upcoming ISO and current observing programs involving IR coronal <span class="hlt">emission</span> <span class="hlt">lines</span>, together with a table with a complete <span class="hlt">line</span> list of infrared transitions within the ground configurations 2s2 2p(k), 3s2 3p(k), and the first excited configurations 2s 2p and 3s 3p of highly ionized astrophysically abundant elements. The temperature and density parameter space for dominant cooling via IR coronal <span class="hlt">lines</span> is presented, and the relationship of IR and optical coronal <span class="hlt">lines</span> is discussed. It is found that, under physical conditions found in Seyfert nuclei, 14 of 70 transitions examined have significant population inversions in levels that give rise to IR coronal <span class="hlt">lines</span>. Several IR coronal <span class="hlt">line</span> transitions were found to have laser gain lengths that correspond to column densities of 10 exp 24-25/sq cm which are modeled to exist in Seyfert nuclei. Observations that can reveal inverted level populations and laser gain in IR coronal <span class="hlt">lines</span> are suggested.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19850012171','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19850012171"><span>Twilight Intensity Variation of the Infrared Hydroxyl <span class="hlt">Airglow</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lowe, R. P.; Gilbert, K. L.; Niciejewski, R. J.</p> <p>1984-01-01</p> <p>The vibration rotation bands of the hydroxyl radical are the strongest features in the night <span class="hlt">airglow</span> and are exceeded in intensity in the dayglow only by the infrared atmospheric bands of oxygen. The variation of intensity during evening twilight is discussed. Using a ground-based Fourier Transform Spectrometer (FTS), hydroxyl intensity measurements as early as 3 deg solar depression were made. Models of the twilight behavior show that this should be sufficient to provide measurement of the main portion of the twilight intensity change. The instrument was equipped with a liquid nitrogen-cooled germanium detector whose high sensitivity combined with the efficiency of the FTS technique permits spectra of the region 1.1 to 1.6 microns at high signal-to-noise to be obtained in two minutes. The use of a polarizer at the entrance aperture of the instrument reduces the intensity of scattered sunlight by a factor of at least ten for zenith observations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19930052412&hterms=centaurus&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dcentaurus','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19930052412&hterms=centaurus&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dcentaurus"><span>The discovery of pulsed iron <span class="hlt">line</span> <span class="hlt">emission</span> from Centaurus X-3</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Day, C. S. R.; Nagase, F.; Asai, K.; Takeshima, T.</p> <p>1993-01-01</p> <p>We present the first discovery of pulsed iron <span class="hlt">line</span> <span class="hlt">emission</span> from an X-ray binary, namely Cen X-3. Compared with the continuum pulsations, the iron <span class="hlt">line</span> pulsations are shallow (50 percent change in amplitude), smeared (the profile is a single-peaked sinusoid) and phase-shifted (by about half a cycle). We also discuss the constraints on the origin of the <span class="hlt">line</span> imposed by this discovery and by other observations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018sptz.prop14049H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018sptz.prop14049H"><span>Nebular <span class="hlt">Line</span> <span class="hlt">Emission</span> and Stellar Mass of Bright z 8 Galaxies "Super-Eights"</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Holwerda, Benne; Bouwens, Rychard; Trenti, Michele; Oesch, Pascal; Labbe, Ivo; Smit, Renske; Roberts-Borsani, Guido; Bernard, Stephanie; Bridge, Joanna</p> <p>2018-05-01</p> <p>Searches for the Lyman-alpha <span class="hlt">emission</span> from the very first galaxies ionizing the Universe have proved to be extremely difficult with limited success beyond z 7 (<3% detections). However, a search of all CANDELS yielded four bright z 8 sources with associated strong Lyman-alpha <span class="hlt">lines</span>, despite the Universe expected to be 70% neutral at this time. The key to their selection is an extremely red IRAC color ([3.6]-[4.5]> 0.5, Roberts-Borsani+ 2016), indicative of very strong nebular <span class="hlt">line</span> <span class="hlt">emission</span>. Do such extreme <span class="hlt">line</span> emitting galaxies produce most of the photons to reionize the Universe? We propose to expand the sample of bright z 8 galaxies with reliable IRAC colors with seven more Y-band dropouts found with HST and confirmed through HST/Spitzer. The Spitzer observations will test how many of bright z 8 galaxies are IRAC-red and measure both their stellar mass and [OIII]+Hbeta <span class="hlt">line</span> strength. Together with Keck/VLT spectroscopy, they will address these questions: I) Do all luminous z 8 galaxies show such red IRAC colors ([OIII] <span class="hlt">emission</span> / hard spectra)? II) Is luminosity or a red IRAC color the dominant predictor for Lyman-alpha <span class="hlt">emission</span>? III) Or are these sources found along exceptionally transparent sightlines into the early Universe? With 11 bright z 8 sources along different <span class="hlt">lines</span>-of-sight, all prime targets for JWST, we will aim to determine which of the considered factors (luminosity, color, sight-<span class="hlt">line</span>) drives the high Lyman-alpha prevalence (100%) and insight into the sources reionizing the Universe.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19910031919&hterms=deming&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Ddeming','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19910031919&hterms=deming&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Ddeming"><span>Observations of the 12.3 micron Mg I <span class="hlt">emission</span> <span class="hlt">line</span> during a major solar flare</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Deming, Drake; Jennings, Donald E.; Osherovich, Vladimir; Wiedemann, Gunter; Hewagama, Tilak</p> <p>1990-01-01</p> <p>The extremely Zeeman-sensitive 12.32 micron Mg I solar <span class="hlt">emission</span> <span class="hlt">line</span> was observed during a 3B/X5.7 solar flare on October 24, 1989. When compared to postflare values, Mg I <span class="hlt">emission-line</span> intensity in the penumbral flare ribbon was 20 percent greater at the peak of the flare in soft X-rays, and the 12 micron continuum intensity was 7 percent greater. The flare also excited the <span class="hlt">emission</span> <span class="hlt">line</span> in the umbra where it is normally absent. The umbral flare <span class="hlt">emission</span> exhibits a Zeeman splitting 200 G less than the adjacent penumbra, suggesting that it is excited at higher altitude. The absolute penumbral magnetic field strength did not change by more than 100 G between the flare peak and postflare period. However, a change in the inclination of the field <span class="hlt">lines</span>, probably related to the formation and development of the flare loop system, was seen.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017RScI...88h3513N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017RScI...88h3513N"><span>Linearized spectrum correlation analysis for <span class="hlt">line</span> <span class="hlt">emission</span> measurements</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nishizawa, T.; Nornberg, M. D.; Den Hartog, D. J.; Sarff, J. S.</p> <p>2017-08-01</p> <p>A new spectral analysis method, Linearized Spectrum Correlation Analysis (LSCA), for charge exchange and passive ion Doppler spectroscopy is introduced to provide a means of measuring fast spectral <span class="hlt">line</span> shape changes associated with ion-scale micro-instabilities. This analysis method is designed to resolve the fluctuations in the <span class="hlt">emission</span> <span class="hlt">line</span> shape from a stationary ion-scale wave. The method linearizes the fluctuations around a time-averaged <span class="hlt">line</span> shape (e.g., Gaussian) and subdivides the spectral output channels into two sets to reduce contributions from uncorrelated fluctuations without averaging over the fast time dynamics. In principle, small fluctuations in the parameters used for a <span class="hlt">line</span> shape model can be measured by evaluating the cross spectrum between different channel groupings to isolate a particular fluctuating quantity. High-frequency ion velocity measurements (100-200 kHz) were made by using this method. We also conducted simulations to compare LSCA with a moment analysis technique under a low photon count condition. Both experimental and synthetic measurements demonstrate the effectiveness of LSCA.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017MNRAS.472.2468H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017MNRAS.472.2468H"><span>Synthetic nebular <span class="hlt">emission</span> from massive galaxies - I: origin of the cosmic evolution of optical <span class="hlt">emission-line</span> ratios</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hirschmann, Michaela; Charlot, Stephane; Feltre, Anna; Naab, Thorsten; Choi, Ena; Ostriker, Jeremiah P.; Somerville, Rachel S.</p> <p>2017-12-01</p> <p>Galaxies occupy different regions of the [O III]λ5007/H β-versus-[N II]λ6584/H α <span class="hlt">emission-line</span> ratio diagram in the distant and local Universe. We investigate the origin of this intriguing result by modelling self-consistently, for the first time, nebular <span class="hlt">emission</span> from young stars, accreting black holes (BHs) and older, post-asymptotic giant branch (post-AGB) stellar populations in galaxy formation simulations in a full cosmological context. In post-processing, we couple new-generation nebular-<span class="hlt">emission</span> models with high-resolution, cosmological zoom-in simulations of massive galaxies to explore which galaxy physical properties drive the redshift evolution of the optical-<span class="hlt">line</span> ratios [O III]λ5007/H β, [N II]λ6584/H α, [S II]λλ6717, 6731/H α and [O I]λ6300/H α. The <span class="hlt">line</span> ratios of simulated galaxies agree well with observations of both star-forming and active local Sloan Digital Sky Survey galaxies. Towards higher redshifts, at fixed galaxy stellar mass, the average [O III]/H β is predicted to increase and [N II]/H α, [S II]/H α and [O I]/H α to decrease - widely consistent with observations. At fixed stellar mass, we identify star formation history, which controls nebular <span class="hlt">emission</span> from young stars via the ionization parameter, as the primary driver of the cosmic evolution of [O III]/H β and [N II]/H α. For [S II]/H α and [O I]/H α, this applies only to redshifts greater than z = 1.5, the evolution at lower redshift being driven in roughly equal parts by nebular <span class="hlt">emission</span> from active galactic nuclei and post-AGB stellar populations. Instead, changes in the hardness of ionizing radiation, ionized-gas density, the prevalence of BH accretion relative to star formation and the dust-to-metal mass ratio (whose impact on the gas-phase N/O ratio we model at fixed O/H) play at most a minor role in the cosmic evolution of simulated galaxy <span class="hlt">line</span> ratios.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015NewA...36...64E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015NewA...36...64E"><span>On the origin of the iron fluorescent <span class="hlt">line</span> <span class="hlt">emission</span> from the Galactic Ridge</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Eze, R. N. C.</p> <p>2015-04-01</p> <p>The Galactic Ridge X-ray <span class="hlt">Emission</span> (GRXE) spectrum has strong iron <span class="hlt">emission</span> <span class="hlt">lines</span> at 6.4, 6.7, and 7.0 keV, each corresponding to the neutral (or low-ionized), He-like, and H-like iron ions. The 6.4 keV fluorescence <span class="hlt">line</span> is due to irradiation of neutral (or low ionized) material (iron) by hard X-ray sources, indicating uniform presence of the cold matter in the Galactic plane. In order to resolve the origin of the cold fluorescent matter, we examined the contribution of the 6.4 keV <span class="hlt">line</span> <span class="hlt">emission</span> from white dwarf surfaces in the hard X-ray emitting symbiotic stars (hSSs) and magnetic cataclysmic variables (mCVs) to the GRXE. In our spectral analysis of 4 hSSs and 19 mCVs observed with Suzaku, we were able to resolve the three iron <span class="hlt">emission</span> <span class="hlt">lines</span>. We found that the equivalent-widths (EWs) of the 6.4 keV <span class="hlt">lines</span> of hSSs are systematically higher than those of mCVs, such that the EWs of the merged hSSs and mCVs are 179-11+46 eV and 93-3+20 eV, respectively. The EW of hSSs compares favorably with the typical EWs of the 6.4 keV <span class="hlt">line</span> in the GRXE of 90-300 eV depending on Galactic positions. Average 6.4 keV <span class="hlt">line</span> luminosities of the hSSs and mCVs are 9.2 ×1039 and 1.6 ×1039 photons s-1, respectively, indicating that hSSs are intrinsically more efficient 6.4 keV <span class="hlt">line</span> emitters than mCVs. We estimated required space densities of hSSs and mCVs to account for all the GRXE 6.4 keV <span class="hlt">line</span> <span class="hlt">emission</span> flux to be 2 ×10-7 pc-3 and 1 ×10-6 pc-3, respectively. We also estimated the actual 6.4 keV <span class="hlt">line</span> contribution from the mCVs with a known space density, which is as much as 20% of the observed GRXE flux, and for the hSSs, for which only five hSSs are known, we noted that they could contribute a significant percentage to the observed GRXE flux since we believe there is still more hSSs yet to be discovered in the Galaxy. We therefore conclude that the GRXE 6.4 keV <span class="hlt">line</span> flux could be significantly explained by hSSs and mCVs 6.4 keV <span class="hlt">line</span> flux.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002PhyS...66..444S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002PhyS...66..444S"><span>Study of Opacity Effects on <span class="hlt">Emission</span> <span class="hlt">Lines</span> at EXTRAP T2R RFP</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Stancalie, Viorica; Rachlew, Elisabeth</p> <p></p> <p>We have investigated the influence of opacity on hydrogen (H-α and Ly-β) and Li-like oxygen <span class="hlt">emission</span> <span class="hlt">lines</span> from the EXTRAP T2R reversed field pinch. We used the Atomic Data Analysis System (AzDAS) based on the escape factor approximation for radiative transfer to calculate metastable and excited population densities via a collisional-radiative model. Population escape factor, emergent escape factor and modified <span class="hlt">line</span> profiles are plotted vs. optical depth. The simulated <span class="hlt">emission</span> <span class="hlt">line</span> ratios in the density/temperature plane are in good agreement with experimental data for electron density and temperature measurements.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/10511501','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/10511501"><span>A Highly Doppler Blueshifted Fe-K <span class="hlt">Emission</span> <span class="hlt">Line</span> in the High-Redshift QSO PKS 2149-306.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Yaqoob; George; Nandra; Turner; Zobair; Serlemitsos</p> <p>1999-11-01</p> <p>We report the results from an ASCA observation of the high-luminosity, radio-loud quasar PKS 2149-306 (redshift 2.345), covering the approximately 1.7-30 keV band in the quasar frame. We find the source to have a luminosity approximately 6x1047 ergs s-1 in the 2-10 keV band (quasar frame). We detect an <span class="hlt">emission</span> <span class="hlt">line</span> centered at approximately 17 keV in the quasar frame. <span class="hlt">Line</span> <span class="hlt">emission</span> at this energy has not been observed in any other active galaxy or quasar to date. We present evidence rejecting the possibility that this <span class="hlt">line</span> is the result of instrumental artifacts or a serendipitous source. The most likely explanation is blueshifted Fe-K <span class="hlt">emission</span> (the equivalent width is EW approximately 300+/-200 eV, quasar frame). Bulk velocities of the order of 0.75c are implied by the data. We show that Fe-K <span class="hlt">line</span> photons originating in an accretion disk and Compton scattering off a leptonic jet aligned along the disk axis can account for the <span class="hlt">emission</span> <span class="hlt">line</span>. Curiously, if the <span class="hlt">emission-line</span> feature recently discovered in another quasar (PKS 0637-752, z=0.654) at 1.6 keV in the quasar frame is due to blueshifted O vii <span class="hlt">emission</span>, the Doppler blueshifting factor in both quasars is similar ( approximately 2.7-2.8).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19940026443','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19940026443"><span>Solar measurements from the <span class="hlt">Airglow</span>-Solar Spectrometer Instrument (ASSI) on the San Marco 5 satellite</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Woods, Thomas N.</p> <p>1994-01-01</p> <p>The analysis of the solar spectral irradiance from the <span class="hlt">Airglow</span>-Solar Spectrometer Instrument (ASSI) on the San Marco 5 satellite is the focus for this research grant. A pre-print copy of the paper describing the calibrations of and results from the San Marco ASSI is attached to this report. The calibration of the ASSI included (1) transfer of photometric calibration from a rocket experiment and the Solar Mesosphere Explorer (SME), (2) use of the on-board radioactive calibration sources, (3) validation of the ASSI sensitivity over its field of view, and (4) determining the degradation of the spectrometers. We have determined that the absolute values for the solar irradiance needs adjustment in the current proxy models of the solar UV irradiance, and the amount of solar variability from the proxy models are in reasonable agreement with the ASSI measurements. This research grant also has supported the development of a new solar EUV irradiance proxy model. We expected that the magnetic flux is responsible for most of the heating, via Alfen waves, in the chromosphere, transition region, and corona. From examining time series of solar irradiance data and magnetic fields at different levels, we did indeed find that the chromospheric <span class="hlt">emissions</span> correlate best with the large magnetic field levels.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19920069720&hterms=deming&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Ddeming','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19920069720&hterms=deming&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Ddeming"><span>Limb observations of the 12.32 micron solar <span class="hlt">emission</span> <span class="hlt">line</span> during the 1991 July total eclipse</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Deming, Drake; Jennings, Donald E.; Mccabe, George; Noyes, Robert; Wiedemann, Gunter; Espenak, Fred</p> <p>1992-01-01</p> <p>The limb profile of the Mg I 12.32-micron <span class="hlt">emission</span> <span class="hlt">line</span> is determined by occultation in the July 11, 1991 total solar eclipse over Mauna Kea. It is shown that the <span class="hlt">emission</span> peaks are very close to the 12-micron continuum limb, as predicted by recent theory for this <span class="hlt">line</span> as a non-LTE photospheric <span class="hlt">emission</span>. The increase in optical depth for this extreme limb-viewing situation indicates that most of the observed <span class="hlt">emission</span> arises from above the chromospheric temperature minimum, and it is found that this <span class="hlt">emission</span> is extended to heights well in excess of the model predictions. The <span class="hlt">line</span> <span class="hlt">emission</span> can be observed as high as 2000 km above the 12-micron continuum limb, whereas theory predicts it to remain observable no higher than about 500 km above the continuum limb. The substantial limb extension observed in this <span class="hlt">line</span> is quantitatively consistent with limb extensions seen in the far-IR continuum, and it is concluded that it is indicative of departures from gravitational hydrostatic equilibrium, or spatial inhomogeneities, in the upper solar atmosphere.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1998PhDT.......136R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1998PhDT.......136R"><span>Spectral properties of X-ray selected narrow <span class="hlt">emission</span> <span class="hlt">line</span> galaxies</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Romero-Colmenero, E.</p> <p>1998-03-01</p> <p>This thesis reports a study of the X-ray and optical properties of two samples of X-ray selected Narrow <span class="hlt">Emission</span> <span class="hlt">Line</span> Galaxies (NELGs), and their comparison with the properties of broad <span class="hlt">line</span> Active Galactic Nuclei (AGN). One sample (18 NELGs) is drawn from the ROSAT International X-ray Optical Survey (RIXOS), the other (19 NELGs and 33 AGN) from the ROSAT UK Deep Survey. ROSAT multi-channel X-ray spectra have been extracted and fitted with power-law, bremsstrahlung and black body models for the brighter RIXOS sources. In most cases, power-law and bremsstrahlung models provide the best results. The average spectral energy index, alpha, of the RIXOS NELGs is 0.96 +/- 0.07, similar to that of AGN (alpha~1). For the fainter RIXOS NELGs, as well as for all the UK Deep Survey sources, counts in three spectral bands have been extracted and fitted with a power-law model, assuming the Galactic value for N_H. The brighter RIXOS sources demonstrated that the results obtained by these two different extraction and fitting procedures provide consistent results. Two average X-ray spectra, one for the NELGs and another for the AGN, were created from the UK Deep Survey sources. The power-law slope of the average NELG is alpha = 0.45 +/- 0.09, whilst that of the AGN is alpha = 0.96 +/- 0.03. ROSAT X-ray surveys have shown that the fractional surface density of NELGs increases with respect to AGN at faint fluxes (<= 2e-15 ergs cm-2 s-1), thus suggesting that NELGs are important contributors to the residual soft (<2 keV) X-ray background (XRB). Moreover, the spectral slope of this background (alpha~0.4, 1-10 keV) is harder than that of AGN (alpha~1), which are known to contribute most of the XRB at higher flux levels. The work presented in this thesis shows unequivocally for the first time that the integrated spectrum of the faintest NELGs (alpha~0.4) is consistent with that of the soft X-ray background, finally reconciling it with the properties of the sources that are thought to</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1998PhDT.......240R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1998PhDT.......240R"><span>Spectral properties of x-ray selected narrow <span class="hlt">emission</span> <span class="hlt">line</span> galaxies</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Romero Colmenero, Encarnacion</p> <p></p> <p>This thesis reports a study of the X-ray and optical properties of two samples of X-ray selected Narrow <span class="hlt">Emission</span> <span class="hlt">Line</span> Galaxies (NELGs), and their comparison with the properties of broad <span class="hlt">line</span> Active Galactic Nuclei (AGN). One sample (18 NELGs) is drawn from the ROSAT International X-ray Optical Survey (RIXOS), the other (19 NELGs and 33 AGN) from the ROSAT UK Deep Survey. ROSAT multi-channel X-ray spectra have been extracted and fitted with power-law, bremsstrahlung and black body models for the brighter RIXOS sources. In most cases, power-law and bremsstrahlung models provide the best results. The average spectral energy index, alpha, of the RIXOS NELGs is 0.96 +/- 0.07, similar to that of AGN (alpha ~ 1). For the fainter RIXOS NELGs, as well as for all the UK Deep Survey sources, counts in three spectral bands have been extracted and fitted with a power-law model, assuming the Galactic value for NH. The brighter RIXOS sources demonstrated that the results obtained by these two different extraction and fitting procedures provide consistent results. Two average X-ray spectra, one for the NELGs and another for the AGN, were created from the UK Deep Survey sources. The power-law spectral slope of the average NELG is S = 0.45 +/- 0.09, whilst that of the AGN is S = 0.96 +/- 0.03. ROSAT X-ray surveys have shown that the fractional surface density of NELGs increases with respect to AGN at faint fluxes (< 2 x 10-15erg cm-2 s -1), thus suggesting that NELGs are important contributors to the residual soft (< 2 keV) X-ray background (XRB). Moreover, the spectral slope of this background (S ~ 0.4, 1-10 keV) is harder than that of AGN (S ~ 1), which are known to contribute most of the XRB at higher flux levels. The work presented in this thesis shows unequivocally for the first time that the integrated spectrum of the faintest NELGs (alpha ~ 0.4) is consistent with that of the soft X-ray background, finally reconciling it with the properties of the sources that are thought to</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JPhCS.901a2006J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JPhCS.901a2006J"><span>Time variations of oxygen <span class="hlt">emission</span> <span class="hlt">lines</span> and solar wind dynamic parameters in low latitude region</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jamlongkul, P.; Wannawichian, S.; Mkrtichian, D.; Sawangwit, U.; A-thano, N.</p> <p>2017-09-01</p> <p>Aurora phenomenon is an effect of collision between precipitating particles with gyromotion along Earth’s magnetic field and Earth’s ionospheric atoms or molecules. The particles’ precipitation occurs normally around polar regions. However, some auroral particles can reach lower latitude regions when they are highly energetic. A clear <span class="hlt">emission</span> from Earth’s aurora is mostly from atomic oxygen. Moreover, the sun’s activities can influence the occurrence of the aurora as well. This work studies time variations of oxygen <span class="hlt">emission</span> <span class="hlt">lines</span> and solar wind parameters, simultaneously. The emission’s spectral <span class="hlt">lines</span> were observed by Medium Resolution Echelle Spectrograph (MRES) along with 2.4 meters diameter telescope at Thai National Observatory, Intanon Mountain, Chiang Mai, Thailand. Oxygen (OI) <span class="hlt">emission</span> <span class="hlt">lines</span> were calibrated by Dech-Fits spectra processing program and Dech95 2D image processing program. The correlations between oxygen <span class="hlt">emission</span> <span class="hlt">lines</span> and solar wind dynamics will be analyzed. This result could be an evidence of the aurora in low latitude region.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AAS...22930401M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AAS...22930401M"><span>The SAMI Galaxy Survey: Publicly Available Spatially Resolved <span class="hlt">Emission</span> <span class="hlt">Line</span> Data Products</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Medling, Anne; Green, Andrew W.; Ho, I.-Ting; Groves, Brent; Croom, Scott; SAMI Galaxy Survey Team</p> <p>2017-01-01</p> <p>The SAMI Galaxy Survey is collecting optical integral field spectroscopy of up to 3400 nearby (z<0.1) galaxies with a range of stellar masses and in a range of environments. The first public data release contains nearly 800 galaxies from the Galaxy And Mass Assembly (GAMA) Survey. In addition to releasing the reduced data cubes, we also provide <span class="hlt">emission</span> <span class="hlt">line</span> fits (flux and kinematic maps of strong <span class="hlt">emission</span> <span class="hlt">lines</span> including Halpha and Hbeta, [OII]3726,29, [OIII]4959,5007, [OI]6300, [NII]6548,83, and [SII]6716,31), extinction maps, star formation classification masks, and star formation rate maps. We give an overview of the data available for your favorite <span class="hlt">emission</span> <span class="hlt">line</span> science and present a few early science results. For example, a sample of edge-on disk galaxies show enhanced extraplanar <span class="hlt">emission</span> related to SF-driven outflows, which are correlated with a bursty star formation history and higher star formation rate surface densities. Interestingly, the star formation rate surface densities of these wind hosts are 5-100 times lower than the canonical threshold for driving winds (0.1 MSun/yr/kpc2), indicating that galactic winds may be more important in normal star-forming galaxies than previously thought.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20000086194&hterms=molecular+electronics&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dmolecular%2Belectronics','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20000086194&hterms=molecular+electronics&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dmolecular%2Belectronics"><span>Red Fluorescent <span class="hlt">Line</span> <span class="hlt">Emission</span> from Hydrogen Molecules in Diffuse Molecular Clouds</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Neufeld, David A.; Spaans, Marco</p> <p>1996-01-01</p> <p>We have modeled the fluorescent pumping of electronic and vibrational <span class="hlt">emissions</span> of molecular hydrogen (H2) within diffuse molecular clouds that are illuminated by ultraviolet continuum radiation. Fluorescent <span class="hlt">line</span> intensities are predicted for transitions at ultraviolet, infrared, and red visible wavelengths as functions of the gas density, the visual extinction through the cloud, and the intensity of the incident UV continuum radiation. The observed intensity in each fluorescent transition is roughly proportional to the integrated rate of H2 photodissociation along the <span class="hlt">line</span> of sight. Although the most luminous fluorescent <span class="hlt">emissions</span> detectable from ground-based observatories lie at near-infrared wavelengths, we argue that the lower sky brightness at visible wavelengths makes the red fluorescent transitions a particularly sensitive probe. Fabry-Perot spectrographs of the type that have been designed to observe very faint diffuse Ha <span class="hlt">emissions</span> are soon expected to yield sensitivities that will be adequate to detect H2 vibrational <span class="hlt">emissions</span> from molecular clouds that are exposed to ultraviolet radiation no stronger than the mean radiation field within the Galaxy. Observations of red H2 fluorescent <span class="hlt">emission</span> together with cospatial 21 cm H I observations could serve as a valuable probe of the gas density in diffuse molecular clouds.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012ESASP.702E..74D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012ESASP.702E..74D"><span>Achieving EMC <span class="hlt">Emissions</span> Compliance for an Aeronautics Power <span class="hlt">Line</span> Communications System</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dominiak, S.; Vos, G.; ter Meer, T.; Widmer, H.</p> <p>2012-05-01</p> <p>Transmitting data over the power distribution network - Power <span class="hlt">Line</span> Communications (PLC) -provides an interesting solution to reducing the weight and complexity of wiring networks in commercial aircraft. One of the potential roadblocks for the introduction of this technology is achieving EMC <span class="hlt">emissions</span> compliance. In this article an overview of the EMC conducted and radiated <span class="hlt">emissions</span> testing for PLC- enabled aeronautics equipment is presented. Anomalies resulting from chamber resonances leading to discrepancies between the conducted <span class="hlt">emissions</span> tests and the measured radiated <span class="hlt">emissions</span> are identified and described. Measurements made according to the current version of the civil aeronautical EMC standard, EUROCAE ED-14F (RTCA DO-160F), show that PLC equipment can achieve full EMC <span class="hlt">emissions</span> compliance.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFM.P14C..03L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFM.P14C..03L"><span>Polarisation of auroral <span class="hlt">emission</span> <span class="hlt">lines</span> in the Earth's upper atmosphere : first results and perspectives</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lamy, H.; Barthelemy, M.; Simon Wedlund, C.; Lilensten, J.; Bommier, V.</p> <p>2011-12-01</p> <p>Polarisation of light is a key observable to provide information about asymmetry or anisotropy within a radiative source. Following the pioneering and controversial work of Duncan in 1959, the polarisation of auroral <span class="hlt">emission</span> <span class="hlt">lines</span> in the Earth's upper atmosphere has been overlooked for a long time, even though the red intense auroral <span class="hlt">line</span> (6300Å) produced by collisional impacts with electrons precipitating along magnetic field <span class="hlt">lines</span> is a good candidate to search for polarisation. This problem was investigated again by Lilensten et al (2006) and observations were obtained by Lilensten et al (2008) confirming that the red auroral <span class="hlt">emission</span> <span class="hlt">line</span> is polarised. More recent measurements obtained by Barthélemy et al (2011) are presented and discussed. The results are compared to predictions of the theoretical work of Bommier et al (2011) and are in good agreement. Following these encouraging results, a new dedicated spectropolarimeter is currently under construction between BIRA-IASB and IPAG to provide simultaneously the polarisation of the red <span class="hlt">line</span> and of other interesting auroral <span class="hlt">emission</span> <span class="hlt">lines</span> such as N2+ 1NG (4278Å), other N2 bands, etc... Perspectives regarding the theoretical polarisation of some of these <span class="hlt">lines</span> will be presented. The importance of these polarisation measurements in the framework of atmospheric modeling and geomagnetic activity will be discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017MNRAS.472L..99L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017MNRAS.472L..99L"><span>Disc origin of broad optical <span class="hlt">emission</span> <span class="hlt">lines</span> of the TDE candidate PTF09djl</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liu, F. K.; Zhou, Z. Q.; Cao, R.; Ho, L. C.; Komossa, S.</p> <p>2017-11-01</p> <p>An otherwise dormant supermassive black hole (SMBH) in a galactic nucleus flares up when it tidally disrupts a star passing by. Most of the tidal disruption events (TDEs) and candidates discovered in the optical/UV have broad optical <span class="hlt">emission</span> <span class="hlt">lines</span> with complex and diverse profiles of puzzling origin. In this Letter, we show that the double-peaked broad H α <span class="hlt">line</span> of the TDE candidate PTF09djl can be well modelled with a relativistic elliptical accretion disc and the peculiar substructures with one peak at the <span class="hlt">line</span> rest wavelength and the other redshifted to about 3.5 × 104 km s-1 are mainly due to the orbital motion of the emitting matter within the disc plane of large inclination 88° and pericentre orientation nearly vertical to the observer. The accretion disc has an extreme eccentricity 0.966 and semimajor axis of 340 BH Schwarzschild radii. The viewing angle effects of large disc inclination lead to significant attenuation of He <span class="hlt">emission</span> <span class="hlt">lines</span> originally produced at large electron scattering optical depth and to the absence/weakness of He <span class="hlt">emission</span> <span class="hlt">lines</span> in the spectra of PTF09djl. Our results suggest that the diversities of <span class="hlt">line</span> intensity ratios among the <span class="hlt">line</span> species in optical TDEs are probably due to the differences of disc inclinations.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_13 --> <div id="page_14" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="261"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015MNRAS.451..508B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015MNRAS.451..508B"><span>Pulse-phase dependence of <span class="hlt">emission</span> <span class="hlt">lines</span> in the X-ray pulsar 4U 1626-67</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Beri, Aru; Paul, Biswajit; Dewangan, Gulab C.</p> <p>2015-07-01</p> <p>We present results from a pulse-phase-resolved spectroscopy of the complex <span class="hlt">emission</span> <span class="hlt">lines</span> around 1 keV in the unique accretion-powered X-ray pulsar 4U 1626-67, using the observation made with XMM-Newton in 2003. In this source, the redshifted and blueshifted <span class="hlt">emission</span> <span class="hlt">lines</span> and the linewidths measured earlier with Chandra suggest their accretion-disc origin. Another possible signature of <span class="hlt">lines</span> produced in the accretion disc can be a modulation of the <span class="hlt">line</span> strength with the pulse phase. We have found that the <span class="hlt">line</span> fluxes have pulse-phase dependence, making 4U 1626-67 only the second pulsar after Hercules X-1 to show such variability. The O VII <span class="hlt">line</span> at 0.568 keV from 4U 1626-67 varied by a factor of ˜4, stronger than the continuum variability, which supports the accretion-disc origin. The <span class="hlt">line</span> flux variability can appear due to variable illumination of the accretion disc by the pulsar or, more likely, a warp-like structure in the accretion disc. We also discuss some further possible diagnostics of the accretion disc in 4U 1626-67 with pulse-phase-resolved <span class="hlt">emission-line</span> spectroscopy.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMSA42A..07R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMSA42A..07R"><span>Nighttime medium scale traveling ionospheric disturbances in southern hemisphere using FORMOSAT-2/ISUAL 630.0 nm <span class="hlt">airglow</span> images</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rajesh, P. K.; Lin, C. C. H.; Liu, T. J. Y.; Chen, A. B. C.; Hsu, R. R.; Chen, C. H.; Huba, J. D.</p> <p>2017-12-01</p> <p>In this work characteristics of nighttime medium-scale travelling ionospheric disturbances (MSTID) are investigated using 630.0 nm limb images by Imager of Sprites and Upper Atmospheric Lightnings (ISUAL), onboard FORMOSAT-2 satellite. The limb integrated measurements, when projected to a horizontal plane, reveal bands of intensity perturbation with distinct southwest to northeast orientation in the southern hemisphere. <span class="hlt">Airglow</span> simulations are carried out by artificially introducing MSTID fluctuations in model electron density to confirm if such azimuthally oriented features could be identified in the ISUAL viewing geometry. Further statistical analysis shows more MSTID occurrence in solstices with peak in June-July months. The wavelengths of the observed perturbations were in the range 150-300 km. The wave fronts were oriented about 30°-50° from the east-west plane, indicating that coupled Perkins and Es-layer instability might be important in the MSTID generation. The results demonstrate that space based <span class="hlt">airglow</span> imaging is an effective method for global investigation of MSTID events that are appropriately aligned with the viewing geometry.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=223424','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=223424"><span><span class="hlt">EMISSION-LINE</span> OBJECTS PROJECTED UPON THE GALACTIC BULGE*</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Herbig, G. H.</p> <p>1969-01-01</p> <p>Low-dispersion slit spectrograms have been obtained of 34 faint objects that lie in the direction of the galactic bulge and have the Hα <span class="hlt">line</span> in <span class="hlt">emission</span> upon a detectable continuum. Eleven of these are certain or probable symbiotic stars. A rough comparison with R CrB stars in the same area suggests that these brightest symbiotics in the bulge have in the mean Mv ≈ -3 to -4, which suggest Population II red giants rather than conventional Population I M-type objects. The sample also contains a number of hot stars having H and [O II] or [O III] in <span class="hlt">emission</span>, as well as four conventional Be stars, and six certain or possible planetary nebulae. Images PMID:16578699</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/16578699','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/16578699"><span><span class="hlt">Emission-line</span> objects projected upon the galactic bulge.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Herbig, G H</p> <p>1969-08-01</p> <p>Low-dispersion slit spectrograms have been obtained of 34 faint objects that lie in the direction of the galactic bulge and have the Halpha <span class="hlt">line</span> in <span class="hlt">emission</span> upon a detectable continuum. Eleven of these are certain or probable symbiotic stars. A rough comparison with R CrB stars in the same area suggests that these brightest symbiotics in the bulge have in the mean M(v) approximately -3 to -4, which suggest Population II red giants rather than conventional Population I M-type objects. The sample also contains a number of hot stars having H and [O II] or [O III] in <span class="hlt">emission</span>, as well as four conventional Be stars, and six certain or possible planetary nebulae.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018MNRAS.tmp.1342S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018MNRAS.tmp.1342S"><span>Imaging Extended <span class="hlt">Emission-Line</span> Regions of Obscured AGN with the Subaru Hyper Suprime-Cam Survey</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sun, Ai-Lei; Greene, Jenny E.; Zakamska, Nadia L.; Goulding, Andy; Strauss, Michael A.; Huang, Song; Johnson, Sean; Kawaguchi, Toshihiro; Matsuoka, Yoshiki; Marsteller, Alisabeth A.; Nagao, Tohru; Toba, Yoshiki</p> <p>2018-05-01</p> <p>Narrow-<span class="hlt">line</span> regions excited by active galactic nuclei (AGN) are important for studying AGN photoionization and feedback. Their strong [O III] <span class="hlt">lines</span> can be detected with broadband images, allowing morphological studies of these systems with large-area imaging surveys. We develop a new broad-band imaging technique to reconstruct the images of the [O III] <span class="hlt">line</span> using the Subaru Hyper Suprime-Cam (HSC) Survey aided with spectra from the Sloan Digital Sky Survey (SDSS). The technique involves a careful subtraction of the galactic continuum to isolate <span class="hlt">emission</span> from the [O III]λ5007 and [O III]λ4959 <span class="hlt">lines</span>. Compared to traditional targeted observations, this technique is more efficient at covering larger samples without dedicated observational resources. We apply this technique to an SDSS spectroscopically selected sample of 300 obscured AGN at redshifts 0.1 - 0.7, uncovering extended <span class="hlt">emission-line</span> region candidates with sizes up to tens of kpc. With the largest sample of uniformly derived narrow-<span class="hlt">line</span> region sizes, we revisit the narrow-<span class="hlt">line</span> region size - luminosity relation. The area and radii of the [O III] <span class="hlt">emission-line</span> regions are strongly correlated with the AGN luminosity inferred from the mid-infrared (15 μm rest-frame) with a power-law slope of 0.62^{+0.05}_{-0.06}± 0.10 (statistical and systematic errors), consistent with previous spectroscopic findings. We discuss the implications for the physics of AGN <span class="hlt">emission-line</span> regions and future applications of this technique, which should be useful for current and next-generation imaging surveys to study AGN photoionization and feedback with large statistical samples.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JMP....59d2103M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JMP....59d2103M"><span>Spontaneous <span class="hlt">emission</span> and atomic <span class="hlt">line</span> shift in causal perturbation theory</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Marzlin, Karl-Peter; Fitzgerald, Bryce</p> <p>2018-04-01</p> <p>We derive a spontaneous <span class="hlt">emission</span> rate and <span class="hlt">line</span> shift for two-level atoms coupled to the radiation field using causal perturbation theory. In this approach, employing the theory of distribution splitting prevents the occurrence of divergent integrals. Our method confirms the result for an atomic decay rate but suggests that the cutoff frequency for the atomic <span class="hlt">line</span> shift is determined by the atomic mass, rather than the Bohr radius or electron mass.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/7071653-toyota-inspection-system-vehicular-emissions-assembly-lines','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/7071653-toyota-inspection-system-vehicular-emissions-assembly-lines"><span>Toyota's inspection system for vehicular <span class="hlt">emissions</span> at assembly <span class="hlt">lines</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Tanaka, T.; Nakano, H.; Usami, I.</p> <p>1976-01-01</p> <p>In order that all Toyota production vehicles may satisfy the <span class="hlt">emission</span> requirements and be free from possible defects such as catalytic converter damage, a system called ECAS, which allows us to assure satisfactory basic <span class="hlt">emission</span> performance levels has been developed and put into actual use at assembly <span class="hlt">lines</span>. This system consists of the following four tests: Idle Test, Functional Test, Short Cycle Test and Steady State Inspection Test. By using this system, all operations from vehicle setup, on a chassis dynamometer to statistical analysis of the data, measurement, judgement of the obtained data, type-out of the results, indication for actionmore » to be taken, data filing and statistical treatment of the data, are processed automatically and controlled by the computer. In the Short Cycle Test the up-stream <span class="hlt">emissions</span> of the vehicle, tracing Toyota's unique short cyclic mode on a chassis dynamometer, are continuously measured. Based on the <span class="hlt">emission</span> levels during each mode and the total <span class="hlt">emission</span> level obtained from the above test we can diagnose, not only the <span class="hlt">emission</span> control systems of a vehicle and its engine conditions such as valve clearance maladjustment and carburetor defects, but also the <span class="hlt">emission</span> characteristics of this vehicle.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017ApJ...846..102M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017ApJ...846..102M"><span><span class="hlt">Emission</span> <span class="hlt">Line</span> Properties of Seyfert Galaxies in the 12 μm Sample</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Malkan, Matthew A.; Jensen, Lisbeth D.; Rodriguez, David R.; Spinoglio, Luigi; Rush, Brian</p> <p>2017-09-01</p> <p>We present optical and ultraviolet spectroscopic measurements of the <span class="hlt">emission</span> <span class="hlt">lines</span> of 81 Seyfert 1 and 104 Seyfert 2 galaxies that comprise nearly all of the IRAS 12 μm AGN sample. We have analyzed the <span class="hlt">emission-line</span> luminosity functions, reddening, and other diagnostics. For example, the narrow-<span class="hlt">line</span> regions (NLR) of Seyfert 1 and 2 galaxies do not significantly differ from each other in most of these diagnostics. Combining the Hα/Hβ ratio with a new reddening indicator—the [S II]6720/[O II]3727 ratio—we find the average E(B-V) is 0.49 ± 0.35 for type 1 and 0.52 ± 0.26 for type 2 Seyferts. The NLR of Sy 1s has an ionization level insignificantly higher than that of Sy 2s. For the broad-<span class="hlt">line</span> region (BLR), we find that the C IV equivalent width correlates more strongly with [O III]/Hβ than with UV luminosity. Our bright sample of local active galaxies includes 22 Seyfert nuclei with extremely weak broad wings in Hα, known as Seyfert 1.9s and 1.8s, depending on whether or not broad Hβ wings are detected. Aside from these weak broad <span class="hlt">lines</span>, our low-luminosity Seyferts are more similar to the Sy 2s than to Sy 1s. In a BPT diagram, we find that Sy 1.8s and 1.9s overlap the region occupied by Sy 2s. We compare our results on optical <span class="hlt">emission</span> <span class="hlt">lines</span> with those obtained by previous investigators, using AGN subsamples from the Sloan Digital Sky Survey. The luminosity functions of forbidden <span class="hlt">emission</span> <span class="hlt">lines</span> [O II]λ3727 Å, [O III]λ5007 Å, and [S II]λ6720 Å in Sy 1s and Sy 2s are indistinguishable. They all show strong downward curvature. Unlike the LFs of Seyfert galaxies measured by the Sloan Digital Sky Survey, ours are nearly flat at low luminosities. The larger number of faint Sloan “AGN” is attributable to their inclusion of weakly emitting LINERs and H II+AGN “composite” nuclei, which do not meet our spectral classification criteria for Seyferts. In an Appendix, we have investigated which <span class="hlt">emission</span> <span class="hlt">line</span> luminosities can provide the most reliable</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19810050790&hterms=mit+sloan&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dmit%2Bsloan','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19810050790&hterms=mit+sloan&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dmit%2Bsloan"><span>X-ray <span class="hlt">line</span> <span class="hlt">emission</span> from the Puppis A supernova remnant - Oxygen <span class="hlt">lines</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Winkler, P. F.; Clark, G. W.; Markert, T. H.; Petre, R.; Canizares, C. R.</p> <p>1981-01-01</p> <p>Six prominent X-ray <span class="hlt">emission</span> <span class="hlt">lines</span> of O VII and O VIII have been detected from a portion of the Puppis A supernova remnant in observations with the Einstein Observatory Focal Plane Crystal Spectrometer. The <span class="hlt">lines</span> are sufficiently well resolved to serve as diagnostics of the emitting plasma. From the relative intensities of the <span class="hlt">lines</span>, it is inferred that the population of O VIII is about 1.5 times that of O VII, and that electron collisions are the dominant excitation mechanism in the plasma. A locus of allowed electron temperatures and interstellar-absorption column densities is derived: 1.5 x 10 to the 6th K, and (2-6) x 10 to the 21st per sq cm. The data are consistent with either a thin plasma source in equilibrium at a temperature of 2.2 x 10 to the 6th K with a column density of 4 x 10 to the 21st per sq cm, or with a nonequilibrium source in which the electrons have been shock-heated to a higher temperature and oxygen is underionized.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-iss029e005853.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-iss029e005853.html"><span><span class="hlt">Airglow</span> on the horizon against the starry sky view taken by the Expedition 29 crew</span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>2011-09-17</p> <p>ISS029-E-005853 (17 Sept. 2011) --- This is one of a series of night time images photographed by one of the Expedition 29 crew members from the International Space Station. The image features <span class="hlt">airglow</span> on the horizon against a starry sky with Russian spacecraft Soyuz and Progress in the foreground. Nadir coordinates are 27.8 degrees south latitude and 137.6 west longitude. The photo was taken at 11:32:37 GMT, Sept. 17, 2011.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AAS...22731805S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AAS...22731805S"><span>Weak <span class="hlt">Emission-line</span> Quasars in the Context of a Modified Baldwin Effect</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shemmer, Ohad</p> <p>2016-01-01</p> <p>Based on spectroscopic data for a sample of high-redshift quasars, I will show that the anti-correlation between the rest-frame equivalent width (EW) of the C IV λ1549 broad-<span class="hlt">emission</span> <span class="hlt">line</span> and the Hβ-based Eddington ratio extends across the widest possible ranges of redshift (0 < z < 3.5) and bolometric luminosity(~1044 < L < ~1048 erg s-1). Given this anti-correlation, hereby referred to as a modified Baldwin effect (MBE), weak <span class="hlt">emission</span> <span class="hlt">line</span> quasars (WLQs), typically showing EW(C IV) < ~10 Å, are expected to have extremely high Eddington ratios (L/LEdd > ~4). I will present new near-infrared spectroscopy of the broad Hβ <span class="hlt">line</span>, as well as complementary EW(C IV) information, for all WLQs for which such information is currently available, nine sources in total. I will show that while four of these WLQs can be accommodated by the MBE, the otherfive deviate significantly from this relation, at the > ~3σ level, by exhibiting C IV <span class="hlt">lines</span> much weaker than predicted from their Hβ-based Eddington ratios. Assuming the supermassive black hole masses in all quasars can be determined reliably using the single-epoch Hβ-method, these results indicate that EW(C IV)cannot depend solely on the Eddington ratio. I will briefly discuss a strategy for further investigation into the roles that basic physical properties play in controlling the relative strengths of broad-<span class="hlt">emission</span> <span class="hlt">lines</span> in quasars.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19950035234&hterms=Archetypes&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DArchetypes','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19950035234&hterms=Archetypes&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DArchetypes"><span>(12)CO (3-2) & (1-0) <span class="hlt">emission</span> <span class="hlt">line</span> observations of nearby starburst galaxy nuclei</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Devereux, Nicholas; Taniguchi, Yoshiaki; Sanders, D. B.; Nakai, N.; Young, J. S.</p> <p>1994-01-01</p> <p>New measurements of the (12)CO (1-0) and (12)CO (3-2) <span class="hlt">line</span> <span class="hlt">emission</span> are presented for the nuclei of seven nearby starburst galaxies selected from a complete sample of 21 nearby starburst galaxies for which the nuclear star formation rates are measured to be comparable to the archetype starburst galaxies M82 and NGC 253. The new observations capitalize on the coincidence between the beam size of the 45 m Nobeyama telescope at 115 GHz and that of the 15 m James Clerk Maxwell Telescope at 345 GHz to measure the value of the (12)CO (3-2)/(1-0) <span class="hlt">emission</span> <span class="hlt">line</span> ratio in a 15 sec (less than or equal to 2.5 kpc) diameter region centered on the nuclear starburst. In principle, the (12)CO (3-2)/(1-0) <span class="hlt">emission</span> <span class="hlt">line</span> ratio provides a measure of temperature and optical depth for the (12)CO gas. The error weighted mean value of the (12)CO (3-2)/(1-0) <span class="hlt">emission</span> <span class="hlt">line</span> ratio measured for the seven starburst galaxy nuclei is -0.64 +/- 0.06. The (12)CO (3-2)/(1-0) <span class="hlt">emission</span> <span class="hlt">line</span> ratio measured for the starburst galaxy nuclei is significantly higher than the average value measured for molecular gas in the disk of the Galaxy, implying warmer temperatures for the molecular gas in starburst galaxy nuclei. On the other hand, the (12)CO (3-2)/(1-0) <span class="hlt">emission</span> <span class="hlt">line</span> ratio measured for the starburst galaxy nuclei is not as high as would be expected if the molecular gas were hot, greater than 20 K, and optically thin, tau much less than 1. The total mass of molecular gas contained within the central 1.2-2.8 kpc diameter region of the starburst galaxy nuclei ranges from 10(exp 8) to 10(exp 9) solar mass. While substantial, the molecular gas mass represents only a small percentage, approximately 9%-16%, of the dynamical mass in the same region.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19750013109','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19750013109"><span>On the physical association of the peculiar <span class="hlt">emission</span>: <span class="hlt">Line</span> stars HD 122669 and HD 122691</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Garrison, R. F.; Hiltner, W. A.; Sanduleak, N.</p> <p>1975-01-01</p> <p>Spectroscopic and photometric observations indicate a physical association between the peculiar early-type <span class="hlt">emission-line</span> stars HD 122669 and HD 122691. The latter has undergone a drastic change in the strength of its <span class="hlt">emission</span> <span class="hlt">lines</span> during the past twenty years. There is some indication that both stars vary with shorter time scales.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018AcSpe.143...78D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018AcSpe.143...78D"><span>Improved documentation of spectral <span class="hlt">lines</span> for inductively coupled plasma <span class="hlt">emission</span> spectrometry</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Doidge, Peter S.