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Sample records for emission line diagnostics

  1. Iron Line Diagnostics of Narrow Emission Line Galaxies

    NASA Astrophysics Data System (ADS)

    Nousek, John A.

    1996-05-01

    This report describes the activities at Penn State University supported by NASA Grant NAG5-2528, 'Iron Line Diagnostics of Narrow Emission Line Galaxies'. The aim of this investigation was to accurately measure the iron (Fe K) line emission in two X-ray selected Seyfert 2 galaxies (NGC 2992 and MCG-5-23-16). The astrophysics being probed was to determine whether the Fe line was narrow, broad or both. The broad line component is very important as a probe of the nature of the innermost accretion onto the central engine in AGN's.

  2. Polarization diagnostics for cool core cluster emission lines

    SciTech Connect

    Sparks, W. B.; Pringle, J. E.; Cracraft, M.; Meyer, E. T.; Carswell, R. F.; Voit, G. M.; Donahue, M.; Hough, J. H.; Manset, N.

    2014-01-01

    The nature of the interaction between low-excitation gas filaments at ∼10{sup 4} K, seen in optical line emission, and diffuse X-ray emitting coronal gas at ∼10{sup 7} K in the centers of galaxy clusters remains a puzzle. The presence of a strong, empirical correlation between the two gas phases is indicative of a fundamental relationship between them, though as yet of undetermined cause. The cooler filaments, originally thought to have condensed from the hot gas, could also arise from a merger or the disturbance of cool circumnuclear gas by nuclear activity. Here, we have searched for intrinsic line emission polarization in cool core galaxy clusters as a diagnostic of fundamental transport processes. Drawing on developments in solar astrophysics, direct energetic particle impact induced polarization holds the promise to definitively determine the role of collisional processes such as thermal conduction in the ISM physics of galaxy clusters, while providing insight into other highly anisotropic excitation mechanisms such as shocks, intense radiation fields, and suprathermal particles. Under certain physical conditions, theoretical calculations predict of the order of 10% polarization. Our observations of the filaments in four nearby cool core clusters place stringent upper limits (≲ 0.1%) on the presence of emission line polarization, requiring that if thermal conduction is operative, the thermal gradients are not in the saturated regime. This limit is consistent with theoretical models of the thermal structure of filament interfaces.

  3. Galaxy evolution across the optical emission-line diagnostic diagrams?

    NASA Astrophysics Data System (ADS)

    Vitale, M.; Fuhrmann, L.; García-Marín, M.; Eckart, A.; Zuther, J.; Hopkins, A. M.

    2015-01-01

    Context. The discovery of the M - σ relation, the local galaxy bimodality, and the link between black-hole and host-galaxy properties have raised the question of whether active galactic nuclei (AGN) play a role in galaxy evolution. AGN feedback is one of the biggest observational challenges of modern extragalactic astrophysics. Several theoretical models implement AGN feedback to explain the observed galaxy luminosity function and, possibly, the color and morphological transformation of spiral galaxies into passive ellipticals. Aims: For understanding the importance of AGN feedback, a study of the AGN populations in the radio-optical domain is crucial. A mass sequence linking star-forming galaxies and AGN has already been noted in previous works, and it is now investigated as a possible evolutionary sequence. Methods: We observed a sample of 119 intermediate-redshift (0.04 ≤ z< 0.4) SDSS-FIRST radio emitters with the Effelsberg 100-m telescope at 4.85 and 10.45 GHz and obtained spectral indices. The sample includes star-forming galaxies, composite galaxies (with mixed contribution to line emission from star formation and AGN activity), Seyferts, and low ionization narrow emission region (LINER) galaxies. With these sources we search for possible evidence of spectral evolution and a link between optical and radio emission in intermediate-redshift galaxies. Results: We find indications of spectral index flattening in high-metallicity star-forming galaxies, composite galaxies, and Seyferts. This "flattening sequence" along the [NII]-based emission-line diagnostic diagram is consistent with the hardening of galaxy ionizing field, thanks to nuclear activity. After combining our data with FIRST measurements at 1.4 GHz, we find that the three-point radio spectra of Seyferts and LINERs show substantial differences, which are attributable to small radio core components and larger (arcsecond sized) jet/lobe components, respectively. A visual inspection of FIRST images

  4. Nuclear activity versus star formation: emission-line diagnostics at ultraviolet and optical wavelengths

    NASA Astrophysics Data System (ADS)

    Feltre, A.; Charlot, S.; Gutkin, J.

    2016-03-01

    In the context of observations of the rest-frame ultraviolet and optical emission from distant galaxies, we explore the emission-line properties of photoionization models of active and inactive galaxies. Our aim is to identify new line-ratio diagnostics to discriminate between gas photoionization by active galactic nuclei (AGN) and star formation. We use a standard photoionization code to compute the emission from AGN narrow-line regions and compare this with calculations of the nebular emission from star-forming galaxies achieved using the same code. We confirm the appropriateness of widely used optical spectral diagnostics of nuclear activity versus star formation and explore new diagnostics at ultraviolet wavelengths. We find that combinations of a collisionally excited metal line or line multiplet, such as C IV λλ1548, 1551, O III] λλ1661, 1666, N III] λ1750, [Si III] λ1883+Si III] λ1892 and [C III] λ1907+C III] λ1909, with the He II λ1640 recombination line are individually good discriminants of the nature of the ionizing source. Diagrams involving at least three of these lines allow an even more stringent distinction between active and inactive galaxies, as well as valuable constraints on interstellar gas parameters and the shape of the ionizing radiation. Several line ratios involving Ne-based emission lines, such as [Ne IV] λ2424, [Ne III] λ3343 and [Ne V] λ3426, are also good diagnostics of nuclear activity. Our results provide a comprehensive framework to identify the sources of photoionization and physical conditions of the ionized gas from the ultraviolet and optical nebular emission from galaxies. This will be particularly useful to interpret observations of high-redshift galaxies with future facilities, such as the James Webb Space Telescope and extremely large ground-based telescopes.

  5. Luminosity Dependence and Redshift Evolution of Strong Emission-Line Diagnostics in Star-Forming Galaxies

    NASA Astrophysics Data System (ADS)

    Cowie, L. L.; Barger, A. J.; Songaila, A.

    2016-01-01

    We examine the redshift evolution of standard strong emission-line diagnostics for Hβ-selected star-forming galaxies using the local SDSS sample and a new z=0.2{--}2.3 sample obtained from Hubble Space Telescope WFC3 grism and Keck DEIMOS and MOSFIRE data. We use the SDSS galaxies to show that there is a systematic dependence of the strong emission-line properties on Balmer-line luminosity, which we interpret as showing that both the N/O abundance and the ionization parameter increase with increasing line luminosity. Allowing for the luminosity dependence tightens the diagnostic diagrams and the metallicity calibrations. The combined SDSS and high-redshift samples show that there is no redshift evolution in the line properties once the luminosity correction is applied, i.e., all galaxies with a given L({{H}}β ) have similar strong emission-line distributions at all the observed redshifts. We argue that the best metal diagnostic for the high-redshift galaxies may be a luminosity-adjusted version of the [N ii]6584/Hα metallicity relation. Based in part on data obtained at 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.

  6. GAS EXCITATION IN ULIRGs: MAPS OF DIAGNOSTIC EMISSION-LINE RATIOS IN SPACE AND VELOCITY

    SciTech Connect

    Soto, Kurt T.; Martin, Crystal L.

    2012-11-15

    Emission-line spectra extracted at multiple locations across 39 ultraluminous infrared galaxies have been compiled into a spectrophotometric atlas. Line profiles of H{alpha}, [N II], [S II], [O I], H{beta}, and [O III] are resolved and fit jointly with common velocity components. Diagnostic ratios of these line fluxes are presented in a series of plots, showing how the Doppler shift, line width, gas excitation, and surface brightness change with velocity at fixed position and also with distance from the nucleus. One general characteristic of these spectra is the presence of shocked gas extending many kiloparsecs from the nucleus. In some systems, the rotation curves of the emitting gas indicate motions that suggest gas disks, which are most frequent at early merger stages. At these early merger stages, the emission line ratios indicate the presence of shocked gas, which may be triggered by the merger event. We also report the general characteristics of the integrated spectra.