</p> <p>2018-05-01</p> <p>An approach to improving the documentation of weak spectral <span class="hlt">lines</span> falling near the prominent analytical <span class="hlt">lines</span> used in inductively coupled plasma optical <span class="hlt">emission</span> spectrometry (ICP-OES) is described. Measurements of ICP <span class="hlt">emission</span> spectra in the regions around several hundred prominent <span class="hlt">lines</span>, using concentrated solutions (up to 1% w/v) of some 70 elements, and comparison of the observed spectra with both recent published work and with the output of a computer program that allows calculation of transitions between the known energy levels, show that major improvements can be made in the coverage of spectral atlases for ICP-OES, with respect to "classical" <span class="hlt">line</span> tables. It is argued that the atomic spectral data (wavelengths, energy levels) required for the reliable identification and documentation of a large majority of the weak interfering <span class="hlt">lines</span> of the elements detectable by ICP-OES now exist, except for most of the observed <span class="hlt">lines</span> of the lanthanide elements. In support of this argument, examples are provided from a detailed analysis of a spectral window centered on the prominent Pb II 220.353 nm <span class="hlt">line</span>, and from a selected <span class="hlt">line</span>-rich spectrum (W). Shortcomings in existing analyses are illustrated with reference to selected spectral interferences due to Zr. This approach has been used to expand the spectral-<span class="hlt">line</span> library used in commercial ICP-ES instruments (Agilent 700-ES/5100-ES). The precision of wavelength measurements is evaluated in terms of the shot-noise limit, while the absolute accuracy of wavelength measurement is characterised through comparison with a small set of precise Ritz wavelengths for Sb I, and illustrated through the identification of Zr III <span class="hlt">lines</span>; it is further shown that fractional-pixel absolute wavelength accuracies can be achieved. Finally, problems with the wavelengths and classifications of certain Au I <span class="hlt">lines</span> are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015ApJ...811...42S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015ApJ...811...42S"><span>The Sloan Digital Sky Survey Reverberation Mapping Project: Ensemble Spectroscopic Variability of Quasar Broad <span class="hlt">Emission</span> <span class="hlt">Lines</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sun, Mouyuan; Trump, Jonathan R.; Shen, Yue; Brandt, W. N.; Dawson, Kyle; Denney, Kelly D.; Hall, Patrick B.; Ho, Luis C.; Horne, Keith; Jiang, Linhua; Richards, Gordon T.; Schneider, Donald P.; Bizyaev, Dmitry; Kinemuchi, Karen; Oravetz, Daniel; Pan, Kaike; Simmons, Audrey</p> <p>2015-09-01</p> <p>We explore the variability of quasars in the Mg ii and {{H}}β broad <span class="hlt">emission</span> <span class="hlt">lines</span> and ultraviolet/optical continuum <span class="hlt">emission</span> using the Sloan Digital Sky Survey Reverberation Mapping project (SDSS-RM). This is the largest spectroscopic study of quasar variability to date: our study includes 29 spectroscopic epochs from SDSS-RM over 6 months, containing 357 quasars with Mg ii and 41 quasars with {{H}}β . On longer timescales, the study is also supplemented with two-epoch data from SDSS-I/II. The SDSS-I/II data include an additional 2854 quasars with Mg ii and 572 quasars with {{H}}β . The Mg ii <span class="hlt">emission</span> <span class="hlt">line</span> is significantly variable ({{Δ }}f/f∼ 10% on ∼100-day timescales), a necessary prerequisite for its use for reverberation mapping studies. The data also confirm that continuum variability increases with timescale and decreases with luminosity, and the continuum light curves are consistent with a damped random-walk model on rest-frame timescales of ≳ 5 days. We compare the <span class="hlt">emission-line</span> and continuum variability to investigate the structure of the broad-<span class="hlt">line</span> region. Broad-<span class="hlt">line</span> variability shows a shallower increase with timescale compared to the continuum <span class="hlt">emission</span>, demonstrating that the broad-<span class="hlt">line</span> transfer function is not a δ-function. {{H}}β is more variable than Mg ii (roughly by a factor of ∼1.5), suggesting different excitation mechanisms, optical depths and/or geometrical configuration for each <span class="hlt">emission</span> <span class="hlt">line</span>. The ensemble spectroscopic variability measurements enabled by the SDSS-RM project have important consequences for future studies of reverberation mapping and black hole mass estimation of 1\\lt z\\lt 2 quasars.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19800023683','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19800023683"><span>Atomic <span class="hlt">emission</span> <span class="hlt">lines</span> in the near ultraviolet; hydrogen through krypton, section 1</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kelly, R. L.</p> <p>1979-01-01</p> <p>A compilation of spectra from the first 36 elements was prepared from published literature available through October 1977. In most cases, only those <span class="hlt">lines</span> which were actually observed in <span class="hlt">emission</span> or absorption are listed. The wavelengths included range from 2000 Angstroms to 3200 Angstroms with some additional <span class="hlt">lines</span> up to 3500 Angstroms. Only <span class="hlt">lines</span> of stripped atoms are reported; no molecular bands are included.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19800023684','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19800023684"><span>Atomic <span class="hlt">emission</span> <span class="hlt">lines</span> in the near ultraviolet; hydrogen through krypton, section 2</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kelly, R. L.</p> <p>1979-01-01</p> <p>A compilation of spectra from the first 36 elements was prepared from published literature available through October 1977. In most cases, only those <span class="hlt">lines</span> which were actually observed in <span class="hlt">emission</span> or absorption are listed. The wavelengths included range from 2000 Angstroms to 3200 Angstroms with some additional <span class="hlt">lines</span> up to 3500 Angstroms. Only <span class="hlt">lines</span> of stripped atoms are reported; no molecular bands are included.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018FrASS...5...19B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018FrASS...5...19B"><span>Exploring possible relations between optical variability time scales and broad <span class="hlt">emission</span> <span class="hlt">line</span> shapes in AGN</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bon, Edi; Jovanović, Predrag; Marziani, Paola; Bon, Nataša; Otašević, Aleksandar</p> <p>2018-06-01</p> <p>Here we investigate the connection of broad <span class="hlt">emission</span> <span class="hlt">line</span> shapes and continuum light curve variability time scales of type-1 Active Galactic Nuclei (AGN). We developed a new model to describe optical broad <span class="hlt">emission</span> <span class="hlt">lines</span> as an accretion disk model of a <span class="hlt">line</span> profile with additional ring <span class="hlt">emission</span>. We connect ring radii with orbital time scales derived from optical light curves, and using Kepler's third law, we calculate mass of central supermassive black hole (SMBH). The obtained results for central black hole masses are in a good agreement with other methods. This indicates that the variability time scales of AGN may not be stochastic, but rather connected to the orbital time scales which depend on the central SMBH mass.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018MNRAS.473.1394S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018MNRAS.473.1394S"><span>Polarized Balmer <span class="hlt">line</span> <span class="hlt">emission</span> from supernova remnant shock waves efficiently accelerating cosmic rays</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shimoda, Jiro; Ohira, Yutaka; Yamazaki, Ryo; Laming, J. Martin; Katsuda, Satoru</p> <p>2018-01-01</p> <p>Linearly polarized Balmer <span class="hlt">line</span> <span class="hlt">emissions</span> from supernova remnant shocks are studied taking into account the energy loss of the shock owing to the production of non-thermal particles. The polarization degree depends on the downstream temperature and the velocity difference between upstream and downstream regions. The former is derived once the <span class="hlt">line</span> width of the broad component of the H α <span class="hlt">emission</span> is observed. Then, the observation of the polarization degree tells us the latter. At the same time, the estimated value of the velocity difference independently predicts adiabatic downstream temperature that is derived from Rankine Hugoniot relations for adiabatic shocks. If the actually observed downstream temperature is lower than the adiabatic temperature, there is a missing thermal energy which is consumed for particle acceleration. It is shown that a larger energy-loss rate leads to more highly polarized H α <span class="hlt">emission</span>. Furthermore, we find that polarized intensity ratio of H β to H α also depends on the energy-loss rate and that it is independent of uncertain quantities such as electron temperature, the effect of Lyman <span class="hlt">line</span> trapping and our <span class="hlt">line</span> of sight.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22661274-origin-flare-emission-iris-sji-filter-balmer-continuum-spectral-lines','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22661274-origin-flare-emission-iris-sji-filter-balmer-continuum-spectral-lines"><span>On the Origin of the Flare <span class="hlt">Emission</span> in IRIS ’ SJI 2832 Filter:Balmer Continuum or Spectral <span class="hlt">Lines</span>?</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Kleint, Lucia; Krucker, Säm; Heinzel, Petr</p> <p></p> <p>Continuum (“white-light,” WL) <span class="hlt">emission</span> dominates the energetics of flares. Filter-based observations, such as the IRIS SJI 2832 filter, show WL-like brightenings during flares, but it is unclear whether the <span class="hlt">emission</span> arises from real continuum <span class="hlt">emission</span> or enhanced spectral <span class="hlt">lines</span>, possibly turning into <span class="hlt">emission</span>. The difficulty in filter-based observations, contrary to spectral observations, is to determine which processes contribute to the observed brightening during flares. Here we determine the contribution of the Balmer continuum and the spectral <span class="hlt">line</span> <span class="hlt">emission</span> to IRIS ’ SJI 2832 <span class="hlt">emission</span> by analyzing the appropriate passband in simultaneous IRIS NUV spectra. We find that spectral <span class="hlt">line</span> emissionmore » can contribute up to 100% to the observed slitjaw images (SJI) <span class="hlt">emission</span>, that the relative contributions usually temporally vary, and that the highest SJI enhancements that are observed are most likely because of the Balmer continuum. We conclude that care should be taken when calling SJI 2832 a continuum filter during flares, because the influence of the <span class="hlt">lines</span> on the <span class="hlt">emission</span> can be significant.« less</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_14 --> <div id="page_15" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="281"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017ApJ...836...58M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017ApJ...836...58M"><span>Searching for Dwarf H Alpha <span class="hlt">Emission-line</span> Galaxies within Voids III: First Spectra</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Moody, J. Ward; Draper, Christian; McNeil, Stephen; Joner, Michael D.</p> <p>2017-02-01</p> <p>The presence or absence of dwarf galaxies with {M}r\\prime > -14 in low-density voids is determined by the nature of dark matter halos. To better understand what this nature is, we are conducting an imaging survey through redshifted Hα filters to look for <span class="hlt">emission-line</span> dwarf galaxies in the centers of two nearby galaxy voids called FN2 and FN8. Either finding such dwarfs or establishing that they are not present is a significant result. As an important step in establishing the robustness of the search technique, we have observed six candidates from the survey of FN8 with the Gillett Gemini telescope and GMOS spectrometer. All of these candidates had <span class="hlt">emission</span>, although none was Hα. The <span class="hlt">emission</span> in two objects was the [O III]λ4959, 5007 doublet plus Hβ, and the <span class="hlt">emission</span> in the remaining four was the [O II]λ3727 doublet, all from objects beyond the void. While no objects were within the void, these spectra show that the survey is capable of finding <span class="hlt">emission-line</span> dwarfs in the void centers that are as faint as {M}r\\prime ˜ -12.4, should they be present. These spectra also show that redshifts estimated from our filtered images are accurate to several hundred km s-1 if the <span class="hlt">line</span> is identified correctly, encouraging further work in finding ways to conduct redshift surveys through imaging alone.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22364056-alma-determine-spectroscopic-redshift-fir-iii-emission-lines','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22364056-alma-determine-spectroscopic-redshift-fir-iii-emission-lines"><span>ALMA WILL DETERMINE THE SPECTROSCOPIC REDSHIFT z > 8 WITH FIR [O III] <span class="hlt">EMISSION</span> <span class="hlt">LINES</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Inoue, A. K.; Shimizu, I.; Tamura, Y.</p> <p></p> <p>We investigate the potential use of nebular <span class="hlt">emission</span> <span class="hlt">lines</span> in the rest-frame far-infrared (FIR) for determining spectroscopic redshift of z > 8 galaxies with the Atacama Large Millimeter/submillimeter Array (ALMA). After making a <span class="hlt">line</span> <span class="hlt">emissivity</span> model as a function of metallicity, especially for the [O III] 88 μm <span class="hlt">line</span> which is likely to be the strongest FIR <span class="hlt">line</span> from H II regions, we predict the <span class="hlt">line</span> fluxes from high-z galaxies based on a cosmological hydrodynamics simulation of galaxy formation. Since the metallicity of galaxies reaches at ∼0.2 Z {sub ☉} even at z > 8 in our simulation, we expectmore » the [O III] 88 μm <span class="hlt">line</span> as strong as 1.3 mJy for 27 AB objects, which is detectable at a high significance by <1 hr integration with ALMA. Therefore, the [O III] 88 μm <span class="hlt">line</span> would be the best tool to confirm the spectroscopic redshifts beyond z = 8.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JGRA..122.8770T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JGRA..122.8770T"><span>Sixteen year variation of horizontal phase velocity and propagation direction of mesospheric and thermospheric waves in <span class="hlt">airglow</span> images at Shigaraki, Japan</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Takeo, D.; Shiokawa, K.; Fujinami, H.; Otsuka, Y.; Matsuda, T. S.; Ejiri, M. K.; Nakamura, T.; Yamamoto, M.</p> <p>2017-08-01</p> <p>We analyzed the horizontal phase velocity of gravity waves and medium-scale traveling ionospheric disturbances (MSTIDs) by using the three-dimensional fast Fourier transform method developed by Matsuda et al. (2014) for 557.7 nm (altitude: 90-100 km) and 630.0 nm (altitude: 200-300 km) <span class="hlt">airglow</span> images obtained at Shigaraki MU Observatory (34.8°N, 136.1°E, dip angle: 49°) over ˜16 years from 16 March 1999 to 20 February 2015. The analysis of 557.7 nm <span class="hlt">airglow</span> images shows clear seasonal variation of the propagation direction of gravity waves in the mesopause region. In spring, summer, fall, and winter, the peak directions are northeastward, northeastward, northwestward, and southwestward, respectively. The difference in east-west propagation direction between summer and winter is probably caused by the wind filtering effect due to the zonal mesospheric jet. Comparison with tropospheric reanalysis data shows that the difference in north-south propagation direction between summer and winter is caused by differences in the latitudinal location of wave sources due to convective activity in the troposphere relative to Shigaraki. The analysis of 630.0 nm <span class="hlt">airglow</span> images shows that the propagation direction of MSTIDs is mainly southwestward with a minor northeastward component throughout the 16 years. A clear negative correlation is seen between the yearly power spectral density of MSTIDs and F10.7 solar flux. This negative correlation with solar activity may be explained by the linear growth rate of the Perkins instability and secondary wave generation of gravity waves in the thermosphere.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AAS...22733404Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AAS...22733404Z"><span>The Impact of Diffuse Ionized Gas on <span class="hlt">Emission-line</span> Ratios and Gas Metallicity Measurements</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, Kai; Yan, Renbin; MaNGA Team</p> <p>2016-01-01</p> <p>Diffuse Ionized Gas (DIG) is prevalent in star-forming galaxies. Using a sample of galaxies observed by MaNGA, we demonstrate how DIG in star-forming galaxies impact the measurements of <span class="hlt">emission</span> <span class="hlt">line</span> ratios, hence the gas-phase metallicity measurements and the interpretation of diagnostic diagrams. We demonstrate that <span class="hlt">emission</span> <span class="hlt">line</span> surface brightness (SB) is a reasonably good proxy to separate HII regions from regions dominated by diffuse ionized gas. For spatially-adjacent regions or regions at the same radius, many <span class="hlt">line</span> ratios change systematically with <span class="hlt">emission</span> <span class="hlt">line</span> surface brightness, reflecting a gradual increase of dominance by DIG towards low SB. DIG could significantly bias the measurement of gas metallicity and metallicity gradient. Because DIG tend to have a higher temperature than HII regions, at fixed metallicity DIG displays lower [NII]/[OII] ratios. DIG also show lower [OIII]/[OII] ratios than HII regions, due to extended partially-ionized regions that enhance all low-ionization <span class="hlt">lines</span> ([NII], [SII], [OII], [OI]). The contamination by DIG is responsible for a substantial portion of the scatter in metallicity measurements. At different surface brightness, <span class="hlt">line</span> ratios and <span class="hlt">line</span> ratio gradients can differ systematically. As DIG fraction could change with radius, it can affect the metallicity gradient measurements in systematic ways. The three commonly used strong-<span class="hlt">line</span> metallicity indicators, R23, [NII]/[OII], O3N2, are all affected in different ways. To make robust metallicity gradient measurements, one has to properly isolate HII regions and correct for DIG contamination. In <span class="hlt">line</span> ratio diagnostic diagrams, contamination by DIG moves HII regions towards composite or LINER-like regions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA083025','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA083025"><span>Theoretical Investigation of the Effects of Atmospheric Gravity Waves on the Hydroxyl <span class="hlt">Emissions</span> of the Atmosphere.</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>1979-12-31</p> <p>of response etc. have been treated by Thome (1968), Testud and Francois (1971), Klostermeyer (1972a,b) and Porter and Tuan (1974). With the ex...and provided a suitable physical -2- -- 2 - -- explanation. Subsequent theoretical papers by Testud and Francois (1971), Klostermeyer (1971a,b) and...01 <span class="hlt">airglow</span> <span class="hlt">emission</span> intensity on Oct. 28-29, 1961, Nature 195, 481-482 (1962). (26) Testud , J. and P. Francois, Importance of diffusion processes in</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018AIPC.1953n0028K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018AIPC.1953n0028K"><span>Study of chemical shift in Kα, Kβ1,3 and Kβ// X-ray <span class="hlt">emission</span> <span class="hlt">lines</span> of 37Rb compounds with WDXRF</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kainth, Harpreet Singh; Singh, Ranjit; Singh, Tejbir; Mehta, D.; Shahi, J. S.; Kumar, Sanjeev</p> <p>2018-05-01</p> <p>The positive and negative chemical shifts in Kα, Kβ1,3 and Kβ// X-ray <span class="hlt">emission</span> <span class="hlt">lines</span> of rubidium compounds were measured with high resolution WDXRF spectrometer. The measured energy shifts in Kα <span class="hlt">emission</span> <span class="hlt">lines</span> ranges from -2.95 eV to -3.64 eV, Kβ1,3 <span class="hlt">emission</span> <span class="hlt">lines</span> ranges from 1.16 eV to 1.32 eV and Kβ// <span class="hlt">emission</span> <span class="hlt">lines</span> ranges from 1.31 eV to 4.36 eV respectively. In the present work, it has been found that chemical shift in Kβ// X-ray <span class="hlt">emission</span> <span class="hlt">lines</span> were found to be larger than Kα and Kβ1,3 X-ray <span class="hlt">emission</span> <span class="hlt">lines</span>. To find the cause of chemical shift, various factors like effective charge, <span class="hlt">line</span> intensity ratio, bond length and electro-negativity were calculated and correlated with the chemical shift.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19820017151','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19820017151"><span>B Stars with and without <span class="hlt">emission</span> <span class="hlt">lines</span>, parts 1 and 2</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Underhill, A. (Editor); Doazan, V. (Editor)</p> <p>1982-01-01</p> <p>The spectra for B stars for which <span class="hlt">emission</span> <span class="hlt">lines</span> occur not on the main sequence, but only among the supergiants, and those B stars for which the presence of <span class="hlt">emission</span> in H ahlpa is considered to be a significant factor in delineating atmospheric structure are examined. The development of models that are compatible with all known facts about a star and with the laws of physics is also discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017ApJ...842...15L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017ApJ...842...15L"><span>An Explanation of Remarkable <span class="hlt">Emission-line</span> Profiles in Post-flare Coronal Rain</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lacatus, Daniela A.; Judge, Philip G.; Donea, Alina</p> <p>2017-06-01</p> <p>We study broad redshifted <span class="hlt">emission</span> in chromospheric and transition region <span class="hlt">lines</span> that appears to correspond to a form of post-flare coronal rain. Profiles of Mg II, C II, and Si IV <span class="hlt">lines</span> were obtained using IRIS before, during, and after the X2.1 flare of 2015 March 11 (SOL2015-03-11T16:22). We analyze the profiles of the five transitions of Mg II (the 3p-3s h and k transitions, and three <span class="hlt">lines</span> belonging to the 3d-3p transitions). We use analytical methods to understand the unusual profiles, together with higher-resolution observational data of similar phenomena observed by Jing et al. The peculiar <span class="hlt">line</span> ratios indicate anisotropic <span class="hlt">emission</span> from the strands that have cross-strand <span class="hlt">line</span> center optical depths (k <span class="hlt">line</span>) of between 1 and 10. The <span class="hlt">lines</span> are broadened by unresolved Alfvénic motions whose energy exceeds the radiation losses in the Mg II <span class="hlt">lines</span> by an order of magnitude. The decay of the <span class="hlt">line</span> widths is accompanied by a decay in the brightness, suggesting a causal connection. If the plasma is ≲99% ionized, ion-neutral collisions can account for the dissipation; otherwise, a dynamical process seems necessary. Our work implies that the motions are initiated during the impulsive phase, to be dissipated as radiation over a period of an hour, predominantly by strong chromospheric <span class="hlt">lines</span>. The coronal “rain” we observe is far more turbulent than most earlier reports have indicated, with implications for plasma heating mechanisms.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19740051854&hterms=Dissociative&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3DDissociative','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19740051854&hterms=Dissociative&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3DDissociative"><span>The 6300 A O/1-D/ <span class="hlt">airglow</span> and dissociative recombination</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wickwar, V. B.; Cogger, L. L.; Carlson, H. C.</p> <p>1974-01-01</p> <p>Measurements of night-time 6300 A <span class="hlt">airglow</span> intensities at the Arecibo Observatory have been compared with dissociative recombination calculations based on electron densities derived from simultaneous incoherent backscatter measurements. The agreement indicates that the nightglow can be fully accounted for by dissociative recombination. The comparisons are examined to determine the importance of quenching, heavy ions, ionization above the F-layer peak, and the temperature parameter of the model atmosphere. Comparable fits between the observed and calculated intensities are found for several available model atmospheres. The least-squares fitting process, used to make the comparisons, produces comparable fits over a wide range of combinations of neutral densities and of reaction constants. Yet, the fitting places constraints upon the possible combinations; these constraints indicate that the latest laboratory chemical constants and densities extrapolated to a base altitude are mutually consistent.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015MNRAS.453..122S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015MNRAS.453..122S"><span>A support vector machine for spectral classification of <span class="hlt">emission-line</span> galaxies from the Sloan Digital Sky Survey</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shi, Fei; Liu, Yu-Yan; Sun, Guang-Lan; Li, Pei-Yu; Lei, Yu-Ming; Wang, Jian</p> <p>2015-10-01</p> <p>The <span class="hlt">emission-lines</span> of galaxies originate from massive young stars or supermassive blackholes. As a result, spectral classification of <span class="hlt">emission-line</span> galaxies into star-forming galaxies, active galactic nucleus (AGN) hosts, or compositions of both relates closely to formation and evolution of galaxy. To find efficient and automatic spectral classification method, especially in large surveys and huge data bases, a support vector machine (SVM) supervised learning algorithm is applied to a sample of <span class="hlt">emission-line</span> galaxies from the Sloan Digital Sky Survey (SDSS) data release 9 (DR9) provided by the Max Planck Institute and the Johns Hopkins University (MPA/JHU). A two-step approach is adopted. (i) The SVM must be trained with a subset of objects that are known to be AGN hosts, composites or star-forming galaxies, treating the strong <span class="hlt">emission-line</span> flux measurements as input feature vectors in an n-dimensional space, where n is the number of strong <span class="hlt">emission-line</span> flux ratios. (ii) After training on a sample of <span class="hlt">emission-line</span> galaxies, the remaining galaxies are automatically classified. In the classification process, we use a 10-fold cross-validation technique. We show that the classification diagrams based on the [N II]/Hα versus other <span class="hlt">emission-line</span> ratio, such as [O III]/Hβ, [Ne III]/[O II], ([O III]λ4959+[O III]λ5007)/[O III]λ4363, [O II]/Hβ, [Ar III]/[O III], [S II]/Hα, and [O I]/Hα, plus colour, allows us to separate unambiguously AGN hosts, composites or star-forming galaxies. Among them, the diagram of [N II]/Hα versus [O III]/Hβ achieved an accuracy of 99 per cent to separate the three classes of objects. The other diagrams above give an accuracy of ˜91 per cent.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2012-title40-vol34/pdf/CFR-2012-title40-vol34-sec1048-320.pdf','CFR2012'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2012-title40-vol34/pdf/CFR-2012-title40-vol34-sec1048-320.pdf"><span>40 CFR 1048.320 - What happens if one of my production-<span class="hlt">line</span> engines fails to meet <span class="hlt">emission</span> standards?</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2012&page.go=Go">Code of Federal Regulations, 2012 CFR</a></p> <p></p> <p>2012-07-01</p> <p>...-<span class="hlt">line</span> engines fails to meet <span class="hlt">emission</span> standards? 1048.320 Section 1048.320 Protection of Environment...-<span class="hlt">line</span> engines fails to meet <span class="hlt">emission</span> standards? If you have a production-<span class="hlt">line</span> engine with final... conformity is automatically suspended for that failing engine. You must take the following actions before...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2010-title40-vol32/pdf/CFR-2010-title40-vol32-sec1048-320.pdf','CFR'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2010-title40-vol32/pdf/CFR-2010-title40-vol32-sec1048-320.pdf"><span>40 CFR 1048.320 - What happens if one of my production-<span class="hlt">line</span> engines fails to meet <span class="hlt">emission</span> standards?</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2010&page.go=Go">Code of Federal Regulations, 2010 CFR</a></p> <p></p> <p>2010-07-01</p> <p>...-<span class="hlt">line</span> engines fails to meet <span class="hlt">emission</span> standards? 1048.320 Section 1048.320 Protection of Environment...-<span class="hlt">line</span> engines fails to meet <span class="hlt">emission</span> standards? If you have a production-<span class="hlt">line</span> engine with final... conformity is automatically suspended for that failing engine. You must take the following actions before...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2011-title40-vol33/pdf/CFR-2011-title40-vol33-sec1048-320.pdf','CFR2011'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2011-title40-vol33/pdf/CFR-2011-title40-vol33-sec1048-320.pdf"><span>40 CFR 1048.320 - What happens if one of my production-<span class="hlt">line</span> engines fails to meet <span class="hlt">emission</span> standards?</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2011&page.go=Go">Code of Federal Regulations, 2011 CFR</a></p> <p></p> <p>2011-07-01</p> <p>...-<span class="hlt">line</span> engines fails to meet <span class="hlt">emission</span> standards? 1048.320 Section 1048.320 Protection of Environment...-<span class="hlt">line</span> engines fails to meet <span class="hlt">emission</span> standards? If you have a production-<span class="hlt">line</span> engine with final... conformity is automatically suspended for that failing engine. You must take the following actions before...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016MNRAS.460..634S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016MNRAS.460..634S"><span>Detection of <span class="hlt">emission</span> <span class="hlt">lines</span> from z ˜ 3 DLAs towards the QSO J2358+0149</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Srianand, Raghunathan; Hussain, Tanvir; Noterdaeme, Pasquier; Petitjean, Patrick; Krühler, Thomas; Japelj, Jure; Pâris, Isabelle; Kashikawa, Nobunari</p> <p>2016-07-01</p> <p>Using VLT/X-shooter, we searched for <span class="hlt">emission</span> <span class="hlt">line</span> galaxies associated with four damped Lyman α systems (DLAs) and one sub-DLA at 2.73 ≤z ≤3.25 towards QSO J2358+0149. We detect [O III] <span class="hlt">emission</span> from a `low-cool' DLA at zabs = 2.9791 (having log N(H I) = 21.69 ± 0.10, [Zn/H] = -1.83 ± 0.18) at an impact parameter of, ρ ˜ 12 kpc. The associated galaxy is compact with a dynamical mass of (1-6) × 109 M⊙, very high excitation ([O III]/[O II] and [O III]/[Hβ] both greater than 10), 12+[O/H]≤8.5 and moderate star formation rate (SFR ≤2 M⊙ yr-1). Such properties are typically seen in the low-z extreme blue compact dwarf galaxies. The kinematics of the gas is inconsistent with that of an extended disc and the gas is part of either a large scale wind or cold accretion. We detect Lyα <span class="hlt">emission</span> from the zabs = 3.2477 DLA [having log N(H I) = 21.12 ± 0.10 and [Zn/H] = -0.97 ± 0.13]. The Lyα <span class="hlt">emission</span> is redshifted with respect to the metal absorption <span class="hlt">lines</span> by 320 km s-1, consistent with the location of the red hump expected in radiative transport models. We derive SFR ˜0.2-1.7 M⊙ yr-1 and Lyα escape fraction of ≥10 per cent. No other <span class="hlt">emission</span> <span class="hlt">line</span> is detected from this system. Because the DLA has a small velocity separation from the quasar (˜500 km s-1) and the DLA <span class="hlt">emission</span> is located within a small projected distance (ρ < 5 kpc), we also explore the possibility that the Lyα <span class="hlt">emission</span> is being induced by the QSO itself. QSO-induced Lyα fluorescence is possible if the DLA is within a physical separation of 340 kpc to the QSO. Detection of stellar continuum light and/or the oxygen <span class="hlt">emission</span> <span class="hlt">lines</span> would disfavour this possibility. We do not detect any <span class="hlt">emission</span> <span class="hlt">line</span> from the remaining three systems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AMT.....9.5955S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AMT.....9.5955S"><span>High-resolution observations of small-scale gravity waves and turbulence features in the OH <span class="hlt">airglow</span> layer</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sedlak, René; Hannawald, Patrick; Schmidt, Carsten; Wüst, Sabine; Bittner, Michael</p> <p>2016-12-01</p> <p>A new version of the Fast <span class="hlt">Airglow</span> Imager (FAIM) for the detection of atmospheric waves in the OH <span class="hlt">airglow</span> layer has been set up at the German Remote Sensing Data Center (DFD) of the German Aerospace Center (DLR) at Oberpfaffenhofen (48.09° N, 11.28° E), Germany. The spatial resolution of the instrument is 17 m pixel-1 in zenith direction with a field of view (FOV) of 11.1 km × 9.0 km at the OH layer height of ca. 87 km. Since November 2015, the system has been in operation in two different setups (zenith angles 46 and 0°) with a temporal resolution of 2.5 to 2.8 s. In a first case study we present observations of two small wave-like features that might be attributed to gravity wave instabilities. In order to spectrally analyse harmonic structures even on small spatial scales down to 550 m horizontal wavelength, we made use of the maximum entropy method (MEM) since this method exhibits an excellent wavelength resolution. MEM further allows analysing relatively short data series, which considerably helps to reduce problems such as stationarity of the underlying data series from a statistical point of view. We present an observation of the subsequent decay of well-organized wave fronts into eddies, which we tentatively interpret in terms of an indication for the onset of turbulence. Another remarkable event which demonstrates the technical capabilities of the instrument was observed during the night of 4-5 April 2016. It reveals the disintegration of a rather homogenous brightness variation into several filaments moving in different directions and with different speeds. It resembles the formation of a vortex with a horizontal axis of rotation likely related to a vertical wind shear. This case shows a notable similarity to what is expected from theoretical modelling of Kelvin-Helmholtz instabilities (KHIs). The comparatively high spatial resolution of the presented new version of the FAIM provides new insights into the structure of atmospheric wave instability and</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009yCat.3256....0C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009yCat.3256....0C"><span>VizieR Online Data Catalog: Vatican <span class="hlt">Emission-line</span> stars (Coyne+ 1974-1983)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Coyne, G. V.; Lee, T. A.; de Graeve, E.; Wisniewski, W.; Corbally, C.; Otten, L. B.; MacConnell, D. J.</p> <p>2009-10-01</p> <p>The survey represents a search for Hα <span class="hlt">emission-line</span> stars, and was conducted with a 12{deg} objective prism on the Vatican Schmidt telescope. The Vatican <span class="hlt">Emission</span> Stars (VES) survey covers the galactic plane (|b|<=5{deg}) between galactic longitudes 58 and 174{deg}. The catalog was re-examined by B. Skiff (Lowell Observatory), and tne VES stars were cross-identified with modern surveys: GSC (Cat. I/255), Tycho-2 (I/256), 2MASS (II/246), IRAS point source catalog (II/125), MSX6C (V/114), CMC14 (I/304), GSC-2.3 (I/305), UCAC2 (I/289). Cross-identifications are also supplied with HD/BD/GCVS names, and with Dearborn catalog of red stars (II/68). Many of the stars in the first four papers are not early-type <span class="hlt">emission-line</span> stars, but instead M giants, where the sharp TiO bandhead at 6544{AA} was mistaken for H-{alpha} <span class="hlt">emission</span> on the objective-prism plates. Based on the revision of paper V and a later list prepared by Jack MacConnell, a column identifies the "non H-alpha" stars explicitly. The links with the Dearborn, IRAS, and MSX catalogues help identify the red stars. These and other identifications and comments are given in the remarks at the end of each <span class="hlt">line</span>, or in longer notes in a separate file, indicated by an asterisk (*) next to the star number. (3 data files).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008yCat.3256....0C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008yCat.3256....0C"><span>VizieR Online Data Catalog: Vatican <span class="hlt">Emission-line</span> stars (Coyne+ 1974-1983)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Coyne, G. V.; Lee, T. A.; de Graeve, E.; Wisniewski, W.; Corbally, C.; Otten, L. B.; MacConnell, D. J.</p> <p>2008-03-01</p> <p>The survey represents a search for Hα <span class="hlt">emission-line</span> stars, and was conducted with a 12{deg} objective prism on the Vatican Schmidt telescope. The Vatican <span class="hlt">Emission</span> Stars (VES) survey covers the galactic plane (|b|<=5{deg}) between galactic longitudes 58 and 174{deg}. The catalog was re-examined by B. Skiff (Lowell Observatory), and tne VES stars were cross-identified with modern surveys: GSC (Cat. I/255), Tycho-2 (I/256), 2MASS (II/246), IRAS point source catalog (II/125), MSX6C (V/114), CMC14 (I/304), GSC-2.3 (I/305), UCAC2 (I/289). Cross-identifications are also supplied with HD/BD/GCVS names, and with Dearborn catalog of red stars (II/68). Many of the stars in the first four papers are not early-type <span class="hlt">emission-line</span> stars, but instead M giants, where the sharp TiO bandhead at 6544{AA} was mistaken for H-{alpha} <span class="hlt">emission</span> on the objective-prism plates. Based on the revision of paper V and a later list prepared by Jack MacConnell, a column identifies the "non H-alpha" stars explicitly. The links with the Dearborn, IRAS, and MSX catalogues help identify the red stars. These and other identifications and comments are given in the remarks at the end of each <span class="hlt">line</span>, or in longer notes in a separate file, indicated by an asterisk (*) next to the star number. (2 data files).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2012-title40-vol34/pdf/CFR-2012-title40-vol34-sec1045-320.pdf','CFR2012'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2012-title40-vol34/pdf/CFR-2012-title40-vol34-sec1045-320.pdf"><span>40 CFR 1045.320 - What happens if one of my production-<span class="hlt">line</span> engines fails to meet <span class="hlt">emission</span> standards?</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2012&page.go=Go">Code of Federal Regulations, 2012 CFR</a></p> <p></p> <p>2012-07-01</p> <p>...-<span class="hlt">line</span> engines fails to meet <span class="hlt">emission</span> standards? 1045.320 Section 1045.320 Protection of Environment... production-<span class="hlt">line</span> engines fails to meet <span class="hlt">emission</span> standards? (a) If you have a production-<span class="hlt">line</span> engine with final... conformity is automatically suspended for that failing engine. You must take the following actions before...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2010-title40-vol32/pdf/CFR-2010-title40-vol32-sec1045-320.pdf','CFR'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2010-title40-vol32/pdf/CFR-2010-title40-vol32-sec1045-320.pdf"><span>40 CFR 1045.320 - What happens if one of my production-<span class="hlt">line</span> engines fails to meet <span class="hlt">emission</span> standards?</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2010&page.go=Go">Code of Federal Regulations, 2010 CFR</a></p> <p></p> <p>2010-07-01</p> <p>...-<span class="hlt">line</span> engines fails to meet <span class="hlt">emission</span> standards? 1045.320 Section 1045.320 Protection of Environment... production-<span class="hlt">line</span> engines fails to meet <span class="hlt">emission</span> standards? (a) If you have a production-<span class="hlt">line</span> engine with final... conformity is automatically suspended for that failing engine. You must take the following actions before...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2011-title40-vol33/pdf/CFR-2011-title40-vol33-sec1054-320.pdf','CFR2011'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2011-title40-vol33/pdf/CFR-2011-title40-vol33-sec1054-320.pdf"><span>40 CFR 1054.320 - What happens if one of my production-<span class="hlt">line</span> engines fails to meet <span class="hlt">emission</span> standards?</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2011&page.go=Go">Code of Federal Regulations, 2011 CFR</a></p> <p></p> <p>2011-07-01</p> <p>...-<span class="hlt">line</span> engines fails to meet <span class="hlt">emission</span> standards? 1054.320 Section 1054.320 Protection of Environment... production-<span class="hlt">line</span> engines fails to meet <span class="hlt">emission</span> standards? (a) If you have a production-<span class="hlt">line</span> engine with final... conformity is automatically suspended for that failing engine. You must take the following actions before...</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_15 --> <div id="page_16" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="301"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2011-title40-vol33/pdf/CFR-2011-title40-vol33-sec1045-320.pdf','CFR2011'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2011-title40-vol33/pdf/CFR-2011-title40-vol33-sec1045-320.pdf"><span>40 CFR 1045.320 - What happens if one of my production-<span class="hlt">line</span> engines fails to meet <span class="hlt">emission</span> standards?</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2011&page.go=Go">Code of Federal Regulations, 2011 CFR</a></p> <p></p> <p>2011-07-01</p> <p>...-<span class="hlt">line</span> engines fails to meet <span class="hlt">emission</span> standards? 1045.320 Section 1045.320 Protection of Environment... production-<span class="hlt">line</span> engines fails to meet <span class="hlt">emission</span> standards? (a) If you have a production-<span class="hlt">line</span> engine with final... conformity is automatically suspended for that failing engine. You must take the following actions before...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2012-title40-vol34/pdf/CFR-2012-title40-vol34-sec1054-320.pdf','CFR2012'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2012-title40-vol34/pdf/CFR-2012-title40-vol34-sec1054-320.pdf"><span>40 CFR 1054.320 - What happens if one of my production-<span class="hlt">line</span> engines fails to meet <span class="hlt">emission</span> standards?</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2012&page.go=Go">Code of Federal Regulations, 2012 CFR</a></p> <p></p> <p>2012-07-01</p> <p>...-<span class="hlt">line</span> engines fails to meet <span class="hlt">emission</span> standards? 1054.320 Section 1054.320 Protection of Environment... production-<span class="hlt">line</span> engines fails to meet <span class="hlt">emission</span> standards? (a) If you have a production-<span class="hlt">line</span> engine with final... conformity is automatically suspended for that failing engine. You must take the following actions before...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012ApJ...747...92M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012ApJ...747...92M"><span>First Detection of Near-infrared <span class="hlt">Line</span> <span class="hlt">Emission</span> from Organics in Young Circumstellar Disks</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mandell, Avi M.; Bast, Jeanette; van Dishoeck, Ewine F.; Blake, Geoffrey A.; Salyk, Colette; Mumma, Michael J.; Villanueva, Geronimo</p> <p>2012-03-01</p> <p>We present an analysis of high-resolution spectroscopy of several bright T Tauri stars using the CRIRES spectrograph on the Very Large Telescope and NIRSPEC spectrograph on the Keck Telescope, revealing the first detections of <span class="hlt">emission</span> from HCN and C2H2 in circumstellar disks at near-infrared wavelengths. Using advanced data reduction techniques, we achieve a dynamic range with respect to the disk continuum of ~500 at 3 μm, revealing multiple <span class="hlt">emission</span> features of H2O, OH, HCN, and C2H2. We also present stringent upper limits for two other molecules thought to be abundant in the inner disk, CH4 and NH3. <span class="hlt">Line</span> profiles for the different detected molecules are broad but centrally peaked in most cases, even for disks with previously determined inclinations of greater than 20°, suggesting that the <span class="hlt">emission</span> has both a Keplerian and non-Keplerian component as observed previously for CO <span class="hlt">emission</span>. We apply two different modeling strategies to constrain the molecular abundances and temperatures: we use a simplified single-temperature local thermal equilibrium (LTE) slab model with a Gaussian <span class="hlt">line</span> profile to make <span class="hlt">line</span> identifications and determine a best-fit temperature and initial abundance ratios, and we compare these values with constraints derived from a detailed disk radiative transfer model assuming LTE excitation but utilizing a realistic temperature and density structure. Abundance ratios from both sets of models are consistent with each other and consistent with expected values from theoretical chemical models, and analysis of the <span class="hlt">line</span> shapes suggests that the molecular <span class="hlt">emission</span> originates from within a narrow region in the inner disk (R < 1 AU). Based partially on observations collected at the European Southern Observatory Very Large Telescope under program ID 179.C-0151, program ID 283.C-5016, and program ID 082.C-0432 (P.I.: Pontopiddan).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMSA24A..07G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMSA24A..07G"><span>Statistical comparisons of gravity wave features derived from OH <span class="hlt">airglow</span> and SABER data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gelinas, L. J.; Hecht, J. H.; Walterscheid, R. L.</p> <p>2017-12-01</p> <p>The Aerospace Corporation's near-IR camera (ANI), deployed at Andes Lidar Observatory (ALO), Cerro Pachon Chile (30S,70W) since 2010, images the bright OH Meinel (4,2) <span class="hlt">airglow</span> band. The imager provides detailed observations of gravity waves and instability dynamics, as described by Hecht et al. (2014). The camera employs a wide-angle lens that views a 73 by 73 degree region of the sky, approximately 120 km x 120 km at 85 km altitude. Image cadence of 30s allows for detailed spectral analysis of the horizontal components of wave features, including the evolution and decay of instability features. The SABER instrument on NASA's TIMED spacecraft provides remote soundings of kinetic temperature profiles from the lower stratosphere to the lower thermosphere. Horizontal and vertical filtering techniques allow SABER temperatures to be analyzed for gravity wave variances [Walterscheid and Christensen, 2016]. Here we compare the statistical characteristics of horizontal wave spectra, derived from <span class="hlt">airglow</span> imagery, with vertical wave variances derived from SABER temperature profiles. The analysis is performed for a period of strong mountain wave activity over the Andes spanning the period between June and September 2012. Hecht, J. H., et al. (2014), The life cycle of instability features measured from the Andes Lidar Observatory over Cerro Pachon on March 24, 2012, J. Geophys. Res. Atmos., 119, 8872-8898, doi:10.1002/2014JD021726. Walterscheid, R. L., and A. B. Christensen (2016), Low-latitude gravity wave variances in the mesosphere and lower thermosphere derived from SABER temperature observation and compared with model simulation of waves generated by deep tropical convection, J. Geophys. Res. Atmos., 121, 11,900-11,912, doi:10.1002/2016JD024843.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22078299-flare-like-variability-mg-ii-lambda-emission-line-gamma-ray-blazar','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22078299-flare-like-variability-mg-ii-lambda-emission-line-gamma-ray-blazar"><span>FLARE-LIKE VARIABILITY OF THE Mg II {lambda}2800 <span class="hlt">EMISSION</span> <span class="hlt">LINE</span> IN THE {gamma}-RAY BLAZAR 3C 454.3</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Leon-Tavares, J.; Chavushyan, V.; Patino-Alvarez, V.</p> <p>2013-02-01</p> <p>We report the detection of a statistically significant flare-like event in the Mg II {lambda}2800 <span class="hlt">emission</span> <span class="hlt">line</span> of 3C 454.3 during the outburst of autumn 2010. The highest levels of <span class="hlt">emission</span> <span class="hlt">line</span> flux recorded over the monitoring period (2008-2011) coincide with a superluminal jet component traversing through the radio core. This finding crucially links the broad <span class="hlt">emission</span> <span class="hlt">line</span> fluctuations to the non-thermal continuum <span class="hlt">emission</span> produced by relativistically moving material in the jet and hence to the presence of broad-<span class="hlt">line</span> region clouds surrounding the radio core. If the radio core were located at several parsecs from the central black hole, thenmore » our results would suggest the presence of broad-<span class="hlt">line</span> region material outside the inner parsec where the canonical broad-<span class="hlt">line</span> region is envisaged to be located. We briefly discuss the implications of broad <span class="hlt">emission</span> <span class="hlt">line</span> material ionized by non-thermal continuum in the context of virial black hole mass estimates and gamma-ray production mechanisms.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017SPIE10466E..1NI','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017SPIE10466E..1NI"><span>Anomalous broadening and shift of <span class="hlt">emission</span> <span class="hlt">lines</span> in filaments</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ilyin, A. A.; Golik, S. S.; Shmirko, K. A.; Mayor, A. Yu.; Proschenko, D. Yu.</p> <p>2017-11-01</p> <p>The temporal evolution of width and shift of N I 746.8 and O I 777.4 nm <span class="hlt">lines</span> is investigated in filament plasma produced by tightly focused femtosecond laser pulse (0.9 mJ, 48 fs). Nitrogen <span class="hlt">line</span> shift is determined by joint action of electron impact shift and far-off resonance AC Stark effect. Intensive (I 1010 W/cm2 ) electric field of ASE and postpulses result in possible LS coupling break for O I 3p 5P level and generation of Rabi sidebands. The blue-shifted main femtosecond pulse and Rabi sideband cause the stimulated <span class="hlt">emission</span> of N21+ system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018ApJ...859...50F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018ApJ...859...50F"><span>Microlensing and Intrinsic Variability of the Broad <span class="hlt">Emission</span> <span class="hlt">Lines</span> of Lensed Quasars</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fian, C.; Guerras, Eduardo; Mediavilla, E.; Jiménez-Vicente, J.; Muñoz, J. A.; Falco, E. E.; Motta, V.; Hanslmeier, A.</p> <p>2018-05-01</p> <p>We study the broad <span class="hlt">emission</span> <span class="hlt">lines</span> in a sample of 11 gravitationally lensed quasars with at least two epochs of observation to identify intrinsic variability and to disentangle it from microlensing. To improve our statistical significance and emphasize trends, we also include 15 lens systems with single-epoch spectra. Mg II and C III] <span class="hlt">emission</span> <span class="hlt">lines</span> are only weakly affected by microlensing, but C IV shows strong microlensing in some cases, even for regions of the <span class="hlt">line</span> core, presumably associated with small projected velocities. However, excluding the strongly microlensed cases, there is a strikingly good match, on average, between the red wings of the C IV and C III] profiles. Analysis of these results supports the existence of two regions in the broad-<span class="hlt">line</span> region (BLR), one that is insensitive to microlensing (of size ≳50 lt-day and kinematics not confined to a plane) and another that shows up only when it is magnified by microlensing (of size of a few light-days, comparable to the accretion disk). Both regions can contribute in different proportions to the <span class="hlt">emission</span> <span class="hlt">lines</span> of different species and, within each <span class="hlt">line</span> profile, to different velocity bins, all of which complicates detailed studies of the BLR based on microlensing size estimates. The strength of the microlensing indicates that some spectral features that make up the pseudo-continuum, such as the shelf-like feature at λ1610 or several Fe III blends, may in part arise from an inner region of the accretion disk. In the case of Fe II, microlensing is strong in some blends but not in others. This opens up interesting possibilities to study quasar accretion disk kinematics. Intrinsic variability seems to affect the same features prone to microlensing, with similar frequency and amplitude, but does not induce outstanding profile asymmetries. We measure intrinsic variability (≲20%) of the wings with respect to the cores in the C IV, C III], and Mg II <span class="hlt">lines</span> consistent with reverberation mapping studies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19478778','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19478778"><span>Broad <span class="hlt">line</span> <span class="hlt">emission</span> from iron K- and L-shell transitions in the active galaxy 1H 0707-495.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Fabian, A C; Zoghbi, A; Ross, R R; Uttley, P; Gallo, L C; Brandt, W N; Blustin, A J; Boller, T; Caballero-Garcia, M D; Larsson, J; Miller, J M; Miniutti, G; Ponti, G; Reis, R C; Reynolds, C S; Tanaka, Y; Young, A J</p> <p>2009-05-28</p> <p>Since the 1995 discovery of the broad iron K-<span class="hlt">line</span> <span class="hlt">emission</span> from the Seyfert galaxy MCG-6-30-15 (ref. 1), broad iron K <span class="hlt">lines</span> have been found in <span class="hlt">emission</span> from several other Seyfert galaxies, from accreting stellar-mass black holes and even from accreting neutron stars. The iron K <span class="hlt">line</span> is prominent in the reflection spectrum created by the hard-X-ray continuum irradiating dense accreting matter. Relativistic distortion of the <span class="hlt">line</span> makes it sensitive to the strong gravity and spin of the black hole. The accompanying iron L-<span class="hlt">line</span> <span class="hlt">emission</span> should be detectable when the iron abundance is high. Here we report the presence of both iron K and iron L <span class="hlt">emission</span> in the spectrum of the narrow-<span class="hlt">line</span> Seyfert 1 galaxy 1H 0707-495. The bright iron L <span class="hlt">emission</span> has enabled us to detect a reverberation lag of about 30 s between the direct X-ray continuum and its reflection from matter falling into the black hole. The observed reverberation timescale is comparable to the light-crossing time of the innermost radii around a supermassive black hole. The combination of spectral and timing data on 1H 0707-495 provides strong evidence that we are witnessing <span class="hlt">emission</span> from matter within a gravitational radius, or a fraction of a light minute, from the event horizon of a rapidly spinning, massive black hole.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016SoPh..291.3549V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016SoPh..291.3549V"><span>Neutral Hydrogen and Its <span class="hlt">Emission</span> <span class="hlt">Lines</span> in the Solar Corona</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vial, Jean-Claude; Chane-Yook, Martine</p> <p>2016-12-01</p> <p>Since the Lyman-α rocket observations of Gabriel ( Solar Phys. 21, 392, 1971), it has been realized that the hydrogen (H) <span class="hlt">lines</span> could be observed in the corona and that they offer an interesting diagnostic for the temperature, density, and radial velocity of the coronal plasma. Moreover, various space missions have been proposed to measure the coronal magnetic and velocity fields through polarimetry in H <span class="hlt">lines</span>. A necessary condition for such measurements is to benefit from a sufficient signal-to-noise ratio. The aim of this article is to evaluate the <span class="hlt">emission</span> in three representative <span class="hlt">lines</span> of H for three different coronal structures. The computations have been performed with a full non-local thermodynamic-equilibrium (non-LTE) code and its simplified version without radiative transfer. Since all collisional and radiative quantities (including incident ionizing and exciting radiation) are taken into account, the ionization is treated exactly. Profiles are presented at two heights (1.05 and 1.9 solar radii, from Sun center) in the corona, and the integrated intensities are computed at heights up to five solar radii. We compare our results with previous computations and observations ( e.g. Lα from Ultraviolet Coronal Spectrometer) and find a rough (model-dependent) agreement. Since the Hα <span class="hlt">line</span> is a possible candidate for ground-based polarimetry, we show that in order to detect its <span class="hlt">emission</span> in various coronal structures, it is necessary to use a very narrow (less than 2 Å wide) bandpass filter.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018ApJ...856..171Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018ApJ...856..171Z"><span>A New Diagnostic Diagram of Ionization Sources for High-redshift <span class="hlt">Emission</span> <span class="hlt">Line</span> Galaxies</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, Kai; Hao, Lei</p> <p>2018-04-01</p> <p>We propose a new diagram, the kinematics–excitation (KEx) diagram, which uses the [O III] λ5007/Hβ <span class="hlt">line</span> ratio and the [O III] λ5007 <span class="hlt">emission</span> <span class="hlt">line</span> width (σ [O III]) to diagnose the ionization source and physical properties of active galactic nuclei (AGNs) and star-forming galaxies (SFGs). The KEx diagram is a suitable tool to classify <span class="hlt">emission</span> <span class="hlt">line</span> galaxies at intermediate redshift because it uses only the [O III] λ5007 and Hβ <span class="hlt">emission</span> <span class="hlt">lines</span>. We use the main galaxy sample of SDSS DR7 and the Baldwin‑Phillips‑Terlevich (BPT) diagnostic to calibrate the diagram at low redshift. The diagram can be divided into three regions: the KEx-AGN region, which consists mainly of pure AGNs, the KEx-composite region, which is dominated by composite galaxies, and the KEx-SFG region, which contains mostly SFGs. LINERs strongly overlap with the composite and AGN regions. AGNs are separated from SFGs in this diagram mainly because they preferentially reside in luminous and massive galaxies and have higher [O III]/Hβ than SFGs. The separation between AGNs and SFGs is even cleaner thanks to the additional 0.15/0.12 dex offset in σ [O III] at fixed luminosity/stellar mass. We apply the KEx diagram to 7866 galaxies at 0.3 < z < 1 in the DEEP2 Galaxy Redshift Survey, and compare it to an independent X-ray classification scheme using Chandra observations. X-ray AGNs are mostly located in the KEx-AGN region, while X-ray SFGs are mostly located in the KEx-SFG region. Almost all Type 1 AGNs lie in the KEx-AGN region. These tests support the reliability of this classification diagram for <span class="hlt">emission</span> <span class="hlt">line</span> galaxies at intermediate redshift. At z ∼ 2, the demarcation <span class="hlt">line</span> between SFGs and AGNs is shifted by ∼0.3 dex toward higher values of σ [O III] due to evolution effects.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20100024527','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20100024527"><span>HST WFC3 Early Release Science: <span class="hlt">Emission-Line</span> Galaxies from IR Grism Observations</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Straughn, A. N.; Kuntschner, H.; Kuemmel, M.; Walsh, J. R.; Cohen, S. H.; Gardner, J. P.; Windhorst, R. A.; O'Connell, R. W.; Pirzkal, N.; Meurer, G.; <a style="text-decoration: none; " href="javascript:void(0); " onClick="displayelement('author_20100024527'); toggleEditAbsImage('author_20100024527_show'); toggleEditAbsImage('author_20100024527_hide'); "> <img style="display:inline; width:12px; height:12px; " src="images/arrow-up.gif" width="12" height="12" border="0" alt="hide" id="author_20100024527_show"> <img style="width:12px; height:12px; display:none; " src="images/arrow-down.gif" width="12" height="12" border="0" alt="hide" id="author_20100024527_hide"></p> <p>2010-01-01</p> <p>We present grism spectra of <span class="hlt">emission</span> <span class="hlt">line</span> galaxies (ELGs) from 0.6-1.6 microns from the Wide Field Camera 3 (WFC3) on the Hubble Space Telescope (HST). These new infrared grism data augment previous optical Advanced Camera for Surveys G800L (0.6-0.95 micron) grism data in GOODS South, extending the wavelength coverage well past the G800L red cutoff. The ERS grism field was observed at a depth of 2 orbits per grism, yielding spectra of hundreds of faint objects, a subset of which are presented here. ELGs are studied via the Ha, [O III ], and [OII] <span class="hlt">emission</span> <span class="hlt">lines</span> detected in the redshift ranges 0.2 less than or equal to z less than or equal to 1.6, 1.2 less than or equal to z less than or equal to 2.4 and 2.0 less than or equal to z less than or equal to 3.6 respectively in the G102 (0.8-1.1 microns; R approximately 210) and C141 (1.1-1.6 microns; R approximately 130) grisms. The higher spectral resolution afforded by the WFC3 grisms also reveals <span class="hlt">emission</span> <span class="hlt">lines</span> not detectable with the G800L grism (e.g., [S II] and [S III] <span class="hlt">lines</span>). From these relatively shallow observations, <span class="hlt">line</span> luminosities, star formation rates, and grism spectroscopic redshifts are determined for a total of 25 ELGs to M(sub AB)(F098M) approximately 25 mag. The faintest source in our sample with a strong but unidentified <span class="hlt">emission</span> <span class="hlt">line</span>--is MAB(F098M)=26.9 mag. We also detect the expected trend of lower specific star formation rates for the highest mass galaxies in the sample, indicative of downsizing and discovered previously from large surveys. These results demonstrate the remarkable efficiency and capability of the WFC3 NIR grisms for measuring galaxy properties to faint magnitudes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20170002463','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20170002463"><span>Unreported <span class="hlt">Emission</span> <span class="hlt">Lines</span> of Rb, Ce, La, Sr, Y, Zr, Pb and Se Detected Using Laser-Induced Breakdown Spectroscopy</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lepore, K. H.; Mackie, J.; Dyar, M. D.; Fassett, C. I.</p> <p>2017-01-01</p> <p>Information on <span class="hlt">emission</span> <span class="hlt">lines</span> for major and minor elements is readily available from the National Institute of Standards and Technology (NIST) as part of the Atomic Spectra Database. However, tabulated <span class="hlt">emission</span> <span class="hlt">lines</span> are scarce for some minor elements and the wavelength ranges presented on the NIST database are limited to those included in existing studies. Previous work concerning minor element calibration curves measured using laser-induced break-down spectroscopy found evidence of Zn <span class="hlt">emission</span> <span class="hlt">lines</span> that were not documented on the NIST database. In this study, rock powders were doped with Rb, Ce, La, Sr, Y, Zr, Pb and Se in concentrations ranging from 10 percent to 10 parts per million. The difference between normalized spectra collected on samples containing 10 percent dopant and those containing only 10 parts per million were used to identify all <span class="hlt">emission</span> <span class="hlt">lines</span> that can be detected using LIBS (Laser-Induced Breakdown Spectroscopy) in a ChemCam-like configuration at the Mount Holyoke College LIBS facility. These <span class="hlt">emission</span> spectra provide evidence of many previously undocumented <span class="hlt">emission</span> <span class="hlt">lines</span> for the elements measured here.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-iss028e017123.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-iss028e017123.html"><span>Earth Observation</span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>2011-07-15</p> <p>ISS028-E-017123 (16 July 2011) --- Separate atmospheric optical phenomena were captured in this electronic still photograph from the Inernational Space Station. The thin greenish band stretching along the Earth's horizon is <span class="hlt">airglow</span>; light emitted by the atmosphere from a layer about 30 kilometers thick and about 100 kilometers in altitude. The predominant <span class="hlt">emission</span> in <span class="hlt">airglow</span> is the green 5577 Angstrom wavelength light from atomic oxygen atoms. <span class="hlt">Airglow</span> is always and everywhere present in the atmosphere; it results from the recombination of molecules that have been broken apart by solar radiation during the day. But <span class="hlt">airglow</span> is so faint that it can only be seen at night by looking "edge on" at the <span class="hlt">emission</span> layer, such as the view astronauts and cosmonauts have in orbit. The second phenomenon is the appearnce of Aurora Australis.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22370542-galaxy-emission-line-classification-using-three-dimensional-line-ratio-diagrams','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22370542-galaxy-emission-line-classification-using-three-dimensional-line-ratio-diagrams"><span>Galaxy <span class="hlt">emission</span> <span class="hlt">line</span> classification using three-dimensional <span class="hlt">line</span> ratio diagrams</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Vogt, Frédéric P. A.; Dopita, Michael A.; Kewley, Lisa J.</p> <p>2014-10-01</p> <p>Two-dimensional (2D) <span class="hlt">line</span> ratio diagnostic diagrams have become a key tool in understanding the excitation mechanisms of galaxies. The curves used to separate the different regions—H II-like or excited by an active galactic nucleus (AGN)—have been refined over time but the core technique has not evolved significantly. However, the classification of galaxies based on their <span class="hlt">emission</span> <span class="hlt">line</span> ratios really is a multi-dimensional problem. Here we exploit recent software developments to explore the potential of three-dimensional (3D) <span class="hlt">line</span> ratio diagnostic diagrams. We introduce the ZQE diagrams, which are a specific set of 3D diagrams that separate the oxygen abundance and themore » ionization parameter of H II region-like spectra and also enable us to probe the excitation mechanism of the gas. By examining these new 3D spaces interactively, we define the ZE diagnostics, a new set of 2D diagnostics that can provide the metallicity of objects excited by hot young stars and that cleanly separate H II region-like objects from the different classes of AGNs. We show that these ZE diagnostics are consistent with the key log [N II]/Hα versus log [O III]/Hβ diagnostic currently used by the community. They also have the advantage of attaching a probability that a given object belongs to one class or the other. Finally, we discuss briefly why ZQE diagrams can provide a new way to differentiate and study the different classes of AGNs in anticipation of a dedicated follow-up study.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1999AJ....117.1014H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1999AJ....117.1014H"><span>The Relationship between Ultraviolet <span class="hlt">Line</span> <span class="hlt">Emission</span> and Magnetic Field Strength in Magnetic Cataclysmic Variables</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Howell, Steve B.; Cash, Jennifer; Mason, Keith O.; Herzog, Adrienne E.</p> <p>1999-02-01</p> <p>We present the first UV spectral observations of six magnetic cataclysmic variables discovered by the ROSAT Wide Field Camera (WFC). Using the^ International Ultraviolet Explorer (IUE), 1200-3400 Å spectra were obtained of the AM Herculis stars RE 0531-46, RE 1149+28, RE 1844-74, QS Tel (RE 1938-46), and HU Aqr (RE 2107-05) and the DQ Herculis star PQ Gem (RE 0751+14). The high-state UV spectra are dominated by strong <span class="hlt">emission</span> <span class="hlt">lines</span>. Continuum flux distributions for these stars (from 100 to 5500 Å) reveal that over this entire range, none of the spectral energy distributions can be fitted by a single-valued blackbody. Our new UV observations and additional archival IUE spectra were used to discover a correlation between the strength of the high-state UV <span class="hlt">emission</span> <span class="hlt">lines</span> and the strength of the white dwarf magnetic field. Model spectral results are used to confirm the production of the UV <span class="hlt">emission</span> <span class="hlt">lines</span> by photoionization from X-ray and EUV photons.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016A%26A...592A..23B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016A%26A...592A..23B"><span>The different origins of high- and low-ionization broad <span class="hlt">emission</span> <span class="hlt">lines</span> revealed by gravitational microlensing in the Einstein cross</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Braibant, L.; Hutsemékers, D.; Sluse, D.; Anguita, T.</p> <p>2016-07-01</p> <p>We investigate the kinematics and ionization structure of the broad <span class="hlt">emission</span> <span class="hlt">line</span> region of the gravitationally lensed quasar QSO2237+0305 (the Einstein cross) using differential microlensing in the high- and low-ionization broad <span class="hlt">emission</span> <span class="hlt">lines</span>. We combine visible and near-infrared spectra of the four images of the lensed quasar and detect a large-amplitude microlensing effect distorting the high-ionization CIV and low-ionization Hα <span class="hlt">line</span> profiles in image A. While microlensing only magnifies the red wing of the Balmer <span class="hlt">line</span>, it symmetrically magnifies the wings of the CIV <span class="hlt">emission</span> <span class="hlt">line</span>. Given that the same microlensing pattern magnifies both the high- and low-ionization broad <span class="hlt">emission</span> <span class="hlt">line</span> regions, these dissimilar distortions of the <span class="hlt">line</span> profiles suggest that the high- and low-ionization regions are governed by different kinematics. Since this quasar is likely viewed at intermediate inclination, we argue that the differential magnification of the blue and red wings of Hα favors a flattened, virialized, low-ionization region whereas the symmetric microlensing effect measured in CIV can be reproduced by an <span class="hlt">emission</span> <span class="hlt">line</span> formed in a polar wind, without the need of fine-tuned caustic configurations. Based on observations made with the ESO-VLT, Paranal, Chile; Proposals 076.B-0197 and 076.B-0607 (PI: Courbin).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JGRD..122..846H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JGRD..122..846H"><span>Numerical modeling of a multiscale gravity wave event and its <span class="hlt">airglow</span> signatures over Mount Cook, New Zealand, during the DEEPWAVE campaign</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Heale, C. J.; Bossert, K.; Snively, J. B.; Fritts, D. C.; Pautet, P.-D.; Taylor, M. J.</p> <p>2017-01-01</p> <p>A 2-D nonlinear compressible model is used to simulate a large-amplitude, multiscale mountain wave event over Mount Cook, NZ, observed as part of the Deep Propagating Gravity Wave Experiment (DEEPWAVE) campaign and to investigate its observable signatures in the hydroxyl (OH) layer. The campaign observed the presence of a λx=200 km mountain wave as part of the 22nd research flight with amplitudes of >20 K in the upper stratosphere that decayed rapidly at <span class="hlt">airglow</span> heights. Advanced Mesospheric Temperature Mapper (AMTM) showed the presence of small-scale (25-28 km) waves within the warm phase of the large mountain wave. The simulation results show rapid breaking above 70 km altitude, with the preferential formation of almost-stationary vortical instabilities within the warm phase front of the mountain wave. An OH <span class="hlt">airglow</span> model is used to identify the presence of small-scale wave-like structures generated in situ by the breaking of the mountain wave that are consistent with those seen in the observations. While it is easy to interpret these feature as waves in OH <span class="hlt">airglow</span> data, a considerable fraction of the features are in fact instabilities and vortex structures. Simulations suggest that a combination of a large westward perturbation velocity and shear, in combination with strong perturbation temperature gradients, causes both dynamic and convective instability conditions to be met particularly where the wave wind is maximized and the temperature gradient is simultaneously minimized. This leads to the inevitable breaking and subsequent generation of smaller-scale waves and instabilities which appear most prominent within the warm phase front of the mountain wave.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018ApJ...854...29M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018ApJ...854...29M"><span>The Number Density Evolution of Extreme <span class="hlt">Emission</span> <span class="hlt">Line</span> Galaxies in 3D-HST: Results from a Novel Automated <span class="hlt">Line</span> Search Technique for Slitless Spectroscopy</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Maseda, Michael V.; van der Wel, Arjen; Rix, Hans-Walter; Momcheva, Ivelina; Brammer, Gabriel B.; Franx, Marijn; Lundgren, Britt F.; Skelton, Rosalind E.; Whitaker, Katherine E.</p> <p>2018-02-01</p> <p>The multiplexing capability of slitless spectroscopy is a powerful asset in creating large spectroscopic data sets, but issues such as spectral confusion make the interpretation of the data challenging. Here we present a new method to search for <span class="hlt">emission</span> <span class="hlt">lines</span> in the slitless spectroscopic data from the 3D-HST survey utilizing the Wide-Field Camera 3 on board the Hubble Space Telescope. Using a novel statistical technique, we can detect compact (extended) <span class="hlt">emission</span> <span class="hlt">lines</span> at 90% completeness down to fluxes of 1.5(3.0)× {10}-17 {erg} {{{s}}}-1 {{cm}}-2, close to the noise level of the grism exposures, for objects detected in the deep ancillary photometric data. Unlike previous methods, the Bayesian nature allows for probabilistic <span class="hlt">line</span> identifications, namely redshift estimates, based on secondary <span class="hlt">emission</span> <span class="hlt">line</span> detections and/or photometric redshift priors. As a first application, we measure the comoving number density of Extreme <span class="hlt">Emission</span> <span class="hlt">Line</span> Galaxies (restframe [O III] λ5007 equivalent widths in excess of 500 Å). We find that these galaxies are nearly 10× more common above z ∼ 1.5 than at z ≲ 0.5. With upcoming large grism surveys such as Euclid and WFIRST, as well as grisms featured prominently on the NIRISS and NIRCam instruments on the James Webb Space Telescope, methods like the one presented here will be crucial for constructing <span class="hlt">emission</span> <span class="hlt">line</span> redshift catalogs in an automated and well-understood manner. This work is based on observations taken by the 3D-HST Treasury Program and the CANDELS Multi-Cycle Treasury Program with the NASA/ESA HST, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19790037878&hterms=new+solar+panel&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dnew%2Bsolar%2Bpanel','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19790037878&hterms=new+solar+panel&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dnew%2Bsolar%2Bpanel"><span>Silicon X-ray <span class="hlt">line</span> <span class="hlt">emission</span> from solar flares and active regions</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Parkinson, J. H.; Wolff, R. S.; Kestenbaum, H. L.; Ku, W. H.-M.; Lemen, J. R.; Long, K. S.; Novick, R.; Suozzo, R. J.; Weisskopf, M. C.</p> <p>1978-01-01</p> <p>New observations of solar flare and active region X-ray spectra obtained with the Columbia University instrument on OSO-8 are presented and discussed. The high sensitivity of the graphite crystal panel has allowed both <span class="hlt">line</span> and continuum spectra to be served with moderate spectral resolution. Observations with higher spectral resolution have been made with a panel of pentaerythritol crystals. Twenty-nine <span class="hlt">lines</span> between 1.5 and 7.0 A have been resolved and identified, including several dielectronic recombination satellite <span class="hlt">lines</span> to Si XIV and Si XIII <span class="hlt">lines</span> which have been observed for the first time. It has been found that thermal continuum models specified by single values of temperature and <span class="hlt">emission</span> measure have fitted the data adequately, there being good agreement with the values of these parameters derived from <span class="hlt">line</span> intensity ratios.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018ApJ...856...78A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018ApJ...856...78A"><span>Intermediate-<span class="hlt">line</span> <span class="hlt">Emission</span> in AGNs: The Effect of Prescription of the Gas Density</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Adhikari, T. P.; Hryniewicz, K.; Różańska, A.; Czerny, B.; Ferland, G. J.</p> <p>2018-03-01</p> <p>The requirement of an intermediate-<span class="hlt">line</span> component in the recently observed spectra of several active galactic nuclei (AGNs) points to the possible existence of a physically separate region between the broad-<span class="hlt">line</span> region (BLR) and narrow-<span class="hlt">line</span> region (NLR). In this paper we explore the <span class="hlt">emission</span> from the intermediate-<span class="hlt">line</span> region (ILR) by using photoionization simulations of the gas clouds distributed radially from the center of the AGN. The gas clouds span distances typical for the BLR, ILR, and NLR, and the appearance of dust at the sublimation radius is fully taken into account in our model. The structure of a single cloud is calculated under the assumption of constant pressure. We show that the slope of the power-law radial profile of the cloud density does not affect the existence of the ILR in major types of AGNs. We found that the low-ionization iron <span class="hlt">line</span>, Fe II, appears to be highly sensitive to the presence of dust and therefore becomes a potential tracer of dust content in <span class="hlt">line</span>-emitting regions. We show that the use of a disk-like cloud density profile computed for the upper part of the atmosphere of the accretion disk reproduces the observed properties of the <span class="hlt">line</span> <span class="hlt">emissivities</span>. In particular, the distance of the Hβ <span class="hlt">line</span> inferred from our model agrees with that obtained from reverberation mapping studies in the Sy1 galaxy NGC 5548.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_16 --> <div id="page_17" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="321"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA008098','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA008098"><span>A Pocket Manual of the Physical and Chemical Characteristics of the Earth’s Atmosphere</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>1974-07-01</p> <p>20305 l< UOHITOAINC AOENCV NAME i AODRESS(" ""•’•"< ’""" Canlralllnt Olflea) READ INSTRUCTIONS BEFORE COMPLETING FORM t. RECIRlENT’l...ABSORPTION OF SOLAR UV - SCHUMANN-RUNGE NET OXYGEN FLUX <span class="hlt">AIRGLOW</span> (MAINLY OH-MEINEL) C02 <span class="hlt">EMISSION</span> (IR) GRAVITY WAVE DISSIPATION NUMBERS IN ERG CM...and lonlzatlon cross-sections of Oot N». and O at solar <span class="hlt">lines</span>. Cross-sections in megabarns (10-18cm2). (Source: R-12, Table3) ’. K Solar <span class="hlt">Line</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.A13D0374H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.A13D0374H"><span>Performance of a <span class="hlt">Line</span> Loss Correction Method for Gas Turbine <span class="hlt">Emission</span> Measurements</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hagen, D. E.; Whitefield, P. D.; Lobo, P.</p> <p>2015-12-01</p> <p>International concern for the environmental impact of jet engine exhaust <span class="hlt">emissions</span> in the atmosphere has led to increased attention on gas turbine engine <span class="hlt">emission</span> testing. The Society of Automotive Engineers Aircraft Exhaust <span class="hlt">Emissions</span> Measurement Committee (E-31) has published an Aerospace Information Report (AIR) 6241 detailing the sampling system for the measurement of non-volatile particulate matter from aircraft engines, and is developing an Aerospace Recommended Practice (ARP) for methodology and system specification. The Missouri University of Science and Technology (MST) Center for Excellence for Aerospace Particulate <span class="hlt">Emissions</span> Reduction Research has led numerous jet engine exhaust sampling campaigns to characterize <span class="hlt">emissions</span> at different locations in the expanding exhaust plume. Particle loss, due to various mechanisms, occurs in the sampling train that transports the exhaust sample from the engine exit plane to the measurement instruments. To account for the losses, both the size dependent penetration functions and the size distribution of the emitted particles need to be known. However in the proposed ARP, particle number and mass are measured, but size is not. Here we present a methodology to generate number and mass correction factors for <span class="hlt">line</span> loss, without using direct size measurement. A lognormal size distribution is used to represent the exhaust aerosol at the engine exit plane and is defined by the measured number and mass at the downstream end of the sample train. The performance of this <span class="hlt">line</span> loss correction is compared to corrections based on direct size measurements using data taken by MST during numerous engine test campaigns. The experimental uncertainty in these correction factors is estimated. Average differences between the <span class="hlt">line</span> loss correction method and size based corrections are found to be on the order of 10% for number and 2.5% for mass.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19820061070&hterms=Dwarf+stars&qs=N%3D0%26Ntk%3DTitle%26Ntx%3Dmode%2Bmatchall%26Ntt%3DDwarf%2Bstars','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19820061070&hterms=Dwarf+stars&qs=N%3D0%26Ntk%3DTitle%26Ntx%3Dmode%2Bmatchall%26Ntt%3DDwarf%2Bstars"><span>Outer atmospheres of cool stars. XII - A survey of IUE ultraviolet <span class="hlt">emission</span> <span class="hlt">line</span> spectra of cool dwarf stars</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Linsky, J. L.; Bornmann, P. L.; Carpenter, K. G.; Hege, E. K.; Wing, R. F.; Giampapa, M. S.; Worden, S. P.</p> <p>1982-01-01</p> <p>Quantitative information is obtained on the chromospheres and transition regions of M dwarf stars, in order to determine how the outer atmospheres of dMe stars differ from dM stars and how they compare with the outer atmospheres of quiet and active G and K type dwarfs. IUE spectra of six dMe and four dM stars, together with ground-based photometry and spectroscopy of the Balmer and Ca II H and K <span class="hlt">lines</span>, show no evidence of flares. It is concluded, regarding the quiescent behavior of these stars, that <span class="hlt">emission-line</span> spectra resemble that of the sun and contain <span class="hlt">emission</span> <span class="hlt">lines</span> formed in regions with 4000-20,000 K temperatures that are presumably analogous to the solar chromosphere, as well as regions with temperatures of 20,000-200,000 K that are presumably analogous to the solar transition region. <span class="hlt">Emission-line</span> surface fluxes are proportional to the <span class="hlt">emission</span> measure over the range of temperatures at which the <span class="hlt">lines</span> are formed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22661441-origin-galactic-diffuse-ray-emission-iron-shell-line-diagnostics','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22661441-origin-galactic-diffuse-ray-emission-iron-shell-line-diagnostics"><span>ORIGIN OF THE GALACTIC DIFFUSE X-RAY <span class="hlt">EMISSION</span>: IRON K-SHELL <span class="hlt">LINE</span> DIAGNOSTICS</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Nobukawa, Masayoshi; Uchiyama, Hideki; Nobukawa, Kumiko K.</p> <p></p> <p>This paper reports detailed K-shell <span class="hlt">line</span> profiles of iron (Fe) and nickel (Ni) of the Galactic Center X-ray <span class="hlt">Emission</span> (GCXE), Galactic Bulge X-ray <span class="hlt">Emission</span> (GBXE), Galactic Ridge X-ray <span class="hlt">Emission</span> (GRXE), magnetic Cataclysmic Variables (mCVs), non-magnetic Cataclysmic Variables (non-mCVs), and coronally Active Binaries (ABs). For the study of the origin of the GCXE, GBXE, and GRXE, the spectral analysis is focused on equivalent widths of the Fe i-K α , Fe xxv-He α , and Fe xxvi-Ly α  <span class="hlt">lines</span>. The global spectrum of the GBXE is reproduced by a combination of the mCVs, non-mCVs, and ABs spectra. On the other hand,more » the GRXE spectrum shows significant data excesses at the Fe i-K α and Fe xxv-He α  <span class="hlt">line</span> energies. This means that additional components other than mCVs, non-mCVs, and ABs are required, which have symbiotic phenomena of cold gas and very high-temperature plasma. The GCXE spectrum shows larger excesses than those found in the GRXE spectrum at all the K-shell <span class="hlt">lines</span> of iron and nickel. Among them the largest ones are the Fe i-K α , Fe xxv-He α , Fe xxvi-Ly α , and Fe xxvi-Ly β  <span class="hlt">lines</span>. Together with the fact that the scale heights of the Fe i-K α , Fe xxv-He α , and Fe xxvi-Ly α <span class="hlt">lines</span> are similar to that of the central molecular zone (CMZ), the excess components would be related to high-energy activity in the extreme envelopment of the CMZ.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018AAS...23114713D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018AAS...23114713D"><span>Rings of Molecular <span class="hlt">Line</span> <span class="hlt">Emission</span> in the Disk Orbiting the Young, Close Binary V4046 Sgr</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dickson-Vandervelde, Dorothy; Kastner, Joel H.; Qi, C.; Forveille, Thierry; Hily-Blant, Pierre; Oberg, Karin; Wilner, David; Andrews, Sean; Gorti, Uma; Rapson, Valerie; Sacco, Germano; Principe, David</p> <p>2018-01-01</p> <p>We present analysis of a suite of subarcsecond ALMA Band 6 (1.1 - 1.4 mm) molecular <span class="hlt">line</span> images of the circumbinary, protoplanetary disk orbiting V4046 Sgr. The ~20 Myr-old V4046 Sgr system, which lies a mere ~73 pc from Earth, consists of a close (separation ~10 Rsun) pair of roughly solar-mass stars that are orbited by a gas-rich crcumbinary disk extending to ~350 AU in radius. The ALMA images reveal that the molecules CO and HCN and their isotopologues display centrally peaked surface brightness morphologies, whereas the cyanide group molecules (HC3N, CH3CN), deuterated molecules (DCN, DCO+), hydrocarbons (as traced by C2H), and potential CO ice <span class="hlt">line</span> tracers (N2H+, and H2CO) appear as a sequence of sharp and diffuse rings of increasing radii. The characteristic sizes of these molecular <span class="hlt">emission</span> rings, which range from ~25 to >100 AU in radius, are evident in radial <span class="hlt">emission-line</span> surface brightness profiles extracted from the deprojected disk images. We find that <span class="hlt">emission</span> from 13CO <span class="hlt">emission</span> transitions from optically thin to thick within ~50 AU, whereas C18O <span class="hlt">emission</span> remains optically thin within this radius. We summarize the insight into the physical and chemical processes within this evolved protoplanetary disk that can be obtained from comparisons of the various <span class="hlt">emission-line</span> morphologies with each other and with that of the continuum (large-grain) <span class="hlt">emission</span> on size scales of tens of AU.This research is supported by NASA Exoplanets program grant NNX16AB43G to RIT</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AcSpe.138...97I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AcSpe.138...97I"><span>Anomalous broadening and shift of <span class="hlt">emission</span> <span class="hlt">lines</span> in a femtosecond laser plasma filament in air</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ilyin, A. A.; Golik, S. S.; Shmirko, K. A.; Mayor, A. Yu.; Proschenko, D. Yu.</p> <p>2017-12-01</p> <p>The temporal evolution of the width and shift of N I 746.8 and O I 777.4 nm <span class="hlt">lines</span> is investigated in a filament plasma produced by a tightly focused femtosecond laser pulse (0.9 mJ, 48 fs). The nitrogen <span class="hlt">line</span> shift and width are determined by the joint action of electron impact shift and the far-off resonance AC Stark effect. The intensive (I = 1.2·1010 W/cm2) electric field of ASE (amplified spontaneous <span class="hlt">emission</span>) and post-pulses result in a possible LS coupling break for the O I 3p 5P level and the generation of Rabi sidebands. The blueshifted main femtosecond pulse and Rabi sideband cause the stimulated <span class="hlt">emission</span> of the N2 1+ system. The maximal widths of <span class="hlt">emission</span> <span class="hlt">lines</span> are approximately 6.7 times larger than the calculated Stark widths.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19930032519&hterms=gaussian&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dgaussian','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19930032519&hterms=gaussian&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dgaussian"><span>Errors associated with fitting Gaussian profiles to noisy <span class="hlt">emission-line</span> spectra</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lenz, Dawn D.; Ayres, Thomas R.</p> <p>1992-01-01</p> <p>Landman et al. (1982) developed prescriptions to predict profile fitting errors for Gaussian <span class="hlt">emission</span> <span class="hlt">lines</span> perturbed by white noise. We show that their scaling laws can be generalized to more complicated signal-dependent 'noise models' of common astronomical detector systems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1994A%26A...284..545K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1994A%26A...284..545K"><span>Carbon monoxide <span class="hlt">line</span> <span class="hlt">emission</span> from photon dominated regions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Koester, B.; Stoerzer, H.; Stutzki, J.; Sternberg, A.</p> <p>1994-04-01</p> <p>We present a theoretical study of (12)CO and (13)CO rotational <span class="hlt">line</span> <span class="hlt">emission</span> from photon dominated regions (PDRs). We incorporate the effects of clumpy cloud structure by computing the physical structures of plane-parallel photo dominated PDRs with finite thickness which are illuminated by UV-radiation fields from either one or both sides. We examine the influence of the gas density (no (H) = 10 4/cu cm to 107/cu cm), the UV intensity (chi = 103 to 106 times the intensity of the average interstellar UV field), the cloud thickness (measured in units of the visual extinction (AV, 2 less than or = AV less than or = 10) and the Doppler width (1 km/s and 3 km/s) on the emergent CO <span class="hlt">line</span> center brightness temperatures. We explicitly include the effects of the C-13 chemistry on the <span class="hlt">line</span> intensities. The high brightness temperatures of the (13)CO J = 6 to 5 <span class="hlt">line</span> observed in several sources can be explained as originating in high density PDRs (n(H) greater than or = 106/cu cm) which are illuminated from two sides and under the assumption that several PDR clumps lie along the <span class="hlt">line</span> of sight. To model the observed low-J (12)CO and (13)CO <span class="hlt">line</span> ratios the models require densities of close to 105/cu cm or higher. Due to chemical fractionation the isotopic <span class="hlt">line</span> intensity ratios for (12)CI/(13)CI can be a factor 2 to 3 lower than the intrinsic isotopic C-12/C-13 ratio. The high-J (12)CO brightness temperatures that we find are in general agreement with earlier PDR models.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..15.8129B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..15.8129B"><span>Network for the Detection of Mesopause Change (NDMC): What can we learn from <span class="hlt">airglow</span> measurements in terms of better understanding atmospheric dynamics?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bittner, Michael</p> <p>2013-04-01</p> <p>The international Network for the Detection of Mesopause Change (NDMC, http://wdc.dlr.de/ndmc) is a global program with the mission to promote international cooperation among research groups investigating the mesopause region (80-100 km) with the goal of early identification of changing climate signals. NDMC is contributing to the European Project "Atmospheric dynamics Research Infrastructure in Europe, ARISE". Measurements of the <span class="hlt">airglow</span> at the mesopause altitude region (80-100km) from most of the European NDMC stations including spectro-photometers and imagers allow monitoring atmospheric variability at time scales comprising long-term trends, annual and seasonal variability, planetary and gravity waves and infrasonic signals. The measurements also allow validating satellite-based measurements such as from the TIMED-SABER instrument. Examples will be presented for <span class="hlt">airglow</span> measurements and for related atmospheric dynamics analysis on the abovementioned spatio-temporal scales and comparisons with satellite-based instruments as well as with LIDAR soundings in order to demonstrate the contribution of NDMC to the ARISE project.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012PhDT.......192S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012PhDT.......192S"><span>The nature of the [O III] <span class="hlt">emission</span> <span class="hlt">line</span> system in the black hole hosting globular cluster RZ2109</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Steele, Matthew M.</p> <p></p> <p>This work, focused on the description and understanding of the nature of a [O III] <span class="hlt">emission</span> <span class="hlt">line</span> source associated with an accreting stellar mass black hole in a globlar cluster, is comprised of three papers. In the first paper, we present a multi-facility study of the optical spectrum of the extra- galactic globular cluster RZ2109, which hosts a bright black hole X-ray source. The optical spectrum of RZ2109 shows strong and very broad [O III]lambdalambda4959,5007 <span class="hlt">emission</span> in addition to the stellar absorption <span class="hlt">lines</span> typical of a globular cluster. We use observations over an extended period of time to constrain the variability of these [O III] <span class="hlt">emission</span> <span class="hlt">lines</span>. We find that the equivalent width of the <span class="hlt">lines</span> is similar in all of the datasets; the change in L[O III]lambda5007 is ≤ 10% between the first and last observations, which were separated by 467 days. The velocity profile of the <span class="hlt">line</span> also shows no significant variability over this interval. Using a simple geometric model we demonstrate that the observed [O III]lambda5007 <span class="hlt">line</span> velocity structure can be described by a two component model with most of the flux contributed by a bipolar conical outflow of about 1,600 km s -1 , and the remainder from a Gaussian component with a FWHM of several hundred km s-1 . In the second paper, we present an analysis of the elemental composition of the <span class="hlt">emission</span> <span class="hlt">line</span> system associated with the black hole hosting globular cluster RZ2109 located in NGC4472. From medium resolution GMOS optical spectroscopy we find a [O III]lambda5007/Hbeta <span class="hlt">emission</span> <span class="hlt">line</span> ratio of 106 for a 3200 km s-1 measurement aperture covering the full velocity width of the [O III]lambda5007 <span class="hlt">line</span>, with a 95% confidence level lower and upper limits of [O III]lambda5007/Hbeta > 35.7 and < -110 (Hbeta absorption). For a narrower 600 km s-1 aperture covering the highest luminosity velocity structure in the <span class="hlt">line</span> complex, we find [O III]lambda5007/Hbeta = 62, with corresponding 95% confidence lower and upper limits of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22520038-connections-between-uv-optical-fe-ii-emission-lines-type-agns','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22520038-connections-between-uv-optical-fe-ii-emission-lines-type-agns"><span>THE CONNECTIONS BETWEEN THE UV AND OPTICAL Fe ii <span class="hlt">EMISSION</span> <span class="hlt">LINES</span> IN TYPE 1 AGNs</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Kovacević-Dojcinović, Jelena; Popović, Luka Č., E-mail: jkovacevic@aob.bg.ac.rs, E-mail: lpopovic@aob.bg.ac.rs</p> <p></p> <p>We investigate the spectral properties of the UV (λλ2650–3050 Å) and optical (λλ4000–5500 Å) Fe ii <span class="hlt">emission</span> features in a sample of 293 Type 1 active galactic nuclei (AGNs) from the Sloan Digital Sky Survey database. We explore different correlations between their <span class="hlt">emission</span> <span class="hlt">line</span> properties, as well as the correlations with other <span class="hlt">emission</span> <span class="hlt">lines</span> from the spectral range. We find several interesting correlations and outline the most interesting results as follows. (i) There is a kinematical connection between the UV and optical Fe ii <span class="hlt">lines</span>, indicating that the UV and optical Fe ii <span class="hlt">lines</span> originate from the outer part ofmore » the broad <span class="hlt">line</span> region, the so-called intermediate <span class="hlt">line</span> region. (ii) The unexplained anticorrelations of the optical Fe ii equivalent width (EW Fe ii{sub opt}) versus EW [O iii] 5007 Å and EW Fe ii{sub opt} versus FWHM Hβ have not been detected for the UV Fe ii <span class="hlt">lines</span>. (iii) The significant averaged redshift in the UV Fe ii <span class="hlt">lines</span>, which is not present in optical Fe ii, indicates an inflow in the UV Fe ii emitting clouds, and probably their asymmetric distribution. (iv) Also, we confirm the anticorrelation between the intensity ratio of the optical and UV Fe ii <span class="hlt">lines</span> and the FWHM of Hβ, and we find the anticorrelations of this ratio with the widths of Mg ii 2800 Å, optical Fe ii, and UV Fe ii. This indicates a very important role for the column density and microturbulence in the emitting gas. We discuss the starburst activity in high-density regions of young AGNs as a possible explanation of the detected optical Fe ii correlations and intensity <span class="hlt">line</span> ratios of the UV and optical Fe ii <span class="hlt">lines</span>.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22654395-solar-flare-termination-shock-synthetic-emission-line-profiles-fe-xxi-line','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22654395-solar-flare-termination-shock-synthetic-emission-line-profiles-fe-xxi-line"><span>Solar Flare Termination Shock and Synthetic <span class="hlt">Emission</span> <span class="hlt">Line</span> Profiles of the Fe xxi 1354.08 Å <span class="hlt">Line</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Guo, Lijia; Li, Gang; Reeves, Kathy</p> <p></p> <p>Solar flares are among the most energetic phenomena that occur in the solar system. In the standard solar flare model, a fast mode shock, often referred to as the flare termination shock (TS), can exist above the loop-top source of hard X-ray <span class="hlt">emissions</span>. The existence of the TS has been recently related to spectral hardening of a flare’s hard X-ray spectra at energies >300 keV. Observations of the Fe xxi 1354.08 Å <span class="hlt">line</span> during solar flares by the Interface Region Imaging Spectrograph ( IRIS ) spacecraft have found significant redshifts with >100 km s{sup −1}, which is consistent with amore » reconnection downflow. The ability to detect such a redshift with IRIS suggests that one may be able to use IRIS observations to identify flare TSs. Using a magnetohydrodynamic simulation to model magnetic reconnection of a solar flare and assuming the existence of a TS in the downflow of the reconnection plasma, we model the synthetic <span class="hlt">emission</span> of the Fe xxi 1354.08 <span class="hlt">line</span> in this work. We show that the existence of the TS in the solar flare may manifest itself in the Fe xxi 1354.08 Å <span class="hlt">line</span>.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22521828-dissecting-power-sources-low-luminosity-emission-line-galaxy-nuclei-via-comparison-hst-stis-ground-based-spectra','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22521828-dissecting-power-sources-low-luminosity-emission-line-galaxy-nuclei-via-comparison-hst-stis-ground-based-spectra"><span>DISSECTING THE POWER SOURCES OF LOW-LUMINOSITY <span class="hlt">EMISSION-LINE</span> GALAXY NUCLEI VIA COMPARISON OF HST-STIS AND GROUND-BASED SPECTRA</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Constantin, Anca; Castillo, Christopher A.; Shields, Joseph C.</p> <p></p> <p>Using a sample of ∼100 nearby <span class="hlt">line</span>-emitting galaxy nuclei, we have built the currently definitive atlas of spectroscopic measurements of Hα and neighboring <span class="hlt">emission</span> <span class="hlt">lines</span> at subarcsecond scales. We employ these data in a quantitative comparison of the nebular <span class="hlt">emission</span> in Hubble Space Telescope (HST) and ground-based apertures, which offer an order-of-magnitude difference in contrast, and provide new statistical constraints on the degree to which transition objects and low-ionization nuclear <span class="hlt">emission-line</span> regions (LINERs) are powered by an accreting black hole at ≲10 pc. We show that while the small-aperture observations clearly resolve the nebular <span class="hlt">emission</span>, the aperture dependence in themore » <span class="hlt">line</span> ratios is generally weak, and this can be explained by gradients in the density of the <span class="hlt">line</span>-emitting gas: the higher densities in the more nuclear regions potentially flatten the excitation gradients, suppressing the forbidden <span class="hlt">emission</span>. The transition objects show a threefold increase in the incidence of broad Hα <span class="hlt">emission</span> in the high-resolution data, as well as the strongest density gradients, supporting the composite model for these systems as accreting sources surrounded by star-forming activity. The narrow-<span class="hlt">line</span> LINERs appear to be the weaker counterparts of the Type 1 LINERs, where the low accretion rates cause the disappearance of the broad-<span class="hlt">line</span> component. The enhanced sensitivity of the HST observations reveals a 30% increase in the incidence of accretion-powered systems at z ≈ 0. A comparison of the strength of the broad-<span class="hlt">line</span> <span class="hlt">emission</span> detected at different epochs implies potential broad-<span class="hlt">line</span> variability on a decade-long timescale, with at least a factor of three in amplitude.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19820041529&hterms=carbon+emissions&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dcarbon%2Bemissions','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19820041529&hterms=carbon+emissions&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dcarbon%2Bemissions"><span>Carbon and oxygen X-ray <span class="hlt">line</span> <span class="hlt">emission</span> from the interstellar medium</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Schnopper, H. W.; Delvaille, J. P.; Rocchia, R.; Blondel, C.; Cheron, C.; Christy, J. C.; Ducros, R.; Koch, L.; Rothenflug, R.</p> <p>1982-01-01</p> <p>A soft X-ray, 0.3-1.0 keV spectrum from a 1 sr region which includes a portion of the North Polar Spur, obtained by three rocketborne lithium-drifted silicon detectors, shows the C V, C VI, O VII and O VIII <span class="hlt">emission</span> <span class="hlt">lines</span>. The spectrum is well fitted by a two-component, modified Kato (1976) model, where the coronal <span class="hlt">emission</span> is in collisional equilibrium, with interstellar medium and North Polar Spur temperatures of 1.1 and 3.8 million K, respectively.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2010-title40-vol12/pdf/CFR-2010-title40-vol12-part63-subpartUUU-app36.pdf','CFR'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2010-title40-vol12/pdf/CFR-2010-title40-vol12-part63-subpartUUU-app36.pdf"><span>40 CFR Table 36 to Subpart Uuu of... - Work Practice Standards for HAP <span class="hlt">Emissions</span> From Bypass <span class="hlt">Lines</span></span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2010&page.go=Go">Code of Federal Regulations, 2010 CFR</a></p> <p></p> <p>2010-07-01</p> <p>... <span class="hlt">Emissions</span> From Bypass <span class="hlt">Lines</span> 36 Table 36 to Subpart UUU of Part 63 Protection of Environment ENVIRONMENTAL... Refineries: Catalytic Cracking Units, Catalytic Reforming Units, and Sulfur Recovery Units Pt. 63, Subpt. UUU, Table 36 Table 36 to Subpart UUU of Part 63—Work Practice Standards for HAP <span class="hlt">Emissions</span> From Bypass <span class="hlt">Lines</span>...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2011-title40-vol12/pdf/CFR-2011-title40-vol12-part63-subpartUUU-app36.pdf','CFR2011'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2011-title40-vol12/pdf/CFR-2011-title40-vol12-part63-subpartUUU-app36.pdf"><span>40 CFR Table 36 to Subpart Uuu of... - Work Practice Standards for HAP <span class="hlt">Emissions</span> From Bypass <span class="hlt">Lines</span></span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2011&page.go=Go">Code of Federal Regulations, 2011 CFR</a></p> <p></p> <p>2011-07-01</p> <p>... <span class="hlt">Emissions</span> From Bypass <span class="hlt">Lines</span> 36 Table 36 to Subpart UUU of Part 63 Protection of Environment ENVIRONMENTAL... Refineries: Catalytic Cracking Units, Catalytic Reforming Units, and Sulfur Recovery Units Pt. 63, Subpt. UUU, Table 36 Table 36 to Subpart UUU of Part 63—Work Practice Standards for HAP <span class="hlt">Emissions</span> From Bypass <span class="hlt">Lines</span>...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JGRA..12212430O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JGRA..12212430O"><span>First Study on the Occurrence Frequency of Equatorial Plasma Bubbles over West Africa Using an All-Sky <span class="hlt">Airglow</span> Imager and GNSS Receivers</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Okoh, Daniel; Rabiu, Babatunde; Shiokawa, Kazuo; Otsuka, Yuichi; Segun, Bolaji; Falayi, Elijah; Onwuneme, Sylvester; Kaka, Rafiat</p> <p>2017-12-01</p> <p>This is the first paper that reports the occurrence frequency of equatorial plasma bubbles and their dependences of local time, season, and geomagnetic activity based on <span class="hlt">airglow</span> imaging observations at West Africa. The all-sky imager, situated in Abuja (Geographic: 8.99°N, 7.38°E; Geomagnetic: 1.60°S), has a 180° fisheye view covering almost the entire airspace of Nigeria. Plasma bubbles are observed for 70 nights of the 147 clear-sky nights from 9 June 2015 to 31 January 2017. Differences between nighttime and daytime ROTIs were also computed as a proxy of plasma bubbles using Global Navigation Satellite Systems (GNSS) receivers within the coverage of the all-sky imager. Most plasma bubble occurrences are found during equinoxes and least occurrences during solstices. The occurrence rate of plasma bubbles was highest around local midnight and lower for hours farther away. Most of the postmidnight plasma bubbles were observed around the months of December to March, a period that coincides with the harmattan period in Nigeria. The on/off status of plasma bubble in <span class="hlt">airglow</span> and GNSS observations were in agreement for 67.2% of the total 768 h, while we suggest several reasons responsible for the remaining 32.8% when the <span class="hlt">airglow</span> and GNSS bubble status are inconsistent. A majority of the plasma bubbles were observed under relatively quiet geomagnetic conditions (Dst ≥ -40 and Kp ≤ 3), but there was no significant pattern observed in the occurrence rate of plasma bubbles as a function of geomagnetic activity. We suggest that geomagnetic activities could have either suppressed or promoted the occurrence of plasma bubbles.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014ApJ...793..100M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014ApJ...793..100M"><span>Constraining UV Continuum Slopes of Active Galactic Nuclei with CLOUDY Models of Broad-<span class="hlt">line</span> Region Extreme-ultraviolet <span class="hlt">Emission</span> <span class="hlt">Lines</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Moloney, Joshua; Shull, J. Michael</p> <p>2014-10-01</p> <p>Understanding the composition and structure of the broad-<span class="hlt">line</span> region (BLR) of active galactic nuclei (AGNs) is important for answering many outstanding questions in supermassive black hole evolution, galaxy evolution, and ionization of the intergalactic medium. We used single-epoch UV spectra from the Cosmic Origins Spectrograph (COS) on the Hubble Space Telescope to measure EUV <span class="hlt">emission-line</span> fluxes from four individual AGNs with 0.49 <= z <= 0.64, two AGNs with 0.32 <= z <= 0.40, and a composite of 159 AGNs. With the CLOUDY photoionization code, we calculated <span class="hlt">emission-line</span> fluxes from BLR clouds with a range of density, hydrogen ionizing flux, and incident continuum spectral indices. The photoionization grids were fit to the observations using single-component and locally optimally emitting cloud (LOC) models. The LOC models provide good fits to the measured fluxes, while the single-component models do not. The UV spectral indices preferred by our LOC models are consistent with those measured from COS spectra. EUV <span class="hlt">emission</span> <span class="hlt">lines</span> such as N IV λ765, O II λ833, and O III λ834 originate primarily from gas with electron temperatures between 37,000 K and 55,000 K. This gas is found in BLR clouds with high hydrogen densities (n H >= 1012 cm-3) and hydrogen ionizing photon fluxes (ΦH >= 1022 cm-2 s-1). Based on observations made with the NASA/ESA Hubble Space Telescope, obtained from the data archive at the Space Telescope Science Institute. STScI is operated by the Association of Universities for Research in Astronomy, Inc. under NASA contract NAS5-26555.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1992GMS....66..191F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1992GMS....66..191F"><span><span class="hlt">Airglow</span> and aurora in the atmospheres of Venus and Mars</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fox, J. L.</p> <p></p> <p>Measurements and models of the luminosity that originates in the Martian and Venusian atmospheres, including dayglow, nightglow and aurora, are compared. Most of the <span class="hlt">emission</span> features considered appear in the UV and visible regions of the spectrum and arise from electronic transitions of thermospheric species. Spatially and temporally variable intensities of the oxygen 1304 and 1356 A <span class="hlt">lines</span> have been observed on the nightside of Venus and have been labeled 'auroral', that is, ascribed to electron precipitation. Only a future aeronomy mission to Mars could unequivocally determine whether such <span class="hlt">emissions</span> are present on the nightside of Mars.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017RaSc...52..896H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017RaSc...52..896H"><span>Ionospheric-thermospheric UV tomography: 3. A multisensor technique for creating full-orbit reconstructions of atmospheric UV <span class="hlt">emission</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hei, Matthew A.; Budzien, Scott A.; Dymond, Kenneth F.; Nicholas, Andrew C.; Paxton, Larry J.; Schaefer, Robert K.; Groves, Keith M.</p> <p>2017-07-01</p> <p>We present the Volume <span class="hlt">Emission</span> Rate Tomography (VERT) technique for inverting satellite-based, multisensor limb and nadir measurements of atmospheric ultraviolet <span class="hlt">emission</span> to create whole-orbit reconstructions of atmospheric volume <span class="hlt">emission</span> rate. The VERT approach is more general than previous ionospheric tomography methods because it can reconstruct the volume <span class="hlt">emission</span> rate field irrespective of the particular excitation mechanisms (e.g., radiative recombination, photoelectron impact excitation, and energetic particle precipitation in auroras); physical models are then applied to interpret the <span class="hlt">airglow</span>. The technique was developed and tested using data from the Special Sensor Ultraviolet Limb Imager and Special Sensor Ultraviolet Spectrographic Imager instruments aboard the Defense Meteorological Satellite Program F-18 spacecraft and planned for use with upcoming remote sensing missions. The technique incorporates several features to optimize the tomographic solutions, such as the use of a nonnegative algorithm (Richardson-Lucy, RL) that explicitly accounts for the Poisson statistics inherent in optical measurements, capability to include extinction effects due to resonant scattering and absorption of the photons from the <span class="hlt">lines</span> of sight, a pseudodiffusion-based regularization scheme implemented between iterations of the RL code to produce smoother solutions, and the capability to estimate error bars on the solutions. Tests using simulated atmospheric <span class="hlt">emissions</span> verify that the technique performs well in a variety of situations, including daytime, nighttime, and even in the challenging terminator regions. Lastly, we consider ionospheric nightglow and validate reconstructions of the nighttime electron density against Advanced Research Project Agency (ARPA) Long-range Tracking and Identification Radar (ALTAIR) incoherent scatter radar data.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_17 --> <div id="page_18" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="341"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JGRD..121..650C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JGRD..121..650C"><span>Intermittency of gravity wave momentum flux in the mesopause region observed with an all-sky <span class="hlt">airglow</span> imager</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cao, Bing; Liu, Alan Z.</p> <p>2016-01-01</p> <p>The intermittency of gravity wave momentum flux (MF) near the OH <span class="hlt">airglow</span> layer (˜87 km) in the mesopause region is investigated for the first time using observation of all-sky <span class="hlt">airglow</span> imager over Maui, Hawaii (20.7°N, 156.3°W), and Cerro Pachón, Chile (30.3°S, 70.7°W). At both sites, the probability density function (pdf) of gravity wave MF shows two distinct distributions depending on the magnitude of the MF. For MF smaller (larger) than ˜16 m2 s-2 (0.091 mPa), the pdf follows a lognormal (power law) distribution. The intermittency represented by the Bernoulli proxy and the percentile ratio shows that gravity waves have higher intermittency at Maui than at Cerro Pachón, suggesting more intermittent background variation above Maui. It is found that most of the MF is contributed by waves that occur very infrequently. But waves that individually contribute little MF are also important because of their higher occurrence frequencies. The peak contribution is from waves with MF around ˜2.2 m2 s-2 at Cerro Pachón and ˜5.5 m2 s-2 at Maui. Seasonal variations of the pdf and intermittency imply that the background atmosphere has larger influence on the observed intermittency in the mesopause region.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19960012265','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19960012265"><span>Response of the upper atmosphere to variations in the solar soft x-ray irradiance. Ph.D. Thesis</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Bailey, Scott Martin</p> <p>1995-01-01</p> <p>Terrestrial far ultraviolet (FUV) <span class="hlt">airglow</span> <span class="hlt">emissions</span> have been suggested as a means for remote sensing the structure of the upper atmosphere. The energy which leads to the excitation of FUV <span class="hlt">airglow</span> <span class="hlt">emissions</span> is solar irradiance at extreme ultraviolet (EUV) and soft x-ray wavelengths. Solar irradiance at these wavelengths is known to be highly variable; studies of nitric oxide (NO) in the lower thermosphere have suggested a variability of more than an order of magnitude in the solar soft x-ray irradiance. To properly interpret the FUV airflow, the magnitude of the solar energy deposition must be known. Previous analyses have used the electron impact excited Lyman-Birge-Hopfield (LBH) bands of N2 to infer the flux of photoelectrons in the atmosphere and thus to infer the magnitude of the solar irradiance. This dissertation presents the first simultaneous measurements of the FUV <span class="hlt">airglow</span>, the major atmospheric constituent densities, and the solar EUV and soft x-ray irradiances. The measurements were made on three flights of an identical sounding rocket payload at different levels of solar activity. The linear response in brightness of the LBH bands to variations in solar irradiance is demonstrated. In addition to the N2 LBH bands, atomic oxygen <span class="hlt">lines</span> at 135.6 and 130.4 nm are also studied. Unlike the LBH bands, these <span class="hlt">emissions</span> undergo radiative transfer effects in the atmosphere. The OI <span class="hlt">emission</span> at 135.6 nm is found to be well modeled using a radiative transfer calculation and the known excitation processes. Unfortunately, the assumed processes leading to OI 130.4 nm excitation are found to be insufficient to reproduce the observed variability of this <span class="hlt">emission</span>. Production of NO in the atmosphere is examined; it is shown that a lower than previously reported variability in the solar soft x-ray irradiance is required to explain the variability of NO.