  7. Chemical abundances in high-redshift galaxies: a powerful new emission line diagnostic

    NASA Astrophysics Data System (ADS)

    Dopita, Michael A.; Kewley, Lisa J.; Sutherland, Ralph S.; Nicholls, David C.

    2016-02-01

    This Letter presents a new, remarkably simple diagnostic specifically designed to derive chemical abundances for high redshift galaxies. It uses only the Hα, [N ii] and [S ii] emission lines, which can usually be observed in a single grating setting, and is almost linear up to an abundance of 12+log (O/H) = 9.05. It can be used over the full abundance range encountered in high redshift galaxies. By its use of emission lines located close together in wavelength, it is also independent of reddening. Our diagnostic depends critically on the calibration of the N/O ratio. However, by using realistic stellar atmospheres combined with the N/O vs. O/H abundance calibration derived locally from stars and H ii regions, and allowing for the fact that high-redshift H ii regions have both high ionisation parameters and high gas pressures, we find that the observations of high-redshift galaxies can be simply explained by the models without having to invoke arbitrary changes in N/O ratio, or the presence of unusual quantities of Wolf-Rayet stars in these galaxies.

  8. Database of emission lines

    NASA Astrophysics Data System (ADS)

    Binette, L.; Ortiz, P.; Joguet, B.; Rola, C.

    1998-11-01

    A widely accessible data bank (available through Netscape) and consiting of all (or most) of the emission lines 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 emission line diagrams.

  9. Adding Emission Line Diagnostics To The Infrared Database of Extragalactic Observables from Spitzer (IDEOS)

    NASA Astrophysics Data System (ADS)

    Spoon, Henrik

    During the cryogenic phase of the successful Spitzer mission the Infrared Spectrograph (IRS) made observations of about 15,000 objects. Among these are low-resolution (highresolution) spectra of more than 4200 (1800) galaxies beyond the Local Group. Results have been published in a great number of papers, led not only by hardcore infrared observers but increasingly also by non-native infrared astronomers. As the PI team of the IRS instrument, we are especially proud of the achievements of the IRS spectrograph, and we feel a special obligation to enhance the legacy value of its many observations. In 2011 we completed the Cornell Atlas of Spitzer-IRS Sources (CASSIS), containing homogeneously, expert-reduced low-resolution IRS spectra for over 13,000 observations. Earlier this year we added more than 7,000 spectra obtained with the high-resolution modules. All of these spectra benefit from the availability of our empirically derived super-sampled point-spread functions, which reduce the effects of bad and low-level rogue pixels in all IRS modules. All spectra are available for download from our CASSIS web portal. Building on this legacy, in 2013 we also started working on the soon to be completed Infrared Database of Extragalactic Observables from Spitzer (IDEOS), which contains mid-IR observables extracted from the low-resolution spectra in CASSIS. IDEOS provides astronomers with widely varying scientific interests access to diagnostics that were previously available only for limited samples, or available on the-fly only to expert users. Here we propose to continue these efforts by measuring the emission line fluxes for 3,000-4,500 galaxies in the CASSIS atlas to add powerful emission line diagnostics to our existing suite of mid-IR observables in IDEOS. IDEOS will be a great asset for future users of NASA's James Webb Space Telescope to select their samples and estimate required integration times. The completion of IDEOS will further coincide with the completion of

  10. Upgrading electron temperature and electron density diagnostic diagrams of forbidden line emission

    NASA Astrophysics Data System (ADS)

    Proxauf, B.; Öttl, S.; Kimeswenger, S.

    2014-01-01

    Context. Diagnostic diagrams of forbidden lines have been a useful tool for observers for many decades now. They are used to obtain information on the basic physical properties of thin gaseous nebulae. Some diagnostic diagrams are in wavelength domains that were difficult to apply either due to missing wavelength coverage or the low resolution of older spectrographs. Furthermore, most of the diagrams were calculated using just the species involved as a single atom gas, although several are affected by well-known fluorescence mechanisms as well. Additionally, the atomic data have improved up to the present time. Aims: The aim of this work is to recalculate well-known, but also sparsely used, unnoted diagnostics diagrams. The new diagrams provide observers with modern, easy-to-use recipes for determining electron temperature and densities. Methods: The new diagnostic diagrams were calculated using large grids of parameter space in the photoionization code CLOUDY. For a given basic parameter (e.g., electron density or temperature), the solutions with cooling-heating-equilibrium were chosen to derive the diagnostic diagrams. Empirical numerical functions were fitted to provide formulas usable in, e.g., data reduction pipelines. Results: The resulting diagrams differ significantly from those used up to now and will improve thermodynamic calculations. To our knowledge, detailed, directly applicable fit formulas are given for the first time, leading to the calculation of electron temperature or density from the line ratios.

  11. Mid-IR Properties of an Unbiased AGN Sample of the Local Universe. 1; Emission-Line Diagnostics

    NASA Technical Reports Server (NTRS)

    Weaver, K. A.; Melendez, M.; Muhotzky, R. F.; Kraemer, S.; Engle, K.; Malumuth. E.; Tueller, J.; Markwardt, C.; Berghea, C. T.; Dudik, R. P.; Winter, L. M.; Armus, L.

    2010-01-01

    \\Ve compare mid-IR emission-lines 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 emission-lines, [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 emission lines primarily arise in gas ionized by the AGN. We also compared the mid-IR emission-lines 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 emission line 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 line emission. Overall, we present a different set of emission line diagnostics to distinguish between AGN and star forming galaxies that can be used as a tool to find new AGN.

  12. Development of a Temperature Diagnostic Based on the Emission Lines of Fluorine-Like Ions

    NASA Astrophysics Data System (ADS)

    Lepson, Jaan K.; Beiersdorfer, Peter; Kaita, Robert; Majeski, Richard; Boyle, Dennis

    2016-06-01

    We used the Flexible Atomic Code to calculate theoretical intensities of extreme ultraviolet emission lines of fluorine-like Al IV, Si VI, and S VIII at electron temperatures Te from 1 eV to well above 100 eV, and found that the intensity ratio of the 3-->2 and 2-->2 transitions is temperature sensitive. We tested these calculations by measuring the relevant Al IV emission in the 115-320 Å spectral region on the Lithium Tokamak Experiment at the Princeton Plasma Physics Laboratory. Spectra were taken with the Long Wavelength Extreme Ultraviolet Spectrometer, LoWEUS, which has a resolution of ~0.3 Å. We identified emission from neon-like Al V as well as fluorine-like Al IV. Our data include emission from Li II and Li III, and O IV-VI, which we used for wavelength calibration. We used the oxygen line intensities from CHIANTI to calculate the intensity response function for the region we studied. The measurements confirm that the ratio of the intensity of the 3-->2 feature at 133 Å to a pair of 2-->2 lines at 278 Å and 281 Å can be used to derive temperature estimates for the emitting region of the plasma. Our measurements indicate a temperature Te of ~16 ± 2 eV from the 133/278 Å line pair and ~17.5 ±2 eV from the 133/281 Å line pair, which is close to the temperature of maximum abundance of fluorine-like Al.This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344 and supported by the U.S. Department of Energy Basic Plasma Science Program.

  13. Hydrogen transport diagnostics by atomic and molecular emission line profiles simultaneously measured for large helical device

    SciTech Connect

    Fujii, K.; Shikama, T.; Hasuo, M.; Goto, M.; Morita, S.

    2013-01-15

    We observe the Balmer-{alpha}, -{beta}, and -{gamma} lines of hydrogen atoms and Q branches of the Fulcher-{alpha} band of hydrogen molecules simultaneously with their polarization resolved for large helical device. From the fit including the line splits and the polarization dependences by the Zeeman effect, the emission locations, intensities, and the temperatures of the atoms and molecules are determined. The emission locations of the hydrogen atoms are determined outside but close to the last closed flux surface (LCFS). The results are consistent with a previous work (Phys. Plasmas 12, 042501 (2005)). On the other hand, the emission locations of the molecules are determined to be in the divertor legs, which is farer from those of the atoms. The kinetic energy of the atoms is 1 {approx} 20 eV, while the rotational temperature of molecules is {approx}0.04 eV. Additionally, substantial wings, which originate from high velocity atoms and are not reproduced by the conventional spectral analysis, are observed in the Balmer line profiles. We develop a one-dimensional model to simulate the transport of the atoms and molecules. The model reproduces the differences of the emission locations of the atoms and molecules when their initial temperatures are assumed to be 3 eV and 0.04 eV, respectively. From the model, the wings of the Balmer-{alpha} line is attributed to the high velocity atoms exist deep inside the LCFS, which are generated by the charge exchange collisions with hot protons there.

  14. Modelling the Pan-Spectral Energy Distribution of Starburst Galaxies: III. Emission Line Diagnostics of Ensembles of H II Regions

    SciTech Connect

    Dopita, M A; Fischera, J; Sutherland, R S; Kewley, L J; Leitherer, C; Tuffs, R J; Popescu, C C; van Breugel, W; Groves, B A

    2006-05-10

    We have built, as far as possible, fully self-consistent models of H II regions around aging clusters of stars. These produce strong emission line diagnostics applicable to either individual H II regions in galaxies, or to the integrated emission line spectra of disk or starburst galaxies. The models assume that the expansion and internal pressure of individual H II regions is driven by the net input of mechanical energy from the central cluster, be it through winds or supernova events. This eliminates the ionization parameter as a free variable, replacing it with a parameter which depends on the ratio of the cluster mass to the pressure in the surrounding interstellar medium. These models explain why H II regions with low abundances have high excitation, and demonstrate that at least part of the warm ionized medium is the result of overlapping faint, old, large, and low pressure H II regions. We present a number of line ratios (at both optical and IR wavelengths) that provide reliable abundance diagnostics for either single H II regions or for integrated galaxy spectra, and others that are sensitive to the age of the cluster stars exciting individual H II regions.

  15. Emission Signatures from Sub-parsec Binary Supermassive Black Holes. I. Diagnostic Power of Broad Emission Lines

    NASA Astrophysics Data System (ADS)

    Nguyen, Khai; Bogdanović, Tamara

    2016-09-01

    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 emission-line 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 that 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 emission-line 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 emission-line 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 emission lines in observed SBHB candidates and we discuss improved treatment of radiative transfer effects, which will allow a direct statistical comparison of the two groups.

  16. VIMOS integral field spectroscopy of blue compact galaxies. I. Morphological properties, diagnostic emission-line ratios, and kinematics

    NASA Astrophysics Data System (ADS)

    Cairós, L. M.; Caon, N.; Weilbacher, P. M.

    2015-05-01

    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. Emission lines 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 emission-lines, as well as diagnostic line ratios, extinction, and kinematic maps. Results: An atlas has been produced with the following: emission-line fluxes and continuum emission; ionization, interstellar extinction, and electron density maps from line ratios; velocity and velocity dispersion fields. From integrated spectroscopy, it includes tables of the extinction corrected line fluxes and equivalent widths, diagnostic-line 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

  17. Fe Line Diagnostics of Cataclysmic Variables and Galactic Ridge X-Ray Emission

    NASA Astrophysics Data System (ADS)

    Xu, Xiao-jie; Wang, Q. Daniel; Li, Xiang-Dong

    2016-02-01

    The properties of the Galactic Ridge X-ray Emission (GRXE) observed in the 2-10 keV band place fundamental constraints on various types of X-ray sources in the Milky Way. Although the primarily discrete origin of the emission is now well established, the responsible populations of these sources remain uncertain, especially at relatively low fluxes. To provide insights into this issue, we systematically characterize the Fe emission line properties of the candidate types of the sources in the solar neighborhood and compare them with those measured for the GRXE. Our source sample includes 6 symbiotic stars, 16 intermediate polars (IPs), 3 polars, 16 quiescent dwarf novae, and 4 active binaries (ABs); they are all observed with the Suzaku X-ray Observatory. The data of about one-fourth of these sources are analyzed for the first time. We find that the mean equivalent width (EW6.7) of the 6.7 keV line and the mean 7.0/6.7 keV line ratio are 107 ± 16.0 eV and 0.71 ± 0.04 for IPs and 221 ± 135 eV and 0.44 ± 0.14 for polars, respectively, which are all substantially different from those (490 ± 15 eV and 0.2 ± 0.08) for the GRXE. Instead, the GRXE values are better agreed by the EW6.7 (438 ± 84.6 eV) and the ratio (0.27 ± 0.06) observed for the DNe. We further find that the EW6.7 is strongly correlated with the 2-10 keV luminosity of the DNe, which can be characterized by the relation {{EW}}6.7={(438+/- 95{{eV}})(L/{10}31{erg}{{{s}}}-1)}(-0.31+/- 0.15). Accounting for this correlation, the agreement can be improved further, especially when the contributions from other class sources to the GRXE are considered, which all have low EW6.7 values. We conclude that the GRXE mostly consists of typically faint but numerous DNe, plus ABs, while magnetic cataclysmic variables are probably mainly the high-flux representatives of the responsible populations and dominate the GRXE only in harder energy bands.

  18. Real-time control of tearing modes using a line-of-sight electron cyclotron emission diagnostic

    NASA Astrophysics Data System (ADS)

    Hennen, B. A.; Westerhof, E.; Nuij, P. W. J. M.; Oosterbeek, J. W.; de Baar, M. R.; Bongers, W. A.; Bürger, A.; Thoen, D. J.; Steinbuch, M.; TEXTOR Team

    2010-10-01

    The stability and performance of tokamak plasmas are limited by instabilities such as neoclassical tearing modes. This paper reports on an experimental proof of principle of a feedback control approach for real-time, autonomous suppression and stabilization of tearing modes in a tokamak. The system combines an electron cyclotron emission diagnostic for sensing of the tearing modes in the same sight line with a steerable electron cyclotron resonance heating and current drive (ECRH/ECCD) antenna. A methodology for fast detection of q = m/n = 2/1 tearing modes and retrieval of their location, rotation frequency and phase is presented. Set-points to establish alignment of the ECRH/ECCD deposition location with the centre of the tearing mode are generated in real time and forwarded in closed loop to the steerable launcher and as a modulation pulse train to the gyrotron. Experimental results demonstrate the capability of the control system to track externally perturbed tearing modes in real time.

  19. Comparing Narrow- and Broad-line AGNs in a New Diagnostic Diagram for Emission-line Galaxies Based on WISE Data

    NASA Astrophysics Data System (ADS)

    Coziol, R.; Torres-Papaqui, J. P.; Andernach, H.

    2015-06-01

    Using a new color-color diagnostic diagram in the mid-infrared (MIR) built from WISE data, the MIRDD, we compare narrow-emission-line galaxies (NELGs) that exhibit different activity types (star-forming galaxies (SFGs) and active galactic nuclei (AGNs), i.e., LINERs, Seyfert 2 galaxies (Sy2s), and Transition-type Objects (TOs)), as determined using one standard diagnostic diagram in the optical (BPT-VO), with broad-line AGNs (QSOs and Sy1s) and BL Lac objects at low redshift (z≤slant 0.25). We show that the BL Lac objects occupy the same region as the LINERs in the MIRDD, whereas the QSOs and Sy1s occupy an intermediate region between the LINERs and the Sy2s. In the MIRDD these galaxies trace a sequence that can be reproduced by a power law, {{F}ν }={{ν }α }, where the spectral index, α, varies from 0 to -2, which is similar to what is observed in the optical/ultraviolet part of the spectra of AGNs with different luminosities. For the NELGs with different activity types, we perform a stellar-population synthesis analysis, confirming that their specific positions in the MIRD depend on their star formation histories (SFH) and demonstrating that the W2-W3 color is tightly correlated with the level of star formation in their host galaxies. In good agreement with the SFH analysis, a comparison of their MIR colors with the colors yielded by spectral energy distributions (SEDs) of galaxies with different activity types shows that the SED of the LINERs is similar to the SEDs of the QSOs and Sy1s, consistent with AGN galaxies with mild star formation, whereas the SEDs of the Sy2s and TOs are consistent with AGN galaxies with strong star formation components. For the BL Lac objects, we show that their blue MIR colors can only be fitted with an SED that has no star formation component, consistent with AGNs in elliptical-type galaxies. From their similarities in MIR colors and SEDs, we infer that, in the nearby universe, the level of star formation activity most probably

  20. Active galactic nuclei emission line diagnostics and the mass-metallicity relation up to redshift z ∼ 2: The impact of selection effects and evolution