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017A%26A...603A.138A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017A%26A...603A.138A"><span>Herschel GASPS spectral observations of T Tauri stars in Taurus. Unraveling far-infrared <span class="hlt">line</span> <span class="hlt">emission</span> from jets and discs</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Alonso-Martínez, M.; Riviere-Marichalar, P.; Meeus, G.; Kamp, I.; Fang, M.; Podio, L.; Dent, W. R. F.; Eiroa, C.</p> <p>2017-07-01</p> <p>Context. At early stages of stellar evolution young stars show powerful jets and/or outflows that interact with protoplanetary discs and their surroundings. Despite the scarce knowledge about the interaction of jets and/or outflows with discs, spectroscopic studies based on Herschel and ISO data suggests that gas shocked by jets and/or outflows can be traced by far-IR (FIR) <span class="hlt">emission</span> in certain sources. Aims: We want to provide a consistent catalogue of selected atomic ([OI] and [CII]) and molecular (CO, H2O, and OH) <span class="hlt">line</span> fluxes observed in the FIR, separate and characterize the contribution from the jet and the disc to the observed <span class="hlt">line</span> <span class="hlt">emission</span>, and place the observations in an evolutionary picture. Methods: The atomic and molecular FIR (60-190 μm) <span class="hlt">line</span> <span class="hlt">emission</span> of protoplanetary discs around 76 T Tauri stars located in Taurus are analysed. The observations were carried out within the Herschel key programme Gas in Protoplanetary Systems (GASPS). The spectra were obtained with the Photodetector Array Camera and Spectrometer (PACS). The sample is first divided in outflow and non-outflow sources according to literature tabulations. With the aid of archival stellar/disc and jet/outflow tracers and model predictions (PDRs and shocks), correlations are explored to constrain the physical mechanisms behind the observed <span class="hlt">line</span> <span class="hlt">emission</span>. Results: Outflow sources exhibit brighter atomic and molecular <span class="hlt">emission</span> <span class="hlt">lines</span> and higher detection rates than non-outflow sources. The <span class="hlt">line</span> detection fractions decrease with SED evolutionary status (from Class I to Class III). We find correlations between [OI] 63.18 μm and [OI] 6300 Å, o-H2O 78.74 μm, CO 144.78 μm, OH 79.12+79.18 μm, and the continuum flux at 24 μm. The atomic <span class="hlt">line</span> ratios can be explain either by fast (Vshock > 50 km s-1) dissociative J-shocks at low densities (n 103 cm-3) occurring along the jet and/or PDR <span class="hlt">emission</span> (G0 > 102, n 103-106 cm-3). To account for the [CII] absolute fluxes, PDR <span class="hlt">emission</span> or UV irradiation of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1997PhDT.........2P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1997PhDT.........2P"><span>Study of Star Formation Regions with Molecular Hydrogen <span class="hlt">Emission</span> <span class="hlt">Lines</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pak, Soojong</p> <p></p> <p>The goal of my dissertation is to understand the large-scale, near-infrared (near-IR) H2 <span class="hlt">emission</span> from the central kiloparsec (kpc) regions of galaxies, and to study the structure and physics of photon-dominated regions (or photodissociation regions, hereafter PDRs). In order to explore the near-IR H2 <span class="hlt">lines</span>, our group built the University of Texas near-IR Fabry-Perot Spectrometer optimized for observations of extended, low surface brightness sources. In this instrument project, I designed and built a programmable high voltage DC amplifier for the Fabry-Perot piezoelectric transducers, a temperature-controlled cooling box for the Fabry-Perot etalon, instrument control software, and data reduction software. With this instrument, we observed H2 <span class="hlt">emission</span> <span class="hlt">lines</span> in the inner 400 pc of the Galaxy, the central ~1 kpc of NGC 253 and M82, and the star formation regions in the Magellanic Clouds. We also observed the Magellanic Clouds in the CO J=1/to0 <span class="hlt">line</span>. We found that the H2 <span class="hlt">emission</span> is very extended in the central kpc of the galaxies and is mostly UV-excited. The ratios of the H2 (1,0) S(1) luminosities to the far-IR continuum luminosities in the central kpc regions do not change from the Galactic center to starburst galaxies and to ultraluminous IR bright galaxies. Using the data from the Magellanic Clouds, we studied the microscopic structure of star forming clouds. We compiled data sets including our H2 (1,0) S(1) and CO J=1/to0 results and published (C scII) and far-IR data from the Magellanic Clouds, and compared these observations with models we made using a PDR code and a radiative transfer code. Assuming the cloud is spherical, we derived the physical sizes of H2, (C scII), and CO <span class="hlt">emission</span> regions. The average cloud size appears to increase as the metallicity decreases. Our results agree with the theory of photoionization-regulated star formation in which the interplay between the ambipolar diffusion and ionization by far-UV photons determines the size of stable</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20050158830','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20050158830"><span>Satellite Studies of Storm-Time Thermospheric Winds</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Fejer, Bela G.</p> <p>2005-01-01</p> <p>In this project we have studied the climatology and storm-time dependence of longitude-averaged mid- and low-latitude thermospheric neutral winds observed by the WINDII instrument on board the UARS satellite. This satellite is in a circular, 57 deg inclination orbit at a height of 585 km; the orbit precesses at a rate of 5 deg per day. WINDII is a Michelson interferometer that measures Doppler shifts of the green <span class="hlt">line</span> (557.7 nm) and red <span class="hlt">line</span> (630.0 nm) <span class="hlt">airglow</span> <span class="hlt">emissions</span> at the Earth's limb, covering latitudes up to 72 deg.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004A%26A...413...97G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004A%26A...413...97G"><span>The nuclear region of low luminosity flat radio spectrum sources. II. <span class="hlt">Emission-line</span> spectra</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gonçalves, A. C.; Serote Roos, M.</p> <p>2004-01-01</p> <p>We report on the spectroscopic study of 19 low luminosity Flat Radio Spectrum (LL FRS) sources selected from Marchã's et al. (\\cite{March96}) 200 mJy sample. In the optical, these objects are mainly dominated by the host galaxy starlight. After correcting the data for this effect, we obtain a new set of spectra clearly displaying weak <span class="hlt">emission</span> <span class="hlt">lines</span>; such features carry valuable information concerning the excitation mechanisms at work in the nuclear regions of LL FRS sources. We have used a special routine to model the spectra and assess the intensities and velocities of the <span class="hlt">emission</span> <span class="hlt">lines</span>; we have analyzed the results in terms of diagnostic diagrams. Our analysis shows that 79% of the studied objects harbour a Low Ionization Nuclear <span class="hlt">Emission-line</span> Region (or LINER) whose contribution was swamped by the host galaxy starlight. The remaining objects display a higher ionization spectrum, more typical of Seyferts; due to the poor quality of the spectra, it was not possible to identify any possible large Balmer components. The fact that we observe a LINER-type spectrum in LL FRS sources supports the idea that some of these objects could be undergoing an ADAF phase; in addition, such a low ionization <span class="hlt">emission-line</span> spectrum is in agreement with the black hole mass values and sub-Eddington accretion rates published for some FRS sources. Based on observations collected at the Multiple Mirror Telescope on Mt. Hopkins. Full Fig. 1 is only available in electronic form at http://www.edpsciences.org</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMSM23B2616N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMSM23B2616N"><span>Mid-latitude Narrowband Stimulated Electromagnetic <span class="hlt">Emissions</span> (NSEE): New Observations and Modeling</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nossa, E.; Mahmoudian, A.; Isham, B.; Bernhardt, P. A.; Briczinski, S. J., Jr.</p> <p>2017-12-01</p> <p>High power electromagnetic waves (EM) transmitted from the ground interact with the local plasma in the ionosphere and can produce Stimulated Electromagnetic <span class="hlt">Emissions</span> (SEE) through the parametric decay instability (PDI). The classical SEE features known as wideband SEE (WSEE) with frequency offset of 1 kHz up to 100 kHz have been observed and studied in detail in the 1980s and 1990s. A new era of ionospheric remote sensing techniques was begun after the recent update of the HF transmitter at the HAARP. Sideband <span class="hlt">emissions</span> of unprecedented strength have been reported during recent campaigns at HAARP, reaching up to 10 dB relative to the reflected pump wave which are by far the strongest spectral features of secondary radiation that have been reported. These <span class="hlt">emissions</span> known as narrowband SEE (NSEE) are shifted by only up to a few tens of Hertz from radio-waves transmitted at several megahertz. One of these new NSEE features are <span class="hlt">emission</span> <span class="hlt">lines</span> within 100 Hz of the pump frequency and are produced through magnetized stimulated Brillouin scatter (MSBS) process. Stimulated Brillouin Scatter (SBS) is a strong SEE mode involving a direct parametric decay of the pump wave into an electrostatic wave (ES) and a secondary EM wave that sometimes could be stronger than the HF pump. SBS has been studied in laboratory plasma experiments by the interaction of high power lasers with plasmas. The SBS instability in magnetized ionospheric plasma was observed for the first time at HAARP in 2010. Our recent work at HAARP has shown that MSBS <span class="hlt">emission</span> <span class="hlt">lines</span> can be used to asses electron temperature in the heated region, ion mass spectrometry, determine minor ion species and their densities in the ionosphere, study the physics associated with electron acceleration and artificial <span class="hlt">airglow</span>. Here, we present new observations of narrowband SEE (NSEE) features at the new mid-latitude heating facility at Arecibo. This includes the direct mode conversion of pump wave through MSBS process. Collected</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1994ApJS...93..485H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1994ApJS...93..485H"><span><span class="hlt">Emission-line</span> studies of young stars. 4: The optical forbidden <span class="hlt">lines</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hamann, Fred</p> <p>1994-08-01</p> <p>Optical forbidden <span class="hlt">line</span> strengths and profiles are discussed for a sample of 30 T Tauri stars and 12 Herbig Ae-Be stars. Transitions of (C I), (N II), (O I), (O II), (S II), (Ca II), (Cr II), (Fe II), and (Ni II) are detected. Profile variability occurred in DG Tau and probably other sources. The ensemble profiles can be divided into four generic components that may represent distinct emitting regions; (1) narrow rest-velocity <span class="hlt">lines</span>, (2) 'low'-velocity <span class="hlt">lines</span> (peaking at less than or approximately +/- 50 km s-1), (3) 'high'-velocity (usually greater than or approximately +/- 100 km s-1) blueshifted peaks or wings, and (4) high-velocity redshifted peaks. Among T Tauri stars, the rest-velocity <span class="hlt">lines</span> appear most often in sources with weak and narrow permitted <span class="hlt">lines</span>, such as the Ca II triplet. The low- and high-velocity blueshifted components usually appear together in sources with strong and broad Ca II triplet <span class="hlt">lines</span>. If the velocity-shifted <span class="hlt">lines</span> form in jets, the smallest (full) opening angles required by the profiles are less than or approximately 20 deg for the narrow, blueshifted (Ca II) <span class="hlt">lines</span> of DG Tau and HL Tau. Other <span class="hlt">lines</span> in DG Tau are much broader, implying larger opening angles or greater velocity dispersions. The variability in DG Tau also implies significant changes in the collimation or velocity coherence on timescales of a few years. RW Aur and AS 353A have blue- and redshifted <span class="hlt">line</span> peaks that could form in oppositely directed jets. The strong (S II) lambda 6716 and lambda 6731 <span class="hlt">lines</span> in RW Aur are exclusively redshifted and require opening angles less than or approximately 60 deg. Measurements of different profiles in the same spectrum show that the physical conditions change with the <span class="hlt">line</span>-of-sight velocities. The most persistent trends are for more (N II) and (O II) and less (O I) lambda 5577 flux at high velocities. Constraints on the physical conditions are derived by modeling the <span class="hlt">emission</span> <span class="hlt">lines</span> via multilevel ions in 'coronal ionization equilibrium</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19950030391&hterms=dg&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Ddg','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19950030391&hterms=dg&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Ddg"><span><span class="hlt">Emission-line</span> studies of young stars. 4: The optical forbidden <span class="hlt">lines</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hamann, Fred</p> <p>1994-01-01</p> <p>Optical forbidden <span class="hlt">line</span> strengths and profiles are discussed for a sample of 30 T Tauri stars and 12 Herbig Ae-Be stars. Transitions of (C I), (N II), (O I), (O II), (S II), (Ca II), (Cr II), (Fe II), and (Ni II) are detected. Profile variability occurred in DG Tau and probably other sources. The ensemble profiles can be divided into four generic components that may represent distinct emitting regions; (1) narrow rest-velocity <span class="hlt">lines</span>, (2) 'low'-velocity <span class="hlt">lines</span> (peaking at less than or approximately +/- 50 km s(exp -1)), (3) 'high'-velocity (usually greater than or approximately +/- 100 km s(exp -1)) blueshifted peaks or wings, and (4) high-velocity redshifted peaks. Among T Tauri stars, the rest-velocity <span class="hlt">lines</span> appear most often in sources with weak and narrow permitted <span class="hlt">lines</span>, such as the Ca II triplet. The low- and high-velocity blueshifted components usually appear together in sources with strong and broad Ca II triplet <span class="hlt">lines</span>. If the velocity-shifted <span class="hlt">lines</span> form in jets, the smallest (full) opening angles required by the profiles are less than or approximately 20 deg for the narrow, blueshifted (Ca II) <span class="hlt">lines</span> of DG Tau and HL Tau. Other <span class="hlt">lines</span> in DG Tau are much broader, implying larger opening angles or greater velocity dispersions. The variability in DG Tau also implies significant changes in the collimation or velocity coherence on timescales of a few years. RW Aur and AS 353A have blue- and redshifted <span class="hlt">line</span> peaks that could form in oppositely directed jets. The strong (S II) lambda 6716 and lambda 6731 <span class="hlt">lines</span> in RW Aur are exclusively redshifted and require opening angles less than or approximately 60 deg. Measurements of different profiles in the same spectrum show that the physical conditions change with the <span class="hlt">line</span>-of-sight velocities. The most persistent trends are for more (N II) and (O II) and less (O I) lambda 5577 flux at high velocities. Constraints on the physical conditions are derived by modeling the <span class="hlt">emission</span> <span class="hlt">lines</span> via multilevel ions in 'coronal ionization</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017SPIE10256E..4FR','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017SPIE10256E..4FR"><span>Simulation of the fixed optical path difference of near infrared wind imaging interferometer</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rong, Piao; Zhang, Chunmin; Yan, Tingyu; Liu, Dongdong; Li, Yanfen</p> <p>2017-02-01</p> <p>As an important part of the earth, atmosphere plays a vital role in filtering the solar radiation, adjusting the temperature and organizing the water circulation and keeping human survival. The passive atmospheric wind measurement is based on the imaging interferometer technology and Doppler effect of electromagnetic wave. By using the wind imaging interferometer to get four interferograms of <span class="hlt">airglow</span> <span class="hlt">emission</span> <span class="hlt">lines</span>, the atmospheric wind velocity, temperature, pressure and <span class="hlt">emission</span> rate can be derived. Exploring the multi-functional and integrated innovation of detecting wind temperature, wind velocity and trace gas has become a research focus in the field. In the present paper, the impact factors of the fixed optical path difference(OPD) of near infrared wind imaging interferometer(NIWII) are analyzed and the optimum value of the fixed optical path difference is simulated, yielding the optimal results of the fixed optical path difference is 20 cm in near infrared wave band (the O2(a1Δg) <span class="hlt">airglow</span> <span class="hlt">emission</span> at 1.27 microns). This study aims at providing theoretical basis and technical support for the detection of stratosphere near infrared wind field and giving guidance for the design and development of near infrared wind imaging interferometer.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018MNRAS.473..271V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018MNRAS.473..271V"><span>CO <span class="hlt">line</span> <span class="hlt">emission</span> from galaxies in the Epoch of Reionization</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vallini, L.; Pallottini, A.; Ferrara, A.; Gallerani, S.; Sobacchi, E.; Behrens, C.</p> <p>2018-01-01</p> <p>We study the CO <span class="hlt">line</span> luminosity (LCO), the shape of the CO spectral <span class="hlt">line</span> energy distribution (SLED), and the value of the CO-to-H2 conversion factor in galaxies in the Epoch of Reionization (EoR). For this aim, we construct a model that simultaneously takes into account the radiative transfer and the clumpy structure of giant molecular clouds (GMCs) where the CO <span class="hlt">lines</span> are excited. We then use it to post-process state-of-the-art zoomed, high resolution (30 pc), cosmological simulation of a main-sequence (M* ≈ 1010 M⊙, SFR ≈ 100 M⊙ yr- 1) galaxy, 'Althæa', at z ≈ 6. We find that the CO <span class="hlt">emission</span> traces the inner molecular disc (r ≈ 0.5 kpc) of Althæa with the peak of the CO surface brightness co-located with that of the [C II] 158 μm <span class="hlt">emission</span>. Its LCO(1-0) = 104.85 L⊙ is comparable to that observed in local galaxies with similar stellar mass. The high (Σgas ≈ 220 M⊙ pc- 2) gas surface density in Althæa, its large Mach number (M ≈ 30) and the warm kinetic temperature (Tk ≈ 45 K) of GMCs yield a CO SLED peaked at the CO(7-6) transition, i.e. at relatively high-J and a CO-to-H2 conversion factor α _CO≈ 1.5 M_{⊙} (K km s^{-1} pc^2)^{-1} lower than that of the Milky Way. The Atacama Large Millimeter/submillimeter Array observing time required to detect (resolve) at 5σ the CO(7-6) <span class="hlt">line</span> from galaxies similar to Althæa is ≈13 h (≈38 h).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19780057142&hterms=2441&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3D%2526%25232441','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19780057142&hterms=2441&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3D%2526%25232441"><span>Nightglow <span class="hlt">emissions</span> of OH/X 2 pi/ - Comparison of theory and measurements in the /9-3/ band</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Frederick, J. E.; Rusch, D. W.; Liu, S. C.</p> <p>1978-01-01</p> <p>The visible <span class="hlt">airglow</span> experiments on the Atmosphere Explorer C and E satellites have viewed the (9-3) band nightglow <span class="hlt">emission</span> of the excited hydroxyl radical in the lower thermosphere at tropical latitudes. The surface brightnesses observed at similar local times vary by approximately a factor of 2. Comparison of the measurements with time-dependent photochemical calculations shows reasonable agreement and indicates that temporal changes in atmospheric transport processes are the most likely explanation of the nightglow variations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2012-title40-vol34/pdf/CFR-2012-title40-vol34-sec1042-320.pdf','CFR2012'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2012-title40-vol34/pdf/CFR-2012-title40-vol34-sec1042-320.pdf"><span>40 CFR 1042.320 - What happens if one of my production-<span class="hlt">line</span> engines fails to meet <span class="hlt">emission</span> standards?</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2012&page.go=Go">Code of Federal Regulations, 2012 CFR</a></p> <p></p> <p>2012-07-01</p> <p>...-<span class="hlt">line</span> engines fails to meet <span class="hlt">emission</span> standards? 1042.320 Section 1042.320 Protection of Environment... if one of my production-<span class="hlt">line</span> engines fails to meet <span class="hlt">emission</span> standards? (a) If you have a production....315(a)), the certificate of conformity is automatically suspended for that failing engine. You must...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2011-title40-vol33/pdf/CFR-2011-title40-vol33-sec1042-320.pdf','CFR2011'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2011-title40-vol33/pdf/CFR-2011-title40-vol33-sec1042-320.pdf"><span>40 CFR 1042.320 - What happens if one of my production-<span class="hlt">line</span> engines fails to meet <span class="hlt">emission</span> standards?</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2011&page.go=Go">Code of Federal Regulations, 2011 CFR</a></p> <p></p> <p>2011-07-01</p> <p>...-<span class="hlt">line</span> engines fails to meet <span class="hlt">emission</span> standards? 1042.320 Section 1042.320 Protection of Environment... if one of my production-<span class="hlt">line</span> engines fails to meet <span class="hlt">emission</span> standards? (a) If you have a production....315(a)), the certificate of conformity is automatically suspended for that failing engine. You must...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2010-title40-vol32/pdf/CFR-2010-title40-vol32-sec1042-320.pdf','CFR'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2010-title40-vol32/pdf/CFR-2010-title40-vol32-sec1042-320.pdf"><span>40 CFR 1042.320 - What happens if one of my production-<span class="hlt">line</span> engines fails to meet <span class="hlt">emission</span> standards?</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2010&page.go=Go">Code of Federal Regulations, 2010 CFR</a></p> <p></p> <p>2010-07-01</p> <p>...-<span class="hlt">line</span> engines fails to meet <span class="hlt">emission</span> standards? 1042.320 Section 1042.320 Protection of Environment... if one of my production-<span class="hlt">line</span> engines fails to meet <span class="hlt">emission</span> standards? (a) If you have a production....315(a)), the certificate of conformity is automatically suspended for that failing engine. You must...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=18270','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=18270"><span>Nebular and auroral <span class="hlt">emission</span> <span class="hlt">lines</span> of [Cl iii] in the optical spectra of planetary nebulae</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Keenan, Francis P.; Aller, Lawrence H.; Ramsbottom, Catherine A.; Bell, Kenneth L.; Crawford, Fergal L.; Hyung, Siek</p> <p>2000-01-01</p> <p>Electron impact excitation rates in Cl III, recently determined with the R-matrix code, are used to calculate electron temperature (Te) and density (Ne) <span class="hlt">emission</span> <span class="hlt">line</span> ratios involving both the nebular (5517.7, 5537.9 Å) and auroral (8433.9, 8480.9, 8500.0 Å) transitions. A comparison of these results with observational data for a sample of planetary nebulae, obtained with the Hamilton Echelle Spectrograph on the 3-m Shane Telescope, reveals that the R1 = I(5518 Å)/I(5538 Å) intensity ratio provides estimates of Ne in excellent agreement with the values derived from other <span class="hlt">line</span> ratios in the echelle spectra. This agreement indicates that R1 is a reliable density diagnostic for planetary nebulae, and it also provides observational support for the accuracy of the atomic data adopted in the <span class="hlt">line</span> ratio calculations. However the [Cl iii] 8433.9 Å <span class="hlt">line</span> is found to be frequently blended with a weak telluric <span class="hlt">emission</span> feature, although in those instances when the [Cl iii] intensity may be reliably measured, it provides accurate determinations of Te when ratioed against the sum of the 5518 and 5538 Å <span class="hlt">line</span> fluxes. Similarly, the 8500.0 Å <span class="hlt">line</span>, previously believed to be free of contamination by the Earth's atmosphere, is also shown to be generally blended with a weak telluric <span class="hlt">emission</span> feature. The [Cl iii] transition at 8480.9 Å is found to be blended with the He i 8480.7 Å <span class="hlt">line</span>, except in planetary nebulae that show a relatively weak He i spectrum, where it also provides reliable estimates of Te when ratioed against the nebular <span class="hlt">lines</span>. Finally, the diagnostic potential of the near-UV [Cl iii] <span class="hlt">lines</span> at 3344 and 3354 Å is briefly discussed. PMID:10759562</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20040071151&hterms=black+matter&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dblack%2Bmatter','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20040071151&hterms=black+matter&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dblack%2Bmatter"><span>Evidence for Doppler-Shifted Iron <span class="hlt">Emission</span> <span class="hlt">Lines</span> in Black Hole Candidate 4U 1630-47</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Cui, Wei; Chen, Wan; Zhang, Shuang Nan</p> <p>2000-01-01</p> <p>We report the first detection of a pair of correlated the X-ray spectrum of black hole candidate 4U 1630-47 outburst, based on Rossi X-Ray Timing Explorer (RXTE) <span class="hlt">emission</span> <span class="hlt">lines</span> in during its 1996 observations of the source. At the peak plateau of the outburst, the <span class="hlt">emission</span> <span class="hlt">lines</span> are detected, centered mostly at approx. 5.7 and approx. 7.7 keV, respectively, while the <span class="hlt">line</span> energies exhibit random variability approx. 5%. Interestingly, the <span class="hlt">lines</span> move in a concerted manner to keep their separation roughly constant. The <span class="hlt">lines</span> also vary greatly in strength, but with the lower energy <span class="hlt">line</span> always much stronger than the higher energy one. The measured equivalent width ranges from approx. 50 to approx. 270 eV for the former, and from insignificant detection to approx. 140 eV for the latter; the two are reasonably correlated. The correlation between the <span class="hlt">lines</span> implies a causal connection; perhaps they share a common origin. Both <span class="hlt">lines</span> may arise from a single K & alpha; <span class="hlt">line</span> of highly ionized iron that is Doppler shifted either in a Keplerian accretion disk or in a bipolar outflow or even both. In both scenarios, a change in the <span class="hlt">line</span> energy might simply reflect a change in the ionization state of <span class="hlt">line</span>-emitting matter. We discuss the implication of the results and also raise some questions about such interpretations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018MNRAS.477..904X','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018MNRAS.477..904X"><span><span class="hlt">Emission-line</span> diagnostics of nearby H II regions including interacting binary populations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Xiao, Lin; Stanway, Elizabeth R.; Eldridge, J. J.</p> <p>2018-06-01</p> <p>We present numerical models of the nebular <span class="hlt">emission</span> from H II regions around young stellar populations over a range of compositions and ages. The synthetic stellar populations include both single stars and interacting binary stars. We compare these models to the observed <span class="hlt">emission</span> <span class="hlt">lines</span> of 254 H II regions of 13 nearby spiral galaxies and 21 dwarf galaxies drawn from archival data. The models are created using the combination of the BPASS (Binary Population and Spectral Synthesis) code with the photoionization code CLOUDY to study the differences caused by the inclusion of interacting binary stars in the stellar population. We obtain agreement with the observed <span class="hlt">emission</span> <span class="hlt">line</span> ratios from the nearby star-forming regions and discuss the effect of binary-star evolution pathways on the nebular ionization of H II regions. We find that at population ages above 10 Myr, single-star models rapidly decrease in flux and ionization strength, while binary-star models still produce strong flux and high [O III]/H β ratios. Our models can reproduce the metallicity of H II regions from spiral galaxies, but we find higher metallicities than previously estimated for the H II regions from dwarf galaxies. Comparing the equivalent width of H β <span class="hlt">emission</span> between models and observations, we find that accounting for ionizing photon leakage can affect age estimates for H II regions. When it is included, the typical age derived for H II regions is 5 Myr from single-star models, and up to 10 Myr with binary-star models. This is due to the existence of binary-star evolution pathways, which produce more hot Wolf-Rayet and helium stars at older ages. For future reference, we calculate new BPASS binary maximal starburst <span class="hlt">lines</span> as a function of metallicity, and for the total model population, and present these in Appendix A.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016APS..DPPP10102L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016APS..DPPP10102L"><span>X-ray <span class="hlt">Emission</span> <span class="hlt">Line</span> Anisotropy Effects on the Isoelectronic Temperature Measurement Method</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liedahl, Duane; Barrios, Maria; Brown, Greg; Foord, Mark; Gray, William; Hansen, Stephanie; Heeter, Robert; Jarrott, Leonard; Mauche, Christopher; Moody, John; Schneider, Marilyn; Widmann, Klaus</p> <p>2016-10-01</p> <p>Measurements of the ratio of analogous <span class="hlt">emission</span> <span class="hlt">lines</span> from isoelectronic ions of two elements form the basis of the isoelectronic method of inferring electron temperatures in laser-produced plasmas, with the expectation that atomic modeling errors cancel to first order. Helium-like ions are a common choice in many experiments. Obtaining sufficiently bright signals often requires sample sizes with non-trivial <span class="hlt">line</span> optical depths. For <span class="hlt">lines</span> with small destruction probabilities per scatter, such as the 1s2p-1s2 He-like resonance <span class="hlt">line</span>, repeated scattering can cause a marked angular dependence in the escaping radiation. Isoelectronic <span class="hlt">lines</span> from near-Z equimolar dopants have similar optical depths and similar angular variations, which leads to a near angular-invariance for their <span class="hlt">line</span> ratios. Using Monte Carlo simulations, we show that possible ambiguities associated with anisotropy in deriving electron temperatures from X-ray <span class="hlt">line</span> ratios are minimized by exploiting this isoelectronic invariance.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19870009796&hterms=zoo&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dzoo','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19870009796&hterms=zoo&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dzoo"><span>IUE observations of the Henize-Carlson sample of peculiar <span class="hlt">emission</span> <span class="hlt">line</span> supergiants: The galactic analogs of the Magellanic Zoo</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Shore, Steven N.; Brown, Douglas N.; Sanduleak, N.</p> <p>1986-01-01</p> <p>Some 15 stars from the Carlson-Henize survey of southern peculiar <span class="hlt">emission</span> <span class="hlt">line</span> stars were studied. From both the optical and UV spectra, they appear to be galactic counterparts of the most extreme early-type <span class="hlt">emission</span> <span class="hlt">line</span> supergiants of the Magellanic Clouds.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_18 --> <div id="page_19" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="361"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018E%26ES..108d2029Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018E%26ES..108d2029Z"><span>Status and Needs Research for On-<span class="hlt">line</span> Monitoring of VOCs <span class="hlt">Emissions</span> from Stationary Sources</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhou, Gang; Wang, Qiang; Zhong, Qi; Zhao, Jinbao; Yang, Kai</p> <p>2018-01-01</p> <p>Based on atmospheric volatile organic compounds (VOCs) pollution control requirements during the twelfth-five year plan and the current status of monitoring and management at home and abroad, instrumental architecture and technical characteristics of continuous <span class="hlt">emission</span> monitoring systems (CEMS) for VOCs <span class="hlt">emission</span> from stationary sources are investigated and researched. Technological development needs of VOCs <span class="hlt">emission</span> on-<span class="hlt">line</span> monitoring techniques for stationary sources in china are proposed from the system sampling pretreatment technology and analytical measurement techniques.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017A%26A...600A..23T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017A%26A...600A..23T"><span>(Sub)millimeter <span class="hlt">emission</span> <span class="hlt">lines</span> of molecules in born-again stars</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tafoya, D.; Toalá, J. A.; Vlemmings, W. H. T.; Guerrero, M. A.; De Beck, E.; González, M.; Kimeswenger, S.; Zijlstra, A. A.; Sánchez-Monge, Á.; Treviño-Morales, S. P.</p> <p>2017-04-01</p> <p>Context. Born-again stars provide a unique possibility to study the evolution of the circumstellar envelope of evolved stars in human timescales. Up until now, most of the observations of the circumstellar material in these stars have been limited to studying the relatively hot gas and dust. In other evolved stars, the <span class="hlt">emission</span> from rotational transitions of molecules, such as CO, is commonly used to study the cool component of their circumstellar envelopes. Thus, the detection and study of molecular gas in born-again stars is of great importance when attempting to understand their composition and chemical evolution. In addition, the molecular <span class="hlt">emission</span> is an invaluable tool for exploring the physical conditions, kinematics, and formation of asymmetric structures in the circumstellar envelopes of these evolved stars. However, up until now, all attempts to detect molecular <span class="hlt">emission</span> from the cool material around born-again stars have failed. Aims: We searched for <span class="hlt">emission</span> from rotational transitions of molecules in the hydrogen-deficient circumstellar envelopes of born-again stars to explore the chemical composition, kinematics, and physical parameters of the relatively cool gas. Methods: We carried out observations using the APEX and IRAM 30 m telescopes to search for molecular <span class="hlt">emission</span> toward four well-studied born-again stars, V4334 Sgr, V605 Aql, A30, and A78, that are thought to represent an evolutionary sequence. Results: For the first time, we detected <span class="hlt">emission</span> from HCN and H13CN molecules toward V4334 Sgr, and CO <span class="hlt">emission</span> in V605 Aql. No molecular <span class="hlt">emission</span> was detected above the noise level toward A30 and A78. The detected <span class="hlt">lines</span> exhibit broad linewidths ≳150 km s-1, which indicates that the <span class="hlt">emission</span> comes from gas ejected during the born-again event, rather than from the old planetary nebula. A first estimate of the H12CN/H13CN abundance ratio in the circumstellar environment of V4334 Sgr is ≈3, which is similar to the value of the 12C/13C ratio measured</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19950035664&hterms=How+Program&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DTitle%26N%3D0%26No%3D20%26Ntt%3DHow%2Bto%2BProgram','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19950035664&hterms=How+Program&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DTitle%26N%3D0%26No%3D20%26Ntt%3DHow%2Bto%2BProgram"><span>How fast do quasar <span class="hlt">emission</span> <span class="hlt">lines</span> vary? First results from a program to monitor the Balmer <span class="hlt">lines</span> of the Palomar-Green Quasars</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Maoz, Dan; Smith, Paul S.; Jannuzi, Buell T.; Kaspi, Shai; Netzer, Hagai</p> <p>1994-01-01</p> <p>We have monitored spectrophotometrically a subsample (28) of the Palomar-Green Bright Quasar Sample for 2 years in order to test for correlations between continuum and <span class="hlt">emission-line</span> variations and to determine the timescales relevant to mapping the broad-<span class="hlt">line</span> regions of high-luminosity active galactic nuclei (AGNs). Half of the quasars showed optical continuum variations with amplitudes in the range 20-75%. The rise and fall time for the continuum variations is typically 0.5-2 years. In most of the objects with continuum variations, we detect correlated variations in the broad H-alpha and H-beta <span class="hlt">emission</span> <span class="hlt">lines</span>. The amplitude of the <span class="hlt">line</span> variations is usually 2-4 times smaller than the optical continuum fluctuations. We present light curves and analyze spectra for six of the variable quasars with 1000-10,000 A luminosity in the range 0.3-4 x 10(exp 45) ergs/s. In four of these objects the <span class="hlt">lines</span> respond to the continuum variations with a lag that is smaller than or comparable to our typical sampling interval (a few months). Although continued monitoring is required to confirm these results and increase their accuracy, the present evidence indicates that quasars with the above luminosities have broad-<span class="hlt">line</span> regions smaller than about 1 1t-yr. Two of the quasars monitored show no detectable <span class="hlt">line</span> variations despite relatively large-amplitude continuum changes. This could be a stronger manifestation of the low-amplitude <span class="hlt">line</span>-response phenomenon we observe in the other quasars.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1998JGR...10329215B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1998JGR...10329215B"><span>Atomic and molecular <span class="hlt">emissions</span> in the middle ultraviolet dayglow</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bucsela, Eric J.; Cleary, David D.; Dymond, Kenneth F.; McCoy, Robert P.</p> <p>1998-12-01</p> <p>Dayglow spectra in the middle ultraviolet, obtained during a sounding rocket flight from White Sands Missile Range in 1992, have been analyzed to determine the altitude distributions of thermospheric atomic and molecular species and to address a number of problems related to <span class="hlt">airglow</span> excitation mechanisms. Among the atomic and molecular profiles retrieved are the N2 second positive, N2 Vegard-Kaplan and NO gamma band systems, and the OI 297.2 nm, OII 247.0 nm, and NII 214.3 nm <span class="hlt">emissions</span>. A self-consistent study of the <span class="hlt">emission</span> profiles was conducted by comparing observed intensities with one another and to forward models. Model photoelectron and photon fluxes were generated by the field <span class="hlt">line</span> interhemispheric plasma model (FLIP) and two solar flux models. Neutral densities were obtained from mass-spectrometer/incoherent scatter (MSIS)-90. The results from the data analysis suggest that the major species' densities are within 40% of MSIS values. Evidence for the accuracy of the modeled densities and fluxes is seen in the close agreement between the calculated and observed intensities of the N2 second positive <span class="hlt">emission</span>. Analysis of the OI 297.2 nm <span class="hlt">emission</span> shows that the reaction N2(A)+O is the dominant source of O(1S) in the daytime thermosphere. The data imply that the vibrationally averaged yield of O(1S) from the reaction is 0.43+/-0.12, which is smaller than the laboratory value measured for the N2(A,v'=0) level. The cause of a disagreement between model and data for the Vegard-Kaplan <span class="hlt">emission</span> is unclear, but the discrepancy can be eliminated if the N2(A)+O quenching coefficient or the A state lifetime is increased by a factor between 2 and 4. The observed intensity of OII 247.0 nm is greater than expected by a factor of 2, implying possible inadequacies in the EUVAC and/or EUV91 solar models used in the analysis.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014cosp...40E2427P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014cosp...40E2427P"><span>Electron ionization of metastable nitrogen and oxygen atoms in relation to the auroral <span class="hlt">emissions</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pandya, Siddharth; Joshipura, K. N.</p> <p></p> <p>Atomic and molecular excited metastable states (EMS) are exotic systems due to their special properties like long radiative life-time, large size (average radius) and large polarizability along with relatively smaller first ionization energy compared to their respective ground states (GS). The present work includes our theoretical calculations on electron impact ionization of metastable atomic states N( (2) P), N( (2) D) of nitrogen and O( (1) S), O( (1) D) of oxygen. The targets of our present interest, are found to be present in our Earth's ionosphere and they play an important role in auroral <span class="hlt">emissions</span> observed in Earth’s auroral regions [1] as also in the <span class="hlt">emissions</span> observed from cometary coma [2, 3] and <span class="hlt">airglow</span> <span class="hlt">emissions</span>. In particular, atomic oxygen in EMS can radiate, the visible O( (1) D -> (3) P) doublet 6300 - 6364 Å red doublet, the O( (1) S -> (1) D) 5577 Å green <span class="hlt">line</span>, and the ultraviolet O( (1) S -> (3) P) 2972 Å <span class="hlt">line</span>. For metastable atomic nitrogen one observes the similar <span class="hlt">emissions</span>, in different wavelengths, from (2) D and (2) P states. At the Earth's auroral altitudes, from where these <span class="hlt">emissions</span> take place in the ionosphere, energetic electrons are also present. In particular, if the metastable N as well as O atoms are ionized by the impact of electrons then these species are no longer available for <span class="hlt">emissions</span>. This is a possible loss mechanism, and hence it is necessary to analyze the importance of electron ionization of the EMS of atomic O and N, by calculating the relevant cross sections. In the present paper we investigate electron ionization of the said metastable species by calculating relevant total cross sections. Our quantum mechanical calculations are based on projected approximate ionization contribution in the total inelastic cross sections [4]. Detailed results and discussion along with the significance of these calculations will be presented during the COSPAR-2014. References [1] A.Bhardwaj, and G. R. Gladstone, Rev. Geophys., 38</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011hers.prop.1989C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011hers.prop.1989C"><span>OT2_jcernich_9: Time Variability of Thermal Molecular <span class="hlt">Line</span> <span class="hlt">Emission</span> in IRC+10216</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cernicharo, J.</p> <p>2011-09-01</p> <p>We have found during our GT <span class="hlt">line</span> survey of IRC+10216 and the search for hydrides (OT1 proposal) that some molecular <span class="hlt">lines</span> present a strong intensity variation with time due to the role of infrared pumping. For some <span class="hlt">lines</span> the intensity change in six months reaches a factor 3 (CCH). We have checked that the effect is not instrumental and than it arises from physical processes ignored so far in the radiative transfer models. We propose to observe the CCH and HNC <span class="hlt">lines</span> within bands 1a-5b of HIFI every four months (three observing slots) to allow a detailed study of the variation of thermal molecular <span class="hlt">emission</span>, and dust <span class="hlt">emission</span>, in this prototype of AGB C-rich object. The settings will also provide, as a bonus, many <span class="hlt">lines</span> of SiO, SiS, CS, HCN, CO and 13CO for which intensity variations of up to 30% have been found. In addition, a few specificc settings for HCN and CO will complete the observations. SPIRE and PACS observations will complement, with lower spectral resolution, the whole spectrum of each of these molecules and will provide a global view of the total intensity change of these <span class="hlt">lines</span> with time. A crude estimate of the distance could be also obtained from the observed time lags between the blue and red parts of the <span class="hlt">line</span> profiles observed with HIFI.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22524882-alma-imaging-co-line-emission-ngc','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22524882-alma-imaging-co-line-emission-ngc"><span>ALMA IMAGING OF THE CO (6-5) <span class="hlt">LINE</span> <span class="hlt">EMISSION</span> IN NGC 7130</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Zhao, Yinghe; Lu, Nanyao; Xu, C. Kevin</p> <p>2016-04-01</p> <p>In this paper, we report our high-resolution (0.″20 × 0.″14 or ∼70 × 49 pc) observations of the CO(6-5) <span class="hlt">line</span> <span class="hlt">emission</span>, which probes warm and dense molecular gas, and the 434 μm dust continuum in the nuclear region of NGC 7130, obtained with the Atacama Large Millimeter Array (ALMA). The CO <span class="hlt">line</span> and dust continuum fluxes detected in our ALMA observations are 1230 ± 74 Jy km s{sup −1} and 814 ± 52 mJy, respectively, which account for 100% and 51% of their total fluxes. We find that the CO(6-5) and dust <span class="hlt">emissions</span> are generally spatially correlated, but their brightest peaks show an offset of ∼70 pc, suggestingmore » that the gas and dust <span class="hlt">emissions</span> may start decoupling at this physical scale. The brightest peak of the CO(6-5) <span class="hlt">emission</span> does not spatially correspond to the radio continuum peak, which is likely dominated by an active galactic nucleus (AGN). This, together with our additional quantitative analysis, suggests that the heating contribution of the AGN to the CO(6-5) <span class="hlt">emission</span> in NGC 7130 is negligible. The CO(6-5) and the extinction-corrected Pa-α maps display striking differences, suggestive of either a breakdown of the correlation between warm dense gas and star formation at linear scales of <100 pc or a large uncertainty in our extinction correction to the observed Pa-α image. Over a larger scale of ∼2.1 kpc, the double-lobed structure found in the CO(6-5) <span class="hlt">emission</span> agrees well with the dust lanes in the optical/near-infrared images.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018MNRAS.476.4520K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018MNRAS.476.4520K"><span>On the Brγ <span class="hlt">line</span> <span class="hlt">emission</span> of the Herbig Ae/Be star MWC 120</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kreplin, Alexander; Tambovtseva, Larisa; Grinin, Vladimir; Kraus, Stefan; Weigelt, Gerd; Wang, Yang</p> <p>2018-06-01</p> <p>The origin of the Br γ <span class="hlt">line</span> in Herbig Ae/Be stars is still an open question. It has been proposed that a fraction of the 2.166-μm Br γ <span class="hlt">emission</span> might emerge from a disc wind, the magnetosphere and other regions. Investigations of the Br γ <span class="hlt">line</span> in young stellar objects are important to improve our understanding of the accretion-ejection process. Near-infrared long-baseline interferometry enables the investigation of the Br γ <span class="hlt">line</span>-emitting region with high spatial and high spectral resolution. We observed the Herbig Ae/Be star MWC 120 with the Astronomical Multi-Beam Recombiner (AMBER) on the Very Large Telescope Interferometer (VLTI) in different spectral channels across the Br γ <span class="hlt">line</span> with a spectral resolution of R ˜ 1500. Comparison of the visibilities, differential and closure phases in the continuum and the <span class="hlt">line</span>-emitting region with geometric and radiative transfer disc-wind models leads to constraints on the origin and dynamics of the gas emitting the Br γ light. Geometric modelling of the visibilities reveals a <span class="hlt">line-emission</span> region about two times smaller than the K-band continuum region, which indicates a scenario where the Br γ <span class="hlt">emission</span> is dominated by an extended disc wind rather than by a much more compact magnetospheric origin. To compare our data with a physical model, we applied a state-of-the-art radiative transfer disc-wind model. We find that all measured visibilities, differential and closure phases of MWC 120 can be approximately reproduced by a disc-wind model. A comparison with other Herbig stars indicates a correlation of the modelled inner disc-wind radii with the corresponding Alfvén radii for late spectral type stars.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009MNRAS.396..788S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009MNRAS.396..788S"><span>Mapping low- and high-density clouds in astrophysical nebulae by imaging forbidden <span class="hlt">line</span> <span class="hlt">emission</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Steiner, J. E.; Menezes, R. B.; Ricci, T. V.; Oliveira, A. S.</p> <p>2009-06-01</p> <p><span class="hlt">Emission</span> <span class="hlt">line</span> ratios have been essential for determining physical parameters such as gas temperature and density in astrophysical gaseous nebulae. With the advent of panoramic spectroscopic devices, images of regions with <span class="hlt">emission</span> <span class="hlt">lines</span> related to these physical parameters can, in principle, also be produced. We show that, with observations from modern instruments, it is possible to transform images taken from density-sensitive forbidden <span class="hlt">lines</span> into images of <span class="hlt">emission</span> from high- and low-density clouds by applying a transformation matrix. In order to achieve this, images of the pairs of density-sensitive <span class="hlt">lines</span> as well as the adjacent continuum have to be observed and combined. We have computed the critical densities for a series of pairs of <span class="hlt">lines</span> in the infrared, optical, ultraviolet and X-rays bands, and calculated the pair <span class="hlt">line</span> intensity ratios in the high- and low-density limit using a four- and five-level atom approximation. In order to illustrate the method, we applied it to Gemini Multi-Object Spectrograph (GMOS) Integral Field Unit (GMOS-IFU) data of two galactic nuclei. We conclude that this method provides new information of astrophysical interest, especially for mapping low- and high-density clouds; for this reason, we call it `the ld/hd imaging method'. Based on observations obtained at the Gemini Observatory, which is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the National Science Foundation on behalf of the Gemini partnership: the National Science Foundation (United States); the Science and Technology Facilities Council (United Kingdom); the National Research Council (Canada), CONICYT (Chile); the Australian Research Council (Australia); Ministério da Ciência e Tecnologia (Brazil) and Secretaria de Ciencia y Tecnologia (Argentina). E-mail: steiner@astro.iag.usp.br</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19910004854','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19910004854"><span>Origin and dynamics of <span class="hlt">emission</span> <span class="hlt">line</span> clouds in cooling flow environments</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Loewenstein, Michael</p> <p>1990-01-01</p> <p>The author suggests that since clouds are born co-moving in a turbulent intra-cluster medium (ICM), the allowed parameter space can now be opened up to a more acceptable range. Large-scale motions can be driven in the central parts of cooling flows by a number of mechanisms including the motion of the central and other galaxies, and the dissipation of advected, focussed rotational and magnetic energy. In addition to the velocity width paradox, two other paradoxes (Heckman et al. 1989) can be solved if the ICM is turbulent. Firstly, the heating source for the <span class="hlt">emission</span> <span class="hlt">line</span> regions has always been puzzling - <span class="hlt">line</span> luminosities are extremely high for a given (optical or radio) galaxy luminosity compared to those in non-cooling flow galaxies, therefore a mechanism peculiar to cooling flows must be at work. However most, if not all, previously suggested heating mechanisms either fail to provide enough ionization or give the wrong <span class="hlt">line</span> ratios, or both. The kinetic energy in the turbulence provides a natural energy source if it can be efficiently converted to cloud heat. Researchers suggest that this can be done via magneto-hydrodynamic waves through plasma slip. Secondly, while the x ray observations indicate extended mass deposition, the optical <span class="hlt">line</span> <span class="hlt">emission</span> is more centrally concentrated. Since many of the turbulence-inducing mechanisms are strongest in the central regions of the ICM, so is the method of heating. In other words material is dropping out everywhere but only being lit up in the center.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19920028465&hterms=Seventeen&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3DSeventeen','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19920028465&hterms=Seventeen&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3DSeventeen"><span><span class="hlt">Emission-line</span> galaxies in the third list of the Case Low-Dispersion Northern Sky Survey</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Weistrop, Donna; Downes, Ronald A.</p> <p>1991-01-01</p> <p>Observations of 47 galaxies in the third Case list are reported. Thirty-five of the galaxies in the sample were selected for the presence of <span class="hlt">emission</span> <span class="hlt">lines</span> on the objective prism plates. At the higher spectral dispersion of the data, significant <span class="hlt">line</span> <span class="hlt">emission</span> was found in 46 of the 47 galaxies. Twenty-six galaxies are found to be undergoing significant bursts of star formation. Ten additional galaxies may be starburst galaxies with low-excitation spectra. Two galaxies are probably type Seyfert 2. The most distant object, CG 200, at a redshift of 0.144, has a strong broad H-alpha <span class="hlt">emission</span> <span class="hlt">line</span>, and is probably a Seyfert 1. Seventeen of the galaxies have been detected by IRAS. Eight of the IRAS galaxies have H-II-region-type spectra and eight have low-ionization starburst spectra. The galaxies represent a mixture of types, ranging from intrinsically faint dwarf galaxies with Mb equalling -16 mag, to powerful galaxies with MB equalling -23 mag. Galaxies CG 234 and CG 235 are interacting, as are galaxies CG 269 and CG 270.