    SciTech Connect

    Juneau, Stéphanie; Bournaud, Frédéric; Daddi, Emanuele; Elbaz, David; Duc, Pierre-Alain; Gobat, Raphael; Jean-Baptiste, Ingrid; Le Floc'h, Émeric; Pannella, Maurilio; Schreiber, Corentin; Trump, Jonathan R.; Dickinson, Mark

    2014-06-10

    Emission line diagnostic diagrams probing the ionization sources in galaxies, such as the Baldwin-Phillips-Terlevich (BPT) diagram, have been used extensively to distinguish active galactic nuclei (AGN) from purely star-forming galaxies. However, they remain poorly understood at higher redshifts. We shed light on this issue with an empirical approach based on a z ∼ 0 reference sample built from ∼300,000 Sloan Digital Sky Survey galaxies, from which we mimic selection effects due to typical emission line detection limits at higher redshift. We combine this low-redshift reference sample with a simple prescription for luminosity evolution of the global galaxy population to predict the loci of high-redshift galaxies on the BPT and Mass-Excitation (MEx) diagnostic diagrams. The predicted bivariate distributions agree remarkably well with direct observations of galaxies out to z ∼ 1.5, including the observed stellar mass-metallicity (MZ) relation evolution. As a result, we infer that high-redshift star-forming galaxies are consistent with having normal interstellar medium (ISM) properties out to z ∼ 1.5, after accounting for selection effects and line luminosity evolution. Namely, their optical line ratios and gas-phase metallicities are comparable to that of low-redshift galaxies with equivalent emission-line luminosities. In contrast, AGN narrow-line regions may show a shift toward lower metallicities at higher redshift. While a physical evolution of the ISM conditions is not ruled out for purely star-forming galaxies and may be more important starting at z ≳ 2, we find that reliably quantifying this evolution is hindered by selections effects. The recipes provided here may serve as a basis for future studies toward this goal. Code to predict the loci of galaxies on the BPT and MEx diagnostic diagrams and the MZ relation as a function of emission line luminosity limits is made publicly available.

  1. MID-INFRARED PROPERTIES OF THE SWIFT BURST ALERT TELESCOPE ACTIVE GALACTIC NUCLEI SAMPLE OF THE LOCAL UNIVERSE. I. EMISSION-LINE DIAGNOSTICS

    SciTech Connect

    Weaver, K. A.; Melendez, M.; Mushotzky, R. F.; Kraemer, S.; Engle, K.; Malumuth, E.; Tueller, J.; Markwardt, C.; Berghea, C. T.; Dudik, R. P.; Winter, L. M.; Armus, L.

    2010-06-20

    We compare mid-infrared emission-line properties from high-resolution Spitzer spectra of a hard X-ray (14-195 keV) selected sample of nearby (z < 0.05) active galactic nuclei (AGNs) detected by the Burst Alert Telescope (BAT) aboard Swift. The luminosity distribution for the mid-infrared emission lines, [O IV] 25.89 {mu}m, [Ne II] 12.81 {mu}m, [Ne III] 15.56 {mu}m, and [Ne V] 14.32/24.32 {mu}m, and hard X-ray continuum show no differences between Seyfert 1 and Seyfert 2 populations; however, six newly discovered BAT AGNs are 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 fluxes and luminosities suggests that the emission lines primarily arise in gas ionized by the AGNs. We also compare the mid-infrared emission lines in the BAT AGNs with those from published studies of ULIRGs, Palomar-Green quasars, star-forming galaxies, and LINERs. We find that the BAT AGN sample falls into a distinctive region when comparing the [Ne III]/[Ne II] and the [O IV]/[Ne III] ratios. These line ratios are lower in sources that have been previously classified in the mid-infrared/optical as AGNs than those found for the BAT AGNs, suggesting that, in our X-ray selected sample, the AGNs represent the main contribution to the observed line emission. These ratios represent a new emission line diagnostic for distinguishing between AGNs and star-forming galaxies.

  2. DIAGNOSTIC LINE EMISSION FROM EXTREME ULTRAVIOLET AND X-RAY-ILLUMINATED DISKS AND SHOCKS AROUND LOW-MASS STARS

    SciTech Connect

    Hollenbach, David; Gorti, U.

    2009-10-01

    Extreme ultraviolet (EUV; 13.6 eV diagnostic lines (e.g., [Ne II] 12.8 {mu}m and [O I] 6300 A) that we model as functions of key parameters such as EUV luminosity and spectral shape, X-ray luminosity and spectral shape, and wind mass loss rate and shock speed. Comparing our models with observations, we conclude that either internal shocks in the winds or X-rays incident on the disk surfaces often produce the observed [Ne II] line, although there are cases where EUV may dominate. Shocks created by the oblique interaction of winds with disks are unlikely [Ne II] sources because these shocks are too weak to ionize Ne. Even if [Ne II] is mainly produced by X-rays or internal wind shocks, the neon observations typically place upper limits of {approx}<10{sup 42} s{sup -1} on the EUV photon luminosity of these young low-mass stars. The observed [O I] 6300 A line has both a low velocity component (LVC) and a high velocity component. The latter likely arises in internal wind shocks. For the former we find that X-rays likely produce more [O I] luminosity than either the EUV layer, the transition layer between the EUV and X-ray layer, or the shear layer where the protostellar wind shocks and entrains disk material in a radial flow across the surface of the disk. Our soft X-ray models produce [O I] LVCs with luminosities up to 10{sup -4} L{sub sun}, but may not be able to explain the most luminous LVCs.

  3. CORONAL EMISSION LINES AS THERMOMETERS

    SciTech Connect

    Judge, Philip G.

    2010-01-10

    Coronal emission-line intensities are commonly used to measure electron temperatures using emission measure and/or line ratio methods. In the presence of systematic errors in atomic excitation calculations and data noise, the information on underlying temperature distributions is fundamentally limited. Increasing the number of emission lines used does not necessarily improve the ability to discriminate between different kinds of temperature distributions.

  4. PEARS Emission Line Galaxies

    NASA Technical Reports Server (NTRS)

    Pirzkal, Nor; Rothberg, Barry; Ly, Chun; Rhoads, James E.; Malhotra, Sangeeta; Grogin, Norman A.; Dahlen, Tomas; Meurer, Gerhardt R.; Walsh, Jeremy; Hathi, Nimish P.; Cohen, Seth; Belini, Andrea; Holwerda, Benne W.; Straughn, Amber; Mechtley, Matthew

    2012-01-01

    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 emission line regions (ELRs) within a single galaxy. 1162 [OII], [OIII] and/or H-alpha emission lines 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 line 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.

  5. Spectral Line Shapes as a Diagnostic Tool in Magnetic Fusion

    SciTech Connect

    Stamm, R; Capes, H; Demura, A; Godbert-Mouret, L; Koubiti, M; Marandet, Y; Mattioli, M; Rosato, J; Rosmej, F; Fournier, K B

    2006-07-22

    Spectral line shapes and intensities are used for obtaining information on the various regions of magnetic fusion devices. Emission from low principal quantum numbers of hydrogen isotopes is analyzed for understanding the complex recycling mechanism. Lines emitted from high principal quantum numbers of hydrogen and helium are dominated by Stark effect, allowing an electronic density diagnostic in the divertor. Intensities of lines emitted by impurities are fitted for a better knowledge of ion transport in the confined plasma.

  6. Spectral classification of emission-line galaxies

    NASA Astrophysics Data System (ADS)

    Dessauges-Zavadsky, M.; Pindao, M.; Maeder, A.; Kunth, D.