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018MNRAS.474.2617B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018MNRAS.474.2617B"><span>First light - II. <span class="hlt">Emission</span> <span class="hlt">line</span> extinction, population III stars, and X-ray binaries</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Barrow, Kirk S. S.; Wise, John H.; Aykutalp, Aycin; O'Shea, Brian W.; Norman, Michael L.; Xu, Hao</p> <p>2018-02-01</p> <p>We produce synthetic spectra and observations for metal-free stellar populations and high-mass X-ray binaries in the Renaissance Simulations at a redshift of 15. We extend our methodology from the first paper in the series by modelling the production and extinction of <span class="hlt">emission</span> <span class="hlt">lines</span> throughout a dusty and metal-enriched interstellar and circum-galactic media extracted from the simulation, using a Monte Carlo calculation. To capture the impact of high-energy photons, we include all frequencies from hard X-ray to far-infrared with enough frequency resolution to discern <span class="hlt">line</span> <span class="hlt">emission</span> and absorption profiles. The most common <span class="hlt">lines</span> in our sample in order of their rate of occurrence are Ly α, the C IV λλ1548, 1551 doublet, H α, and the Ca II λλλ8498, 8542, 8662 triplet. The best scenario for a direct observation of a metal-free stellar population is a merger between two Population III Galaxies. In mergers between metal-enriched and metal-free stellar populations, some characteristics may be inferred indirectly. Single Population III galaxies are too dim to be observed photometrically at z = 15. Ly α <span class="hlt">emission</span> is discernible by JWST as an increase in J200w - J277w colour off the intrinsic stellar tracks. Observations of metal-free stars will be difficult, though not impossible, with the next generation of space telescopes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ApJ...821...33R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ApJ...821...33R"><span>Broad Hβ <span class="hlt">Emission-line</span> Variability in a Sample of 102 Local Active Galaxies</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Runco, Jordan N.; Cosens, Maren; Bennert, Vardha N.; Scott, Bryan; Komossa, S.; Malkan, Matthew A.; Lazarova, Mariana S.; Auger, Matthew W.; Treu, Tommaso; Park, Daeseong</p> <p>2016-04-01</p> <p>A sample of 102 local (0.02 ≤ z ≤ 0.1) Seyfert galaxies with black hole masses MBH > 107M⊙ was selected from the Sloan Digital Sky Survey (SDSS) and observed using the Keck 10 m telescope to study the scaling relations between MBH and host galaxy properties. We study profile changes of the broad Hβ <span class="hlt">emission</span> <span class="hlt">line</span> within the three to nine year time frame between the two sets of spectra. The variability of the broad Hβ <span class="hlt">emission</span> <span class="hlt">line</span> is of particular interest, not only because it is used to estimate MBH, but also because its strength and width are used to classify Seyfert galaxies into different types. At least some form of broad-<span class="hlt">line</span> variability (in either width or flux) is observed in the majority (∼66%) of the objects, resulting in a Seyfert-type change for ∼38% of the objects, likely driven by variable accretion and/or obscuration. The broad Hβ <span class="hlt">line</span> virtually disappears in 3/102 (∼3%) extreme cases. We discuss potential causes for these changing look active galactic nuclei. While similar dramatic transitions have previously been reported in the literature, either on a case-by-case basis or in larger samples focusing on quasars at higher redshifts, our study provides statistical information on the frequency of Hβ <span class="hlt">line</span> variability in a sample of low-redshift Seyfert galaxies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017A%26A...607A..32B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017A%26A...607A..32B"><span>Constraining the geometry and kinematics of the quasar broad <span class="hlt">emission</span> <span class="hlt">line</span> region using gravitational microlensing. I. Models and simulations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Braibant, L.; Hutsemékers, D.; Sluse, D.; Goosmann, R.</p> <p>2017-11-01</p> <p>Recent studies have shown that <span class="hlt">line</span> profile distortions are commonly observed in gravitationally lensed quasar spectra. Often attributed to microlensing differential magnification, <span class="hlt">line</span> profile distortions can provide information on the geometry and kinematics of the broad <span class="hlt">emission</span> <span class="hlt">line</span> region (BLR) in quasars. We investigate the effect of gravitational microlensing on quasar broad <span class="hlt">emission</span> <span class="hlt">line</span> profiles and their underlying continuum, combining the <span class="hlt">emission</span> from simple representative BLR models with generic microlensing magnification maps. Specifically, we considered Keplerian disk, polar, and equatorial wind BLR models of various sizes. The effect of microlensing has been quantified with four observables: μBLR, the total magnification of the broad <span class="hlt">emission</span> <span class="hlt">line</span>; μcont, the magnification of the underlying continuum; as well as red/blue, RBI and wings/core, WCI, indices that characterize the <span class="hlt">line</span> profile distortions. The simulations showed that distortions of <span class="hlt">line</span> profiles, such as those recently observed in lensed quasars, can indeed be reproduced and attributed to the differential effect of microlensing on spatially separated regions of the BLR. While the magnification of the <span class="hlt">emission</span> <span class="hlt">line</span> μBLR sets an upper limit on the BLR size and, similarly, the magnification of the continuum μcont sets an upper limit on the size of the continuum source, the <span class="hlt">line</span> profile distortions mainly depend on the BLR geometry and kinematics. We thus built (WCI,RBI) diagrams that can serve as diagnostic diagrams to discriminate between the various BLR models on the basis of quantitative measurements. It appears that a strong microlensing effect puts important constraints on the size of the BLR and on its distance to the high-magnification caustic. In that case, BLR models with different geometries and kinematics are more prone to produce distinctive <span class="hlt">line</span> profile distortions for a limited number of caustic configurations, which facilitates their discrimination. When the microlensing</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19960054493','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19960054493"><span>The Analysis of <span class="hlt">Emission</span> <span class="hlt">Lines</span>; A Meeting in Honour of the 70th Birthdays of D. E. Osterbrock and M. J. Seaton</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Williams, Robert (Editor); Livio, Mario (Editor); Dufour, Reginald J.</p> <p>1994-01-01</p> <p>A review of the field of astronomical spectroscopy with emphasis on <span class="hlt">emission</span> <span class="hlt">lines</span> in astrophysical plasmas is presented. A brief history of UV spectroscopy instruments is given, following by a discussion and tabulation of major atlases of UV <span class="hlt">emission-line</span> objects to date (mid-1994). A discussion of the major diagnostic UV <span class="hlt">emission</span> <span class="hlt">lines</span> in the approx. 912-3200 A spectral region that are useful for determining electron densities, temperatures, abundances, and extinction in low- to moderate density plasmas is given, with examples of applications to selected objects. The review concludes by presenting some recent results from HST, HUT, and IUE on UV <span class="hlt">emission-line</span> spectroscopy of nebulae and active galaxies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AAS...22734236T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AAS...22734236T"><span><span class="hlt">Emission</span> <span class="hlt">line</span> galaxy pairs up to z=1.5 from the WISP survey</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Teplitz, Harry I.; Dai, Yu Sophia; Malkan, Matthew Arnold; Scarlata, Claudia; Colbert, James W.; Atek, Hakim; Bagley, Micaela B.; Baronchelli, Ivano; Bedregal, Alejandro; Beck, Melanie; Bunker, Andrew; Dominguez, Alberto; Hathi, Nimish P.; Henry, Alaina L.; Mehta, Vihang; Pahl, Anthony; Rafelski, Marc; Ross, Nathaniel; Rutkowski, Michael J.; Siana, Brian D.; WISPs Team</p> <p>2016-01-01</p> <p>We present a sample of spectroscopically identified <span class="hlt">emission</span> <span class="hlt">line</span> galaxy pairs up to z=1.5 from WISPs (WFC3 Infrared Spectroscopic Parallel survey) using high resolution direct and grism images from HST. We searched ~150 fields with a covered area of ~600 arcmin^2, and a comoving volume of > 400 Gpc^3 at z=1-2, and found ~80 very close physical pairs (projected separation Dp < 50 h^{-1}kpc, relative velocity d_v < 500 kms^{-1}), and ~100 close physical pairs (50 < Dp < 100 h^{-1}kpc, d_v < 1000 kms^{-1}) of <span class="hlt">emission</span> <span class="hlt">line</span> galaxies, including two dozen triplets and quadruples. In this poster we present the multi-wavelength data, star formation rate (SFR), mass ratio, and study the merger rate evolution with this special galaxy pair sample.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19910057592&hterms=zero+point+energy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dzero%2Bpoint%2Benergy','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19910057592&hterms=zero+point+energy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dzero%2Bpoint%2Benergy"><span>GRIS observations of Al-26 gamma-ray <span class="hlt">line</span> <span class="hlt">emission</span> from two points in the Galactic plane</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Teegarden, B. J.; Barthelmy, S. D.; Gehrels, N.; Tueller, J.; Leventhal, M.</p> <p>1991-01-01</p> <p>Both of the Gamma-Ray Imaging Spectrometer (GRIS) experiment's two observations of the Galactic center region, at l = zero and 335 deg respectively, detected Al-26 gamma-ray <span class="hlt">line</span> <span class="hlt">emission</span>. While these observations are consistent with the assumed high-energy gamma-ray distribution, they are consistent with other distributions as well. The data suggest that the Al-26 <span class="hlt">emission</span> is distributed over Galactic longitude rather than being confined to a point source. The GRIS data also indicate that the 1809 keV <span class="hlt">line</span> is broadened.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2001A%26A...380..341B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2001A%26A...380..341B"><span>Coronal loop hydrodynamics. The solar flare observed on November 12, 1980 revisited: The UV <span class="hlt">line</span> <span class="hlt">emission</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Betta, R. M.; Peres, G.; Reale, F.; Serio, S.</p> <p>2001-12-01</p> <p>We revisit a well-studied solar flare whose X-ray <span class="hlt">emission</span> originating from a simple loop structure was observed by most of the instruments on board SMM on November 12, 1980. The X-ray <span class="hlt">emission</span> of this flare, as observed with the XRP, was successfully modeled previously. Here we include a detailed modeling of the transition region and we compare the hydrodynamic results with the UVSP observations in two EUV <span class="hlt">lines</span>, measured in areas smaller than the XRP rasters, covering only some portions of the flaring loop (the top and the foot-points). The single loop hydrodynamic model, which fits well the evolution of coronal <span class="hlt">lines</span> (those observed with the XRP and the Fe XXI 1354.1 Å <span class="hlt">line</span> observed with the UVSP) fails to model the flux level and evolution of the O V 1371.3 Å<span class="hlt">line</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1425612-reverberation-mapping-optical-emission-lines-five-active-galaxies','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1425612-reverberation-mapping-optical-emission-lines-five-active-galaxies"><span>Reverberation Mapping of Optical <span class="hlt">Emission</span> <span class="hlt">Lines</span> in Five Active Galaxies</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Fausnaugh, M. M.; Grier, C. J.; Bentz, M. C.; ...</p> <p>2017-05-10</p> <p>We present the first results from an optical reverberation mapping campaign executed in 2014 targeting the active galactic nuclei (AGNs) MCG+08-11-011, NGC 2617, NGC 4051, 3C 382, and Mrk 374. Our targets have diverse and interesting observational properties, including a “changing look” AGN and a broad-<span class="hlt">line</span> radio galaxy. Based on continuum-Hβ lags, we measure black hole masses for all five targets. We also obtain Hγ and He II λ4686 lags for all objects except 3C 382. The He II λ4686 lags indicate radial stratification of the BLR, and the masses derived from different <span class="hlt">emission</span> <span class="hlt">lines</span> are in general agreement. Themore » relative responsivities of these <span class="hlt">lines</span> are also in qualitative agreement with photoionization models. Finally, these spectra have extremely high signal-to-noise ratios (100–300 per pixel) and there are excellent prospects for obtaining velocity-resolved reverberation signatures.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22663611-reverberation-mapping-optical-emission-lines-five-active-galaxies','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22663611-reverberation-mapping-optical-emission-lines-five-active-galaxies"><span>Reverberation Mapping of Optical <span class="hlt">Emission</span> <span class="hlt">Lines</span> in Five Active Galaxies</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Fausnaugh, M. M.; Denney, K. D.; Peterson, B. M.</p> <p>2017-05-10</p> <p>We present the first results from an optical reverberation mapping campaign executed in 2014 targeting the active galactic nuclei (AGNs) MCG+08-11-011, NGC 2617, NGC 4051, 3C 382, and Mrk 374. Our targets have diverse and interesting observational properties, including a “changing look” AGN and a broad-<span class="hlt">line</span> radio galaxy. Based on continuum-H β lags, we measure black hole masses for all five targets. We also obtain H γ and He ii λ 4686 lags for all objects except 3C 382. The He ii λ 4686 lags indicate radial stratification of the BLR, and the masses derived from different <span class="hlt">emission</span> <span class="hlt">lines</span> aremore » in general agreement. The relative responsivities of these <span class="hlt">lines</span> are also in qualitative agreement with photoionization models. These spectra have extremely high signal-to-noise ratios (100–300 per pixel) and there are excellent prospects for obtaining velocity-resolved reverberation signatures.« less</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_19 --> <div id="page_20" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="381"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19850028663&hterms=Abreu&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DAbreu%252C%2Bc.','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19850028663&hterms=Abreu&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DAbreu%252C%2Bc."><span>Tomographic inversion of satellite photometry</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Solomon, S. C.; Hays, P. B.; Abreu, V. J.</p> <p>1984-01-01</p> <p>An inversion algorithm capable of reconstructing the volume <span class="hlt">emission</span> rate of thermospheric <span class="hlt">airglow</span> features from satellite photometry has been developed. The accuracy and resolution of this technique are investigated using simulated data, and the inversions of several sets of observations taken by the Visible <span class="hlt">Airglow</span> Experiment are presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22520084-lick-agn-monitoring-project-spectroscopic-campaign-emission-line-light-curves','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22520084-lick-agn-monitoring-project-spectroscopic-campaign-emission-line-light-curves"><span>THE LICK AGN MONITORING PROJECT 2011: SPECTROSCOPIC CAMPAIGN AND <span class="hlt">EMISSION-LINE</span> LIGHT CURVES</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Barth, Aaron J.; Bennert, Vardha N.; Canalizo, Gabriela</p> <p>2015-04-15</p> <p>In the Spring of 2011 we carried out a 2.5 month reverberation mapping campaign using the 3 m Shane telescope at Lick Observatory, monitoring 15 low-redshift Seyfert 1 galaxies. This paper describes the observations, reductions and measurements, and data products from the spectroscopic campaign. The reduced spectra were fitted with a multicomponent model in order to isolate the contributions of various continuum and <span class="hlt">emission-line</span> components. We present light curves of broad <span class="hlt">emission</span> <span class="hlt">lines</span> and the active galactic nucleus (AGN) continuum, and measurements of the broad Hβ <span class="hlt">line</span> widths in mean and rms spectra. For the most highly variable AGNs wemore » also measured broad Hβ <span class="hlt">line</span> widths and velocity centroids from the nightly spectra. In four AGNs exhibiting the highest variability amplitudes, we detect anticorrelations between broad Hβ width and luminosity, demonstrating that the broad-<span class="hlt">line</span> region “breathes” on short timescales of days to weeks in response to continuum variations. We also find that broad Hβ velocity centroids can undergo substantial changes in response to continuum variations; in NGC 4593, the broad Hβ velocity shifted by ∼250 km s{sup −1} over a 1 month period. This reverberation-induced velocity shift effect is likely to contribute a significant source of confusion noise to binary black hole searches that use multi-epoch quasar spectroscopy to detect binary orbital motion. We also present results from simulations that examine biases that can occur in measurement of broad-<span class="hlt">line</span> widths from rms spectra due to the contributions of continuum variations and photon-counting noise.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20160010315&hterms=light&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dlight','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20160010315&hterms=light&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dlight"><span>The Lick AGN Monitoring Project 2011: Spectroscopic Campaign and <span class="hlt">Emission-line</span> Light Curves</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Barth, Aaron J.; Bennert, Vardha N.; Canalizo, Gabriela; Filippenko, Alexei V.; Gates, Elinor L.; Greene, Jenny E..; Li, Weidong; Malkan, Matthew A.; Pancoast, Anna; Sand, David J.; <a style="text-decoration: none; " href="javascript:void(0); " onClick="displayelement('author_20160010315'); toggleEditAbsImage('author_20160010315_show'); toggleEditAbsImage('author_20160010315_hide'); "> <img style="display:inline; width:12px; height:12px; " src="images/arrow-up.gif" width="12" height="12" border="0" alt="hide" id="author_20160010315_show"> <img style="width:12px; height:12px; display:none; " src="images/arrow-down.gif" width="12" height="12" border="0" alt="hide" id="author_20160010315_hide"></p> <p>2016-01-01</p> <p>In the Spring of 2011 we carried out a 2.5 month reverberation mapping campaign using the 3 m Shane telescope at Lick Observatory, monitoring 15 low-redshift Seyfert 1 galaxies. This paper describes the observations, reductions and measurements, and data products from the spectroscopic campaign. The reduced spectra were fitted with a multicomponent model in order to isolate the contributions of various continuum and <span class="hlt">emission-line</span> components. We present light curves of broad <span class="hlt">emission</span> <span class="hlt">lines</span> and the active galactic nucleus (AGN) continuum, and measurements of the broad Hß <span class="hlt">line</span> widths in mean and rms spectra. For the most highly variable AGNs we also measured broad H beta <span class="hlt">line</span> widths and velocity centroids from the nightly spectra. In four AGNs exhibiting the highest variability amplitudes, we detect anticorrelations between broad H beta width and luminosity, demonstrating that the broad-<span class="hlt">line</span> region "breathes" on short timescales of days to weeks in response to continuum variations. We also find that broad H beta velocity centroids can undergo substantial changes in response to continuum variations; in NGC 4593, the broad H beta velocity shifted by approximately 250 km s(exp -1) over a 1 month period. This reverberation-induced velocity shift effect is likely to contribute a significant source of confusion noise to binary black hole searches that use multi-epoch quasar spectroscopy to detect binary orbital motion. We also present results from simulations that examine biases that can occur in measurement of broad-<span class="hlt">line</span> widths from rms spectra due to the contributions of continuum variations and photon-counting noise.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27312046','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27312046"><span>Detection of an oxygen <span class="hlt">emission</span> <span class="hlt">line</span> from a high-redshift galaxy in the reionization epoch.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Inoue, Akio K; Tamura, Yoichi; Matsuo, Hiroshi; Mawatari, Ken; Shimizu, Ikkoh; Shibuya, Takatoshi; Ota, Kazuaki; Yoshida, Naoki; Zackrisson, Erik; Kashikawa, Nobunari; Kohno, Kotaro; Umehata, Hideki; Hatsukade, Bunyo; Iye, Masanori; Matsuda, Yuichi; Okamoto, Takashi; Yamaguchi, Yuki</p> <p>2016-06-24</p> <p>The physical properties and elemental abundances of the interstellar medium in galaxies during cosmic reionization are important for understanding the role of galaxies in this process. We report the Atacama Large Millimeter/submillimeter Array detection of an oxygen <span class="hlt">emission</span> <span class="hlt">line</span> at a wavelength of 88 micrometers from a galaxy at an epoch about 700 million years after the Big Bang. The oxygen abundance of this galaxy is estimated at about one-tenth that of the Sun. The nondetection of far-infrared continuum <span class="hlt">emission</span> indicates a deficiency of interstellar dust in the galaxy. A carbon <span class="hlt">emission</span> <span class="hlt">line</span> at a wavelength of 158 micrometers is also not detected, implying an unusually small amount of neutral gas. These properties might allow ionizing photons to escape into the intergalactic medium. Copyright © 2016, American Association for the Advancement of Science.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AAS...22510304H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AAS...22510304H"><span>AGN Space Telescope and Optical Reverberation Mapping Project. IV. Velocity-Delay Mapping of Broad <span class="hlt">Emission</span> <span class="hlt">Lines</span> in NGC 5548</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Horne, Keith D.; Agn Storm Team</p> <p>2015-01-01</p> <p>Two-dimensional velocity-delay maps of AGN broad <span class="hlt">emission</span> <span class="hlt">line</span> regions can be recovered by modelling observations of reverberating <span class="hlt">emission-line</span> profiles on the assumption that the <span class="hlt">line</span> profile variations are driven by changes in ionising radiation from a compact source near the black hole. The observable light travel time delay resolves spatial structure on iso-delay paraboloids, while the doppler shift resolves kinematic structure along the observer's <span class="hlt">line</span>-of-sight. Velocity-delay maps will be presented and briefly discussed for the Lyman alpha, CIV and Hbeta <span class="hlt">line</span> profiles based on the HST and ground-based spectrophotometric monitoring of NGC 5548 during the 2014 AGN STORM campaign.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AAS...21541529B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AAS...21541529B"><span>Ongoing Search for Metal <span class="hlt">Line</span> <span class="hlt">Emission</span> in Intermediate and High Velocity Clouds with WHAM</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Barger, K. A.; Haffner, L. M.; Madsen, G. J.; Hill, A. S.; Wakker, B. P.</p> <p>2010-01-01</p> <p>We present new observations of the ionized gas in Complexes A, K, and L obtained with the Wisconsin H-Alpha Mapper (WHAM). To date, there have been only a limited number of studies of the ionized components of intermediate and high velocity clouds. Investigating their <span class="hlt">emission</span> provides a rare probe of the physical conditions of the clouds and the halo they are embedded within. These types of measurements will help guide discussion of the origin and evolution of these neutral halo structures. Here we follow up on the H-alpha maps we have presented elsewhere with deeper observations in H-alpha, [S II], [N II], and [O I]. Distance constraints from absorption studies place this gas in the mid to lower Galactic halo. Complex A has been constrained to a distance of 8-10 kpc (Wakker et al. 2008); Complex K has an upper limit of 6.8 kpc; and Complex L at a distance of 8-15 kpc (Wakker 2000). Some halo gas structures have clear metal <span class="hlt">line</span> <span class="hlt">emission</span> (e.g., Smith Cloud; Hill et al. 2009 and this meeting); however, the lack of [S II] <span class="hlt">emission</span> toward Complex C combined with absorption-<span class="hlt">line</span> observations demonstrates that it has very low metallically (Wakker, et al. 1999). Such discoveries reveal ongoing gas replenishment of the evolving Milky Way. Here, we find a similar lack of <span class="hlt">emission</span> toward the high-velocity Complex A. In particular, the cores of its cloud components designated III and IV show no evidence for metal <span class="hlt">line</span> <span class="hlt">emission</span> in our new observations, which places new constraints on the metallically of this complex. These observations were taken with WHAM at Kitt Peak, and we thank the excellent, decade-long support from its staff. WHAM operations are supported through NSF award AST-0607512.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1417168-first-light-ii-emission-line-extinction-population-iii-stars-ray-binaries','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1417168-first-light-ii-emission-line-extinction-population-iii-stars-ray-binaries"><span>First Light II: <span class="hlt">Emission</span> <span class="hlt">Line</span> Extinction, Population III Stars, and X-ray Binaries</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Barrow, Kirk S. S.; Wise, John H.; Aykutalp, Aycin; ...</p> <p>2017-11-17</p> <p>Here, we produce synthetic spectra and observations for metal-free stellar populations and high-mass X-ray binaries in the Renaissance Simulations at a redshift of 15. We extend our methodology from the first paper in the series by modelling the production and extinction of <span class="hlt">emission</span> <span class="hlt">lines</span> throughout a dusty and metal-enriched interstellar and circum-galactic media extracted from the simulation, using a Monte Carlo calculation. To capture the impact of high-energy photons, we include all frequencies from hard X-ray to far-infrared with enough frequency resolution to discern <span class="hlt">line</span> <span class="hlt">emission</span> and absorption profiles. The most common <span class="hlt">lines</span> in our sample in order of theirmore » rate of occurrence are Ly α, the C iv λλ1548, 1551 doublet, H α, and the Ca ii λλλ8498, 8542, 8662 triplet. The best scenario for a direct observation of a metal-free stellar population is a merger between two Population III Galaxies. In mergers between metal-enriched and metal-free stellar populations, some characteristics may be inferred indirectly. Single Population III galaxies are too dim to be observed photometrically at z = 15. Ly α <span class="hlt">emission</span> is discernible by JWST as an increase in J200w – J277w colour off the intrinsic stellar tracks. Observations of metal-free stars will be difficult, though not impossible, with the next generation of space telescopes.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/1417168-first-light-ii-emission-line-extinction-population-iii-stars-ray-binaries','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/1417168-first-light-ii-emission-line-extinction-population-iii-stars-ray-binaries"><span>First Light II: <span class="hlt">Emission</span> <span class="hlt">Line</span> Extinction, Population III Stars, and X-ray Binaries</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Barrow, Kirk S. S.; Wise, John H.; Aykutalp, Aycin</p> <p></p> <p>Here, we produce synthetic spectra and observations for metal-free stellar populations and high-mass X-ray binaries in the Renaissance Simulations at a redshift of 15. We extend our methodology from the first paper in the series by modelling the production and extinction of <span class="hlt">emission</span> <span class="hlt">lines</span> throughout a dusty and metal-enriched interstellar and circum-galactic media extracted from the simulation, using a Monte Carlo calculation. To capture the impact of high-energy photons, we include all frequencies from hard X-ray to far-infrared with enough frequency resolution to discern <span class="hlt">line</span> <span class="hlt">emission</span> and absorption profiles. The most common <span class="hlt">lines</span> in our sample in order of theirmore » rate of occurrence are Ly α, the C iv λλ1548, 1551 doublet, H α, and the Ca ii λλλ8498, 8542, 8662 triplet. The best scenario for a direct observation of a metal-free stellar population is a merger between two Population III Galaxies. In mergers between metal-enriched and metal-free stellar populations, some characteristics may be inferred indirectly. Single Population III galaxies are too dim to be observed photometrically at z = 15. Ly α <span class="hlt">emission</span> is discernible by JWST as an increase in J200w – J277w colour off the intrinsic stellar tracks. Observations of metal-free stars will be difficult, though not impossible, with the next generation of space telescopes.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2010-title40-vol32/pdf/CFR-2010-title40-vol32-sec1051-320.pdf','CFR'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2010-title40-vol32/pdf/CFR-2010-title40-vol32-sec1051-320.pdf"><span>40 CFR 1051.320 - What happens if one of my production-<span class="hlt">line</span> vehicles or engines fails to meet <span class="hlt">emission</span> standards?</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2010&page.go=Go">Code of Federal Regulations, 2010 CFR</a></p> <p></p> <p>2010-07-01</p> <p>...-<span class="hlt">line</span> vehicles or engines fails to meet <span class="hlt">emission</span> standards? 1051.320 Section 1051.320 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF <span class="hlt">EMISSIONS</span> FROM RECREATIONAL ENGINES AND VEHICLES Testing Production-<span class="hlt">Line</span> Vehicles and Engines § 1051.320 What happens if one...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22364260-constraining-milky-way-hot-gas-halo-vii-viii-emission-lines','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22364260-constraining-milky-way-hot-gas-halo-vii-viii-emission-lines"><span>CONSTRAINING THE MILKY WAY'S HOT GAS HALO WITH O VII AND O VIII <span class="hlt">EMISSION</span> <span class="hlt">LINES</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Miller, Matthew J.; Bregman, Joel N., E-mail: mjmil@umich.edu, E-mail: jbregman@umich.edu</p> <p>2015-02-10</p> <p>The Milky Way hosts a hot (≈2 × 10{sup 6} K), diffuse, gaseous halo based on detections of z = 0 O VII and O VIII absorption <span class="hlt">lines</span> in quasar spectra and <span class="hlt">emission</span> <span class="hlt">lines</span> in blank-sky spectra. Here we improve constraints on the structure of the hot gas halo by fitting a radial model to a much larger sample of O VII and O VIII <span class="hlt">emission</span> <span class="hlt">line</span> measurements from XMM-Newton/EPIC-MOS spectra compared to previous studies (≈650 sightlines). We assume a modified β-model for the halo density distribution and a constant-density Local Bubble from which we calculate <span class="hlt">emission</span> to compare withmore » the observations. We find an acceptable fit to the O VIII <span class="hlt">emission</span> <span class="hlt">line</span> observations with χ{sub red}{sup 2} (dof) = 1.08 (644) for best-fit parameters of n{sub o}r{sub c}{sup 3β}=1.35±0.24 cm{sup –3} kpc{sup 3β} and β = 0.50 ± 0.03 for the hot gas halo and negligible Local Bubble contribution. The O VII observations yield an unacceptable χ{sub red}{sup 2} (dof) = 4.69 (645) for similar best-fit parameters, which is likely due to temperature or density variations in the Local Bubble. The O VIII fitting results imply hot gas masses of M(<50 kpc) = 3.8{sub −0.3}{sup +0.3}×10{sup 9} M{sub ⊙} and M(<250 kpc) = 4.3{sub −0.8}{sup +0.9}×10{sup 10} M{sub ⊙}, accounting for ≲50% of the Milky Way's missing baryons. We also explore our results in the context of optical depth effects in the halo gas, the halo gas cooling properties, temperature and entropy gradients in the halo gas, and the gas metallicity distribution. The combination of absorption and <span class="hlt">emission</span> <span class="hlt">line</span> analyses implies a sub-solar gas metallicity that decreases with radius, but that also must be ≥0.3 Z {sub ☉} to be consistent with the pulsar dispersion measure toward the Large Magellanic Cloud.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19890024249&hterms=deming&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Ddeming','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19890024249&hterms=deming&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Ddeming"><span>Solar magnetic field studies using the 12 micron <span class="hlt">emission</span> <span class="hlt">lines</span>. I - Quiet sun time series and sunspot slices</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Deming, Drake; Boyle, Robert J.; Jennings, Donald E.; Wiedemann, Gunter</p> <p>1988-01-01</p> <p>The use of the extremely Zeeman-sensitive IR <span class="hlt">emission</span> <span class="hlt">line</span> Mg I, at 12.32 microns, to study solar magnetic fields. Time series observations of the <span class="hlt">line</span> in the quiet sun were obtained in order to determine the response time of the <span class="hlt">line</span> to the five-minute oscillations. Based upon the velocity amplitude and average period measured in the <span class="hlt">line</span>, it is concluded that it is formed in the temperature minimum region. The magnetic structure of sunspots is investigated by stepping a small field of view in linear 'slices' through the spots. The region of penumbral <span class="hlt">line</span> formation does not show the Evershed outflow common in photospheric <span class="hlt">lines</span>. The <span class="hlt">line</span> intensity is a factor of two greater in sunspot penumbrae than in the photosphere, and at the limb the penumbral <span class="hlt">emission</span> begins to depart from optical thinness, the <span class="hlt">line</span> source function increasing with height. For a spot near disk center, the radial decrease in absolute magnetic field strength is steeper than the generally accepted dependence.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22518505-broad-emission-line-variability-sample-local-active-galaxies','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22518505-broad-emission-line-variability-sample-local-active-galaxies"><span>BROAD Hβ <span class="hlt">EMISSION-LINE</span> VARIABILITY IN A SAMPLE OF 102 LOCAL ACTIVE GALAXIES</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Runco, Jordan N.; Cosens, Maren; Bennert, Vardha N.</p> <p>2016-04-10</p> <p>A sample of 102 local (0.02 ≤ z ≤ 0.1) Seyfert galaxies with black hole masses M{sub BH} > 10{sup 7}M{sub ⊙} was selected from the Sloan Digital Sky Survey (SDSS) and observed using the Keck 10 m telescope to study the scaling relations between M{sub BH} and host galaxy properties. We study profile changes of the broad Hβ <span class="hlt">emission</span> <span class="hlt">line</span> within the three to nine year time frame between the two sets of spectra. The variability of the broad Hβ <span class="hlt">emission</span> <span class="hlt">line</span> is of particular interest, not only because it is used to estimate M{sub BH}, but also because its strengthmore » and width are used to classify Seyfert galaxies into different types. At least some form of broad-<span class="hlt">line</span> variability (in either width or flux) is observed in the majority (∼66%) of the objects, resulting in a Seyfert-type change for ∼38% of the objects, likely driven by variable accretion and/or obscuration. The broad Hβ <span class="hlt">line</span> virtually disappears in 3/102 (∼3%) extreme cases. We discuss potential causes for these changing look active galactic nuclei. While similar dramatic transitions have previously been reported in the literature, either on a case-by-case basis or in larger samples focusing on quasars at higher redshifts, our study provides statistical information on the frequency of Hβ <span class="hlt">line</span> variability in a sample of low-redshift Seyfert galaxies.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19910062682&hterms=1776&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3D1776','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19910062682&hterms=1776&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3D1776"><span>Ultraviolet Fe VII absorption and Fe II <span class="hlt">emission</span> <span class="hlt">lines</span> of central stars of planetary nebulae</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Cheng, Kwang-Ping; Feibelman, Walter A.; Bruhweiler, Frederick C.</p> <p>1991-01-01</p> <p>The SWP camera of the IUE satellite was used in the high-dispersion mode to search for Fe VII absorption and Fe II high-excitation <span class="hlt">emission</span> <span class="hlt">lines</span> in five additional very hot central stars of planetary nebulae. Some of the Fe VII <span class="hlt">lines</span> were detected at 1208, 1239, and 1332 A in all the objects of this program, LT 5, NGC 6058, NGC 7094, A43, and Lo 1 (= K1-26), as well as some of the Fe II <span class="hlt">emission</span> <span class="hlt">lines</span> at A 1360, 1776, 1869, 1881, 1884, and 1975 A. Two additional objects, NGC 2867 and He 2-131, were obtained from the IUE archive and were evaluated. The present study probably exhausts the list of candidates that are sufficiently bright and hot to be reached with the high-dispersion mode of the IUE.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/5184742-ultraviolet-fe-vii-absorption-fe-ii-emission-lines-central-stars-planetary-nebulae','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/5184742-ultraviolet-fe-vii-absorption-fe-ii-emission-lines-central-stars-planetary-nebulae"><span>Ultraviolet Fe VII absorption and Fe II <span class="hlt">emission</span> <span class="hlt">lines</span> of central stars of planetary nebulae</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Cheng, Kwang-Ping; Feibelman, W.A.; Bruhweiler, F.C.</p> <p>1991-08-01</p> <p>The SWP camera of the IUE satellite was used in the high-dispersion mode to search for Fe VII absorption and Fe II high-excitation <span class="hlt">emission</span> <span class="hlt">lines</span> in five additional very hot central stars of planetary nebulae. Some of the Fe VII <span class="hlt">lines</span> were detected at 1208, 1239, and 1332 A in all the objects of this program, LT 5, NGC 6058, NGC 7094, A43, and Lo 1 (= K1-26), as well as some of the Fe II <span class="hlt">emission</span> <span class="hlt">lines</span> at A 1360, 1776, 1869, 1881, 1884, and 1975 A. Two additional objects, NGC 2867 and He 2-131, were obtained from themore » IUE archive and were evaluated. The present study probably exhausts the list of candidates that are sufficiently bright and hot to be reached with the high-dispersion mode of the IUE. 17 refs.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012NewAR..56...74P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012NewAR..56...74P"><span>Super-massive binary black holes and <span class="hlt">emission</span> <span class="hlt">lines</span> in active galactic nuclei</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Popović, Luka Č.</p> <p>2012-02-01</p> <p>It is now agreed that mergers play an essential role in the evolution of galaxies and therefore that mergers of supermassive black holes (SMBHs) must have been common. We see the consequences of past supermassive binary black holes (SMBs) in the light profiles of so-called 'core ellipticals' and a small number of SMBs have been detected. However, the evolution of SMBs is poorly understood. Theory predicts that SMBs should spend a substantial amount of time orbiting at velocities of a few thousand kilometers per second. If the SMBs are surrounded by gas observational effects might be expected from accretion onto one or both of the SMBHs. This could result in a binary Active Galactic Nucleus (AGN) system. Like a single AGN, such a system would emit a broad band electromagnetic spectrum and broad and narrow <span class="hlt">emission</span> <span class="hlt">lines</span>. The broad <span class="hlt">emission</span> spectral <span class="hlt">lines</span> emitted from AGNs are our main probe of the geometry and physics of the broad <span class="hlt">line</span> region (BLR) close to the SMBH. There is a group of AGNs that emit very broad and complex <span class="hlt">line</span> profiles, showing two displaced peaks, one blueshifted and one redshifted from the systemic velocity defined by the narrow <span class="hlt">lines</span>, or a single such peak. It has been proposed that such <span class="hlt">line</span> shapes could indicate an SMB system. We discuss here how the presence of an SMB will affect the BLRs of AGNs and what the observational consequences might be. We review previous claims of SMBs based on broad <span class="hlt">line</span> profiles and find that they may have non-SMB explanations as a consequence of a complex BLR structure. Because of these effects it is very hard to put limits on the number of SMBs from broad <span class="hlt">line</span> profiles. It is still possible, however, that unusual broad <span class="hlt">line</span> profiles in combination with other observational effects (<span class="hlt">line</span> ratios, quasi-periodical oscillations, spectropolarimetry, etc.) could be used for SMBs detection. Some narrow <span class="hlt">lines</span> (e.g., [O III]) in some AGNs show a double-peaked profile. Such profiles can be caused by streams in the Narrow</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006RScI...77d3508K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006RScI...77d3508K"><span>Method for measuring radial impurity <span class="hlt">emission</span> profiles using correlations of <span class="hlt">line</span> integrated signals</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kuldkepp, M.; Brunsell, P. R.; Drake, J.; Menmuir, S.; Rachlew, E.</p> <p>2006-04-01</p> <p>A method of determining radial impurity <span class="hlt">emission</span> profiles is outlined. The method uses correlations between <span class="hlt">line</span> integrated signals and is based on the assumption of cylindrically symmetric fluctuations. Measurements at the reversed field pinch EXTRAP T2R show that <span class="hlt">emission</span> from impurities expected to be close to the edge is clearly different in raw as well as analyzed data to impurities expected to be more central. Best fitting of experimental data to simulated correlation coefficients yields <span class="hlt">emission</span> profiles that are remarkably close to <span class="hlt">emission</span> profiles determined using more conventional techniques. The radial extension of the fluctuations is small enough for the method to be used and bandpass filtered signals indicate that fluctuations below 10kHz are cylindrically symmetric. The novel method is not sensitive to vessel window attenuation or wall reflections and can therefore complement the standard methods in the impurity <span class="hlt">emission</span> reconstruction procedure.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19840051483&hterms=zoology&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dzoology','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19840051483&hterms=zoology&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dzoology"><span>The early-type strong <span class="hlt">emission-line</span> supergiants of the Magellanic Clouds - A spectroscopic zoology</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Shore, S. N.; Sanduleak, N.</p> <p>1984-01-01</p> <p>The results of a spectroscopic survey of 21 early-type extreme <span class="hlt">emission</span> <span class="hlt">line</span> supergiants of the Large and Small Magellanic Clouds using IUE and optical spectra are presented. The combined observations are discussed and the literature on each star in the sample is summarized. The classification procedures and the methods by which effective temperatures, bolometric magnitudes, and reddenings were assigned are discussed. The derived reddening values are given along with some results concerning anomalous reddening among the sample stars. The derived mass, luminosity, and radius for each star are presented, and the ultraviolet <span class="hlt">emission</span> <span class="hlt">lines</span> are described. Mass-loss rates are derived and discussed, and the implications of these observations for the evolution of the most massive stars in the Local Group are addressed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120014165','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120014165"><span>Spatially-Resolved HST GRISM Spectroscopy of a Lensed <span class="hlt">Emission</span> <span class="hlt">Line</span> Galaxy at Z to approximately 1</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Frye, Brenda L.; Hurley, Mairead; Bowen, David V.; Meurer, Gerhardt; Sharon, Keren; Straughn, Amber; Coe, Dan; Broadhurst, Tom; Guhathakurta, Puragra</p> <p>2012-01-01</p> <p>We take advantage of gravitational lensing amplification by Abell 1689 (z=0.187) to undertake the first space-based census of <span class="hlt">emission</span> <span class="hlt">line</span> galaxies (ELGs) in the field of a massive lensing cluster. Forty-three ELGs are identified to a flux of i(sub 775)=27.3 via slitless grism spectroscopy. One ELG (at z=0.7895) is very bright owing to lensing magnification by a factor of approx = 4.5. Several Balmer <span class="hlt">emission</span> <span class="hlt">lines</span> detected from ground-based follow-up spectroscopy signal the onset of a major starburst for this low-mass galaxy (M(sub star) approx = 2 x 10(exp 9)Solar Mass) with a high specific star formation rate (approx = 20/ Gyr). From the blue <span class="hlt">emission</span> <span class="hlt">lines</span> we measure a gas-phase oxygen abundance consistent with solar (12+log(O /H)=8.8 +/- O.2). We break the continuous <span class="hlt">line</span>-emitting region of this giant arc into seven approx 1 kpc bins (intrinsic size) and measure a variety of metallicity dependent <span class="hlt">line</span> ratios. A weak trend of increasing metal fraction is seen toward the dynamical center of the galaxy. Interestingly, the metal <span class="hlt">line</span> ratios in a region offset from the center by -lkpc have a placement on the blue HI! region excitation diagram with f([OIII]/ f(H-Beta) and f([NeIII/ f(H-Beta) that can be fit by an AGN. This asymmetrical AGN-like behavior is interpreted as a product of shocks in the direction of the galaxy's extended tail, possibly instigated by a recent galaxy interaction.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AAS...21832201S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AAS...21832201S"><span>Hα Monitoring of Early-Type <span class="hlt">Emission</span> <span class="hlt">Line</span> Stars</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Souza, Steven P.; Boettcher, E.; Wilson, S.; Hosek, M.</p> <p>2011-05-01</p> <p>We have begun a narrowband imaging program to monitor Hα <span class="hlt">emission</span> in early-type stars in young open clusters and associations. A minority of early-type stars, particularly Be stars, show Hα in <span class="hlt">emission</span> due to extended atmospheres and non-equilibrium conditions. <span class="hlt">Emission</span> features commonly vary irregularly over a range of timescales (Porter, J.M. & Rivinus, T., P.A.S.P. 115:1153-1170, 2003). Some of the brightest such stars, e.g. γ Cas, have been spectroscopically monitored for Hα variability to help constrain models of the unstable disk, but there is relatively little ongoing monitoring in samples including fainter stars (Peters, G., Be Star Newsletter 39:3, 2009). Our program uses matched 5nm-wide on-band (656nm) and off-band (645nm) filters, in conjunction with the Hopkins Observatory 0.6-m telescope and CCD camera. Aperture photometry is done on all early-type stars in each frame, and results expressed as on-band to off-band ratios. Though wavelength-dependent information is lost compared with spectroscopy, imaging allows us to observe much fainter (and therefore many more) objects. Observing young clusters, rather than individual target stars, allows us to record multiple known and candidate <span class="hlt">emission</span> <span class="hlt">line</span> stars per frame, and provides multiple "normal" reference stars of similar spectral type. Observations began in the summer of 2010. This project has the potential to produce significant amounts of raw data, so a semi-automated data reduction process has been developed, including astrometric and photometric tasks. Early results, including some preliminary light curves and recovery of known Be stars at least as faint as R=13.9, are presented. We gratefully acknowledge support for student research through an REU grant to the Keck Northeast Astronomy Consortium from the National Science Foundation, and from the Division III Research Funding Committee of Williams College.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20140011265','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20140011265"><span><span class="hlt">Emission</span> <span class="hlt">Lines</span> from the Gas Disk Around TW Hydra and the Origin of the Inner Hole</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gorti, U.; Hollenbach, D.; Najita, J.; Pascucci, I.</p> <p>2011-01-01</p> <p>We compare <span class="hlt">line</span> <span class="hlt">emission</span> calculated from theoretical disk models with optical to submillimeter wavelength observational data of the gas disk surrounding TW Hya and infer the spatial distribution of mass in the gas disk. The model disk that best matches observations has a gas mass ranging from approx.10(exp -4) to 10(exp -5) M for 0.06AU < r < 3.5 AU and approx. 0.06M for 3.5AU < r < 200 AU. We find that the inner dust hole (r < 3.5 AU) in the disk must be depleted of gas by approx. 1-2 orders of magnitude compared with the extrapolated surface density distribution of the outer disk. Grain growth alone is therefore not a viable explanation for the dust hole. CO vibrational <span class="hlt">emission</span> arises within r approx. 0.5 AU from thermal excitation of gas. [O i] 6300Å and 5577Å forbidden <span class="hlt">lines</span> and OH mid-infrared <span class="hlt">emission</span> are mainly due to prompt <span class="hlt">emission</span> following UV photodissociation of OH and water at r < or approx. 0.1 AU and at r approx. 4 AU. [Ne ii] <span class="hlt">emission</span> is consistent with an origin in X-ray heated neutral gas at r < or approx. 10 AU, and may not require the presence of a significant extreme-ultraviolet (h? > 13.6 eV) flux from TW Hya. H2 pure rotational <span class="hlt">line</span> <span class="hlt">emission</span> comes primarily from r approx. 1 to 30 AU. [Oi] 63microns, HCO+, and CO pure rotational <span class="hlt">lines</span> all arise from the outer disk at r approx. 30-120 AU. We discuss planet formation and photoevaporation as causes for the decrease in surface density of gas and dust inside 4 AU. If a planet is present, our results suggest a planet mass approx. 4-7MJ situated at 3 AU. Using our photoevaporation models and the best surface density profile match to observations, we estimate a current photoevaporative mass loss rate of 4x10(exp -9M)/yr and a remaining disk lifetime of approx.5 million years.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_20 --> <div id="page_21" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="401"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2012-title40-vol34/pdf/CFR-2012-title40-vol34-sec1051-320.pdf','CFR2012'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2012-title40-vol34/pdf/CFR-2012-title40-vol34-sec1051-320.pdf"><span>40 CFR 1051.320 - What happens if one of my production-<span class="hlt">line</span> vehicles or engines fails to meet <span class="hlt">emission</span> standards?</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2012&page.go=Go">Code of Federal Regulations, 2012 CFR</a></p> <p></p> <p>2012-07-01</p> <p>...-<span class="hlt">line</span> vehicles or engines fails to meet <span class="hlt">emission</span> standards? 1051.320 Section 1051.320 Protection of... of my production-<span class="hlt">line</span> vehicles or engines fails to meet <span class="hlt">emission</span> standards? (a) If you have a... standards (see § 1051.315(a)), the certificate of conformity is automatically suspended for that failing...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2011-title40-vol33/pdf/CFR-2011-title40-vol33-sec1051-320.pdf','CFR2011'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2011-title40-vol33/pdf/CFR-2011-title40-vol33-sec1051-320.pdf"><span>40 CFR 1051.320 - What happens if one of my production-<span class="hlt">line</span> vehicles or engines fails to meet <span class="hlt">emission</span> standards?</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2011&page.go=Go">Code of Federal Regulations, 2011 CFR</a></p> <p></p> <p>2011-07-01</p> <p>...-<span class="hlt">line</span> vehicles or engines fails to meet <span class="hlt">emission</span> standards? 1051.320 Section 1051.320 Protection of... of my production-<span class="hlt">line</span> vehicles or engines fails to meet <span class="hlt">emission</span> standards? (a) If you have a... standards (see § 1051.315(a)), the certificate of conformity is automatically suspended for that failing...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMSA33A2423T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMSA33A2423T"><span>Long-term variation of horizontal phase velocity and propagation direction of mesospheric and thermospheric gravity waves by using <span class="hlt">airglow</span> images obtained at Shigarkai, Japan</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Takeo, D.; Kazuo, S.; Hujinami, H.; Otsuka, Y.; Matsuda, T. S.; Ejiri, M. K.; Yamamoto, M.; Nakamura, T.</p> <p>2016-12-01</p> <p>Atmospheric gravity waves generated in the lower atmosphere transport momentum into the upper atmosphere and release it when they break. The released momentum drives the global-scale pole-to-pole circulation and causes global mass transport. Vertical propagation of the gravity waves and transportation of momentum depend on horizontal phase velocity of gravity waves according to equation about dispersion relation of waves. Horizontal structure of gravity waves including horizontal phase velocity can be seen in the <span class="hlt">airglow</span> images, and there have been many studies about gravity waves by using <span class="hlt">airglow</span> images. However, long-term variation of horizontal phase velocity spectrum of gravity waves have not been studied yet. In this study, we used 3-D FFT method developed by Matsuda et al., (2014) to analyze the horizontal phase velocity spectrum of gravity waves by using 557.7-nm (altitude of 90-100 km) and 630.0-nm (altitude of 200-300 km) <span class="hlt">airglow</span> images obtained at Shigaraki MU Observatory (34.8 deg N, 136.1 deg E) over 16 years from October 1, 1998 to July 26, 2015. Results about 557.7-nm shows clear seasonal variation of propagation direction of gravity waves in the mesopause region. Between summer and winter, there are propagation direction anisotropies which probably caused by filtering due to zonal mesospheric jet and by difference of latitudinal location of wave sources relative to Shigaraki. Results about 630.0-nm shows clear negative correlation between the yearly power spectrum density of horizontal phase velocity and sunspot number. This negative correlation with solar activity is consistent with growth rate of the Perkins instability, which may play an important role in generating the nighttime medium-scale traveling ionospheric disturbances at middle latitudes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19860018300&hterms=Wave+Energy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3DWave%2BEnergy','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19860018300&hterms=Wave+Energy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3DWave%2BEnergy"><span>Gravity wave vertical energy flux at 95 km</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Jacob, P. G.; Jacka, F.</p> <p>1985-01-01</p> <p>A three-field photometer (3FP) located at Mt. Torrens near Adelaide, is capable of monitoring different <span class="hlt">airglow</span> <span class="hlt">emissions</span> from three spaced fields in the sky. A wheel containing up to six different narrow bandpass interference filters can be rotated, allowing each of the filters to be sequentially placed into each of the three fields. The <span class="hlt">airglow</span> <span class="hlt">emission</span> of interest is the 557.7 nm <span class="hlt">line</span> which has an intensity maximum at 95 km. Each circular field of view is located at the apexes of an equilateral triangle centered on zenith with diameters of 5 km and field separations of 13 km when projected to the 95-km level. The sampling period was 30 seconds and typical data lengths were between 7 and 8 hours. The analysis and results from the interaction of gravity waves on the 557.7 nm <span class="hlt">emission</span> layer are derived using an atmospheric model similar to that proposed by Hines (1960) where the atmosphere is assumed isothermal and perturbations caused by gravity waves are small and adiabatic, therefore, resulting in linearized equations of motion. In the absence of waves, the atmosphere is also considered stationary. Thirteen nights of quality data from January 1983 to October 1984, covering all seasons, are used in this analysis.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018AAS...23231810M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018AAS...23231810M"><span>Steep Hard-X-ray Spectra Indicate Extremely High Accretion Rates in Weak <span class="hlt">Emission-Line</span> Quasars</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Marlar, Andrea; Shemmer, Ohad; Anderson, Scott F.; Brandt, W. Niel; Diamond-Stanic, Aleksandar M.; Fan, Xiaohui; Luo, Bin; Plotkin, Richard; Richards, Gordon T.; Schneider, Donald P.; Wu, Jianfeng</p> <p>2018-06-01</p> <p>We present XMM-Newton imaging spectroscopy of ten weak <span class="hlt">emission-line</span> quasars (WLQs) at 0.928 ≤ z ≤ 3.767, six of which are radio quiet and four which are radio intermediate. The new X-ray data enabled us to measure the hard-X-ray power-law photon index (Γ) in each source with relatively high accuracy. These measurements allowed us to confirm previous reports that WLQs have steeper X-ray spectra, therefore indicating higher accretion rates with respect to "typical" quasars. A comparison between the Γ values of our radio-quiet WLQs and those of a carefully-selected, uniform sample of 84 quasars shows that the first are significantly higher, at the ≥ 3σ level. Collectively, the four radio-intermediate WLQs have lower Γ values with respect to the six radio-quiet WLQs, as may be expected if the spectra of the first group are contaminated by X-ray <span class="hlt">emission</span> from a jet. These results suggest that, in the absence of significant jet <span class="hlt">emission</span> along our <span class="hlt">line</span> of sight, WLQs constitute the extreme high end of the accretion rate distribution in quasars. We detect soft excess <span class="hlt">emission</span> in our lowest-redshift radio-quiet WLQ, in agreement with previous findings suggesting that the prominence of this feature is associated with a high accretion rate. We have not detected signatures of Compton reflection, Fe Kα <span class="hlt">lines</span>, or strong variability between two X-ray epochs in any of our WLQs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018ApJ...857...86S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018ApJ...857...86S"><span>A Falling Corona Model for the Anomalous Behavior of the Broad <span class="hlt">Emission</span> <span class="hlt">Lines</span> in NGC 5548</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sun, Mouyuan; Xue, Yongquan; Cai, Zhenyi; Guo, Hengxiao</p> <p>2018-04-01</p> <p>NGC 5548 has been intensively monitored by the AGN Space Telescope and Optical Reverberation Mapping collaboration. Approximately after half of the light curves, the correlation between the broad <span class="hlt">emission</span> <span class="hlt">lines</span> and the lag-corrected ultraviolet (UV) continua becomes weak. This anomalous behavior is accompanied by an increase of soft X-ray <span class="hlt">emission</span>. We propose a simple model to understand this anomalous behavior, i.e., the corona might fall down, thereby increasing the covering fraction of the inner disk. Therefore, X-ray and extreme-UV <span class="hlt">emission</span> suffer from spectral variations. The UV continua variations are driven by both X-ray and extreme-UV variations. Consequently, the spectral variability induced by the falling corona would dilute the correlation between the broad <span class="hlt">emission</span> <span class="hlt">lines</span> and the UV continua. Our model can explain many additional observational facts, including the dependence of the anomalous behavior on velocity and ionization energy. We also show that the time lag and correlation between the X-ray and the UV variations change as NGC 5548 displays the anomalous behavior. The time lag is dramatically longer than the expectation from disk reprocessing if the anomalous behavior is properly excluded. During the anomalous state, the time lag approaches the light-travel timescale of disk reprocessing albeit with a much weaker correlation. We speculate that the time lag in the normal state is caused by reprocessing of the broad <span class="hlt">line</span> region gas. As NGC 5548 enters the abnormal state, the contribution of the broad <span class="hlt">line</span> region gas is smaller; the time lag reflects disk reprocessing. We also discuss alternative scenarios.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22654465-lyman-continuum-escape-fraction-emission-line-selected-galaxies-less-than','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22654465-lyman-continuum-escape-fraction-emission-line-selected-galaxies-less-than"><span>The Lyman Continuum Escape Fraction of <span class="hlt">Emission</span> <span class="hlt">Line</span>-selected z ∼ 2.5 Galaxies Is Less Than 15%</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Rutkowski, Michael J.; Hayes, Matthew; Scarlata, Claudia</p> <p></p> <p>Recent work suggests that strong <span class="hlt">emission</span> <span class="hlt">line</span>, star-forming galaxies (SFGs) may be significant Lyman continuum leakers. We combine archival Hubble Space Telescope broadband ultraviolet and optical imaging (F275W and F606W, respectively) with <span class="hlt">emission</span> <span class="hlt">line</span> catalogs derived from WFC3 IR G141 grism spectroscopy to search for escaping Lyman continuum (LyC) <span class="hlt">emission</span> from homogeneously selected z ∼ 2.5 SFGs. We detect no escaping Lyman continuum from SFGs selected on [O ii] nebular <span class="hlt">emission</span> ( N = 208) and, within a narrow redshift range, on [O iii]/[O ii]. We measure 1 σ upper limits to the LyC escape fraction relative to the non-ionizingmore » UV continuum from [O ii] emitters, f {sub esc} ≲ 5.6%, and strong [O iii]/[O ii] > 5 ELGs, f {sub esc} ≲ 14.0%. Our observations are not deep enough to detect f {sub esc} ∼ 10% typical of low-redshift Lyman continuum emitters. However, we find that this population represents a small fraction of the star-forming galaxy population at z ∼ 2. Thus, unless the number of extreme <span class="hlt">emission</span> <span class="hlt">line</span> galaxies grows substantially to z ≳ 6, such galaxies may be insufficient for reionization. Deeper survey data in the rest-frame ionizing UV will be necessary to determine whether strong <span class="hlt">line</span> ratios could be useful for pre-selecting LyC leakers at high redshift.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017xru..conf..221T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017xru..conf..221T"><span>An X-ray survey of the Central Molecular Zone: variability of the Fe K <span class="hlt">emission</span> <span class="hlt">line</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Terrier, R.; Clavel, M.</p> <p>2017-10-01</p> <p>The observation of varying non-thermal diffuse X-ray <span class="hlt">emission</span> molecular complexes in the central 300 pc has been interpreted as delayed reflection of a past illumination by bright outbursts of the Galactic SMBH. Determining its light curve over the past centuries requires a detailed knowledge of the gas distribution, which is still lacking. Nevertheless, variability of the reflected <span class="hlt">emission</span> all over of the central 300 pc, in particular in the 6.4 keV Fe K <span class="hlt">line</span>, can bring strong constraints. Thanks to a deep scan of the inner 300 pc with XMM in 2012 and to a similar albeit more shallow scan performed in 2000-2001, we performed a detailed study of variability of the 6.4 keV <span class="hlt">line</span> <span class="hlt">emission</span> in the region, which we present here. We show that the overall 6.4 keV <span class="hlt">emission</span> does not strongly vary on average, but variations are very pronounced on smaller scales. The absence of bright steady <span class="hlt">emission</span> argues against the presence of an echo from an event of multi-centennial duration and most, if not all, of the <span class="hlt">emission</span> can likely be explained by a limited number of relatively short (i.e. up to 10 years) events.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012ApJ...749...60M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012ApJ...749...60M"><span>On the Doppler Velocity of <span class="hlt">Emission</span> <span class="hlt">Line</span> Profiles Formed in the "Coronal Contraflow" that Is the Chromosphere-Corona Mass Cycle</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>McIntosh, Scott W.; Tian, Hui; Sechler, Marybeth; De Pontieu, Bart</p> <p>2012-04-01</p> <p>This analysis begins to explore the complex chromosphere-corona mass cycle using a blend of imaging and spectroscopic diagnostics. Single Gaussian fits (SGFs) to hot <span class="hlt">emission</span> <span class="hlt">line</span> profiles (formed above 1 MK) at the base of coronal loop structures indicate material blueshifts of 5-10 km s-1, while cool <span class="hlt">emission</span> <span class="hlt">line</span> profiles (formed below 1 MK) yield redshifts of a similar magnitude—indicating, to zeroth order, that a temperature-dependent bifurcating flow exists on coronal structures. Image sequences of the same region reveal weakly emitting upward propagating disturbances in both hot and cool <span class="hlt">emission</span> with apparent speeds of 50-150 km s-1. Spectroscopic observations indicate that these propagating disturbances produce a weak <span class="hlt">emission</span> component in the blue wing at commensurate speed, but that they contribute only a few percent to the (ensemble) <span class="hlt">emission</span> <span class="hlt">line</span> profile in a single spatio-temporal resolution element. Subsequent analysis of imaging data shows material "draining" slowly (~10 km s-1) out of the corona, but only in the cooler passbands. We interpret the draining as the return flow of coronal material at the end of the complex chromosphere-corona mass cycle. Further, we suggest that the efficient radiative cooling of the draining material produces a significant contribution to the red wing of cool <span class="hlt">emission</span> <span class="hlt">lines</span> that is ultimately responsible for their systematic redshift as derived from an SGF when compared to those formed in hotter (conductively dominated) domains. The presence of counterstreaming flows complicates the <span class="hlt">line</span> profiles, their interpretation, and asymmetry diagnoses, but allows a different physical picture of the lower corona to develop.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015A%26A...577A..21C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015A%26A...577A..21C"><span>VIMOS integral field spectroscopy of blue compact galaxies. I. Morphological properties, diagnostic <span class="hlt">emission-line</span> ratios, and kinematics</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cairós, L. M.; Caon, N.; Weilbacher, P. M.</p> <p>2015-05-01</p> <p>Context. Blue compact galaxies (BCG) are gas-rich, low-luminosity, low-metallicity systems that undergo a violent burst of star formation. These galaxies offer us a unique opportunity to investigate collective star formation and its effects on galaxy evolution in a relatively simple environment. Spatially resolved spectrophotometric studies of BCGs are essential for a better understanding of the role of starburst-driven feedback processes on the kinematical and chemical evolution of low-mass galaxies near and far. Aims: We carry out an integral field spectroscopic study of a sample of BCGs, with the aim of probing the morphology, kinematics, dust extinction, and excitation mechanisms of their warm interstellar medium. Methods: Eight BCGs were observed with the VIMOS integral field unit at the Very Large Telescope using blue and orange grisms in high-resolution mode. At a spatial sampling of 0''&dotbelow;67 per spaxel, we covered about 30″ × 30″ on the sky, with a wavelength range of 4150...7400 Å. <span class="hlt">Emission</span> <span class="hlt">lines</span> were fitted with a single Gaussian profile to measure their wavelength, flux, and width. From these data we built two-dimensional maps of the continuum and the most prominent <span class="hlt">emission-lines</span>, as well as diagnostic <span class="hlt">line</span> ratios, extinction, and kinematic maps. Results: An atlas has been produced with the following: <span class="hlt">emission-line</span> fluxes and continuum <span class="hlt">emission</span>; ionization, interstellar extinction, and electron density maps from <span class="hlt">line</span> ratios; velocity and velocity dispersion fields. From integrated spectroscopy, it includes tables of the extinction corrected <span class="hlt">line</span> fluxes and equivalent widths, diagnostic-<span class="hlt">line</span> ratios, physical parameters, and the abundances for the brightest star-forming knots and for the whole galaxy. Based on observations made with ESO Telescopes at the Paranal Observatory under program ID 079.B-0445.The reduced datacubes and their error maps (FITS files) are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.A53C0191P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.A53C0191P"><span>Development of On-<span class="hlt">line</span> Wildfire <span class="hlt">Emissions</span> for the Operational Canadian Air Quality Forecast System</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pavlovic, R.; Menard, S.; Chen, J.; Anselmo, D.; Paul-Andre, B.; Gravel, S.; Moran, M. D.; Davignon, D.</p> <p>2013-12-01</p> <p>An <span class="hlt">emissions</span> processing system has been developed to incorporate near-real-time <span class="hlt">emissions</span> from wildfires and large prescribed burns into Environment Canada's real-time GEM-MACH air quality (AQ) forecast system. Since the GEM-MACH forecast domain covers Canada and most of the USA, including Alaska, fire location information is needed for both of these large countries. Near-real-time satellite data are obtained and processed separately for the two countries for organizational reasons. Fire location and fuel consumption data for Canada are provided by the Canadian Forest Service's Canadian Wild Fire Information System (CWFIS) while fire location and <span class="hlt">emissions</span> data for the U.S. are provided by the SMARTFIRE (Satellite Mapping Automated Reanalysis Tool for Fire Incident Reconciliation) system via the on-<span class="hlt">line</span> BlueSky Gateway. During AQ model runs, <span class="hlt">emissions</span> from individual fire sources are injected into elevated model layers based on plume-rise calculations and then transport and chemistry calculations are performed. This 'on the fly' approach to the insertion of <span class="hlt">emissions</span> provides greater flexibility since on-<span class="hlt">line</span> meteorology is used and reduces computational overhead in <span class="hlt">emission</span> pre-processing. An experimental wildfire version of GEM-MACH was run in real-time mode for the summers of 2012 and 2013. 48-hour forecasts were generated every 12 hours (at 00 and 12 UTC). Noticeable improvements in the AQ forecasts for PM2.5 were seen in numerous regions where fire activity was high. Case studies evaluating model performance for specific regions, computed objective scores, and subjective evaluations by AQ forecasters will be included in this presentation. Using the lessons learned from the last two summers, Environment Canada will continue to work towards the goal of incorporating near-real-time intermittent wildfire <span class="hlt">emissions</span> within the operational air quality forecast system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMSH54A..03D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMSH54A..03D"><span>Constraining <span class="hlt">Line</span>-of-sight Confusion in the Corona Using Linearly Polarized Observations of the Infrared FeXIII 1075nm and SiX 1430nm <span class="hlt">Emission</span> <span class="hlt">Lines</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dima, G. I.; Kuhn, J. R.; Berdyugina, S.</p> <p>2017-12-01</p> <p>Measurements of the coronal magnetic field are difficult because of the intrinsically faint <span class="hlt">emission</span> of coronal plasma and the large spurious background due to the bright solar disk. This work addresses the problem of resolving the confusion of the <span class="hlt">line</span>-of-sight (LOS) integration through the optically-thin corona being observed. Work on developing new measuring techniques based on single-point inversions using the Hanle effect has already been described (Dima et al. 2016). It is important to develop a technique to assess when the LOS confusion makes comparing models and observations problematic. Using forward integration of synthetic <span class="hlt">emission</span> through magnetohydrodynamic (MHD) models together with simultaneous linearly polarized observations of the FeXIII 1075nm and SiX 1430nm <span class="hlt">emission</span> <span class="hlt">lines</span> allows us to assess LOS confusion. Since the <span class="hlt">lines</span> are both in the Hanle saturated regime their polarization angles are expected to be aligned as long as the gas is sampling the same magnetic field. If significant contributions to the <span class="hlt">emission</span> is taking place from different regions along the LOS due to the additive nature of the polarized brightness the measured linear polarization between the two <span class="hlt">lines</span> will be offset. The size of the resolution element is important for this determination since observing larger coronal regions will confuse the variation along the LOS with that in the plane-of-sky. We also present comparisons between synthetic linearly polarized <span class="hlt">emission</span> through a global MHD model and observations of the same regions obtained using the 0.5m Scatter-free Observatory for Limb Active Regions and Coronae (SOLARC) telescope located on Haleakala, Maui. This work is being done in preparation for the type of observations that will become possible when the next generation 4m DKIST telescope comes online in 2020.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22599174-electron-beam-generated-ar-sub-plasmas-effect-nitrogen-addition-brightest-argon-emission-lines','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22599174-electron-beam-generated-ar-sub-plasmas-effect-nitrogen-addition-brightest-argon-emission-lines"><span>Electron beam-generated Ar/N{sub 2} plasmas: The effect of nitrogen addition on the brightest argon <span class="hlt">emission</span> <span class="hlt">lines</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Lock, E. H., E-mail: evgeniya.lock@nrl.navy.mil, E-mail: scott.walton@nrl.navy.mil; Petrova, Tz. B.; Petrov, G. M.</p> <p>2016-04-15</p> <p>The effect of nitrogen addition on the <span class="hlt">emission</span> intensities of the brightest argon <span class="hlt">lines</span> produced in a low pressure argon/nitrogen electron beam-generated plasmas is characterized using optical <span class="hlt">emission</span> spectroscopy. In particular, a decrease in the intensities of the 811.5 nm and 763.5 nm <span class="hlt">lines</span> is observed, while the intensity of the 750.4 nm <span class="hlt">line</span> remains unchanged as nitrogen is added. To explain this phenomenon, a non-equilibrium collisional-radiative model is developed and used to compute the population of argon excited states and <span class="hlt">line</span> intensities as a function of gas composition. The results show that the addition of nitrogen to argon modifies the electron energymore » distribution function, reduces the electron temperature, and depopulates Ar metastables in exchange reactions with electrons and N{sub 2} molecules, all of which lead to changes in argon excited states population and thus the <span class="hlt">emission</span> originating from the Ar 4p levels.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20080040165','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20080040165"><span><span class="hlt">Emission-Line</span> Galaxies from the PEARS Hubble Ultra Deep Field: A 2-D Detection Method and First Results</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gardner, J. P.; Straughn, Amber N.; Meurer, Gerhardt R.; Pirzkal, Norbert; Cohen, Seth H.; Malhotra, Sangeeta; Rhoads, james; Windhorst, Rogier A.; Gardner, Jonathan P.; Hathi, Nimish P.; <a style="text-decoration: none; " href="javascript:void(0); " onClick="displayelement('author_20080040165'); toggleEditAbsImage('author_20080040165_show'); toggleEditAbsImage('author_20080040165_hide'); "> <img style="display:inline; width:12px; height:12px; " src="images/arrow-up.gif" width="12" height="12" border="0" alt="hide" id="author_20080040165_show"> <img style="width:12px; height:12px; display:none; " src="images/arrow-down.gif" width="12" height="12" border="0" alt="hide" id="author_20080040165_hide"></p> <p>2007-01-01</p> <p>The Hubble Space Telescope (HST) Advanced Camera for Surveys (ACS) grism PEARS (Probing Evolution And Reionization Spectroscopically) survey provides a large dataset of low-resolution spectra from thousands of galaxies in the GOODS North and South fields. One important subset of objects in these data are <span class="hlt">emission-line</span> galaxies (ELGs), and we have investigated several different methods aimed at systematically selecting these galaxies. Here we present a new methodology and results of a search for these ELGs in the PEARS observations of the Hubble Ultra Deep Field (HUDF) using a 2D detection method that utilizes the observation that many <span class="hlt">emission</span> <span class="hlt">lines</span> originate from clumpy knots within galaxies. This 2D <span class="hlt">line</span>-finding method proves to be useful in detecting <span class="hlt">emission</span> <span class="hlt">lines</span> from compact knots within galaxies that might not otherwise be detected using more traditional 1D <span class="hlt">line</span>-finding techniques. We find in total 96 <span class="hlt">emission</span> <span class="hlt">lines</span> in the HUDF, originating from 81 distinct "knots" within 63 individual galaxies. We find in general that [0 1111 emitters are the most common, comprising 44% of the sample, and on average have high equivalent widths (70% of [0 1111 emitters having rest-frame EW> 100A). There are 12 galaxies with multiple emitting knots; several show evidence of variations in H-alpha flux in the knots, suggesting that the differing star formation properties across a single galaxy can in general be probed at redshifts approximately greater than 0.2 - 0.4. The most prevalent morphologies are large face-on spirals and clumpy interacting systems, many being unique detections owing to the 2D method described here, thus highlighting the strength of this technique.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20080021265','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20080021265"><span>A Multi-Instrument Measurement of a Mesospheric Bore at the Equator</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Shiokawa, K.; Suzuki, S.; Otsuka, Y.; Ogawa, T.; Nakamura, T.; Mlynczak, M. G.; Russell, J. M., III</p> <p>2005-01-01</p> <p>We have made a comprehensive measurement of mesospheric bore phenomenon at the equator at Kototabang, Indonesia (0.2 deg S, 100.3 deg E), using an <span class="hlt">airglow</span> imager, an <span class="hlt">airglow</span> temperature photometer, a meteor radar, and the SABER instrument on board the TIMED satellite. The bore was detected in <span class="hlt">airglow</span> images of both OH-band (peak <span class="hlt">emission</span> altitude: 87 km) and 557.7-nm (96 km) <span class="hlt">emissions</span>, as east-west front-like structure propagating northward with a velocity of 52-58 m/s. Wave trains with a horizontal wavelength of 30-70 km are observed behind the bore front. The <span class="hlt">airglow</span> intensity decreases for all the mesospheric <span class="hlt">emissions</span> of OI (557.7 nm), OH-band, O2-band (altitude: 94 km), and Na (589.3 nm) (90 km) after the bore passage. The rotational temperatures of both OH-band and O2-band also decrease approximately 10 K after the bore passage. An intense shear in northward wind velocity of 80m/s was observed at altitudes of 84-90 km by the meteor radar. Kinetic temperature profile at altitudes of 20-120 km was observed near Kototabang by TIMED/SABER. On the basis of these observations, we discuss generation and ducting of the observed mesospheric bore.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JASTP.135..192W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JASTP.135..192W"><span>Spatial gravity wave characteristics obtained from multiple OH(3-1) <span class="hlt">airglow</span> temperature time series</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wachter, Paul; Schmidt, Carsten; Wüst, Sabine; Bittner, Michael</p> <p>2015-12-01</p> <p>We present a new approach for the detection of gravity waves in OH-<span class="hlt">airglow</span> observations at the measurement site Oberpfaffenhofen (11.27°E, 48.08°N), Germany. The measurements were performed at the German Remote Sensing Data Center (DFD) of the German Aerospace Center (DLR) during the period from February 4th, 2011 to July 6th, 2011. In this case study the observations were carried out by three identical Ground-based Infrared P-branch Spectrometers (GRIPS). These instruments provide OH(3-1) rotational temperature time series, which enable spatio-temporal investigations of gravity wave characteristics in the mesopause region. The instruments were aligned in such a way that their fields of view (FOV) formed an equilateral triangle in the OH-<span class="hlt">emission</span> layer at a height of 87 km. The Harmonic Analysis is applied in order to identify joint temperature oscillations in the three individual datasets. Dependent on the specific gravity wave activity in a single night, it is possible to detect up to four different wave patterns with this method. The values obtained for the waves' periods and phases are then used to derive further parameters, such as horizontal wavelength, phase velocity and the direction of propagation. We identify systematic relationships between periods and amplitudes as well as between periods and horizontal wavelengths. A predominant propagation direction towards the East and North-North-East characterizes the waves during the observation period. There are also indications of seasonal effects in the temporal development of the horizontal wavelength and the phase velocity. During late winter and early spring the derived horizontal wavelengths and the phase velocities are smaller than in the subsequent period from early April to July 2011.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19930026469&hterms=magnetic+cooling&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dmagnetic%2Bcooling','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19930026469&hterms=magnetic+cooling&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dmagnetic%2Bcooling"><span>X-ray and optical <span class="hlt">emission-line</span> filaments in the cooling flow cluster 2A 0335 + 096</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Sarazin, Craig L.; O'Connell, Robert W.; Mcnamara, Brian R.</p> <p>1992-01-01</p> <p>We present a new high-resolution X-ray image of the 2A 0335 + 096 cluster of galaxies obtained with the High Resolution Imager (HRI) aboard the ROSAT satellite. The presence of dense gas having a very short cooling time in the central regions confirms its earlier identification as a cooling flow. The X-ray <span class="hlt">emission</span> from the central regions of the cooling flow shows a great deal of filamentary structure. Using the crude spectral resolution of the HRI, we show that these filaments are the result of excess <span class="hlt">emission</span>, rather than foreground X-ray absorption. Although there are uncertainties in the pointing, many of the X-ray features in the cooling flow region correspond to features in H-alpha optical <span class="hlt">line</span> <span class="hlt">emission</span>. This suggests that the optical <span class="hlt">emission</span> <span class="hlt">line</span> gas has resulted directly from the cooling of X-ray-emitting gas. The filament material cannot be in hydrostatic equilibrium, and it is likely that other forces such as rotation, turbulence, and magnetic fields influence the dynamical state of the gas.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018A%26A...609A.130L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018A%26A...609A.130L"><span>The [CII] 158 μm <span class="hlt">line</span> <span class="hlt">emission</span> in high-redshift galaxies</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lagache, G.; Cousin, M.; Chatzikos, M.</p> <p>2018-02-01</p> <p>Gas is a crucial component of galaxies, providing the fuel to form stars, and it is impossible to understand the evolution of galaxies without knowing their gas properties. The [CII] fine structure transition at 158 μm is the dominant cooling <span class="hlt">line</span> of cool interstellar gas, and is the brightest of <span class="hlt">emission</span> <span class="hlt">lines</span> from star forming galaxies from FIR through metre wavelengths, almost unaffected by attenuation. With the advent of ALMA and NOEMA, capable of detecting [CII]-<span class="hlt">line</span> <span class="hlt">emission</span> in high-redshift galaxies, there has been a growing interest in using the [CII] <span class="hlt">line</span> as a probe of the physical conditions of the gas in galaxies, and as a star formation rate (SFR) indicator at z ≥ 4. In this paper, we have used a semi-analytical model of galaxy evolution (G.A.S.) combined with the photoionisation code CLOUDY to predict the [CII] luminosity of a large number of galaxies (25 000 at z ≃ 5) at 4 ≤ z ≤ 8. We assumed that the [CII]-<span class="hlt">line</span> <span class="hlt">emission</span> originates from photo-dominated regions. At such high redshift, the CMB represents a strong background and we discuss its effects on the luminosity of the [CII] <span class="hlt">line</span>. We studied the L[CII ]-SFR and L[ CII ]-Zg relations and show that they do not strongly evolve with redshift from z = 4 and to z = 8. Galaxies with higher [CII] luminosities tend to have higher metallicities and higher SFRs but the correlations are very broad, with a scatter of about 0.5 and 0.8 dex for L[ CII ]-SFR and L[ CII ]-Zg, respectively. Our model reproduces the L[ CII ]-SFR relations observed in high-redshift star-forming galaxies, with [CII] luminosities lower than expected from local L[ CII ]-SFR relations. Accordingly, the local observed L[ CII ]-SFR relation does not apply at high-z (z ≳ 5), even when CMB effects are ignored. Our model naturally produces the [CII] deficit (i.e. the decrease of L[ CII ]/LIR with LIR), which appears to be strongly correlated with the intensity of the radiation field in our simulated galaxies. We then predict the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013ApJ...771...89O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013ApJ...771...89O"><span>Resolving the Optical <span class="hlt">Emission</span> <span class="hlt">Lines</span> of Lyα Blob "B1" at z = 2.38: Another Hidden Quasar</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Overzier, R. A.; Nesvadba, N. P. H.; Dijkstra, M.; Hatch, N. A.; Lehnert, M. D.; Villar-Martín, M.; Wilman, R. J.; Zirm, A. W.</p> <p>2013-07-01</p> <p>We have used the SINFONI near-infrared integral field unit on the Very Large Telescope to resolve the optical <span class="hlt">emission</span> <span class="hlt">line</span> structure of one of the brightest (L Lyα ≈ 1044 erg s-1) and nearest (z ≈ 2.38) of all Lyα blobs (LABs). The target, known in the literature as object "B1", lies at a redshift where the main optical <span class="hlt">emission</span> <span class="hlt">lines</span> are accessible in the observed near-infrared. We detect luminous [O III] λλ4959, 5007 and Hα <span class="hlt">emission</span> with a spatial extent of at least 32 × 40 kpc (4'' × 5''). The dominant optical <span class="hlt">emission</span> <span class="hlt">line</span> component shows relatively broad <span class="hlt">lines</span> (600-800 km s-1, FWHM) and <span class="hlt">line</span> ratios consistent with active galactic nucleus (AGN) photoionization. The new evidence for AGN photoionization, combined with previously detected C IV and luminous, warm infrared <span class="hlt">emission</span>, suggest that B1 is the site of a hidden quasar. This is confirmed by the fact that [O II] is relatively weak compared with [O III] (extinction-corrected [O III]/[O II] of about 3.8), which is indicative of a high, Seyfert-like ionization parameter. From the extinction-corrected [O III] luminosity we infer a bolometric AGN luminosity of ~3 × 1046 erg s-1, and further conclude that the obscured AGN may be Compton-thick given existing X-ray limits. The large <span class="hlt">line</span> widths observed are consistent with clouds moving within the narrow-<span class="hlt">line</span> region of a luminous QSO. The AGN scenario is capable of producing sufficient ionizing photons to power the Lyα, even in the presence of dust. By performing a census of similar objects in the literature, we find that virtually all luminous LABs harbor obscured quasars. Based on simple duty-cycle arguments, we conclude that AGNs are the main drivers of the Lyα in LABs rather than the gravitational heating and subsequent cooling suggested by cold stream models. We also conclude that the empirical relation between LABs and overdense environments at high redshift must be due to a more fundamental correlation between AGNs (or massive galaxies) and</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012cosp...39.1823S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012cosp...39.1823S"><span>Planned Visible <span class="hlt">Emission</span> <span class="hlt">Line</span> Space Solar Coronagraph on-board Aditya-1</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Singh, Jagdev</p> <p>2012-07-01</p> <p>An imaging visible <span class="hlt">emission</span> <span class="hlt">line</span> internally occulted coronagraph using 20 cm off axis parabolic mirror has been designed and planned to be launched in 2014. The coronagraph will have the facility to take images of the solar simultaneously, in the green [Fe xiv] and the red [Fe x] <span class="hlt">emission</span> <span class="hlt">lines</span> up to 1.5 solar radii with a frequency of about 3 Hz using 0.5 nm pass band filters and the images in continuum at 580 nm up to 3 solar radii. The satellite has been named as Aditya-1 and the scientific objectives of this payload are: (i) to investigate the existence of intensity oscillations for the study of wave driven coronal heating, (ii) to study the dynamics and formation of coronal loops and temperature structure of the coronal features, (iii) to study the origin, cause and acceleration of Coronal Mass Ejections (CME's) and other solar active features, and (iv) Coronal magnetic field topology and the 3-dimensional structures of the CMEs using polarization information. The fabrication of the pay load will be done in the laboratories of LEOS, SAC, ISAC, IIA and USO and launched by ISRO. Here we shall discuss the design and the realization of the mission.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_21 --> <div id="page_22" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="421"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013hers.prop.2605C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013hers.prop.2605C"><span>DDT_jcernich_10: Time Variability of Thermal Molecular <span class="hlt">Line</span> <span class="hlt">Emission</span> in IRC+10216 (4th Epoch)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cernicharo, J.</p> <p>2013-04-01</p> <p>We have found during our GT <span class="hlt">line</span> survey of IRC+10216 and the search for hydrides (OT1 proposal) that some molecular <span class="hlt">lines</span> present a strong intensity variation with time due to the role of infrared pumping. For some <span class="hlt">lines</span> the intensity change in six months reaches a factor 3 (CCH). We have checked that the effect is not instrumental and than it arises from physical processes ignored so far in the radiative transfer models. We propose to observe the CCH and HNC <span class="hlt">lines</span> within bands 1a-5b of HIFI every four months (three observing slots) to allow a detailed study of the variation of thermal molecular <span class="hlt">emission</span>, and dust <span class="hlt">emission</span>, in this prototype of AGB C-rich object. The settings will also provide, as a bonus, many <span class="hlt">lines</span> of SiO, SiS, CS, HCN, CO and 13CO for which intensity variations of up to 30% have been found. In addition, a few specificc settings for HCN and CO will complete the observations. SPIRE and PACS observations will complement, with lower spectral resolution, the whole spectrum of each of these molecules and will provide a global view of the total intensity change of these <span class="hlt">lines</span> with time. A crude estimate of the distance could be also obtained from the observed time lags between the blue and red parts of the <span class="hlt">line</span> profiles observed with HIFI.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20080031148&hterms=Skinner&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DSkinner','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20080031148&hterms=Skinner&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DSkinner"><span>Asymmetric 511 keV Positron Annihilation <span class="hlt">Line</span> <span class="hlt">Emission</span> from the Inner Galactic Disk</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Skinner, Gerry; Weidenspointner, Georg; Jean, Pierre; Knodlseder, Jurgen; Ballmoos, Perer von; Bignami, Giovanni; Diehl, Roland; Strong, Andrew; Cordier, Bertrand; Schanne, Stephane; <a style="text-decoration: none; " href="javascript:void(0); " onClick="displayelement('author_20080031148'); toggleEditAbsImage('author_20080031148_show'); toggleEditAbsImage('author_20080031148_hide'); "> <img style="display:inline; width:12px; height:12px; " src="images/arrow-up.gif" width="12" height="12" border="0" alt="hide" id="author_20080031148_show"> <img style="width:12px; height:12px; display:none; " src="images/arrow-down.gif" width="12" height="12" border="0" alt="hide" id="author_20080031148_hide"></p> <p>2008-01-01</p> <p>A recently reported asymmetry in the 511 keV gamma-ray <span class="hlt">line</span> <span class="hlt">emission</span> from the inner galactic disk is unexpected and mimics an equally unexpected one in the distribution of LMXBs seen at hard X-ray energies. A possible conclusion is that LMXBs are an important source of the positrons whose annihilation gives rise to the <span class="hlt">line</span>. We will discuss these results, their statistical significance and that of any link between the two. The implication of any association between LMXBs and positrons for the strong annihilation radiation from the galactic bulge will be reviewed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19790035031&hterms=solar+intensity+measurement&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dsolar%2Bintensity%2Bmeasurement','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19790035031&hterms=solar+intensity+measurement&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dsolar%2Bintensity%2Bmeasurement"><span>Measurement of the profile and intensity of the solar He I lambda 584-A resonance <span class="hlt">line</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Maloy, J. O.; Hartmann, U. G.; Judge, D. L.; Carlson, R. W.</p> <p>1978-01-01</p> <p>The intensity and profile of the helium resonance <span class="hlt">line</span> at 584 A from the entire disk of the sun was investigated by using a rocket-borne helium-filled spectrometer and a curve-of-growth technique. The <span class="hlt">line</span> profile was found to be accurately represented by a Gaussian profile with full width at half maximum of 122 + or - 10 mA, while the integrated intensity was measured to be 2.6 + or - 1.3 billion photons/s per sq cm at solar activity levels of F(10.7) = 90.8 x 10 to the -22nd per sq m/Hz and Rz = 27. The measured <span class="hlt">line</span> width is in good agreement with previous spectrographic measurements, but the integrated intensity is larger than most previous photoelectric measurements. However, the derived <span class="hlt">line</span> center flux of 20 + or - 10 billion photons/s per sq cm/A is in good agreement with values inferred from <span class="hlt">airglow</span> measurements.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010noao.prop..100V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010noao.prop..100V"><span>Deep <span class="hlt">Emission-Line</span> Imaging of Local Galactic Winds with NEWFIRM: Part II.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Veilleux, Sylvain; Trippe, Margaret; Swaters, Rob; Rupke, David; McCormick, Alex</p> <p>2010-08-01</p> <p>Galactic winds are the primary mechanism by which energy and metals are recycled in galaxies and deposited into the IGM. New observations are revealing the ubiquity of this process, particularly at high redshift. Measurements have shown that winds contain cool (molecular/neutral), warm (partly ionized), and hot (fully ionized) gases. Though most of the wind mass is likely contained in the dusty molecular gas, very little is known about this component. However, our recent observations of M 82 with NEWFIRM on the Mayall 4-m show that H_2 <span class="hlt">emission</span> can be used as a sensitive tracer of the cool molecular wind component. We propose to use NEWFIRM to study the NIR <span class="hlt">emission</span>- <span class="hlt">line</span> properties of a small but representative set of local wind galaxies. Deep images of these objects will be obtained at H_2 2.122 (micron) and [Fe II] 1.644 (micron) and combined with existing optical <span class="hlt">emission-line</span> maps to (1) constrain the importance of molecular gas in the energetics of these winds and (2) determine the nature of the interaction between the central energy injection zone and the wind material. 5 nights were allocated for this program in 10B; we now request to observe the rest of the sample. These data will complement an approved Spitzer program to constrain the hot dust content of these winds, and likely become part of A. McCormick's PhD thesis.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1995A%26AS..109..523S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1995A%26AS..109..523S"><span>Kinematical <span class="hlt">line</span> broadening and spatially resolved <span class="hlt">line</span> profiles from AGN.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Schulz, H.; Muecke, A.; Boer, B.; Dresen, M.; Schmidt-Kaler, T.</p> <p>1995-03-01</p> <p>We study geometrical effects for <span class="hlt">emission-line</span> broadening in the optically thin limit by integrating the projected <span class="hlt">line</span> <span class="hlt">emissivity</span> along prespecified <span class="hlt">lines</span> of sight that intersect rotating or expanding disks or cone-like configurations. Analytical expressions are given for the case that <span class="hlt">emissivity</span> and velocity follow power laws of the radial distance. The results help to interpret spatially resolved spectra and to check the reliability of numerical computations. In the second part we describe a numerical code applicable to any geometrical configuration. Turbulent motions, atmospheric seeing and effects induced by the size of the observing aperture are simulated with appropriate convolution procedures. An application to narrow-<span class="hlt">line</span> Hα profiles from the central region of the Seyfert galaxy NGC 7469 is presented. The shapes and asymmetries as well as the relative strengths of the Hα <span class="hlt">lines</span> from different spatial positions can be explained by <span class="hlt">emission</span> from a nuclear rotating disk of ionized gas, for which the distribution of Hα <span class="hlt">line</span> <span class="hlt">emissivity</span> and the rotation curve are derived. Appreciable turbulent <span class="hlt">line</span> broadening with a Gaussian σ of ~40% of the rotational velocity has to be included to obtain a satisfactory fit.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19790063349&hterms=Atomic+spectroscopy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DAtomic%2Bspectroscopy','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19790063349&hterms=Atomic+spectroscopy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DAtomic%2Bspectroscopy"><span>Spectroscopy of the extreme ultraviolet dayglow at 6.5A resolution - Atomic and ionic <span class="hlt">emissions</span> between 530 and 1240A</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gentieu, E. P.; Feldman, P. D.; Meier, R. R.</p> <p>1979-01-01</p> <p>EUV spectra (530-1500A) of the day <span class="hlt">airglow</span> in up, down and horizontal aspect orientations have been obtained with 6.5A resolution and a limiting sensitivity of 5R from a rocket experiment. Below 834A the spectrum is rich in previously unobserved OII transitions connecting with 4S(0), 2D(0), and 2P(0) states. Recent broad-band photometric observations of geocoronal HeI 584A <span class="hlt">emission</span> in terms of the newly observed OII <span class="hlt">emissions</span> are shown. The OI 989A and OI 1304A <span class="hlt">emissions</span> exhibit similar dependence on altitude and viewing geometry with the OI 989A brightness 1/15 that of OI 1340. <span class="hlt">Emission</span> at 1026A is identified as geocoronal HI Lyman beta rather than OI multiplet <span class="hlt">emission</span> and observed intensities agree well with model estimates. An unexpectedly high NI 1200/NI 1134A brightness ratio is evidence of a significant contribution from photodissociative excitation of N2 to the NI 1200A source function.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMSH53A2150M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMSH53A2150M"><span>Radiance And Irradiance Of The Solar HeII 304 <span class="hlt">Emission</span> <span class="hlt">Line</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>McMullin, D. R.; Floyd, L. E.; Auchère, F.</p> <p>2013-12-01</p> <p>For over 17 years, EIT and the later EUVI instruments aboard SoHO and STEREO, respectively, have provided a time series of radiant images in the HeII 30.4 nm transition region and three coronal <span class="hlt">emission</span> <span class="hlt">lines</span> (FeIX/X, FeXII, and FeXV). While the EIT measurements were gathered from positions approximately on the Earth-Sun axis, EUVI images have been gathered at angles ranging to more than ×90 degrees in solar longitude relative the Earth-Sun axis. Using a Differential <span class="hlt">Emission</span> Measure (DEM) model, these measurements provide a basis for estimates of the spectral irradiance for the solar spectrum of wavelengths between 15 and 50 nm at any position in the heliosphere. In particular, we generate the He 30.4 spectral irradiance in all directions in the heliosphere and examine its time series in selected directions. Such spectra are utilized for two distinct purposes. First, the photoionization rate of neutral He at each position is calculated. Neutral He is of interest because it traverses the heliopause relatively undisturbed and therefore provides a measure of isotopic parameters beyond the heliosphere. Second, we use these generate a time series of estimates of the solar spectral luminosity in the HeII 30.4 nm <span class="hlt">emission</span> <span class="hlt">line</span> extending from the recent past solar cycle 23 minimum into the current weak solar cycle 24 enabling an estimate of its variation over the solar cycle. Because this 30.4~nm spectral luminosity is the sum of such radiation in all directions, its time series is devoid of the 27-day solar rotation periodicity present in indices typically used to represent solar activity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018NIMPB.416...62K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018NIMPB.416...62K"><span>Chemical state analysis of Cl Kα and Kβ1,3 X-ray <span class="hlt">emission</span> <span class="hlt">lines</span> using polychromatic WDXRF spectrometer</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kainth, Harpreet Singh; Upmanyu, Arun; Sharma, Hitesh; Singh, Tejbir; Kumar, Sanjeev</p> <p>2018-02-01</p> <p>With the support of research projects focusing on sampling and data analysing of different varieties of chemical compounds, wavelength dispersive X-ray fluorescence (WDXRF) technique is commonly used in many research laboratories throughout the world wide to determine the elemental composition of various unknown samples. In the present study, first time we have employed polychromatic S8 TIGER WDXRF spectrometer to study the chemical state analysis in Cl Kα and Kβ1,3 X-ray <span class="hlt">emission</span> <span class="hlt">lines</span>. A Voigt function is used to determine the central peak position of the K shell <span class="hlt">emission</span> <span class="hlt">lines</span> in all samples. From the present measurements, it is seen that both positive and negative shifts have been observed in Cl Kα (2.622 keV) and Kβ1,3 (2.817 keV) <span class="hlt">emission</span> peaks. It has been also seen that the effective charge, relative <span class="hlt">line</span>-width and relative intensity ratio I(Kβ1,3/Kα) are found proportional with the chemical shift. Furthermore, a parabolic relation is also established between them.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ApJ...822...64L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ApJ...822...64L"><span>SDSS J163459.82+204936.0: A Ringed Infrared-luminous Quasar with Outflows in Both Absorption and <span class="hlt">Emission</span> <span class="hlt">Lines</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liu, Wen-Juan; Zhou, Hong-Yan; Jiang, Ning; Wu, Xufen; Lyu, Jianwei; Shi, Xiheng; Shu, Xinwen; Jiang, Peng; Ji, Tuo; Wang, Jian-Guo; Wang, Shu-Fen; Sun, Luming</p> <p>2016-05-01</p> <p>SDSS J163459.82+204936.0 is a local (z = 0.1293) infrared-luminous quasar with L IR = 1011.91 {L}⊙ . We present a detailed multiwavelength study of both the host galaxy and the nucleus. The host galaxy, appearing as an early-type galaxy in the optical images and spectra, demonstrates violent, obscured star formation activities with SFR ≈ 140 {M}⊙ yr-1, estimated from either the polycyclic aromatic hydrocarbon <span class="hlt">emission</span> or IR luminosity. The optical to NIR spectra exhibit a blueshifted narrow cuspy component in Hβ, He I λλ5876, 10830, and other <span class="hlt">emission</span> <span class="hlt">lines</span> consistently with an offset velocity of ≈900 {km} {{{s}}}-1, as well as additional blueshifting phenomena in high-ionization <span class="hlt">lines</span> (e.g., a blueshifted broad component of He I λ10830 and the bulk blueshifting of [O III]λ5007), while there exist blueshifted broad absorption <span class="hlt">lines</span> (BALs) in Na I D and He I λλ3889, 10830, indicative of the active galactic nucleus outflows producing BALs and <span class="hlt">emission</span> <span class="hlt">lines</span>. Constrained mutually by the several BALs in the photoionization simulations with Cloudy, the physical properties of the absorption <span class="hlt">line</span> outflow are derived as follows: density 104 < n H ≲ 105 cm-3, ionization parameter 10-1.3 ≲ U ≲ 10-0.7 , and column density 1022.5 ≲ N H ≲ 1022.9 cm-2, which are similar to those derived for the <span class="hlt">emission</span> <span class="hlt">line</span> outflows. This similarity suggests a common origin. Taking advantages of both the absorption <span class="hlt">lines</span> and outflowing <span class="hlt">emission</span> <span class="hlt">lines</span>, we find that the outflow gas is located at a distance of ˜48-65 pc from the nucleus and that the kinetic luminosity of the outflow is 1044-1046 {erg} {{{s}}}-1. J1634+2049 has a off-centered galactic ring on the scale of ˜30 kpc that is proved to be formed by a recent head-on collision by a nearby galaxy for which we spectroscopically measure the redshift. Thus, this quasar is a valuable object in the transitional phase emerging out of dust enshrouding as depicted by the co-evolution scenario invoking galaxy merger (or</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011ApJ...736...62W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011ApJ...736...62W"><span>A Deep Chandra ACIS Study of NGC 4151. II. The Innermost <span class="hlt">Emission</span> <span class="hlt">Line</span> Region and Strong Evidence for Radio Jet-NLR Cloud Collision</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, Junfeng; Fabbiano, Giuseppina; Elvis, Martin; Risaliti, Guido; Mundell, Carole G.; Karovska, Margarita; Zezas, Andreas</p> <p>2011-07-01</p> <p>We have studied the X-ray <span class="hlt">emission</span> within the inner ~150 pc radius of NGC 4151 by constructing high spatial resolution <span class="hlt">emission</span> <span class="hlt">line</span> images of blended O VII, O VIII, and Ne IX. These maps show extended structures that are spatially correlated with the radio outflow and optical [O III] <span class="hlt">emission</span>. We find strong evidence for jet-gas cloud interaction, including morphological correspondences with regions of X-ray enhancement, peaks of near-infrared [Fe II] <span class="hlt">emission</span>, and optical clouds. In these regions, moreover, we find evidence of elevated Ne IX/O VII ratios; the X-ray <span class="hlt">emission</span> of these regions also exceeds that expected from nuclear photoionization. Spectral fitting reveals the presence of a collisionally ionized component. The thermal energy of the hot gas suggests that >~ 0.1% of the estimated jet power is deposited into the host interstellar medium through interaction between the radio jet and the dense medium of the circumnuclear region. We find possible pressure equilibrium between the collisionally ionized hot gas and the photoionized <span class="hlt">line</span>-emitting cool clouds. We also obtain constraints on the extended iron and silicon fluorescent <span class="hlt">emission</span>. Both <span class="hlt">lines</span> are spatially unresolved. The upper limit on the contribution of an extended <span class="hlt">emission</span> region to the Fe Kα <span class="hlt">emission</span> is <~ 5% of the total, in disagreement with a previous claim that 65% of the Fe Kα <span class="hlt">emission</span> originates in the extended narrow <span class="hlt">line</span> region.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120002004','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120002004"><span>A CANDELS WFC3 Grism Study of <span class="hlt">Emission-Line</span> Galaxies at Z approximates 2: A mix of Nuclear Activity and Low-Metallicity Star Formation</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Trump, Jonathan R.; Weiner, Benjamin J.; Scarlata, Claudia; Kocevski, Dale D.; Bell, Eric F.; McGrath, Elizabeth J.; Koo, David C.; Faber, S. M.; Laird, Elise S.; Mozena, Mark; <a style="text-decoration: none; " href="javascript:void(0); " onClick="displayelement('author_20120002004'); toggleEditAbsImage('author_20120002004_show'); toggleEditAbsImage('author_20120002004_hide'); "> <img style="display:inline; width:12px; height:12px; " src="images/arrow-up.gif" width="12" height="12" border="0" alt="hide" id="author_20120002004_show"> <img style="width:12px; height:12px; display:none; " src="images/arrow-down.gif" width="12" height="12" border="0" alt="hide" id="author_20120002004_hide"></p> <p>2011-01-01</p> <p>We present Hubble Space Telescope Wide Field Camera 3 slitless grism spectroscopy of 28 <span class="hlt">emission-line</span> galaxies at z approximates 2, in the GOODS-S region of the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS). The high sensitivity of these grism observations, with > 5-sigma detections of <span class="hlt">emission</span> <span class="hlt">lines</span> to f > 2.5 X 10(exp -18( erg/s/ square cm, means that the galaxies in the sample are typically approximately 7 times less massive (median M(star). = 10(exp 9.5)M(solar)) than previously studied z approximates 2 <span class="hlt">emission-line</span> galaxies. Despite their lower mass, the galaxies have [O-III]/H-Beta ratios which are very similar to previously studied z approximates 2 galaxies and much higher than the typical <span class="hlt">emission-line</span> ratios of local galaxies. The WFC3 grism allows for unique studies of spatial gradients in <span class="hlt">emission</span> <span class="hlt">lines</span>, and we stack the two-dimensional spectra of the galaxies for this purpose. In the stacked data the [O-III] <span class="hlt">emission</span> <span class="hlt">line</span> is more spatially concentrated than the H-Beta <span class="hlt">emission</span> <span class="hlt">line</span> with 98.1% confidence. We additionally stack the X-ray data (all sources are individually undetected), and find that the average L(sub [O-III])/L(sub 0.5.10keV) ratio is intermediate between typical z approximates 0 obscured active galaxies and star-forming galaxies. Together the compactness of the stacked [O-III] spatial profile and the stacked X-ray data suggest that at least some of these low-mass, low-metallicity galaxies harbor weak active galactic nuclei.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/875365','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/875365"><span><span class="hlt">Emission</span> <span class="hlt">line</span> spectra of S VII ? S XIV in the 20 ? 75 ? wavelength region</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Lepson, J K; Beiersdorfer, P; Behar, E</p> <p></p> <p>As part of a larger project to complete a comprehensive catalogue of astrophysically relevant <span class="hlt">emission</span> <span class="hlt">lines</span> in support of new-generation X-ray observatories using the Lawrence Livermore electron beam ion traps EBIT-I and EBIT-II, the authors present observations of sulfur <span class="hlt">lines</span> in the soft X-ray and extreme ultraviolet regions. The database includes wavelength measurements with standard errors, relative intensities, and <span class="hlt">line</span> assignments for 127 transitions of S VII through S XIV between 20 and 75 {angstrom}. The experimental data are complemented with a full set of calculations using the Hebrew University Lawrence Livermore Atomic Code (HULLAC). A comparison of the laboratorymore » data with Chandra measurements of Procyon allows them to identify S VII-S XI <span class="hlt">lines</span>.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22356510-detection-unidentified-emission-line-stacked-ray-spectrum-galaxy-clusters','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22356510-detection-unidentified-emission-line-stacked-ray-spectrum-galaxy-clusters"><span>Detection of an unidentified <span class="hlt">emission</span> <span class="hlt">line</span> in the stacked X-ray spectrum of galaxy clusters</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Bulbul, Esra; Foster, Adam; Smith, Randall K.</p> <p>2014-07-01</p> <p>We detect a weak unidentified <span class="hlt">emission</span> <span class="hlt">line</span> at E = (3.55-3.57) ± 0.03 keV in a stacked XMM-Newton spectrum of 73 galaxy clusters spanning a redshift range 0.01-0.35. When the full sample is divided into three subsamples (Perseus, Centaurus+Ophiuchus+Coma, and all others), the <span class="hlt">line</span> is seen at >3σ statistical significance in all three independent MOS spectra and the PN 'all others' spectrum. It is also detected in the Chandra spectra of the Perseus Cluster. However, it is very weak and located within 50-110 eV of several known <span class="hlt">lines</span>. The detection is at the limit of the current instrument capabilities. Wemore » argue that there should be no atomic transitions in thermal plasma at this energy. An intriguing possibility is the decay of sterile neutrino, a long-sought dark matter particle candidate. Assuming that all dark matter is in sterile neutrinos with m{sub s} = 2E = 7.1 keV, our detection corresponds to a neutrino decay rate consistent with previous upper limits. However, based on the cluster masses and distances, the <span class="hlt">line</span> in Perseus is much brighter than expected in this model, significantly deviating from other subsamples. This appears to be because of an anomalously bright <span class="hlt">line</span> at E = 3.62 keV in Perseus, which could be an Ar XVII dielectronic recombination <span class="hlt">line</span>, although its <span class="hlt">emissivity</span> would have to be 30 times the expected value and physically difficult to understand. Another alternative is the above anomaly in the Ar <span class="hlt">line</span> combined with the nearby 3.51 keV K <span class="hlt">line</span> also exceeding expectation by a factor of 10-20. Confirmation with Astro-H will be critical to determine the nature of this new <span class="hlt">line</span>.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018SPIE10621E..1MT','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018SPIE10621E..1MT"><span>Temperature measurement of burning aluminum powder based on the double <span class="hlt">line</span> method of atomic <span class="hlt">emission</span> spectra</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tang, Huijuan; Hao, Xiaojian; Hu, Xiaotao</p> <p>2018-01-01</p> <p>In the case of conventional contact temperature measurement, there is a delay phenomenon and high temperature resistant materials limitation. By using the faster response speed and theoretically no upper limit of the non-contact temperature method, the measurement system based on the principle of double <span class="hlt">line</span> atomic <span class="hlt">emission</span> spectroscopy temperature measurement is put forward, the structure and theory of temperature measuring device are introduced. According to the atomic spectrum database (ASD), Aluminum(Al) I 690.6 nm and Al I 708.5 nm are selected as the two <span class="hlt">lines</span> in the temperature measurement. The intensity ratio of the two <span class="hlt">emission</span> <span class="hlt">lines</span> was measured by a spectrometer to obtain the temperature of Al burning in pure oxygen, and the result compared to the temperature measured by the thermocouple. It turns out that the temperature correlation between the two methods is good, and it proves the feasibility of the method.