    2000-03-01

    The main goal of this work is to further investigate the classification of emission-line galaxies from the ``Spectrophotometric Catalogue of H II galaxies'' by Terlevich et al. (1991) in a homogeneous and objective way, using the three line-ratio diagrams, called diagnostic diagrams, of Veilleux & Osterbrock (1987). On the basis of the resulting catalogue, we critically discuss the classification methods in the optical range. In particular we compare our classification scheme to the one done by Rola et al. (1997) which is efficient for the classification of redshifted galaxies. We also propose a new diagnostic diagram involving the known intensity ratio R23=([O II],l 3727+[O III] l 4959+{[O III] l 5007)/Hb which appears to be a very good criterion allowing to discriminate the Seyfert 2 from H ii galaxies. The revised catalogue including 314 narrow-emission-line galaxies contains H II galaxies, Seyfert 2 galaxies, Low Ionization Nuclear Emission-Line Regions (hereafter LINERs) galaxies and some particular types of galaxies with the most intriguing ones, called ``ambiguous'', due to the ambiguity of their location in the diagnostic diagrams. These galaxies appear as H II galaxies and as active galactic nuclei (hereafter AGNs) in different diagrams of Veilleux & Osterbrock and constitute certainly a sample of particularly interesting candidates for a thorough study of connections between starbursts and AGNs. Available in electronic form only via anonymous ftp 130.79.128.5 or http://cdsweb.u-strasbg.fr/Abstract.html

  7. Detection of [O I] λ6300 and Other Diagnostic Emission Lines in the Diffuse Ionized Gas of M33 with Gemini-North

    NASA Astrophysics Data System (ADS)

    Voges, E. S.; Walterbos, R. A. M.

    2006-06-01

    We present spectroscopic observations of diffuse ionized gas (DIG) in M33 near the H II region NGC 604. We present the first detection of [O I] λ6300 in the DIG of M33, one of the critical lines for distinguishing photoionization from shock ionization models. We measure [O I]/Hα in the range of 0.04-0.10 and an increase in this ratio with decreasing emission measure. Our measurements of [S II]/Hα and [N II]/Hα also rise with decreasing emission measure, while our [O III]/Hβ measurements remain fairly constant. We have one tentative detection of He I in the region of brightest emission measure, with a ratio of He I/Hα = 0.033 +/- 0.019, indicating that the helium is at least partially ionized. We compare our observed emission-line ratios to photoionization models and find that field star ionization models do not fit our data well. Leaky H II region models are consistent with our data, without the need to invoke additional ionization mechanisms to fit our [O I] or [O III] measurements. The closest large H II region is NGC 604 and is therefore a likely candidate for the source of the ionizing photons for the gas in this region.

  8. Coronal Diagnostics from Cometary Emission

    NASA Astrophysics Data System (ADS)

    Bryans, Paul; Pesnell, William D; Seaton, Daniel B; West, Matthew J

    2014-06-01

    The extreme ultraviolet (EUV) emission observed from sungrazing comets as they pass through the solar atmosphere can be used to infer the properties of the corona. In this paper we will discuss several of these properties that can be estimated from the EUV observations of Comet Lovejoy from AIA/SDO and SWAP/PROBA2. The longevity of the emission allows us to constrain the coronal electron density through which the comet passes. We will also discuss how dispersion of the emitting cometary material we can be used to estimate the local Alfven speed in the corona. Finally, measuring the deformation of the magnetic field as it is impacted by the comet can be used to estimate the magnetic field strength in this location. In the absence of the comet, none of these parameters are directly measurable in the corona. Sungrazing comets are thus unique probes of the solar atmosphere.

  9. MODELING MOLECULAR HYPERFINE LINE EMISSION

    SciTech Connect

    Keto, Eric; Rybicki, George

    2010-06-20

    In this paper, we discuss two approximate methods previously suggested for modeling hyperfine spectral line emission for molecules whose collisional transition rates between hyperfine levels are unknown. Hyperfine structure is seen in the rotational spectra of many commonly observed molecules such as HCN, HNC, NH{sub 3}, N{sub 2}H{sup +}, and C{sup 17}O. The intensities of these spectral lines can be modeled by numerical techniques such as {Lambda}-iteration that alternately solve the equations of statistical equilibrium and the equation of radiative transfer. However, these calculations require knowledge of both the radiative and collisional rates for all transitions. For most commonly observed radio frequency spectral lines, only the net collisional rates between rotational levels are known. For such cases, two approximate methods have been suggested. The first method, hyperfine statistical equilibrium, distributes the hyperfine level populations according to their statistical weight, but allows the population of the rotational states to depart from local thermal equilibrium (LTE). The second method, the proportional method, approximates the collision rates between the hyperfine levels as fractions of the net rotational rates apportioned according to the statistical degeneracy of the final hyperfine levels. The second method is able to model non-LTE hyperfine emission. We compare simulations of N{sub 2}H{sup +} hyperfine lines made with approximate and more exact rates and find that satisfactory results are obtained.

  10. Exhaust emission control and diagnostics

    DOEpatents

    Mazur, Christopher John; Upadhyay, Devesh

    2006-11-14

    A diesel engine emission control system uses an upstream oxidation catalyst and a downstream SCR catalyst to reduce NOx in a lean exhaust gas environment. The engine and upstream oxidation catalyst are configured to provide approximately a 1:1 ratio of NO to NO2 entering the downstream catalyst. In this way, the downstream catalyst is insensitive to sulfur contamination, and also has improved overall catalyst NOx conversion efficiency. Degradation of the system is determined when the ratio provided is no longer near the desired 1:1 ratio. This condition is detected using measurements of engine operating conditions such as from a NOx sensor located downstream of the catalysts. Finally, control action to adjust an injected amount of reductant in the exhaust gas based on the actual NO to NO2 ratio upstream of the SCR catalyst and downstream of the oxidation catalyst.

  11. Diagnostic of the self-healing of metallized polypropylene film by modeling of the broadening emission lines of aluminum emitted by plasma discharge

    SciTech Connect

    Tortai, J.-H.; Bonifaci, N.; Denat, A.; Trassy, C.

    2005-03-01

    Metallized-film capacitors have the property, even under high continuous voltage, to self-heal i.e., to clear a defect in the dielectric. The self-healing process is a consequence of a transient arc discharge. It has been previously shown that during the discharge, due to Joule effect, the metal is vaporized until the arc extinguishes. The discharge duration has been found to be inversely proportional to the mechanical pressure applied on the layers of metallized films making up a capacitor. The aim of this study is to understand the physical processes involved in this spontaneous extinction of the arc discharge. Emission spectroscopy has been used to provide information about the physical properties (temperatures, electronic and neutral particles densities, etc.) of the plasma induces by a self-healing. An analysis, based on the broadenings and shifts of Al atomic lines, of the experimental light spectra obtained has shown that the self-healing process leads to the generation, from the vaporized metal, of a high-density and relatively weakly ionized aluminum plasma. The plasma density increases with the pressure applied on the film layers and, consequently, the density power needed to extend the plasma zone increases as well and the arc discharge goes out faster as experimentally observed.

  12. The Far Infrared Lines of OH as Molecular Cloud Diagnostics

    NASA Astrophysics Data System (ADS)

    Smith, Howard A.; Ashby, Matt; Fischer, Jackie; Gonzales, Eduardo; Spinoglio, Luigi; Dudley, Chris

    There are 15 far-IR lines arising between the lowest eight rotational levels of OH and ISO detected nine of them. Furthermore ISO found the OH lines sometimes in emission and sometimes in absorption in a wide variety of galactic and extragalactic objects ranging from AGB stars to molecular clouds to active galactic nuclei and ultra-luminous IR galaxies. This set of OH lines provides a uniquely valuable diagnostic for many reasons: the lines span a wide wavelength range (28.9μm to 163.2μm); the transitions have fast radiative rates; the abundance of the species is relatively high; the IR continuum plays an important role as a pump; the contribution from shocks is relatively minor; and not least the powerful centimeter-wave radiation from OH allows comparison with radio and VLBI datasets. The problem is that the large number of sensitive free parameters and the large optical depths of the strongest lines make modeling the full set a difficult job. We have used a modified SWAS montecarlo radiative transfer code to analyze the ISO/LWS spectra of a number of objects including in both the lines and the FIR continuum; the DUSTY radiative transfer code was used to insure a self-consistent continuum.

  13. 40 CFR 1033.112 - Emission diagnostics for SCR systems.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 34 2012-07-01 2012-07-01 false Emission diagnostics for SCR systems. 1033.112 Section 1033.112 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EMISSIONS FROM LOCOMOTIVES Emission Standards and Related Requirements § 1033.112 Emission diagnostics for SCR...

  14. 40 CFR 1033.112 - Emission diagnostics for SCR systems.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 33 2014-07-01 2014-07-01 false Emission diagnostics for SCR systems. 1033.112 Section 1033.112 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EMISSIONS FROM LOCOMOTIVES Emission Standards and Related Requirements § 1033.112 Emission diagnostics for SCR...