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018AJ....155...18L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018AJ....155...18L"><span>MASTER OT J132104.04+560957.8: A Polar with Absorption–<span class="hlt">Emission</span> <span class="hlt">Line</span> Reversals</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Littlefield, Colin; Garnavich, Peter; Hoyt, Taylor J.; Kennedy, Mark</p> <p>2018-01-01</p> <p>We present time-resolved photometry and spectroscopy of the recently classified polar MASTER OT J132104.04+560957.8. The spectrum shows a smooth, nonthermal continuum at the time of maximum light, without any individually discernible cyclotron harmonics. Using homogenous cyclotron modeling, we interpret this as cyclotron radiation whose individual harmonics have blended together, and on this basis, we loosely constrain the magnetic-field strength to be less than ∼30 MG. In addition, for about one-tenth of the orbital period, the Balmer and He I <span class="hlt">emission</span> <span class="hlt">lines</span> transition into absorption features, with He II developing an absorption core. We use our observations of this phenomenon to test theoretical models of the accretion curtain and conclude that the H and He I <span class="hlt">lines</span> are produced throughout the curtain, in contravention of theoretical predictions of separate H and He I <span class="hlt">line</span>-forming regions. Moreover, a significant amount of He II <span class="hlt">emission</span> originates within the accretion curtain, implying that the curtain is significantly hotter than expected from theory. Finally, we comment on the object’s long-term photometry, including evidence that it recently transitioned into a prolonged, exceptionally stable high state following a potentially decades-long low state.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018BSRSL..87..316K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018BSRSL..87..316K"><span>Spectroscopic and polarimetric study of radio-quiet weak <span class="hlt">emission</span> <span class="hlt">line</span> quasars</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kumar, Parveen; Chand, Hum; Gopal-Krishna; Srianand, Raghunathan; Stalin, Chelliah Subramonian; Petitjean, Patrick</p> <p>2018-04-01</p> <p>A small subset of optically selected radio-quiet QSOs with weak or no <span class="hlt">emission</span> <span class="hlt">lines</span> may turn out to be the elusive radio-quiet BL Lac objects, or simply be radio-quiet QSOs with an infant/shielded broad <span class="hlt">line</span> region (BLR). High polarisation (p > 3-4%), a hallmark of BL Lacs, can be used to test whether some optically selected ‘radio-quiet weak <span class="hlt">emission</span> <span class="hlt">line</span> QSOs’ (RQWLQs) show a fractional polarisation high enough to qualify as radio-quiet analogues of BL Lac objects. To check this possibility, we have made optical spectral and polarisation measurements of a sample of 19 RQWLQs. Out of these, only 9 sources show a non-significant proper motion (hence very likely extragalactic) and only two of them are found to have p > 1%. For these two RQWLQs, namely J142505.59+035336.2 and J154515.77+003235.2, we found the highest polarization to be 1.59±0.53%, which is again too low to classify them as (radio-quiet) BL Lacs, although one may recall that even genuine BL Lacs sometimes appear weakly polarised. We also present a statistical comparison of the optical spectral index, for a sample of 45 RQWLQs with redshift-luminosity matched control samples of 900 QSOs and an equivalent sample of 120 blazars, assembled from the literature. The spectral index distribution of RQWLQs is found to differ, at a high significance level, from that of blazars. This, too, is consistent with the common view that the mechanism of the central engine in RQWLQs, as a population, is close to that operating in normal QSOs and the primary difference between them is related to the BLR.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22661406-local-ii-emission-line-luminosity-function','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22661406-local-ii-emission-line-luminosity-function"><span>THE LOCAL [C ii] 158 μ m <span class="hlt">EMISSION</span> <span class="hlt">LINE</span> LUMINOSITY FUNCTION</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Hemmati, Shoubaneh; Yan, Lin; Capak, Peter</p> <p></p> <p>We present, for the first time, the local [C ii] 158 μ m <span class="hlt">emission</span> <span class="hlt">line</span> luminosity function measured using a sample of more than 500 galaxies from the Revised Bright Galaxy Sample. [C ii] luminosities are measured from the Herschel PACS observations of the Luminous Infrared Galaxies (LIRGs) in the Great Observatories All-sky LIRG Survey and estimated for the rest of the sample based on the far-infrared (far-IR) luminosity and color. The sample covers 91.3% of the sky and is complete at S{sub 60μm} > 5.24 Jy. We calculate the completeness as a function of [C ii] <span class="hlt">line</span> luminosity and distance, basedmore » on the far-IR color and flux densities. The [C ii] luminosity function is constrained in the range ∼10{sup 7–9} L{sub ⊙} from both the 1/ V{sub max} and a maximum likelihood methods. The shape of our derived [C ii] <span class="hlt">emission</span> <span class="hlt">line</span> luminosity function agrees well with the IR luminosity function. For the CO(1-0) and [C ii] luminosity functions to agree, we propose a varying ratio of [C ii]/CO(1-0) as a function of CO luminosity, with larger ratios for fainter CO luminosities. Limited [C ii] high-redshift observations as well as estimates based on the IR and UV luminosity functions are suggestive of an evolution in the [C ii] luminosity function similar to the evolution trend of the cosmic star formation rate density. Deep surveys using the Atacama Large Millimeter Array with full capability will be able to confirm this prediction.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017MNRAS.472.2808D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017MNRAS.472.2808D"><span>A probabilistic approach to <span class="hlt">emission-line</span> galaxy classification</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>de Souza, R. S.; Dantas, M. L. L.; Costa-Duarte, M. V.; Feigelson, E. D.; Killedar, M.; Lablanche, P.-Y.; Vilalta, R.; Krone-Martins, A.; Beck, R.; Gieseke, F.</p> <p>2017-12-01</p> <p>We invoke a Gaussian mixture model (GMM) to jointly analyse two traditional <span class="hlt">emission-line</span> classification schemes of galaxy ionization sources: the Baldwin-Phillips-Terlevich (BPT) and WH α versus [N II]/H α (WHAN) diagrams, using spectroscopic data from the Sloan Digital Sky Survey Data Release 7 and SEAGal/STARLIGHT data sets. We apply a GMM to empirically define classes of galaxies in a three-dimensional space spanned by the log [O III]/H β, log [N II]/H α and log EW(H α) optical parameters. The best-fitting GMM based on several statistical criteria suggests a solution around four Gaussian components (GCs), which are capable to explain up to 97 per cent of the data variance. Using elements of information theory, we compare each GC to their respective astronomical counterpart. GC1 and GC4 are associated with star-forming galaxies, suggesting the need to define a new starburst subgroup. GC2 is associated with BPT's active galactic nuclei (AGN) class and WHAN's weak AGN class. GC3 is associated with BPT's composite class and WHAN's strong AGN class. Conversely, there is no statistical evidence - based on four GCs - for the existence of a Seyfert/low-ionization nuclear <span class="hlt">emission-line</span> region (LINER) dichotomy in our sample. Notwithstanding, the inclusion of an additional GC5 unravels it. The GC5 appears associated with the LINER and passive galaxies on the BPT and WHAN diagrams, respectively. This indicates that if the Seyfert/LINER dichotomy is there, it does not account significantly to the global data variance and may be overlooked by standard metrics of goodness of fit. Subtleties aside, we demonstrate the potential of our methodology to recover/unravel different objects inside the wilderness of astronomical data sets, without lacking the ability to convey physically interpretable results. The probabilistic classifications from the GMM analysis are publicly available within the COINtoolbox at https://cointoolbox.github.io/GMM_Catalogue/.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19760025002','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19760025002"><span>Heterodyne detection of CO2 <span class="hlt">emission</span> <span class="hlt">lines</span> and wind velocities in the atmosphere of Venus</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Betz, A. L.; Johnson, M. A.; Mclaren, R. A.; Sutton, E. C.</p> <p>1975-01-01</p> <p>Strong 10 micrometer <span class="hlt">line</span> <span class="hlt">emission</span> from (c-12)(o-16)2 in the upper atmosphere of Venus was detected by heterodyne techniques. Observations of the absolute Doppler shift of the <span class="hlt">emission</span> features indicate mean zonal wind velocities less than 10 m/sec in the upper atmosphere near the equator. No evidence was found of the 100 m/sec wind velocity implied by the apparent 4-day rotation period of ultraviolet cloud features.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018PhyS...93c5601M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018PhyS...93c5601M"><span>Identification of S VIII through S XIV <span class="hlt">emission</span> <span class="hlt">lines</span> between 17.5 and 50 nm in a magnetically confined plasma</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>McCarthy, K. J.; Tamura, N.; Combs, S. K.; García, R.; Hernández Sánchez, J.; Navarro, M.; Panadero, N.; Pastor, I.; Soleto, A.; the TJ-II Team</p> <p>2018-03-01</p> <p>43 spectral <span class="hlt">emission</span> <span class="hlt">lines</span> from F-like to Li-like sulphur ions have been identified in the wavelength range from 17.5 to 50 nm in spectra obtained following tracer injection into plasmas created in a magnetically confined plasma device, the stellarator TJ-II. Plasmas created and maintained in this heliac device with electron cyclotron resonance heating achieve central electron temperatures and densities up to 1.5 keV and 8 × 1018 m-3, respectively. Tracer injections were performed with ≤6 × 1016 atoms of sulphur contained within ˜300 μm diameter polystyrene capsules, termed tracer encapsulated solid pellets, using a gas propulsion system to achieve velocities between 250 and 450 m s-1. Once ablation of the exterior polystyrene shell by plasma particles is completed, the sulphur is deposited in the plasma core where it is ionized up to S+13 and transported about the plasma. In order to aid <span class="hlt">line</span> identification, which is made using a number of atomic <span class="hlt">line</span> <span class="hlt">emission</span> databases, spectra are collected before and after injection using a 1 m focal length normal incidence spectrometer equipped with a CCD camera. This work is motivated by the need to clearly identify sulphur <span class="hlt">emission</span> <span class="hlt">lines</span> in the vacuum ultraviolet range of magnetically confined plasmas, as sulphur x-ray <span class="hlt">emission</span> <span class="hlt">lines</span> are regularly observed in both tokamak and stellarator plasmas.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_22 --> <div id="page_23" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="441"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1390286-photometric-redshifts-clustering-emission-line-galaxies-selected-jointly-des-eboss','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1390286-photometric-redshifts-clustering-emission-line-galaxies-selected-jointly-des-eboss"><span>Photometric redshifts and clustering of <span class="hlt">emission</span> <span class="hlt">line</span> galaxies selected jointly by DES and eBOSS</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Jouvel, S.; Delubac, T.; Comparat, J.; ...</p> <p>2017-03-24</p> <p>We present the results of the first test plates of the extended Baryon Oscillation Spectroscopic Survey. This paper focuses on the <span class="hlt">emission</span> <span class="hlt">line</span> galaxies (ELG) population targetted from the Dark Energy Survey (DES) photometry. We analyse the success rate, efficiency, redshift distribution, and clustering properties of the targets. From the 9000 spectroscopic redshifts targetted, 4600 have been selected from the DES photometry. The total success rate for redshifts between 0.6 and 1.2 is 71\\% and 68\\% respectively for a bright and faint, on average more distant, samples including redshifts measured from a single strong <span class="hlt">emission</span> <span class="hlt">line</span>. We find a meanmore » redshift of 0.8 and 0.87, with 15 and 13\\% of unknown redshifts respectively for the bright and faint samples. In the redshift range 0.6« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1390286','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1390286"><span>Photometric redshifts and clustering of <span class="hlt">emission</span> <span class="hlt">line</span> galaxies selected jointly by DES and eBOSS</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Jouvel, S.; Delubac, T.; Comparat, J.</p> <p></p> <p>We present the results of the first test plates of the extended Baryon Oscillation Spectroscopic Survey. This paper focuses on the <span class="hlt">emission</span> <span class="hlt">line</span> galaxies (ELG) population targetted from the Dark Energy Survey (DES) photometry. We analyse the success rate, efficiency, redshift distribution, and clustering properties of the targets. From the 9000 spectroscopic redshifts targetted, 4600 have been selected from the DES photometry. The total success rate for redshifts between 0.6 and 1.2 is 71\\% and 68\\% respectively for a bright and faint, on average more distant, samples including redshifts measured from a single strong <span class="hlt">emission</span> <span class="hlt">line</span>. We find a meanmore » redshift of 0.8 and 0.87, with 15 and 13\\% of unknown redshifts respectively for the bright and faint samples. In the redshift range 0.6« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014MeScT..25i4007H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014MeScT..25i4007H"><span>On-<span class="hlt">line</span> depth measurement for laser-drilled holes based on the intensity of plasma <span class="hlt">emission</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ho, Chao-Ching; Chiu, Chih-Mu; Chang, Yuan-Jen; Hsu, Jin-Chen; Kuo, Chia-Lung</p> <p>2014-09-01</p> <p>The direct time-resolved depth measurement of blind holes is extremely difficult due to the short time interval and the limited space inside the hole. This work presents a method that involves on-<span class="hlt">line</span> plasma <span class="hlt">emission</span> acquisition and analysis to obtain correlations between the machining processes and the optical signal output. Given that the depths of laser-machined holes can be estimated on-<span class="hlt">line</span> using a coaxial photodiode, this was employed in our inspection system. Our experiments were conducted in air under normal atmospheric conditions without gas assist. The intensity of radiation emitted from the vaporized material was found to correlate with the depth of the hole. The results indicate that the estimated depths of the laser-drilled holes were inversely proportional to the maximum plasma light <span class="hlt">emission</span> measured for a given laser pulse number.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/5258689-new-method-determining-temperature-emission-measure-during-solar-flares-from-light-curves-soft-ray-line-fluxes','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/5258689-new-method-determining-temperature-emission-measure-during-solar-flares-from-light-curves-soft-ray-line-fluxes"><span>New method for determining temperature and <span class="hlt">emission</span> measure during solar flares from light curves of soft X-ray <span class="hlt">line</span> fluxes</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Bornmann, P.L.</p> <p></p> <p>I describe a new property of soft X-ray <span class="hlt">line</span> fluxes observed during the decay phase of solar flares and a technique for using this property to determine the plasma temperature and <span class="hlt">emission</span> measure as functions of time. The soft X-ray <span class="hlt">line</span> fluxes analyzed in this paper were observed during the decay phase of the 1980 November 5 flare by the X-Ray Polychromator (XRP) instrument on board the Solar Maximum Mission (SMM). The resonance, intercombination, and forbidden <span class="hlt">lines</span> of Ne IX, Mg XI, Si XIII, S XV, Ca XIX, and Fe XXV, as well as the Lyman-..cap alpha.. <span class="hlt">line</span> of Omore » VIII and the resonance <span class="hlt">lines</span> of Fe XIX, were observed. The rates at which the observed <span class="hlt">line</span> fluxes decayed were not constant. For all but the highest temperature <span class="hlt">lines</span> observed, the rate changed abruptly, causing the fluxes to fall at a more rapid rate later in the flare decay. These changes occurred at earlier times for <span class="hlt">lines</span> formed at higher temperatures. This behavior is proposed to be due to the decreasing temperature of the flare plasma tracking the rise and subsequent fall of each <span class="hlt">line</span> <span class="hlt">emissivity</span> function. This explanation is used to empirically model the observed light curves and to estimate the temperature and the change in <span class="hlt">emission</span> measure of the plasma as a function of time during the decay phase. Estimates are made of various plasma parameters based on the model results.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.A43F2528D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.A43F2528D"><span>On-<span class="hlt">line</span> Field Measurements of Speciated PM1 <span class="hlt">Emission</span> Factors from Common South Asian Combustion Sources</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>DeCarlo, P. F.; Goetz, J. D.; Giordano, M.; Stockwell, C.; Maharjan, R.; Adhikari, S.; Bhave, P.; Praveen, P. S.; Panday, A. K.; Jayarathne, T. S.; Stone, E. A.; Yokelson, R. J.</p> <p>2017-12-01</p> <p>Characterization of aerosol <span class="hlt">emissions</span> from prevalent but under sampled combustion sources in South Asia was performed as part of the Nepal Ambient Monitoring and Source Testing Experiment (NAMaSTE) in April 2015. Targeted <span class="hlt">emission</span> sources included cooking stoves with a variety of solid fuels, brick kilns, garbage burning, crop-residue burning, diesel irrigation pumps, and motorcycles. Real-time measurements of submicron non-refractory particulate mass concentration and composition were obtained using an Aerodyne mini Aerosol Mass Spectrometer (mAMS). Speciated PM1 mass <span class="hlt">emission</span> factors were calculated for all particulate species (e.g. organics, sulfates, nitrates, chlorides, ammonium) and for each source type using the carbon mass balance approach. Size resolved <span class="hlt">emission</span> factors were also acquired using a novel high duty cycle particle time-of-flight technique (ePTOF). Black carbon and brown carbon absorption <span class="hlt">emission</span> factors and absorption Angström exponents were measured using filter loading and scattering corrected attenuation at 370 nm and 880 nm with a dual spot aethalometer (Magee Scientific AE-33). The results indicate that open garbage burning is a strong emitter of organic aerosol, black carbon, and internally mixed particle phase hydrogen chloride (HCl). <span class="hlt">Emissions</span> of HCl were attributed to the presence chlorinated plastics. The primarily coal fired brick kilns were found to be large emitters of sulfate but large differences in the organic and light absorbing component of <span class="hlt">emissions</span> were observed between the two kiln types investigated (technologically advanced vs. traditional). These results, among others, bring on-<span class="hlt">line</span> and field-tested aerosol <span class="hlt">emission</span> measurements to an area of atmoshperic research dominated by off-<span class="hlt">line</span> or laboratory based measurements.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/6260701','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/biblio/6260701"><span>Atomic <span class="hlt">line</span> <span class="hlt">emission</span> analyzer for hydrogen isotopes</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Kronberg, J.W.</p> <p>1993-03-30</p> <p>Apparatus for isotopic analysis of hydrogen comprises a low pressure chamber into which a sample of hydrogen is introduced and then exposed to an electrical discharge to excite the electrons of the hydrogen atoms to higher energy states and thereby cause the <span class="hlt">emission</span> of light on the return to lower energy states, a Fresnel prism made at least in part of a material anomalously dispersive to the wavelengths of interest for dispersing the emitted light, and a photodiode array for receiving the dispersed light. The light emitted by the sample is filtered to pass only the desired wavelengths, such as one of the <span class="hlt">lines</span> of the Balmer series for hydrogen, the wavelengths of which differ slightly from one isotope to another. The output of the photodiode array is processed to determine the relative amounts of each isotope present in the sample. Additionally, the sample itself may be recovered using a metal hydride.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/10146247','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/10146247"><span>Atomic <span class="hlt">line</span> <span class="hlt">emission</span> analyzer for hydrogen isotopes</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Kronberg, J.W.</p> <p>1991-05-08</p> <p>Apparatus for isotopic analysis of hydrogen comprises a low pressure chamber into which a sample of hydrogen is introduced and then exposed to an electrical discharge to excite the electrons of the hydrogen atoms to higher energy states and thereby cause the <span class="hlt">emission</span> of light on the return to lower energy states, a Fresnel prism made at least in part of a material anomalously dispersive to the wavelengths of interest for dispersing the emitted light, and a photodiode array for receiving the dispersed light. The light emitted by the sample is filtered to pass only the desired wavelengths, such as one of the <span class="hlt">lines</span> of the Balmer series for hydrogen, the wavelengths of which differ slightly from one isotope to another. The output of the photodiode array is processed to determine the relative amounts of each isotope present in the sample. Additionally, the sample itself may be recovered using, a metal hydride.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/868722','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/868722"><span>Atomic <span class="hlt">line</span> <span class="hlt">emission</span> analyzer for hydrogen isotopes</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Kronberg, James W.</p> <p>1993-01-01</p> <p>Apparatus for isotopic analysis of hydrogen comprises a low pressure chamber into which a sample of hydrogen is introduced and then exposed to an electrical discharge to excite the electrons of the hydrogen atoms to higher energy states and thereby cause the <span class="hlt">emission</span> of light on the return to lower energy states, a Fresnel prism made at least in part of a material anomalously dispersive to the wavelengths of interest for dispersing the emitted light, and a photodiode array for receiving the dispersed light. The light emitted by the sample is filtered to pass only the desired wavelengths, such as one of the <span class="hlt">lines</span> of the Balmer series for hydrogen, the wavelengths of which differ slightly from one isotope to another. The output of the photodiode array is processed to determine the relative amounts of each isotope present in the sample. Additionally, the sample itself may be recovered using a metal hydride.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016csss.confE.116G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016csss.confE.116G"><span>Mg II Chromospheric <span class="hlt">Emission</span> <span class="hlt">Line</span> Bisectors Of HD39801 And Its Relation With The Activity Cycle</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>García García, Leonardo Enrique; Pérez Martínez, M. Isabel</p> <p>2016-07-01</p> <p>Betelgeuse is a cool star of spectral type M and luminosity class I. In the present work, the activity cycle of Betelgeuse was obtained from the integrated <span class="hlt">emission</span> flux of the Mg II H and K <span class="hlt">lines</span>, using more than 250 spectra taken from the International Ultraviolet Explorer (IUE) online database. Of which it was found, based on a Lomb Scargle periodogram, a cycle of 16 years, along with 2 sub-cycles with a period of the order of 0.60 and 0.65 years, which may be due to turbulence or possible stellar flares. In addition, an analysis of <span class="hlt">line</span> asymmetry was made by means of the chromospheric <span class="hlt">emission</span> <span class="hlt">line</span> bisectors, due to the strong self-absorption observed in this <span class="hlt">lines</span>, the blue and red wings were analyzed independently. In order to measure such asymmetry, a "<span class="hlt">line</span> shift" was calculated, from which several cycles of variability were obtained from a Lomb Scargle periodogram, spanning from few months to 4 years. In the sense, the most significant cycle is about 0.44 and 0.33 years in the blue and red wing respectively. It is worth noting, that the rotation period of the star doesn't play an important role in the variability of the Mg II <span class="hlt">lines</span>. This technique provides us with a new way to study activity cycles of evolved stars.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018SFZ.....4a..14K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018SFZ.....4a..14K"><span>Intensity of <span class="hlt">emission</span> <span class="hlt">lines</span> of the quiescent solar corona: comparison between calculated and observed values</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Krissinel, Boris</p> <p>2018-03-01</p> <p>The paper reports the results of calculations of the center-to-limb intensity of optically thin <span class="hlt">line</span> <span class="hlt">emission</span> in EUV and FUV wavelength ranges. The calculations employ a multicomponent model for the quiescent solar corona. The model includes a collection of loops of various sizes, spicules, and free (inter-loop) matter. Theoretical intensity values are found from probabilities of encountering parts of loops in the <span class="hlt">line</span> of sight with respect to the probability of absence of other coronal components. The model uses 12 loops with sizes from 3200 to 210000 km with different values of rarefaction index and pressure at the loop base and apex. The temperature at loop apices is 1 400 000 K. The calculations utilize the CHIANTI database. The comparison between theoretical and observed <span class="hlt">emission</span> intensity values for coronal and transition region <span class="hlt">lines</span> obtained by the SUMER, CDS, and EIS telescopes shows quite satisfactory agreement between them, particularly for the solar disk center. For the data acquired above the limb, the enhanced discrepancies after the analysis refer to errors in EIS measurements.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018AAS...23132805K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018AAS...23132805K"><span>Clustering Properties of <span class="hlt">Emission</span> <span class="hlt">Line</span> Selected Galaxies over the past 12.5 Gyrs</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Khostovan, Ali Ahmad; Sobral, David; Mobasher, Bahram; Best, Philip N.; Smail, Ian; Matthee, Jorryt; Darvish, Behnam; Nayyeri, Hooshang; Hemmati, Shoubaneh; Stott, John P.</p> <p>2018-01-01</p> <p>In this talk, I will present my latest results on the clustering and dark matter halo (DMH) mass properties of ~7000 narrowband-selected [OIII] and [OII] emitters. I will briefly describe the past work that has been done with our samples (e.g., luminosity functions, evolution of equivalent widths) as motivation of using [OIII] and [OII] emitters to study clustering/halo properties. My talk will focus on our findings regarding the <span class="hlt">line</span> luminosity and stellar mass dependencies with DMH mass. We find strongly increasing and redshift-independent trends between <span class="hlt">line</span> luminosity and DMH mass with evidence for a shallower slope at the bright end consistent with halo masses of ~ 1012.5-13 M⊙. Similar, but weaker, trends between stellar mass and halo mass have also been found. We investigate the inter-dependencies of these trends on halo mass and find that the correlation with <span class="hlt">line</span> luminosity is stronger than with stellar mass. This suggest that active galaxies may be connected with their host DMHs simply based on their <span class="hlt">emission</span> <span class="hlt">line</span> luminosity. If time permits, I will briefly present our most recent results using our sample of ~4000 Lyα emitters, where we find similar trends to that seen with the [OIII] and [OII] samples, as well as previous Hα measurements, which suggests galaxies selected based on <span class="hlt">emission</span> <span class="hlt">lines</span> may be tracing the same subpopulation of star forming galaxies. I will conclude my talk with an interpretation of this connection and suggest that the shallower slope seen for the brightest emitters is evidence for a transitional halo mass as suggested in models where quenching mechanisms truncate star formation activity and reduce the fraction of star forming galaxies with increasing halo mass.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19940014948','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19940014948"><span>Determination of nitrogen to carbon abundance ratios from transition layer <span class="hlt">emission</span> <span class="hlt">lines</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Boehm-Vitense, Erika</p> <p>1992-01-01</p> <p>We have finished studying the nitrogen to carbon abundance ratios for stars with different effective temperatures T(sub eff) and luminosities using transition layer <span class="hlt">emission</span> <span class="hlt">lines</span> and using spectra available in the IUE archives. The N/C abundance ratio determinations using transition layer <span class="hlt">emission</span> <span class="hlt">lines</span> are as accurate as the photospheric abundance determinations as found by comparison of results obtained by both methods for the same stars. Our measurements confirm photospheric abundance determinations in regions of the HR diagram where they can be obtained. Our studies have extended the temperature range to higher temperatures. They have shown the exact positions in the HR diagram where the mixing due to the outer convection zones reaches deep enough to bring nuclear processed material to the surface. This occurs at effective temperatures which are higher by delta log T(sub eff) approximately 0.04 or roughly 400 K than expected theoretically. Since the depth of the convection zone increases rapidly with decreasing T(sub eff) this may indicate considerable overshoot beyond the lower boundary of the convection zone. Our N/C abundance ratio determinations from transition layer <span class="hlt">emission</span> <span class="hlt">lines</span> have confirmed that the actual enrichment observed for some cool giants is larger than expected theoretically, again indicating a larger degree of mixing in several stars either from below or from above. For the supergiants it probably indicates overshoot above the convective core in the progenitor main sequence stars. For the more massive giants this may also be the case, though we did not find a correlation between delta log N/C and the absolute magnitudes, but these are rather uncertain. As byproducts of these studies we also found anomalies in Si/C and N/C abundance ratios for F giants which can be understood as the relict of surface abundance changes for their main sequence progenitors due to diffusion. This anomaly disappears for G giants, for which the depths of the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1982PASJ...34...21K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1982PASJ...34...21K"><span>Variation of the H-Beta <span class="hlt">Emission</span> <span class="hlt">Lines</span> of Yy-Geminorum - Part Two - Change of Sectorial Structures of Active Regions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kodaira, K.; Ichimura, K.</p> <p></p> <p>Sixty-three image-tube spectrograms of YY Gem (4 Å mm-1, λλ4820-4900 Å) are analyzed to yield the radial-velocity curves and the variations in the intensities and the widths of Hβ <span class="hlt">emission</span> <span class="hlt">lines</span> during the quiescent phase at epochs 1980 February 11-16, 1981 January 14-15, and 1981 March 11. The <span class="hlt">emission-line</span> intensity of component A varied in a single-wave mode over an orbital period, with an apparent phase drift, -0.006019 fraction of the period per day from one epoch to another. The pattern of the intensity variation of component B changed within a few years. The ratio of the amplitudes of radial-velocity curves (KA/KB) of Hβ <span class="hlt">emission</span> was found to be 0.91 in February 1980 but 1.01 in January 1981. This modulation in the ratio is interpreted as the results of the varying inhomogeneous distributions of <span class="hlt">emission</span> intensities over the stellar surfaces which are inferred from the observed intensity variations under the assumption of synchronous rotation. A ratio KA/KB = 1.00±001 is proposed as the actual value which would be observed if the effects of inhomogeneities were negligible. The double-wave mode of the <span class="hlt">line</span>-width variation over a period, which was found by Kodaira and Ichimura (1980), persisted for component A but changed into a single-wave mode for component B. No appreciable changes were detected in the average levels of both the intensity and width of Hβ <span class="hlt">emission</span> <span class="hlt">lines</span> within the last few years.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22663227-emission-lines-near-infrared-spectra-infrared-quintuplet-stars-galactic-center','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22663227-emission-lines-near-infrared-spectra-infrared-quintuplet-stars-galactic-center"><span><span class="hlt">Emission</span> <span class="hlt">Lines</span> in the Near-infrared Spectra of the Infrared Quintuplet Stars in the Galactic Center</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Najarro, F.; Geballe, T. R.; Figer, D. F.</p> <p></p> <p>We report the detection of a number of <span class="hlt">emission</span> <span class="hlt">lines</span> in the 1.0–2.4 μ m spectra of four of the five bright-infrared dust-embedded stars at the center of the Galactic center’s (GC) Quintuplet Cluster. Spectroscopy of the central stars of these objects is hampered not only by the large interstellar extinction that obscures all of the objects in the GC, but also by the large amounts of warm circumstellar dust surrounding each of the five stars. The pinwheel morphologies of the dust observed previously around two of them are indicative of Wolf–Rayet colliding wind binaries; however, infrared spectra of eachmore » of the five have until now revealed only dust continua steeply rising to long wavelengths and absorption <span class="hlt">lines</span> and bands from interstellar gas and dust. The <span class="hlt">emission</span> <span class="hlt">lines</span> detected, from ionized carbon and from helium, are broad and confirm that the objects are dusty late-type carbon Wolf–Rayet stars.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017edrs.confE...8L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017edrs.confE...8L"><span>J-Plus: Measuring Ha <span class="hlt">Emission</span> <span class="hlt">Line</span> Flux In The Nearby Universe</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Logroño-García, Rafael; Vilella-Rojo, Gonzalo; López-San Juan, Carlos; Varela, Jesús; Viironen, Kerttu</p> <p>2017-10-01</p> <p>In the present presentation we aim to validate the methodology designed to extract the Ha <span class="hlt">emission</span> <span class="hlt">line</span> flux from J-PLUS data, a twelve optical filter survey carried out with the 2 deg² field of view T80Cam camera, mounted at the JAST/T80 telescope in the OAJ, Teruel, Spain. We use the information of the twelve J-PLUS bands, including the J0660 narrow-band filter located at rest-frame Ha, over 42 deg² to extract de-reddened and [NII] decontaminated Ha <span class="hlt">emission</span> <span class="hlt">line</span> fluxes of 46 star-forming regions with previous SDSS and/or CALIFA spectroscopic information. The agreement of the J-PLUS photometric Ha flux and the spectroscopic one is remarkable, with a ratio R = 1,01 +/- 0,27. This demonstrates that we are able to recover reliable Ha fluxes from J-PLUS photometric data. With an expected final area of 8,500 deg2, the large J-PLUS footprint will permit the study of the spatially resolved star formation rate of thousands nearby galaxies at z 0,015, as well as the influence of the close environment. As an illustrative example, we looked to the close pair of interacting galaxies NGC3994 and NGC3995, finding an enhancement of the star formation rate not only in the central part of NGC3994 but also in outer parts of the disc.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2014-title40-vol13/pdf/CFR-2014-title40-vol13-part63-subpartUUU-app36.pdf','CFR2014'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2014-title40-vol13/pdf/CFR-2014-title40-vol13-part63-subpartUUU-app36.pdf"><span>40 CFR Table 36 to Subpart Uuu of... - Work Practice Standards for HAP <span class="hlt">Emissions</span> From Bypass <span class="hlt">Lines</span></span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2014&page.go=Go">Code of Federal Regulations, 2014 CFR</a></p> <p></p> <p>2014-07-01</p> <p>... 40 Protection of Environment 13 2014-07-01 2014-07-01 false Work Practice Standards for HAP <span class="hlt">Emissions</span> From Bypass <span class="hlt">Lines</span> 36 Table 36 to Subpart UUU of Part 63 Protection of Environment ENVIRONMENTAL..., Subpt. UUU, Table 36 Table 36 to Subpart UUU of Part 63—Work Practice Standards for HAP <span class="hlt">Emissions</span> From...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2013-title40-vol13/pdf/CFR-2013-title40-vol13-part63-subpartUUU-app36.pdf','CFR2013'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2013-title40-vol13/pdf/CFR-2013-title40-vol13-part63-subpartUUU-app36.pdf"><span>40 CFR Table 36 to Subpart Uuu of... - Work Practice Standards for HAP <span class="hlt">Emissions</span> From Bypass <span class="hlt">Lines</span></span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2013&page.go=Go">Code of Federal Regulations, 2013 CFR</a></p> <p></p> <p>2013-07-01</p> <p>... 40 Protection of Environment 13 2013-07-01 2012-07-01 true Work Practice Standards for HAP <span class="hlt">Emissions</span> From Bypass <span class="hlt">Lines</span> 36 Table 36 to Subpart UUU of Part 63 Protection of Environment ENVIRONMENTAL..., Subpt. UUU, Table 36 Table 36 to Subpart UUU of Part 63—Work Practice Standards for HAP <span class="hlt">Emissions</span> From...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2012-title40-vol13/pdf/CFR-2012-title40-vol13-part63-subpartUUU-app36.pdf','CFR2012'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2012-title40-vol13/pdf/CFR-2012-title40-vol13-part63-subpartUUU-app36.pdf"><span>40 CFR Table 36 to Subpart Uuu of... - Work Practice Standards for HAP <span class="hlt">Emissions</span> From Bypass <span class="hlt">Lines</span></span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2012&page.go=Go">Code of Federal Regulations, 2012 CFR</a></p> <p></p> <p>2012-07-01</p> <p>... 40 Protection of Environment 13 2012-07-01 2012-07-01 false Work Practice Standards for HAP <span class="hlt">Emissions</span> From Bypass <span class="hlt">Lines</span> 36 Table 36 to Subpart UUU of Part 63 Protection of Environment ENVIRONMENTAL..., Subpt. UUU, Table 36 Table 36 to Subpart UUU of Part 63—Work Practice Standards for HAP <span class="hlt">Emissions</span> From...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19850012674&hterms=Symbiotic&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3DSymbiotic','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19850012674&hterms=Symbiotic&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3DSymbiotic"><span>Fluorescent excitation of Fe 2, Mn 2, Ti 2, N 1 <span class="hlt">lines</span> by V 4, N 5, O 6: <span class="hlt">Emission</span> <span class="hlt">lines</span> in the spectra of symbiotic stars and Seyfert galaxies</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gilra, D. P.</p> <p>1984-01-01</p> <p>Analysis of the published IUE and ground based high resolution spectra of symbiotic stars, particularly RR Tel, shows that the dominant excitation mechanism of Fe II, Mn II, Ti II, and N I <span class="hlt">lines</span> is the selective fluorescent excitation of some levels by the strong C IV, N V, and O VI <span class="hlt">emission</span> <span class="hlt">lines</span>. The same mechanism should work for the excitation of Fe II <span class="hlt">lines</span> in the spectra of Seyfert galaxies and Q60's whose <span class="hlt">emission</span> spectra are quite similar to those of symbiotic stars. The similarities and differences between the fluroescent excitation mechanism reported herein and the Bowen's mechanism is analyzed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017A%26A...602A.111H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017A%26A...602A.111H"><span>LSDCat: Detection and cataloguing of <span class="hlt">emission-line</span> sources in integral-field spectroscopy datacubes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Herenz, Edmund Christian; Wisotzki, Lutz</p> <p>2017-06-01</p> <p>We present a robust, efficient, and user-friendly algorithm for detecting faint <span class="hlt">emission-line</span> sources in large integral-field spectroscopic datacubes together with the public release of the software package <span class="hlt">Line</span> Source Detection and Cataloguing (LSDCat). LSDCat uses a three-dimensional matched filter approach, combined with thresholding in signal-to-noise, to build a catalogue of individual <span class="hlt">line</span> detections. In a second pass, the detected <span class="hlt">lines</span> are grouped into distinct objects, and positions, spatial extents, and fluxes of the detected <span class="hlt">lines</span> are determined. LSDCat requires only a small number of input parameters, and we provide guidelines for choosing appropriate values. The software is coded in Python and capable of processing very large datacubes in a short time. We verify the implementation with a source insertion and recovery experiment utilising a real datacube taken with the MUSE instrument at the ESO Very Large Telescope. The LSDCat software is available for download at http://muse-vlt.eu/science/tools and via the Astrophysics Source Code Library at http://ascl.net/1612.002</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_23 --> <div id="page_24" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="461"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018SPIE10614E..03P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018SPIE10614E..03P"><span>Amplification of spontaneous <span class="hlt">emission</span> on sodium D-<span class="hlt">lines</span> using nonresonance broadband optical pumping</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Petukhov, T. D.; Evtushenko, G. S.; Tel'minov, E. N.</p> <p>2018-04-01</p> <p>This work describes an experimental study of obtaining the amplified spontaneous <span class="hlt">emission</span> (ASE) on sodium D-<span class="hlt">lines</span> using nonresonance broadband optical pumping. ASE is observed at transitions D2 and D1 <span class="hlt">line</span>: 589 nm (32 P3/2 - 32 S1/2) and 589.6 nm (32 P1/2 - 32 S1/2). The active medium was pumped by the dye laser with FWHM of 5 nm, maximum radiation in the range 584.5-586.5 nm, and pulse energy above 2 mJ. The working temperature of the active medium was 260 °C, initial pressure of buffer gas-helium was 300 torr (operating pressure - 500 torr). A change in the absorption spectra at D <span class="hlt">lines</span> at different temperatures of the active medium and buffer gas pressures was observed</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017ASPC..511..185S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017ASPC..511..185S"><span>Neon and [CII] 158 μm <span class="hlt">Emission</span> <span class="hlt">Line</span> Profiles in Dusty Starbursts and Active Galactic Nuclei</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Samsonyan, A.; Weedman, D.; Lebouteiller, V.; Barry, D.; Sargsyan, L.</p> <p>2017-07-01</p> <p>Identifying and understanding the initial formation of massive galaxies and quasars in the early universe is a fundamental goal of observational cosmology. A rapidly developing capability for tracing luminosity sources to high redshifts is the observation of the [CII] 158 μm <span class="hlt">emission</span> <span class="hlt">line</span> at redshifts z > 4 using ground based submillimeter interferometers, with detections now having been made to z = 7. This has long been known as the strongest far-infrared <span class="hlt">line</span> in most sources, often carrying about 1% of the total source luminosity, and is thought to be associated with star formation because it should arise within the photodissociation region (PDR) surrounding starbursts. The sample of 382 extragalactic sources has been analysed that have mid-infrared,high resolution spectroscopy with the Spitzer Infrared Spectrograph (IRS) and also spectroscopy of the [CII] 158 μm <span class="hlt">line</span> with the Herschel Photodetector Array Camera and Spectrometer (PACS). The <span class="hlt">emission</span> <span class="hlt">line</span> profiles of [NeII] 12.81μm , [NeIII] 15.55 μm , and [CII] 158 μm are studied, and intrinsic <span class="hlt">line</span> widths are determined. All <span class="hlt">line</span> profiles together with overlays comparing positions of PACS and IRS observations are made available in the Cornell Atlas of Spitzer IRS Sources (CASSIS). Sources are classified from AGN to starburst based on equivalent widths of the 6.2 μm polycyclic aromatic hydrocarbon feature. It is found that intrinsic <span class="hlt">line</span> widths do not change among classification for [CII], with median widths of 207 km s-1 for AGN, 248 km s-1 for composites, and 233 km s-1 for starbursts. The [NeII] <span class="hlt">line</span> widths also do not change with classification, but [NeIII] <span class="hlt">lines</span> are progressively broader from starburst to AGN. A small number of objects with unusually broad <span class="hlt">lines</span> or unusual redshift differences in any feature are identified.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017MNRAS.465.4044B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017MNRAS.465.4044B"><span>Dust masses for SN 1980K, SN1993J and Cassiopeia A from red-blue <span class="hlt">emission</span> <span class="hlt">line</span> asymmetries</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bevan, Antonia; Barlow, M. J.; Milisavljevic, D.</p> <p>2017-03-01</p> <p>We present Monte Carlo <span class="hlt">line</span> transfer models that investigate the effects of dust on the very late time <span class="hlt">emission</span> <span class="hlt">line</span> spectra of the core-collapse supernovae SN 1980K and SN 1993J and the young core collapse supernova remnant Cassiopeia A. Their blueshifted <span class="hlt">emission</span> peaks, resulting from the removal by dust of redshifted photons emitted from the far sides of the remnants, and the presence of extended red <span class="hlt">emission</span> wings are used to constrain dust compositions and radii and to determine the masses of dust in the remnants. We estimate dust masses of between 0.08 and 0.15 M⊙ for SN 1993J at year 16, 0.12 and 0.30 M⊙ for SN 1980K at year 30 and ∼1.1 M⊙ for Cas A at year ∼330. Our models for the strong oxygen forbidden <span class="hlt">lines</span> of Cas A require the overall modelled profiles to be shifted to the red by between 700 and 1000 km s-1, consistent with previous estimates for the shift of the dynamical centroid of this remnant.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015A%26A...573A..42L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015A%26A...573A..42L"><span>PyNeb: a new tool for analyzing <span class="hlt">emission</span> <span class="hlt">lines</span>. I. Code description and validation of results</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Luridiana, V.; Morisset, C.; Shaw, R. A.</p> <p>2015-01-01</p> <p>Analysis of <span class="hlt">emission</span> <span class="hlt">lines</span> in gaseous nebulae yields direct measures of physical conditions and chemical abundances and is the cornerstone of nebular astrophysics. Although the physical problem is conceptually simple, its practical complexity can be overwhelming since the amount of data to be analyzed steadily increases; furthermore, results depend crucially on the input atomic data, whose determination also improves each year. To address these challenges we created PyNeb, an innovative code for analyzing <span class="hlt">emission</span> <span class="hlt">lines</span>. PyNeb computes physical conditions and ionic and elemental abundances and produces both theoretical and observational diagnostic plots. It is designed to be portable, modular, and largely customizable in aspects such as the atomic data used, the format of the observational data to be analyzed, and the graphical output. It gives full access to the intermediate quantities of the calculation, making it possible to write scripts tailored to the specific type of analysis one wants to carry out. In the case of collisionally excited <span class="hlt">lines</span>, PyNeb works by solving the equilibrium equations for an n-level atom; in the case of recombination <span class="hlt">lines</span>, it works by interpolation in <span class="hlt">emissivity</span> tables. The code offers a choice of extinction laws and ionization correction factors, which can be complemented by user-provided recipes. It is entirely written in the python programming language and uses standard python libraries. It is fully vectorized, making it apt for analyzing huge amounts of data. The code is stable and has been benchmarked against IRAF/NEBULAR. It is public, fully documented, and has already been satisfactorily used in a number of published papers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22654406-first-comparison-millimeter-continuum-mg-ii-ultraviolet-line-emission-from-solar-chromosphere','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22654406-first-comparison-millimeter-continuum-mg-ii-ultraviolet-line-emission-from-solar-chromosphere"><span>A First Comparison of Millimeter Continuum and Mg ii Ultraviolet <span class="hlt">Line</span> <span class="hlt">Emission</span> from the Solar Chromosphere</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Bastian, T. S.; Chintzoglou, G.; De Pontieu, B.</p> <p></p> <p>We present joint observations of the Sun by the Atacama Large Millimeter/submillimeter Array (ALMA) and the Interface Region Imaging Spectrograph ( IRIS ). Both millimeter/submillimeter- λ continuum <span class="hlt">emission</span> and ultraviolet (UV) <span class="hlt">line</span> <span class="hlt">emission</span> originate from the solar chromosphere and both have the potential to serve as powerful and complementary diagnostics of physical conditions in this enigmatic region of the solar atmosphere. The observations were made of a solar active region on 2015 December 18 as part of the ALMA science verification effort. A map of the Sun’s continuum <span class="hlt">emission</span> was obtained by ALMA at a wavelength of 1.25 mm (239more » GHz). A contemporaneous map was obtained by IRIS in the Mg ii h doublet <span class="hlt">line</span> at 2803.5 Å. While a clear correlation between the 1.25 mm brightness temperature T{sub B} and the Mg ii h <span class="hlt">line</span> radiation temperature T {sub rad} is observed, the slope is <1, perhaps as a result of the fact that these diagnostics are sensitive to different parts of the chromosphere and that the Mg ii h <span class="hlt">line</span> source function includes a scattering component. There is a significant difference (35%) between the mean T{sub B} (1.25 mm) and mean T {sub rad} (Mg ii). Partitioning the maps into “sunspot,” “quiet areas,” and “plage regions” we find the relation between the IRIS Mg ii h <span class="hlt">line</span> T {sub rad} and the ALMA T {sub B} region-dependent. We suggest this may be the result of regional dependences of the formation heights of the IRIS and ALMA diagnostics and/or the increased degree of coupling between the UV source function and the local gas temperature in the hotter, denser gas in plage regions.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/21072653-emission-intensities-line-ratios-from-fast-neutral-helium-beam','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/21072653-emission-intensities-line-ratios-from-fast-neutral-helium-beam"><span><span class="hlt">Emission</span> intensities and <span class="hlt">line</span> ratios from a fast neutral helium beam</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Ahn, J-W.; Craig, D.; Fiksel, G.</p> <p>2007-08-15</p> <p>The <span class="hlt">emission</span> intensities and <span class="hlt">line</span> ratios from a fast neutral helium beam is investigated in the Madison Symmetric Torus (MST) [R. N. Dexter, D. W. Kerst, T. W. Lovell, S. C. Prager, and J. C. Sprott, Fusion Technol. 19, 131 1991]. Predicted He I <span class="hlt">line</span> intensities and <span class="hlt">line</span> ratios from a recently developed collisional-radiative model are compared with experiment. The intensity of singlet <span class="hlt">lines</span> comes mostly (>95%) from the contribution of the ground state population and is very weakly dependent on the initial metastable fraction at the observation point in the plasma core. On the other hand, the intensity ofmore » triplet <span class="hlt">lines</span> is strongly affected by the local metastable state (2{sup 1}S and 2{sup 3}S) populations and the initial metastable fraction plays an important role in determining <span class="hlt">line</span> intensities. The fraction of local metastable states can only be estimated by making use of electron temperature (T{sub e}), electron density (n{sub e}), and effective ion charge (Z{sub eff}) profiles as inputs to the population balance equations. This leads triplet <span class="hlt">lines</span> to be unusable for the investigation of their local plasma parameter dependence. The ratio of singlet <span class="hlt">lines</span> at 667.8 nm and 492.2 nm (I{sub 667}/I{sub 492}) as well as the ratio of 667.8 nm and 501.6 nm <span class="hlt">lines</span> (I{sub 667}/I{sub 501}) has been investigated for the dependence on T{sub e} and n{sub e} both theoretically and experimentally. I{sub 667}/I{sub 492} shows strong dependence on n{sub e} with weak sensitivity to T{sub e}. Measurements and predictions agree quantitatively within a factor of 2. There has been no ratio of singlet <span class="hlt">lines</span> identified to have strong enough T{sub e} dependence yet. The ratios are expected to be reasonably insensitive to the variation of Z{sub eff}.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19810065306&hterms=twilight&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dtwilight','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19810065306&hterms=twilight&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dtwilight"><span>Observations of the Ca/+/ twilight <span class="hlt">airglow</span> from intermediate layers of ionization</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Tepley, C. A.; Meriwether, J. W., Jr.; Walker, J. C. G.; Mathews, J. D.</p> <p>1981-01-01</p> <p>Optical and incoherent scatter radar techniques are applied to detect the presence of Ca(+) in lower thermospheric intermediate layers over Arecibo. The Arecibo 430 MHz radar is used to measure electron densities, and the altitude distribution and density of the calcium ion is inferred from the variation of twilight resonant scattering with solar depression angle. Ca(+) and electron column densities are compared, and results indicate that the composition of low-altitude intermediate layers is 2% Ca(+), which is consistent with rocket mass spectrometer measurements. Fe(+) and Mg(+) ultraviolet resonance <span class="hlt">lines</span> are not detected from the ground due to ozone absorbing all radiation short of 3000 A, and measurements of the neutral iron resonance <span class="hlt">line</span> at 3860 A show that an atmospheric continuum may result in overestimations of <span class="hlt">emission</span> rates at high solar depression angles.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19990111726&hterms=lab+made+black+holes&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dlab%2Bmade%2Bblack%2Bholes','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19990111726&hterms=lab+made+black+holes&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dlab%2Bmade%2Bblack%2Bholes"><span><span class="hlt">Line</span> <span class="hlt">Emission</span> from an Accretion Disk Around a Rotating Black Hole: Toward a Measurement of Frame Dragging</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Bromley, Benjamin C.; Chen, Kaiyou; Miller, Warner A.