  15. The Far Infrared Lines of OH as Molecular Cloud Diagnostics

    NASA Technical Reports Server (NTRS)

    Smith, Howard A.

    2004-01-01

    Future IR missions should give some priority to high resolution spectroscopic observations of the set of far-IR transitions of OH. There are 15 far-IR lines arising between the lowest eight rotational levels of OH, and ISO detected nine of them. Furthermore, ISO found the OH lines, sometimes in emission and sometimes in absorption, in a wide variety of galactic and extragalactic objects ranging from AGB stars to molecular clouds to active galactic nuclei and ultra-luminous IR galaxies. The ISO/LWS Fabry-Perot resolved the 119 m doublet line in a few of the strong sources. This set of OH lines provides a uniquely important diagnostic for many reasons: the lines span a wide wavelength range (28.9 m to 163.2 m); the transitions have fast radiative rates; the abundance of the species is relatively high; the IR continuum plays an important role as a pump; the contribution from shocks is relatively minor; and, not least, the powerful centimeter-wave radiation from OH allows comparison with radio and VLBI datasets. The problem is that the large number of sensitive free parameters, and the large optical depths of the strongest lines, make modeling the full set a difficult job. The SWAS montecarlo radiative transfer code has been used to analyze the ISO/LWS spectra of a number of objects with good success, including in both the lines and the FIR continuum; the DUSTY radiative transfer code was used to insure a self-consistent continuum. Other far IR lines including those from H2O, CO, and [OI] are also in the code. The OH lines all show features which future FIR spectrometers should be able to resolve, and which will enable further refinements in the details of each cloud's structure. Some examples are given, including the case of S140, for which independent SWAS data found evidence for bulk flows.

  16. Electron cyclotron emission diagnostics on KSTAR tokamak.

    PubMed

    Jeong, S H; Lee, K D; Kogi, Y; Kawahata, K; Nagayama, Y; Mase, A; Kwon, M

    2010-10-01

    A new electron cyclotron emission (ECE) diagnostics system was installed for the Second Korea Superconducting Tokamak Advanced Research (KSTAR) campaign. The new ECE system consists of an ECE collecting optics system, an overmode circular corrugated waveguide system, and 48 channel heterodyne radiometer with the frequency range of 110-162 GHz. During the 2 T operation of the KSTAR tokamak, the electron temperatures as well as its radial profiles at the high field side were measured and sawtooth phenomena were also observed. We also discuss the effect of a window on in situ calibration. PMID:21033954

  17. Electron cyclotron emission diagnostics on KSTAR tokamak

    SciTech Connect

    Jeong, S. H.; Lee, K. D.; Kwon, M.; Kogi, Y.; Kawahata, K.; Nagayama, Y.; Mase, A.

    2010-10-15

    A new electron cyclotron emission (ECE) diagnostics system was installed for the Second Korea Superconducting Tokamak Advanced Research (KSTAR) campaign. The new ECE system consists of an ECE collecting optics system, an overmode circular corrugated waveguide system, and 48 channel heterodyne radiometer with the frequency range of 110-162 GHz. During the 2 T operation of the KSTAR tokamak, the electron temperatures as well as its radial profiles at the high field side were measured and sawtooth phenomena were also observed. We also discuss the effect of a window on in situ calibration.

  18. BXO mode-converted electron Bernstein emission diagnostic (invited)

    NASA Astrophysics Data System (ADS)

    Volpe, F.; Laqua, H. P.

    2003-03-01

    Electron temperature profiles at densities above the electron cyclotron emission (ECE) cutoff are measured at the W7-AS stellarator by a novel diagnostic based on black body emission and Bernstein-extraordinary-ordinary mode conversion of electron Bernstein waves (EBWs). The radiation is collected along a special oblique line of sight by an antenna with gaussian optics. This was optimized for maximal conversion efficiency and minimal Doppler broadening by means of EBW ray tracing calculations in full stellarator geometry. The elliptical O-mode polarization detected along the oblique line of sight is changed into a linear polarization by a broadband quarter wave shifter, namely an elliptical waveguide. The signal is spectrum analyzed by an heterodyne radiometer and temperature profiles are derived from spectra by means of ray tracing. The diagnostic was applied to measurements of edge-localized modes to illustrate its advantages in terms of spatial and temporal resolution. Moreover, for the first time, the heat wave propagation method for the determination of local heat transport coefficients was extended beyond the ECE cutoff density by combining EBW emission measurements at the first harmonic (f=66-78 GHz) with modulated EBW heating at the second harmonic (140 GHz).

  19. The Diagnostic Potential of Fe Lines Applied to Protostellar Jets

    NASA Astrophysics Data System (ADS)

    Giannini, T.; Nisini, B.; Antoniucci, S.; Alcalá, J. M.; Bacciotti, F.; Bonito, R.; Podio, L.; Stelzer, B.; Whelan, E. T.

    2013-11-01

    We investigate the diagnostic capabilities of iron lines for tracing the physical conditions of shock-excited gas in jets driven by pre-main sequence stars. We have analyzed the 3000-25000 Å, X-shooter spectra of two jets driven by the pre-main sequence stars ESO-Hα 574 and Par-Lup 3-4. Both spectra are very rich in [Fe II] lines over the whole spectral range; in addition, lines from [Fe III] are detected in the ESO-Hα 574 spectrum. Non-local thermal equilibrium codes solving the equations of the statistical equilibrium along with codes for the ionization equilibrium are used to derive the gas excitation conditions of electron temperature and density and fractional ionization. An estimate of the iron gas-phase abundance is provided by comparing the iron lines emissivity with that of neutral oxygen at 6300 Å. The [Fe II] line analysis indicates that the jet driven by ESO-Hα 574 is, on average, colder (T e ~ 9000 K), less dense (n e ~ 2 × 104 cm-3), and more ionized (x e ~ 0.7) than the Par-Lup 3-4 jet (T e ~ 13,000 K, n e ~ 6 × 104 cm-3, x e < 0.4), even if the existence of a higher density component (n e ~ 2 × 105 cm-3) is probed by the [Fe III] and [Fe II] ultra-violet lines. The physical conditions derived from the iron lines are compared with shock models suggesting that the shock at work in ESO-Hα 574 is faster and likely more energetic than the Par-Lup 3-4 shock. This latter feature is confirmed by the high percentage of gas-phase iron measured in ESO-Hα 574 (50%-60% of its solar abundance in comparison with less than 30% in Par-Lup 3-4), which testifies that the ESO-Hα 574 shock is powerful enough to partially destroy the dust present inside the jet. This work demonstrates that a multiline Fe analysis can be effectively used to probe the excitation and ionization conditions of the gas in a jet without any assumption on ionic abundances. The main limitation on the diagnostics resides in the large uncertainties of the atomic data, which, however, can

  20. Observations of emission lines in M supergiants

    NASA Technical Reports Server (NTRS)

    Lambert, D. L.

    1979-01-01

    Copernicus observations of Mg 2 h and k emission lines from M giants and supergiants are described. Supergiants with extensive circumstellar gas shells show an asymmetric k line. The asymmetry is ascribed to superimposed lines of Fe 1 and Mn 1. The Mg 2 line 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 emission 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.

  1. Fe L-Shell Emission Lines at 7 - 9 Angstroms

    NASA Astrophysics Data System (ADS)

    Chen, Hui; Beiersdorfer, Peter; Brown, Greg; Behar, Edhud

    Fe L-shell emission lines at wavelengths less than 10 angstroms come from n to 2 (n = 4 5 6..) transitions. These lines embed information such as electron density and/or temperature that is of fundamental importance to understanding the physics of astrophysical objects. Unresolved by previous x-ray observatories these low wavelength Fe lines are clearly observable by Chandra and XMM x-ray satellites. To meet the needs of using these lines as diagnostics we have studied the n to 2 transitions (n = 4 5 6..) Fe L-shell lines using the LLNL electron beam ion trap following our Fe L-shell emission line measurements for the 3-2 transitions (Brown et al APJ supp. 2002). Our measurement and its comparison with code simulations will be reported together with a discussion of the possible use of these lines as diagnostics for astrophysics. This work was performed under the auspices of the U.S. DOE by LLNL under contract No. W-7405-Eng-48 and supported by NASA SARA grants to LLNL GSFC and Columbia University.

  2. 40 CFR 1033.110 - Emission diagnostics-general requirements.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 34 2012-07-01 2012-07-01 false Emission diagnostics-general requirements. 1033.110 Section 1033.110 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EMISSIONS FROM LOCOMOTIVES Emission Standards and Related Requirements § 1033.110 Emission...

  3. 40 CFR 1033.110 - Emission diagnostics-general requirements.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 32 2010-07-01 2010-07-01 false Emission diagnostics-general requirements. 1033.110 Section 1033.110 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EMISSIONS FROM LOCOMOTIVES Emission Standards and Related Requirements § 1033.110 Emission...

  4. 40 CFR 1033.110 - Emission diagnostics-general requirements.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 33 2014-07-01 2014-07-01 false Emission diagnostics-general requirements. 1033.110 Section 1033.110 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EMISSIONS FROM LOCOMOTIVES Emission Standards and Related Requirements § 1033.110 Emission...

  5. PROFIT: Emission-line PROfile FITting routine

    NASA Astrophysics Data System (ADS)

    Riffel, Rogemar A.

    2012-04-01

    The PROFIT is an IDL routine to do automated fitting of emission-line profiles by Gaussian curves or Gauss-Hermite series otimized for use in Integral Field and Fabry-Perot data cubes. As output PROFIT gives two-dimensional FITS files for the emission-line flux distribution, centroid velocity, velocity dispersion and higher order Gauss-Hermite moments (h3 and h4).

  6. 40 CFR 1033.112 - Emission diagnostics for SCR systems.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 32 2010-07-01 2010-07-01 false Emission diagnostics for SCR systems....112 Emission diagnostics for SCR systems. Engines equipped with SCR systems using separate reductant.... This section does not apply for SCR systems using the engine's fuel as the reductant. (a)...

  7. Local Group Galaxy Emission-line Survey

    NASA Astrophysics Data System (ADS)

    Blaha, Cindy; Baildon, Taylor; Mehta, Shail; Garcia, Edgar; Massey, Philip; Hodge, Paul W.

    2015-01-01

    We present the results of the Local Group Galaxy Emission-line Survey of Hα emission regions in M31, M33 and seven dwarf galaxies in (NGC6822, IC10, WLM, Sextans A and B, Phoenix and Pegasus). Using data from the Local Group Galaxy Survey (LGGS - see Massey et al, 2006), we used continuum-subtracted Ha emission line images to define emission regions with a faint flux limit of 10 -17 ergs-sec-1-cm-2above the background. We have obtained photometric measurements for roughly 7450 Hα emission regions in M31, M33 and five of the seven dwarf galaxies (no regions for Phoenix or Pegasus). Using these regions, with boundaries defined by Hα-emission flux limits, we also measured fluxes for the continuum-subtracted [OIII] and [SII] images and constructed a catalog of Hα fluxes, region sizes and [OIII]/ Hα and [SII]/ Hα line ratios. The HII region luminosity functions and size distributions for the spiral galaxies M31 and M33 are compared with those of the dwarf galaxies NGC 6822 and IC10. For M31 and M33, the average [SII]/ Hα and [OIII]/ Hα line ratios, plotted as a function of galactocentric radius, display a linear trend with shallow slopes consistent with other studies of metallicity gradients in these galaxies. The galaxy-wide averages of [SII]/ Hα line ratios correlate with the masses of the dwarf galaxies following the previously established dwarf galaxy mass-metallicity relationship. The slope of the luminosity functions for the dwarf galaxies varies with galaxy mass. The Carleton Catalog of this Local Group Emission-line Survey will be made available on-line.

  8. Theoretical quasar emission-line ratios. V - Balmer continuum emission

    NASA Technical Reports Server (NTRS)

    Puetter, R. C.; Levan, P. D.

    1982-01-01

    Isothermal, isobaric models of quasar emission line regions are presented which include an improved treatment of radiative transfer in the bound-free continua, based on a generalization of frequency-integrated line transfer techniques and on the use of a probabilistic radiative transfer equation which explicitly distinguishes between the flux divergence coefficient and the photon escape probability. It is found that Balmer continuum emission can be obtained without compromising observed line ratios. It is also established that optically thin or thick Balmer continuum emission models with blended Fe II line are consistent with 4000-2000 A 'blue bump' observations, and that the improved radiative transfer treatment makes order-of-magnitude corrections to level populations and local cooling rates calculated with past techniques.

  9. Emission Lines and the High Energy Continuum

    NASA Technical Reports Server (NTRS)

    Green, Paul

    1998-01-01

    Quasars show many striking relationships between line and continuum radiation whose origins remain a mystery. FeII, [OIII], Hbeta, and HeII emission line properties correlate with high energy continuum properties such as the relative strength of X-ray emission, and X-ray continuum slope. At the same time, the shape of the high energy continuum may vary with luminosity. An important tool for studying global properties of Quasi Stellar Objects (QSOs) is the co-addition of data for samples of QSOS. We use this to show that X-ray bright (XB) QSOs show stronger emission lines in general, but particularly from the narrow line region. The difference in the [OIII]/Hbeta ratio is particularly striking, and even more so when blended FeII emission is properly subtracted. Weaker narrow forbidden lines ([OII] and NeV) are enhanced by factors of 2 to 3 in both UV and optical XB composite spectra. The physical origin of these diverse and interrelated correlations has yet to be determined. Unfortunately, many physically informative trends intrinsic to QSOs may be masked by dispersion in the data due to either low signal-to-noise or variability. An important tool for studying global properties of QSOs is the co-addition of data for samples of QSOS. We use this to show that X-ray bright (XB) QSOs show stronger emission lines in general, but particularly from the narrow line region. The difference in the [OIII]/Hbeta ratio is particularly striking, and even more so when blended Fell emission is properly subtracted. Weaker narrow forbidden lines ([OII] and NeV) are enhanced by factors of 2 to 3 in both UV and optical XB composite spectra. We describe a large-scale effort now underway to probe these effects in large samples, using both data and analysis as homogeneous as possible. Using an HST FOS Atlas of QSO spectra, with primary comparison to ROSAT PSPC spectral constraints, we will model the Big Blue Bump, its relationship to luminosity and QSO type, and we will analyze and

  10. Investigating Starburst Galaxy Emission Line Equivalent Widths

    NASA Astrophysics Data System (ADS)

    Meskhidze, Helen; Richardson, Chris T.

    2016-01-01

    Modeling star forming galaxies with spectral synthesis codes allows us to study the gas conditions and excitation mechanisms that are necessary to reproduce high ionization emission lines in both local and high-z galaxies. Our study uses the locally optimally-emitting clouds model to develop an atlas of starburst galaxy emission line equivalent widths. Specifically, we address the following question: What physical conditions are necessary to produce strong high ionization emission lines assuming photoionization via starlight? Here we present the results of our photoionization simulations: an atlas spanning 15 orders of magnitude in ionizing flux and 10 orders of magnitude in hydrogen density that tracks over 150 emission lines ranging from the UV to the near IR. Each simulation grid contains ~1.5x104 photoionization models calculated by supplying a spectral energy distribution, grain content, and chemical abundances. Specifically, we will be discussing the effects on the emission line equivalent widths of varying the metallicity of the cloud, Z = 0.2 Z⊙ to Z = 5.0 Z⊙, and varying the star-formation history, using the instantaneous and continuous evolution tracks and the newly released Starburst99 Geneva rotation tracks.

  11. Infrared [Fe II] Emission Lines from Radiative Atomic Shocks

    NASA Astrophysics Data System (ADS)

    Koo, Bon-Chul; Raymond, John C.; Kim, Hyun-Jeong

    2016-06-01

    [Fe II] emission lines are prominent in the infrared (IR) and important as diagnostic tools for radiative atomic shocks. We investigate the emission characteristics of [Fe II] lines using a shock code developed by te{raymond1979} with updated atomic parameters. We first review general characteristics of the IR [Fe II] emission lines from shocked gas, and derive their fluxes as a function of shock speed and ambient density. We have compiled available IR [Fe II] line observations of interstellar shocks and compare them to the ratios predicted from our model. The sample includes both young and old supernova remnants in the Galaxy and the Large Magellanic Cloud and several Herbig-Haro objects. We find that the observed ratios of the IR [Fe II] lines generally fall on our grid of shock models, but the ratios of some mid-IR lines, e.g., fethreefive/fetwofive, fefive/fetwofive, and fefive/feoneseven, are significantly offset from our model grid. We discuss possible explanations and conclude that while uncertainties in the shock modeling and the observations certainly exist, the uncertainty in atomic rates appears to be the major source of discrepancy.