</p> <p>1997-01-01</p> <p><span class="hlt">Line</span> <span class="hlt">emission</span> from an accretion disk and a corotating hot spot about a rotating black hole are considered for possible signatures of the frame-dragging effect. We explicitly compare integrated <span class="hlt">line</span> profiles from a geometrically thin disk about a Schwarzschild and an extreme Kerr black hole, and show that the <span class="hlt">line</span> profile differences are small if the inner radius of the disk is near or above the Schwarzschild stable-orbit limit of radius 6GM/sq c. However, if the inner disk radius extends below this limit, as is Possible in the extreme Kerr spacetime, then differences can become significant, especially if the disk <span class="hlt">emissivity</span> is stronger near the inner regions. We demonstrate that the first three moments of a <span class="hlt">line</span> profile define a three-dimensional space in which the presence of material at small radii becomes quantitatively evident in broad classes of disk models. In the context of the simple, thin disk paradigm, this moment-mapping scheme suggests formally that the iron <span class="hlt">line</span> detected by the Advanced Satellite,for Cosmology and Astrophysics mission from MCG --6-30-15 (Tanaka et al.) is approximately 3 times more likely to originate from a disk about a rotating black hole than from a Schwarzschild system. A statistically significant detection of black hole rotation in this way may be achieved after only modest improvements in the quality of data. We also consider light curves and frequency shifts in <span class="hlt">line</span> <span class="hlt">emission</span> as a function of time for corotating hot spots in extreme Kerr and Schwarzschild geometries. The frequency-shift profile is a valuable measure of orbital parameters and might possibly be used to detect frame dragging even at radii approaching 6GM/sq c if the inclination angle of the orbital plane is large. The light curve from a hot spot shows differences as well, although these too are pronounced only at large inclination angles.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018MNRAS.475..716G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018MNRAS.475..716G"><span>The SAMI Galaxy Survey: Data Release One with <span class="hlt">emission-line</span> physics value-added products</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Green, Andrew W.; Croom, Scott M.; Scott, Nicholas; Cortese, Luca; Medling, Anne M.; D'Eugenio, Francesco; Bryant, Julia J.; Bland-Hawthorn, Joss; Allen, J. T.; Sharp, Rob; Ho, I.-Ting; Groves, Brent; Drinkwater, Michael J.; Mannering, Elizabeth; Harischandra, Lloyd; van de Sande, Jesse; Thomas, Adam D.; O'Toole, Simon; McDermid, Richard M.; Vuong, Minh; Sealey, Katrina; Bauer, Amanda E.; Brough, S.; Catinella, Barbara; Cecil, Gerald; Colless, Matthew; Couch, Warrick J.; Driver, Simon P.; Federrath, Christoph; Foster, Caroline; Goodwin, Michael; Hampton, Elise J.; Hopkins, A. M.; Jones, D. Heath; Konstantopoulos, Iraklis S.; Lawrence, J. S.; Leon-Saval, Sergio G.; Liske, Jochen; López-Sánchez, Ángel R.; Lorente, Nuria P. F.; Mould, Jeremy; Obreschkow, Danail; Owers, Matt S.; Richards, Samuel N.; Robotham, Aaron S. G.; Schaefer, Adam L.; Sweet, Sarah M.; Taranu, Dan S.; Tescari, Edoardo; Tonini, Chiara; Zafar, T.</p> <p>2018-03-01</p> <p>We present the first major release of data from the SAMI Galaxy Survey. This data release focuses on the <span class="hlt">emission-line</span> physics of galaxies. Data Release One includes data for 772 galaxies, about 20 per cent of the full survey. Galaxies included have the redshift range 0.004 < z < 0.092, a large mass range (7.6 < log M*/ M⊙ < 11.6), and star formation rates of ˜10-4 to ˜101M⊙ yr-1. For each galaxy, we include two spectral cubes and a set of spatially resolved 2D maps: single- and multi-component <span class="hlt">emission-line</span> fits (with dust-extinction corrections for strong <span class="hlt">lines</span>), local dust extinction, and star formation rate. Calibration of the fibre throughputs, fluxes, and differential atmospheric refraction has been improved over the Early Data Release. The data have average spatial resolution of 2.16 arcsec (full width at half-maximum) over the 15 arcsec diameter field of view and spectral (kinematic) resolution of R = 4263 (σ = 30 km s-1) around H α. The relative flux calibration is better than 5 per cent, and absolute flux calibration has an rms of 10 per cent. The data are presented online through the Australian Astronomical Observatory's Data Central.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20160010524&hterms=barret&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dbarret','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20160010524&hterms=barret&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dbarret"><span>Ti-44 Gamma-Ray <span class="hlt">Emission</span> <span class="hlt">Lines</span> from SN1987A Reveal an Asymmetric Explosion</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Boggs, S. E.; Harrison, F. A.; Miyasaka, H.; Grefenstette, B. W.; Zoglauer, A.; Fryer, C. L.; Reynolds, S. P.; Alexander, D. M.; An, H.; Barret, D.; <a style="text-decoration: none; " href="javascript:void(0); " onClick="displayelement('author_20160010524'); toggleEditAbsImage('author_20160010524_show'); toggleEditAbsImage('author_20160010524_hide'); "> <img style="display:inline; width:12px; height:12px; " src="images/arrow-up.gif" width="12" height="12" border="0" alt="hide" id="author_20160010524_show"> <img style="width:12px; height:12px; display:none; " src="images/arrow-down.gif" width="12" height="12" border="0" alt="hide" id="author_20160010524_hide"></p> <p>2015-01-01</p> <p>In core-collapse supernovae, titanium-44 (Ti-44) is produced in the innermost ejecta, in the layer of material directly on top of the newly formed compact object. As such, it provides a direct probe of the supernova engine. Observations of supernova 1987A (SN1987A) have resolved the 67.87- and 78.32-kilo-electron volt <span class="hlt">emission</span> <span class="hlt">lines</span> from decay of Ti-44 produced in the supernova explosion. These <span class="hlt">lines</span> are narrow and redshifted with a Doppler velocity of 700 kilometers per second, direct evidence of large-scale asymmetry in the explosion.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016A%26A...594A..93C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016A%26A...594A..93C"><span>Impacts of fragmented accretion streams onto classical T Tauri stars: UV and X-ray <span class="hlt">emission</span> <span class="hlt">lines</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Colombo, S.; Orlando, S.; Peres, G.; Argiroffi, C.; Reale, F.</p> <p>2016-10-01</p> <p>Context. The accretion process in classical T Tauri stars (CTTSs) can be studied through the analysis of some UV and X-ray <span class="hlt">emission</span> <span class="hlt">lines</span> which trace hot gas flows and act as diagnostics of the post-shock downfalling plasma. In the UV-band, where higher spectral resolution is available, these <span class="hlt">lines</span> are characterized by rather complex profiles whose origin is still not clear. Aims: We investigate the origin of UV and X-ray <span class="hlt">emission</span> at impact regions of density structured (fragmented) accretion streams. We study if and how the stream fragmentation and the resulting structure of the post-shock region determine the observed profiles of UV and X-ray <span class="hlt">emission</span> <span class="hlt">lines</span>. Methods: We modeled the impact of an accretion stream consisting of a series of dense blobs onto the chromosphere of a CTTS through two-dimensional (2D) magnetohydrodynamic (MHD) simulations. We explored different levels of stream fragmentation and accretion rates. From the model results, we synthesize C IV (1550 Å) and O VIII (18.97 Å) <span class="hlt">line</span> profiles. Results: The impacts of accreting blobs onto the stellar chromosphere produce reverse shocks propagating through the blobs and shocked upflows. These upflows, in turn, hit and shock the subsequent downfalling fragments. As a result, several plasma components differing for the downfalling velocity, density, and temperature are present altoghether. The profiles of C IV doublet are characterized by two main components: one narrow and redshifted to speed ≈ 50 km s-1 and the other broader and consisting of subcomponents with redshift to speed in the range 200-400 km s-1. The profiles of O VIII <span class="hlt">lines</span> appear more symmetric than C IV and are redshifted to speed ≈ 150 km s-1. Conclusions: Our model predicts profiles of C IV <span class="hlt">line</span> remarkably similar to those observed and explains their origin in a natural way as due to stream fragmentation. Movies are available at http://www.aanda.org</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1983iue..prop.1476L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1983iue..prop.1476L"><span>An <span class="hlt">Emission</span> Measure Analysis of Stars Near the Transition Region Dividing <span class="hlt">Line</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Linsky, Jeffery L.</p> <p></p> <p>We request high dispersion, short wavelength IUE spectra for three of the stars beta Gem (K0III), alpha Tau (K5III), epsilon Gem (G81b) and beta Cam (G0Ib) with exposure times of 16 hours or greater. These data will allow the measurement of <span class="hlt">line</span> profiles, widths and Doppler shifts as well as density sensitive and opacity sensitive <span class="hlt">line</span> ratios. Models of chromospheric and transition region structure will be calculated by <span class="hlt">emission</span> measure techniques and model atmosphere computations for optically thick resonance <span class="hlt">lines</span> such as MgII h and k, including partial redistribution radiation transfer. The chromospheric models will be used to investigate the energy balance of the atmosphere and the nature of the energy deposition processes. These results will be considered in relation to the evolutionary status of the stars, and will be compared with the atmospheric model properties of other stars previously studied by the authors and their collaborators.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19850004534','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19850004534"><span>The X-ray spectrum and time variability of narrow <span class="hlt">emission</span> <span class="hlt">line</span> galaxies</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Mushotzky, R.</p> <p>1981-01-01</p> <p>X-ray spectral and temporal observations are reported for six narrow <span class="hlt">emission</span> <span class="hlt">line</span> galaxies (NELGs), all of which are fitted by power-law X-ray spectra of energy slope 0.8 and have column densities in the <span class="hlt">line</span> of sight greater than 1 x 10 to the 22nd atoms/sq cm. Three of the objects, NGC 526a, NGC 2110 and MCG-5-23-16 are variable in their X-ray flux, and the latter two, along with NGC 5506 and NGC 7582, showed detectable variability in at least one observation. The measured X-ray properties of these NELGs, which also included NGC 2992, strongly resemble those of previously-measured type 1 Seyferts of the same X-ray luminosity and lead to the conclusion of great similarity between the NELGs and low-luminosity type 1 Seyferts. The implications of these observations for the optical <span class="hlt">line</span>-emitting region structure of these galaxies are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018AMT....11..473Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018AMT....11..473Z"><span>Retrieval of O2(1Σ) and O2(1Δ) volume <span class="hlt">emission</span> rates in the mesosphere and lower thermosphere using SCIAMACHY MLT limb scans</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zarboo, Amirmahdi; Bender, Stefan; Burrows, John P.; Orphal, Johannes; Sinnhuber, Miriam</p> <p>2018-01-01</p> <p>We present the retrieved volume <span class="hlt">emission</span> rates (VERs) from the <span class="hlt">airglow</span> of both the daytime and twilight O2(1Σ) band and O2(1Δ) band <span class="hlt">emissions</span> in the mesosphere and lower thermosphere (MLT). The SCanning Imaging Absorption SpectroMeter for Atmospheric CHartographY (SCIAMACHY) onboard the European Space Agency Envisat satellite observes upwelling radiances in limb-viewing geometry during its special MLT mode over the range 50-150 km. In this study we use the limb observations in the visible (595-811 nm) and near-infrared (1200-1360 nm) bands. We have investigated the daily mean latitudinal distributions and the time series of the retrieved VER in the altitude range from 53 to 149 km. The maximal observed VERs of O2(1Δ) during daytime are typically 1 to 2 orders of magnitude larger than those of O2(1Σ). The latter peaks at around 90 km, whereas the O2(1Δ) <span class="hlt">emissivity</span> decreases with altitude, with the largest values at the lower edge of the observations (about 53 km). The VER values in the upper mesosphere (above 80 km) are found to depend on the position of the sun, with pronounced high values occurring during summer for O2(1Δ). O2(1Σ) <span class="hlt">emissions</span> show additional high values at polar latitudes during winter and spring. These additional high values are presumably related to the downwelling of atomic oxygen after large sudden stratospheric warmings (SSWs). Accurate measurements of the O2(1Σ) and O2(1Δ) <span class="hlt">airglow</span>, provided that the mechanism of their production is understood, yield valuable information about both the chemistry and dynamics in the MLT. For example, they can be used to infer the amounts and distribution of ozone, solar heating rates, and temperature in the MLT.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-iss028e018216.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-iss028e018216.html"><span>Shuttle Atlantis enters Earth's Atmosphere</span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>2011-07-21</p> <p>ISS028-E-018216 (21 July 2011) --- This unprecedented view of the space shuttle Atlantis, appearing like a bean sprout against the darkness of space, a faint <span class="hlt">line</span> of <span class="hlt">airglow</span> over a dark cloud-covered Earth, on its way home, was photographed by the crew of the International Space Station. <span class="hlt">Airglow</span> over Earth can be seen in the background.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19930057012&hterms=rio+grande+sul&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Drio%2Bgrande%2Bsul','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19930057012&hterms=rio+grande+sul&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Drio%2Bgrande%2Bsul"><span>Double-peaked broad <span class="hlt">line</span> <span class="hlt">emission</span> from the LINER nucleus of NGC 1097</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Storchi-Bergmann, Thaisa; Baldwin, Jack A.; Wilson, Andrew S.</p> <p>1993-01-01</p> <p>We report the recent appearance of a very broad component in the H-alpha and H-beta <span class="hlt">emission</span> <span class="hlt">lines</span> of the weakly active nucleus of the Sersic-Pastoriza galaxy NGC 1097. The FWZI of the broad component is about 21,000 km/s, and its profile is double-peaked; the presence of a blue, featureless continuum in the nucleus is also suggested. The broad component was first observed in H-alpha in November 2, 1991, and confirmed 11 months later. The H-alpha profile and flux did not change in this time interval. Comparison with previously published spectral data indicates that the broad <span class="hlt">lines</span> have only recently appeared. Together with the relatively high X-ray luminosity and the compact nuclear radio source, our results characterize the presence of a Seyfert 1 nucleus in a galaxy which had previously shown only LINER characteristics. Obscuring material along our <span class="hlt">line</span> of sight to the nucleus appears to have recently cleared, permitting a direct view of the active nucleus. We discuss two possible structures for the broad <span class="hlt">line</span> region, biconical outflow and an accretion disk, that could give rise to the observed profile.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1352630-space-telescope-optical-reverberation-mapping-project-optical-spectroscopic-campaign-emission-line-analysis-ngc','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1352630-space-telescope-optical-reverberation-mapping-project-optical-spectroscopic-campaign-emission-line-analysis-ngc"><span>Space Telescope and Optical Reverberation Mapping Project. V. Optical Spectroscopic Campaign and <span class="hlt">Emission-line</span> Analysis for NGC 5548</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Pei, L.; Fausnaugh, M. M.; Barth, A. J.; ...</p> <p>2017-03-10</p> <p>Here, we present the results of an optical spectroscopic monitoring program targeting NGC 5548 as part of a larger multiwavelength reverberation mapping campaign. The campaign spanned 6 months and achieved an almost daily cadence with observations from five ground-based telescopes. The Hβ and He II λ4686 broad <span class="hlt">emission-line</span> light curves lag that of the 5100 Å optical continuum bymore » $${4.17}_{-0.36}^{+0.36}\\,\\mathrm{days}$$ and $${0.79}_{-0.34}^{+0.35}\\,\\mathrm{days}$$, respectively. The Hβ lag relative to the 1158 Å ultraviolet continuum light curve measured by the Hubble Space Telescope is ~50% longer than that measured against the optical continuum, and the lag difference is consistent with the observed lag between the optical and ultraviolet continua. This suggests that the characteristic radius of the broad-<span class="hlt">line</span> region is ~50% larger than the value inferred from optical data alone. We also measured velocity-resolved <span class="hlt">emission-line</span> lags for Hβ and found a complex velocity-lag structure with shorter lags in the <span class="hlt">line</span> wings, indicative of a broad-<span class="hlt">line</span> region dominated by Keplerian motion. The responses of both the Hβ and He ii <span class="hlt">emission</span> <span class="hlt">lines</span> to the driving continuum changed significantly halfway through the campaign, a phenomenon also observed for C iv, Lyα, He II(+O III]), and Si Iv(+O Iv]) during the same monitoring period. Finally, given the optical luminosity of NGC 5548 during our campaign, the measured Hβ lag is a factor of five shorter than the expected value implied by the R BLR–L AGN relation based on the past behavior of NGC 5548.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017ApJ...837..131P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017ApJ...837..131P"><span>Space Telescope and Optical Reverberation Mapping Project. V. Optical Spectroscopic Campaign and <span class="hlt">Emission-line</span> Analysis for NGC 5548</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pei, L.; Fausnaugh, M. M.; Barth, A. J.; Peterson, B. M.; Bentz, M. C.; De Rosa, G.; Denney, K. D.; Goad, M. R.; Kochanek, C. S.; Korista, K. T.; Kriss, G. A.; Pogge, R. W.; Bennert, V. N.; Brotherton, M.; Clubb, K. I.; Dalla Bontà, E.; Filippenko, A. V.; Greene, J. E.; Grier, C. J.; Vestergaard, M.; Zheng, W.; Adams, Scott M.; Beatty, Thomas G.; Bigley, A.; Brown, Jacob E.; Brown, Jonathan S.; Canalizo, G.; Comerford, J. M.; Coker, Carl T.; Corsini, E. M.; Croft, S.; Croxall, K. V.; Deason, A. J.; Eracleous, Michael; Fox, O. D.; Gates, E. L.; Henderson, C. B.; Holmbeck, E.; Holoien, T. W.-S.; Jensen, J. J.; Johnson, C. A.; Kelly, P. L.; Kim, S.; King, A.; Lau, M. W.; Li, Miao; Lochhaas, Cassandra; Ma, Zhiyuan; Manne-Nicholas, E. R.; Mauerhan, J. C.; Malkan, M. A.; McGurk, R.; Morelli, L.; Mosquera, Ana; Mudd, Dale; Muller Sanchez, F.; Nguyen, M. L.; Ochner, P.; Ou-Yang, B.; Pancoast, A.; Penny, Matthew T.; Pizzella, A.; Poleski, Radosław; Runnoe, Jessie; Scott, B.; Schimoia, Jaderson S.; Shappee, B. J.; Shivvers, I.; Simonian, Gregory V.; Siviero, A.; Somers, Garrett; Stevens, Daniel J.; Strauss, M. A.; Tayar, Jamie; Tejos, N.; Treu, T.; Van Saders, J.; Vican, L.; Villanueva, S., Jr.; Yuk, H.; Zakamska, N. L.; Zhu, W.; Anderson, M. D.; Arévalo, P.; Bazhaw, C.; Bisogni, S.; Borman, G. A.; Bottorff, M. C.; Brandt, W. N.; Breeveld, A. A.; Cackett, E. M.; Carini, M. T.; Crenshaw, D. M.; De Lorenzo-Cáceres, A.; Dietrich, M.; Edelson, R.; Efimova, N. V.; Ely, J.; Evans, P. A.; Ferland, G. J.; Flatland, K.; Gehrels, N.; Geier, S.; Gelbord, J. M.; Grupe, D.; Gupta, A.; Hall, P. B.; Hicks, S.; Horenstein, D.; Horne, Keith; Hutchison, T.; Im, M.; Joner, M. D.; Jones, J.; Kaastra, J.; Kaspi, S.; Kelly, B. C.; Kennea, J. A.; Kim, M.; Kim, S. C.; Klimanov, S. A.; Lee, J. C.; Leonard, D. C.; Lira, P.; MacInnis, F.; Mathur, S.; McHardy, I. M.; Montouri, C.; Musso, R.; Nazarov, S. V.; Netzer, H.; Norris, R. P.; Nousek, J. A.; Okhmat, D. N.; Papadakis, I.; Parks, J. R.; Pott, J.-U.; Rafter, S. E.; Rix, H.-W.; Saylor, D. A.; Schnülle, K.; Sergeev, S. G.; Siegel, M.; Skielboe, A.; Spencer, M.; Starkey, D.; Sung, H.-I.; Teems, K. G.; Turner, C. S.; Uttley, P.; Villforth, C.; Weiss, Y.; Woo, J.-H.; Yan, H.; Young, S.; Zu, Y.</p> <p>2017-03-01</p> <p>We present the results of an optical spectroscopic monitoring program targeting NGC 5548 as part of a larger multiwavelength reverberation mapping campaign. The campaign spanned 6 months and achieved an almost daily cadence with observations from five ground-based telescopes. The Hβ and He II λ4686 broad <span class="hlt">emission-line</span> light curves lag that of the 5100 Å optical continuum by {4.17}-0.36+0.36 {days} and {0.79}-0.34+0.35 {days}, respectively. The Hβ lag relative to the 1158 Å ultraviolet continuum light curve measured by the Hubble Space Telescope is ˜50% longer than that measured against the optical continuum, and the lag difference is consistent with the observed lag between the optical and ultraviolet continua. This suggests that the characteristic radius of the broad-<span class="hlt">line</span> region is ˜50% larger than the value inferred from optical data alone. We also measured velocity-resolved <span class="hlt">emission-line</span> lags for Hβ and found a complex velocity-lag structure with shorter lags in the <span class="hlt">line</span> wings, indicative of a broad-<span class="hlt">line</span> region dominated by Keplerian motion. The responses of both the Hβ and He II <span class="hlt">emission</span> <span class="hlt">lines</span> to the driving continuum changed significantly halfway through the campaign, a phenomenon also observed for C IV, Lyα, He II(+O III]), and Si IV(+O IV]) during the same monitoring period. Finally, given the optical luminosity of NGC 5548 during our campaign, the measured Hβ lag is a factor of five shorter than the expected value implied by the R BLR-L AGN relation based on the past behavior of NGC 5548.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1352630','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1352630"><span>Space Telescope and Optical Reverberation Mapping Project. V. Optical Spectroscopic Campaign and <span class="hlt">Emission-line</span> Analysis for NGC 5548</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Pei, L.; Fausnaugh, M. M.; Barth, A. J.</p> <p></p> <p>Here, we present the results of an optical spectroscopic monitoring program targeting NGC 5548 as part of a larger multiwavelength reverberation mapping campaign. The campaign spanned 6 months and achieved an almost daily cadence with observations from five ground-based telescopes. The Hβ and He II λ4686 broad <span class="hlt">emission-line</span> light curves lag that of the 5100 Å optical continuum bymore » $${4.17}_{-0.36}^{+0.36}\\,\\mathrm{days}$$ and $${0.79}_{-0.34}^{+0.35}\\,\\mathrm{days}$$, respectively. The Hβ lag relative to the 1158 Å ultraviolet continuum light curve measured by the Hubble Space Telescope is ~50% longer than that measured against the optical continuum, and the lag difference is consistent with the observed lag between the optical and ultraviolet continua. This suggests that the characteristic radius of the broad-<span class="hlt">line</span> region is ~50% larger than the value inferred from optical data alone. We also measured velocity-resolved <span class="hlt">emission-line</span> lags for Hβ and found a complex velocity-lag structure with shorter lags in the <span class="hlt">line</span> wings, indicative of a broad-<span class="hlt">line</span> region dominated by Keplerian motion. The responses of both the Hβ and He ii <span class="hlt">emission</span> <span class="hlt">lines</span> to the driving continuum changed significantly halfway through the campaign, a phenomenon also observed for C iv, Lyα, He II(+O III]), and Si Iv(+O Iv]) during the same monitoring period. Finally, given the optical luminosity of NGC 5548 during our campaign, the measured Hβ lag is a factor of five shorter than the expected value implied by the R BLR–L AGN relation based on the past behavior of NGC 5548.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19930013280','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19930013280"><span>A joint program with Japanese investigators to map carbon 2 <span class="hlt">line</span> <span class="hlt">emission</span> from the galaxy</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Low, Frank J.; Nishimura, Tetsuo</p> <p>1993-01-01</p> <p>A large portion of the inner galactic plane has been mapped in the far-infrared (C II) <span class="hlt">line</span> using a balloon-borne survey instrument. Complete coverage is reported from 25 degrees north to 80 degrees south of the galactic center and extending a few degrees on each side of the plane. Effective resolution is 14.1 acrmin (FWHM) and contour levels begin at 2 E -5 ergs/(s x sq. cm x ster). When compared with 100 micron dust <span class="hlt">emission</span> observed by IRAS the (C II) appears well correlated with the dust <span class="hlt">emission</span> except for a 10 degree region centered on the galactic center where <span class="hlt">emission</span> from the gas is much weaker than that from the dust.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_24 --> <div id="page_25" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="481"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19750007444','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19750007444"><span>Time dependent <span class="hlt">emission</span> <span class="hlt">line</span> profiles in the radially streaming particle model of Seyfert galaxy nuclei and quasi-stellar objects</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hubbard, R.</p> <p>1974-01-01</p> <p>The radially-streaming particle model for broad quasar and Seyfert galaxy <span class="hlt">emission</span> features is modified to include sources of time dependence. The results are suggestive of reported observations of multiple components, variability, and transient features in the wings of Seyfert and quasi-stellar <span class="hlt">emission</span> <span class="hlt">lines</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AJ....143...61N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AJ....143...61N"><span>Wide-field Survey of <span class="hlt">Emission-line</span> Stars in IC 1396</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nakano, M.; Sugitani, K.; Watanabe, M.; Fukuda, N.; Ishihara, D.; Ueno, M.</p> <p>2012-03-01</p> <p>We have made an extensive survey of <span class="hlt">emission-line</span> stars in the IC 1396 H II region to investigate the low-mass population of pre-main-sequence (PMS) stars. A total of 639 Hα <span class="hlt">emission-line</span> stars were detected in an area of 4.2 deg2 and their i' photometry was measured. Their spatial distribution exhibits several aggregates near the elephant trunk globule (Rim A) and bright-rimmed clouds at the edge of the H II region (Rim B and SFO 37, 38, 39, 41), and near HD 206267, which is the main exciting star of the H II region. Based on the extinction estimated from the near-infrared color-color diagram, we have selected PMS star candidates associated with IC 1396. The age and mass were derived from the extinction-corrected color-magnitude diagram and theoretical PMS tracks. Most of our PMS candidates have ages of <3 Myr and masses of 0.2-0.6 M ⊙. Although it appears that only a few stars were formed in the last 1 Myr in the east region of the exciting star, the age difference among subregions in our surveyed area is not clear from the statistical test. Our results may suggest that massive stars were born after the continuous formation of low-mass stars for 10 Myr. The birth of the exciting star could be the late stage of slow but contiguous star formation in the natal molecular cloud. It may have triggered the formation of many low-mass stars at the dense inhomogeneity in and around the H II region by a radiation-driven implosion.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22492623-acoustic-emission-magnification-atomic-lines-resolution-laser-breakdown-salt-water-ultrasound-field','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22492623-acoustic-emission-magnification-atomic-lines-resolution-laser-breakdown-salt-water-ultrasound-field"><span>Acoustic <span class="hlt">emission</span> and magnification of atomic <span class="hlt">lines</span> resolution for laser breakdown of salt water in ultrasound field</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Bulanov, Alexey V., E-mail: a-bulanov@me.com; V.I. Il’ichev Pacific Oceanological Institute, Vladivostok, Russia 690041; Nagorny, Ivan G., E-mail: ngrn@mail.ru</p> <p></p> <p>Researches of the acoustic effects accompanying optical breakdown in a water, generated by the focused laser radiation with power ultrasound have been carried out. Experiments were performed by using 532 nm pulses from Brilliant B Nd:YAG laser. Acoustic radiation was produced by acoustic focusing systems in the form hemisphere and ring by various resonance frequencies of 10.7 kHz and 60 kHz. The experimental results are obtained, that show the sharply strengthens effects of acoustic <span class="hlt">emission</span> from a breakdown zone by the joint influence of a laser and ultrasonic irradiation. Essentially various thresholds of breakdown and character of acoustic <span class="hlt">emission</span> inmore » fresh and sea water are found out. The experimental result is established, testifying that acoustic <span class="hlt">emission</span> of optical breakdown of sea water at presence and at absence of ultrasound essentially exceeds acoustic <span class="hlt">emission</span> in fresh water. Atomic <span class="hlt">lines</span> of some chemical elements like a Sodium, Magnesium and so on were investigated for laser breakdown of water with ultrasound field. The effect of magnification of this <span class="hlt">lines</span> resolution for salt water in ultrasound field was obtained.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19980038128','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19980038128"><span>Maynooth Optical Aeronomical Facility</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Mulligan, Francis J.; Niciejewski, Rick J.</p> <p>1994-01-01</p> <p>Ground-based measurements of upper atmospheric parameters, such as temperature and wind velocity, can be made by observing <span class="hlt">airglow</span> <span class="hlt">emissions</span> that have a well-defined altitude profile and that are known to be representative of the emitting region. We describe the optical observatory at Maynooth (53.23 deg N, 6.4 deg W) at which two instruments, a Fabry-Perot interferometer and a Fourier transform spectrometer, are used to record atmospheric <span class="hlt">airglow</span> <span class="hlt">emissions</span> in Ireland at visible and near-infrared wavelengths, respectively. Descriptions of the instruments, data acquisition, and analysis procedures are provided, together with some sample results.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19780058414&hterms=L37&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DL37','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19780058414&hterms=L37&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DL37"><span>The Ca II V/R ratio and mass loss. [stellar spectral <span class="hlt">emission</span> <span class="hlt">lines</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Stencel, R. E.</p> <p>1978-01-01</p> <p>High-dispersion coude spectrograms of 181 MK standards of types early F through late M, including luminosity classes Ia, Ib, II, and III, are analyzed. It is shown that the brightness ratio of the V and R self-reversed <span class="hlt">emission</span> peaks (denoted V/R) in the center of the Ca II K <span class="hlt">line</span> is correlated with spectral type as well as with certain other spectral-type and luminosity-sensitive parameters, including indicators of mass loss and the H-K wing <span class="hlt">emission</span> <span class="hlt">lines</span>. The observations indicate that V/R varies smoothly from less than unity in late K and M giants to greater than unity for G giants. This trend appears to be true for bright giants as well but not necessarily for supergiants and seems to hold for the average V/R for a given star, although short-term variations in V/R occur. It is suggested that the V/R values, which can be interpreted in terms of atmospheric motions, may indirectly relate to effects of evolutionary changes in stellar structure and that V/R among late-type stars could be useful as an indicator of both chromospheric activity and the state of stellar evolution.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011ApJ...742...23W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011ApJ...742...23W"><span>A Deep Chandra ACIS Study of NGC 4151. III. The <span class="hlt">Line</span> <span class="hlt">Emission</span> and Spectral Analysis of the Ionization Cone</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, Junfeng; Fabbiano, Giuseppina; Elvis, Martin; Risaliti, Guido; Karovska, Margarita; Zezas, Andreas; Mundell, Carole G.; Dumas, Gaelle; Schinnerer, Eva</p> <p>2011-11-01</p> <p>This paper is the third in a series in which we present deep Chandra ACIS-S imaging spectroscopy of the Seyfert 1 galaxy NGC 4151, devoted to study its complex circumnuclear X-ray <span class="hlt">emission</span>. <span class="hlt">Emission</span> features in the soft X-ray spectrum of the bright extended <span class="hlt">emission</span> (L 0.3-2 keV ~ 1040 erg s-1) at r > 130 pc (2'') are consistent with blended brighter O VII, O VIII, and Ne IX <span class="hlt">lines</span> seen in the Chandra HETGS and XMM-Newton RGS spectra below 2 keV. We construct <span class="hlt">emission</span> <span class="hlt">line</span> images of these features and find good morphological correlations with the narrow-<span class="hlt">line</span> region clouds mapped in [O III] λ5007. Self-consistent photoionization models provide good descriptions of the spectra of the large-scale <span class="hlt">emission</span>, as well as resolved structures, supporting the dominant role of nuclear photoionization, although displacement of optical and X-ray features implies a more complex medium. Collisionally ionized <span class="hlt">emission</span> is estimated to be lsim12% of the extended <span class="hlt">emission</span>. Presence of both low- and high-ionization spectral components and extended <span class="hlt">emission</span> in the X-ray image perpendicular to the bicone indicates leakage of nuclear ionization, likely filtered through warm absorbers, instead of being blocked by a continuous obscuring torus. The ratios of [O III]/soft X-ray flux are approximately constant (~15) for the 1.5 kpc radius spanned by these measurements, indicating similar relative contributions from the low- and high-ionization gas phases at different radial distances from the nucleus. If the [O III] and X-ray <span class="hlt">emission</span> arise from a single photoionized medium, this further implies an outflow with a wind-like density profile. Using spatially resolved X-ray features, we estimate that the mass outflow rate in NGC 4151 is ~2 M ⊙ yr-1 at 130 pc and the kinematic power of the ionized outflow is 1.7 × 1041 erg s-1, approximately 0.3% of the bolometric luminosity of the active nucleus in NGC 4151.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/11484044','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/11484044"><span>Ground-based observation of <span class="hlt">emission</span> <span class="hlt">lines</span> from the corona of a red-dwarf star.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Schmitt, J H; Wichmann, R</p> <p>2001-08-02</p> <p>All 'solar-like' stars are surrounded by coronae, which contain magnetically confined plasma at temperatures above 106 K. (Until now, only the Sun's corona could be observed in the optical-as a shimmering envelope during a total solar eclipse.) As the underlying stellar 'surfaces'-the photospheres-are much cooler, some non-radiative process must be responsible for heating the coronae. The heating mechanism is generally thought to be magnetic in origin, but is not yet understood even for the case of the Sun. Ultraviolet <span class="hlt">emission</span> <span class="hlt">lines</span> first led to the discovery of the enormous temperature of the Sun's corona, but thermal <span class="hlt">emission</span> from the coronae of other stars has hitherto been detectable only from space, at X-ray wavelengths. Here we report the detection of <span class="hlt">emission</span> from highly ionized iron (Fe XIII at 3,388.1 A) in the corona of the red-dwarf star CN Leonis, using a ground-based telescope. The X-ray flux inferred from our data is consistent with previously measured X-ray fluxes, and the non-thermal <span class="hlt">line</span> width of 18.4 km s-1 indicates great similarities between solar and stellar coronal heating mechanisms. The accessibility and spectral resolution (45,000) of the ground-based instrument are much better than those of X-ray satellites, so a new window to the study of stellar coronae has been opened.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19990014557&hterms=Dissociative&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DDissociative','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19990014557&hterms=Dissociative&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DDissociative"><span><span class="hlt">Line</span> Profile of H Lyman-Beta <span class="hlt">Emission</span> from Dissociative Excitation of H2</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ajello, Joseph M.; Ahmed, Syed M.; Liu, Xian-Ming</p> <p>1996-01-01</p> <p>A high-resolution ultraviolet spectrometer was employed for a measurement of the H Lyman-Beta(H L(sub Beta)) <span class="hlt">emission</span> Doppler <span class="hlt">line</span> profile at 1025.7 A from dissociative excitation of H2 by electron impact. Analysis of the deconvolved <span class="hlt">line</span> profile reveals the existence of a narrow central peak, less than 30 mA full width at half maximum (FWHM), and a broad pedestal base about 260 mA FWHM. Analysis of the red wing of the <span class="hlt">line</span> profile is complicated by a group of Wemer and Lyman rotational <span class="hlt">lines</span> 160-220 mA from the <span class="hlt">line</span> center. Analysis of the blue wing of the <span class="hlt">line</span> profile gives the kinetic-energy distribution. There are two main kinetic-energy components to the H(3p) distribution: (1) a slow distribution with a peak value near 0 eV from singly excited states, and (2) a fast distribution with a peak contribution near 7 eV from doubly excited states. Using two different techniques, the absolute cross section of H L(sub Beta)p is found to be 3.2+/-.8 x 10(exp -19)sq cm at 100-eV electron impact energy. The experimental cross-section and <span class="hlt">line</span>-profile results can be compared to previous studies of H(alpha) (6563.7 A) for principal quantum number n=3 and L(sub alpha)(1215.7 A) for n=2.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012ApJ...754...17F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012ApJ...754...17F"><span>Spatially Resolved HST Grism Spectroscopy of a Lensed <span class="hlt">Emission</span> <span class="hlt">Line</span> Galaxy at z ~ 1</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Frye, Brenda L.; Hurley, Mairead; Bowen, David V.; Meurer, Gerhardt; Sharon, Keren; Straughn, Amber; Coe, Dan; Broadhurst, Tom; Guhathakurta, Puragra</p> <p>2012-07-01</p> <p>We take advantage of gravitational lensing amplification by A1689 (z = 0.187) to undertake the first space-based census of <span class="hlt">emission</span> <span class="hlt">line</span> galaxies (ELGs) in the field of a massive lensing cluster. Forty-three ELGs are identified to a flux of i 775 = 27.3 via slitless grism spectroscopy. One ELG (at z = 0.7895) is very bright owing to lensing magnification by a factor of ≈4.5. Several Balmer <span class="hlt">emission</span> <span class="hlt">lines</span> (ELs) detected from ground-based follow-up spectroscopy signal the onset of a major starburst for this low-mass galaxy (M * ≈ 2 × 109 M ⊙) with a high specific star formation rate (≈20 Gyr-1). From the blue ELs we measure a gas-phase oxygen abundance consistent with solar (12+log(O/H) = 8.8 ± 0.2). We break the continuous <span class="hlt">line</span>-emitting region of this giant arc into seven ~1 kpc bins (intrinsic size) and measure a variety of metallicity-dependent <span class="hlt">line</span> ratios. A weak trend of increasing metal fraction is seen toward the dynamical center of the galaxy. Interestingly, the metal <span class="hlt">line</span> ratios in a region offset from the center by ~1 kpc have a placement on the blue H II region excitation diagram with f ([O III])/f (Hβ) and f ([Ne III])/f (Hβ) that can be fitted by an active galactic nucleus (AGN). This asymmetrical AGN-like behavior is interpreted as a product of shocks in the direction of the galaxy's extended tail, possibly instigated by a recent galaxy interaction. Based, in part, on data obtained with the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and NASA, and was made possible by the generous financial support of the W. M. Keck Foundation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1985erpa.reptQ....D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1985erpa.reptQ....D"><span>Determination of ionospheric electron density profiles from satellite UV (Ultraviolet) <span class="hlt">emission</span> measurements, fiscal year 1984</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Daniell, R. E.; Strickland, D. J.; Decker, D. T.; Jasperse, J. R.; Carlson, H. C., Jr.</p> <p>1985-04-01</p> <p>The possible use of satellite ultraviolet measurements to deduce the ionospheric electron density profile (EDP) on a global basis is discussed. During 1984 comparisons were continued between the hybrid daytime ionospheric model and the experimental observations. These comparison studies indicate that: (1) the essential features of the EDP and certain UV <span class="hlt">emissions</span> can be modelled; (2) the models are sufficiently sensitive to input parameters to yield poor agreement with observations when typical input values are used; (3) reasonable adjustments of the parameters can produce excellent agreement between theory and data for either EDP or <span class="hlt">airglow</span> but not both; and (4) the qualitative understanding of the relationship between two input parameters (solar flux and neutral densities) and the model EDP and <span class="hlt">airglow</span> features has been verified. The development of a hybrid dynamic model for the nighttime midlatitude ionosphere has been initiated. This model is similar to the daytime hybrid model, but uses the sunset EDP as an initial value and calculates the EDP as a function of time through the night. In addition, a semiempirical model has been developed, based on the assumption that the nighttime EDP is always well described by a modified Chapman function. This model has great simplicity and allows the EDP to be inferred in a straightforward manner from optical observations. Comparisons with data are difficult, however, because of the low intensity of the nightglow.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19850025690','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19850025690"><span>Gamma-ray <span class="hlt">line</span> <span class="hlt">emission</span> from Al-26 produced by Wolf-Rayet stars</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Prantzos, N.; Casse, M.; Gros, M.; Doom, C.; Arnould, M.</p> <p>1985-01-01</p> <p>The recent satellite observations of the 1.8 MeV <span class="hlt">line</span> from the decay of Al-26 has given a new impetus to the study of the nucleosynthesis of Al-26. The production and ejection of Al-26 by massive mass-losing stars (Of and WR stars) is discussed in the light of recent stellar models. The longitude distribution of the Al-26 gamma ray <span class="hlt">line</span> <span class="hlt">emission</span> produced by the galactic collection of WR stars is derived based on various estimates of their radial distribution. This longitude profile provides: (1) a specific signature of massive stars on the background of other potential Al-26 sources, as novae, supernovae, certain red giants and possibly AGB stars; and (2) a possible tool to improve the data analysis of the HEAO 3 and SMM experiments.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/15013781','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/15013781"><span>Reprocessing of Soft X-ray <span class="hlt">Emission</span> <span class="hlt">Lines</span> in Black Hole Accretion Disks</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Mauche, C W; Liedahl, D A; Mathiesen, B F</p> <p></p> <p>By means of a Monte Carlo code that accounts for Compton scattering and photoabsorption followed by recombination, we have investigated the radiation transfer of Ly{alpha}, He{alpha}, and recombination continua photons of H- and He-like C, N, O, and Ne produced in the photoionized atmosphere of a relativistic black hole accretion disk. We find that photoelectric opacity causes significant attenuation of photons with energies above the O VIII K-edge; that the conversion efficiencies of these photons into lower-energy <span class="hlt">lines</span> and recombination continua are high; and that accounting for this reprocessing significantly (by factors of 21% to 105%) increases the flux ofmore » the Ly{alpha} and He{alpha} <span class="hlt">emission</span> <span class="hlt">lines</span> of H- and He-like C and O escaping the disk atmosphere.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19780058272&hterms=MOOS&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3DMOOS','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19780058272&hterms=MOOS&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3DMOOS"><span>Ultraviolet observations of cool stars. VI - L alpha and Mg II <span class="hlt">emission</span> <span class="hlt">line</span> profiles /and a search for flux variability/ in Arcturus</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Mcclintock, W.; Moos, H. W.; Henry, R. C.; Linsky, J. L.; Barker, E. S.</p> <p>1978-01-01</p> <p>High-precision, high-resolution profiles of the L alpha and Mg II k chromospheric <span class="hlt">emission</span> <span class="hlt">lines</span> from Arcturus (alpha Boo) obtained with the Princeton Experimental Package aboard the Copernicus satellite are presented. Asymmetries seen in the profiles of these <span class="hlt">lines</span> are probably intrinsic to the star, rather than the result of interstellar absorption. In contrast to previous observations of the Ca II K <span class="hlt">emission</span> <span class="hlt">line</span>, no evidence is found during a three-year period for variability in the profiles or in the total fluxes from these <span class="hlt">lines</span> on time scales ranging from hours to months. Also presented is a flux profile of the O I 1302 <span class="hlt">line</span> and flux upper limits for L beta, O VI 1032, Si III 1206, and O V 1218.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1997ApJ...488..652M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1997ApJ...488..652M"><span>Broad Low-Intensity Wings in the <span class="hlt">Emission-Line</span> Profiles of Four Wolf-Rayet Galaxies</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Méndez, David I.; Esteban, César</p> <p>1997-10-01</p> <p>High-resolution spectroscopic observations have been obtained for the Wolf-Rayet galaxies He 2-10, II Zw 40, POX 4, and Tol 35. Several subregions have been selected in each slit position in order to investigate possible spatial variations in the <span class="hlt">line</span> profiles, radial velocities, and ionization conditions of the gas. The most remarkable feature of the spectra is the presence of asymmetric broad low-intensity wings in the profiles of the brightest <span class="hlt">emission</span> <span class="hlt">lines</span>. These spectral features are detected farther out from the star-forming knots, showing linear dimensions between 300 pc and 4.1 kpc. The maximum expansion velocity measured for this gas is between 120 and 340 km s-1 and appears to be quite constant along the slit for all the objects. Additional general properties of the spectra are (1) the quoted <span class="hlt">emission-line</span> ratios are similar in the narrow and broad components, (2) no systematic differences of the behavior of the broad and narrow components have been found along the major and minor axis of the galaxies, and (3) the spatial distribution of the ionized gas is peaked centrally. Different mechanisms capable of producing the observed broad spectral features are discussed: cloud-cloud collisions in virialized gas, ``academic'' superbubbles, champagne flows, and superbubble blowout. It is concluded that superbubble blowout expanding over a cloudy medium can explain the observational properties in a reasonable manner.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018A%26A...612A.102T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018A%26A...612A.102T"><span>An X-ray survey of the central molecular zone: Variability of the Fe Kα <span class="hlt">emission</span> <span class="hlt">line</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Terrier, R.; Clavel, M.; Soldi, S.; Goldwurm, A.; Ponti, G.; Morris, M. R.; Chuard, D.</p> <p>2018-05-01</p> <p>There is now abundant evidence that the luminosity of the Galactic super-massive black hole (SMBH) has not always been as low as it is nowadays. The observation of varying non-thermal diffuse X-ray <span class="hlt">emission</span> in molecular complexes in the central 300 pc has been interpreted as delayed reflection of a past illumination by bright outbursts of the SMBH. The observation of different variability timescales of the reflected <span class="hlt">emission</span> in the Sgr A molecular complex can be well explained if the X-ray <span class="hlt">emission</span> of at least two distinct and relatively short events (i.e. about 10 yr or less) is currently propagating through the region. The number of such events or the presence of a long-duration illumination are open questions. Variability of the reflected <span class="hlt">emission</span> all over of the central 300 pc, in particular in the 6.4 keV Fe Kα <span class="hlt">line</span>, can bring strong constraints. To do so we performed a deep scan of the inner 300 pc with XMM-Newton in 2012. Together with all the archive data taken over the course of the mission, and in particular a similar albeit more shallow scan performed in 2000-2001, this allows for a detailed study of variability of the 6.4 keV <span class="hlt">line</span> <span class="hlt">emission</span> in the region, which we present here. We show that the overall 6.4 keV <span class="hlt">emission</span> does not strongly vary on average, but variations are very pronounced on smaller scales. In particular, most regions showing bright reflection <span class="hlt">emission</span> in 2000-2001 significantly decrease by 2012. We discuss those regions and present newly illuminated features. The absence of bright steady <span class="hlt">emission</span> argues against the presence of an echo from an event of multi-centennial duration and most, if not all, of the <span class="hlt">emission</span> can likely be explained by a limited number of relatively short (i.e. up to 10 yr) events. Images of the Fe Kα <span class="hlt">emission</span> as FITS files are only available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/612/A102</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AAS...22925018C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AAS...22925018C"><span>Determining Black Hole Mass of AGN using FWHM of H-beta <span class="hlt">Emission</span> <span class="hlt">Line</span> and Luminosity Relations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cameron, Thomas Jacob; Burris, Debra L.</p> <p>2017-01-01</p> <p>At the center of some active galaxies are super-massive black holes and for some time the accepted method of measuring the mass of such galaxies has been the method used by Vestergaard and Peterson, among others. By using the luminosity function which is related to H-β <span class="hlt">emission</span> spectra from these black holes, both for cosmic redshift and for Fe-II <span class="hlt">emissions</span> using IRAF. From there, H-β can accurately measure the full width half max of the H-beta <span class="hlt">line</span> in these spectrum as well as the luminosity and these paired with the O-III <span class="hlt">lines</span> give us an estimate on the mass of the black hole. The purpose of this is to compare it to the values obtained from the Mass-Pitch Angle relation being proposed by Kennefick et al. (2016 in preparation)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006AAS...208.4705H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006AAS...208.4705H"><span>GBT Observations of Radio Recombination <span class="hlt">Line</span> <span class="hlt">Emission</span> Associated with Supernova Remnants W28 and W44</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hewitt, John W.; Yusef-Zadeh, F.</p> <p>2006-06-01</p> <p>Since the 1970's weak radio recombination <span class="hlt">line</span>(RRL) <span class="hlt">emission</span> has been observed toward several supernova remnants. It has remained unclear if this <span class="hlt">emission</span> is in fact associated with these remnants or due to intervening sources such as extended HII envelopes along the <span class="hlt">line</span> of sight. To explore the origin of this emitting gas we have recently undertaken Green Bank Telescope (GBT) observations of prominent supernova remnants W28 and W44 which are well-known to be interacting with molecular clouds. Eight alpha and beta RRL transitions were mapped at C-Band (4-6 GHz) with 2.5' resolution. Maps cover 0.5 and 0.25 square degrees of W28 and W44, respectively, permitting comparison with the distribution of X-rays, Radio, and H-alpha <span class="hlt">emission</span>. Both remnants are observed to have a mixed-morphology: a radio-continuum shell centrally-filled by thermal X-rays. We find the observed velocity of RRL <span class="hlt">emission</span> is near the systemic velocity of both remnants as traced by OH(1720 MHz) masers. Preliminary results are presented exploring the association of the RRL-emitting gas with these interacting supernova remants and implications for the origins of the hot thermal X-ray plasma that fills their centers. Support for this work was provided by the NSF through The GBT Student Support Program from the NRAO.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/7308673-analysis-ionospheric-dayglow-from-observations-naval-postgraduate-school-middle-ultraviolet-spectrograph-mustang-master-thesis','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/7308673-analysis-ionospheric-dayglow-from-observations-naval-postgraduate-school-middle-ultraviolet-spectrograph-mustang-master-thesis"><span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Marron, A.C.</p> <p></p> <p>Middle ultraviolet spectra of the atmospheric <span class="hlt">airglow</span> were obtained from a March 1992 rocket flight of the NPS MUSTANG instrument. These spectra are analyzed from 1900 A to 3100 A, over an altitude range of 100 km to 320 km. The data are modeled with computer generated synthetic spectra for the following <span class="hlt">emissions</span>: N2 Vegard Kaplan (VK); N2 Lyman-Birge-Hopfield (LBH); and NO Gamma, Delta, and Epsilon bands. A best fit procedure was developed. The resulting synthetic spectra agree well with obtained <span class="hlt">airglow</span> data. Confirmation was made of the theoretical self absorption versus non-self absorption processes of the NO (0,0), (1,0),more » (2,0) gamma resonance band <span class="hlt">emissions</span>. NO self absorption is a necessary inclusion of any atmospheric nitric oxide analysis stratagem. Profiles of temperature versus altitude and NO column density versus altitude for the rocket flight are estimated. <span class="hlt">Airglow</span>, Ionosphere, Ultraviolet spectroscopy.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMSA21A2512K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMSA21A2512K"><span>Statistical study on the variations of OH and O2 rotational temperatures observed by SATI at King Sejong Station (62.22S, 58.78W), Antarctica</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kim, J.; Kim, J. H.; Jee, G.; Lee, C.; Kim, Y.</p> <p>2017-12-01</p> <p>Spectral <span class="hlt">Airglow</span> Temperature Imager (SATI) installed at King Sejong Station (62.22S, 58.78W), Antarctica, has been continuously measured the <span class="hlt">airglow</span> <span class="hlt">emissions</span> from OH (6-2) Meinel and O2 (0-1) atmospheric bands since 2002, in order to investigate the dynamics of the polar MLT region. The measurements allow us to derive the rotational temperature at peak <span class="hlt">emission</span> heights known as about 87 km and 94 km for OH and O2 <span class="hlt">airglows</span>, respectively. In this study, we briefly introduce improved analysis technique that modified original analysis code. The major change compared to original program is the improvement of the function to find the exact center position in the observed image. In addition to brief introduction of the improved technique, we also present the results statistically investigating the periodic variations on the temperatures of two layers during the period of 2002 through 2011 and compare our results with those from the temperatures measured by satellite.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006AdSpR..38.2374C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006AdSpR..38.2374C"><span>Observation of temperatures and <span class="hlt">emission</span> rates from the OH and O 2 nightglow over a southern high latitude station</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chung, J.-K.; Kim, Y. H.; Won, Y.-I.; Moon, B. K.; Oh, T. H.</p> <p>2006-01-01</p> <p>A Spectral <span class="hlt">Airglow</span> Temperature Imager (SATI) was operated at King Sejong Station (62°13'S, 58°47'W), Korea Antarctic Research Station during the period of March, 2002-September, 2003. We analyze rotational temperatures and <span class="hlt">emission</span> rates of the O 2 (0-1) and OH (6-2) nightglows obtained at 67 nights with clear sky lasting more than 4 h. A spectral analysis of the dataset shows two dominant oscillations with periods of 4 and 6 h. The 6-h oscillations have a nearly constant phase, whereas the 4-h oscillations have nearly random phases. Although the harmonic periods of both oscillations are suggestive of tidal origin, the 4-h oscillation may have interference by other sources such as gravity waves. The 6-h oscillations could be interpreted as zonally symmetric non-migrating tides because migrating tides except high order modes have very weak amplitudes at high latitudes according to the classical tidal theory. For most cases of the observed oscillations the temperature peak leads the intensity peak, which is consistent with theoretical models for zonally symmetric tides, but contrary to other theoretical models for waves. It is needed to resolve among theoretical models whether or not zonally symmetric tide cause temperature variation prior to intensity variation in mesospheric <span class="hlt">airglows</span>.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_25 --> <div class="footer-extlink text-muted" style="margin-bottom:1rem; text-align:center;">Some links on this page may take you to non-federal websites. 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