  12. Discovery of Polarized Line Emission in SN 1006

    NASA Astrophysics Data System (ADS)

    Sparks, W. B.; Pringle, J. E.; Carswell, R. F.; Long, K. S.; Cracraft, M.

    2015-12-01

    Laming predicted that the narrow Balmer line core of the ∼3000 km s‑1 shock in the SN 1006 remnant would be significantly polarized due to electron and proton impact polarization. Here, based on deep spectrally resolved polarimetry obtained with the European Southern Observatory (ESO)’s Very Large Telescope (VLT), we report the discovery of polarized line emission with a polarization degree of 1.3% and position angle orthogonal to the SNR filament. Correcting for an unpolarized broad line component, the implied narrow line polarization is ≈2.0%, close to the predictions of Laming. The predicted polarization is primarily sensitive to shock velocity and post-shock temperature equilibration. By measuring polarization for the SN 1006 remnant, we validate and enable a new diagnostic that has important applications in a wide variety of astrophysical situations, such as shocks, intense radiation fields, high energy particle streams, and conductive interfaces.

  13. Bright emission lines in new Seyfert galaxies

    SciTech Connect

    Afanasev, V.L.; Denisiuk, E.K.; Lipovetskii, V.A.; Shapovalova, A.I.

    1983-01-01

    Observational data are given on bright emission lines (H-alpha, H-beta, and forbidden N II, S II, and O III) for 14 recently discovered Seyfert galaxies. The investigated objects can be divided into three groups, which correspond approximately to the first (5 objects), the intermediate (4 objects), and the second (4 objects) Seyfert types. Attention is drawn to the properties of the galaxy Markaryan 1018, which has features of both the first and the second type and is distinguished by the weakness of its emission lines, which is probably due to a gas deficit. 7 references.

  14. Emission lines from hot astrophysical plasmas

    NASA Astrophysics Data System (ADS)

    Raymond, John C.

    The spectral lines which dominate the X-ray emission of hot, optically thin astrophysical plasmas reflect the elemental abundances, temperature distribution, and other physical parameters of the emitting gas. The accuracy and level of detail with which these parameters can be inferred are limited by the measurement uncertainties and uncertainties in atomic rates used to compute the model spectrum. This paper discusses the relative importance and the likely uncertainties in the various atomic rates and the likely uncertainties in the overall ionization balance and spectral line emissivities predicted by the computer codes currently used to fit X-ray spectral data.

  15. Molecular Hydrogen Line Emission from Photodissociation Regions

    NASA Astrophysics Data System (ADS)

    Chrysostomou, Antonio

    1993-01-01

    radiatively rather than by shocks. The diagnostic line ratio of the H2 v = 1-0 S(1) and 2-1 S(1) transitions is approximately 3 over the region observed implying that the lower levels of the molecule are slightly thermalised by the warm gas. The constancy of the ratio further implies that the collisional deexcitation rate must be constant along this region. This may be taken to mean that the physical conditions do not change along the region and that we are observing the surface of the PDR. The profile of the molecular emission along the slit can be successfully modelled if it is assumed that the large scale surface geometry in the region can be described by a parabola. The ortho to para ratio of H2, measured in the three PDR sources (M17 northern bar, NGC 2023 and Hubble 12), is less than the expected value for a hot (~300 K) gas in thermodynamic equilibrium (ie. 3). The measured values fall in the range 1.3 - 2.3. Modelling the orth to para ratio using the rates of spin conversion of the H2 molecule do not satisfy the observations. Some other form of processing the ortho to para ratio must be occuring and three different models are considered. First, a different reformation mechanism is considered which allows the newly formed molecule to reside on the surface of the grain for a certain amount of time before it evaporates into the gas. The second model describes a dynamic PDR. Hot gas at the surface of the PDR is allowed to escape setting up an advancing photodissociation front. If the front advances into the cooler gas before there is enough time for spin changing interactions to take place, then the measured ortho to para ratios will have values characteristic of the cooler (T ~ 50 - 150 K) gas. Both of these models can successfully reproduce the observed ortho to para ratios. The third model assumes that there is some processing of the ortho to para ratio during the fluorescent cascade, after it has been excited by ultraviolet photons. This model is not successful at

  16. Integration of On-Line and Off-Line Diagnostic Algorithms for Aircraft Engine Health Management

    NASA Technical Reports Server (NTRS)

    Kobayashi, Takahisa; Simon, Donald L.

    2007-01-01

    This paper investigates the integration of on-line and off-line diagnostic algorithms for aircraft gas turbine engines. The on-line diagnostic algorithm is designed for in-flight fault detection. It continuously monitors engine outputs for anomalous signatures induced by faults. The off-line diagnostic algorithm is designed to track engine health degradation over the lifetime of an engine. It estimates engine health degradation periodically over the course of the engine s life. The estimate generated by the off-line algorithm is used to update the on-line algorithm. Through this integration, the on-line algorithm becomes aware of engine health degradation, and its effectiveness to detect faults can be maintained while the engine continues to degrade. The benefit of this integration is investigated in a simulation environment using a nonlinear engine model.

  17. Extreme Ultraviolet Emission Lines of Iron Fe XI-XIII

    NASA Astrophysics Data System (ADS)

    Lepson, Jaan; Beiersdorfer, P.; Brown, G. V.; Liedahl, D. A.; Brickhouse, N. S.; Dupree, A. K.

    2013-04-01

    The extreme ultraviolet (EUV) spectral region (ca. 20--300 Å) is rich in emission lines from low- to mid-Z ions, particularly from the middle charge states of iron. Many of these emission lines 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 lines that contribute to the richness of the EUV region. Laboratory measurements have been made to verify and benchmark the lines. 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 line identification. We also present new calculations by the Hebrew University - Lawrence Livermore Atomic Code (HULLAC), which we also utilized for line identification. We found that HULLAC does a creditable job of reproducing the forest of lines we observed in the EBIT spectra, although line positions are in need of adjustment, and line intensities often differed from those observed. We identify or confirm a number of new lines 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.

  18. Vaccum and beam diagnostic controls for ORIC beam lines

    SciTech Connect

    Tatum, B.A.

    1991-01-01

    Vacuum and beam diagnostic equipment on beam lines from the Oak Ridge Isochronous Cyclotron, ORIC, is now controlled by a new dedicated system. The new system is based on an industrial programmable logic controller with an IBM AT personal computer providing control room operator interface. Expansion of this system requires minimal reconfiguration and programming, thus facilitating the construction of additional beam lines. Details of the implementation, operation, and performance of the system are discussed. 2 refs., 2 figs.

  19. The emission line - continuum connection in galaxies

    NASA Astrophysics Data System (ADS)

    Sodre, Laerte; Albernaz-Sirico, Ana Carolina

    2015-08-01

    Star-forming galaxies with a blue continuum tend to present prominent emission lines, whereas in red galaxies emission lines are associated mostly to nuclear activity or to certain stellar populations, like post-AGB stars. In this work we have used tools of machine learning to investigate how theemission line equivalent widths of galaxies are related to their optical continuum. From the analysis of a sample of high S/N spectra of SDSS/DR9 we show that indeed it is possible to estimate with good accuracy the equivalent width of the most intense emission lines from galaxy continuum information only for star-forming galaxies and AGNs (LINERS and Seyfer 2 emitters) by using simple relationships (linear and/or polynomial models) between the EWs and the relative flux at certain wavelengths. An important motivation for this work is to produce realistic spectra to test the data reduction pipelines of the new generation of galaxy surveys, like J-PAS and PFS/SuMIRe.

  20. MG II h&k line diagnostics of IM Pegasi

    NASA Astrophysics Data System (ADS)

    Olah, K.; Marik, D.; Houdebine, E. R.; Dempsey, R. C.; Budding, E.

    1998-02-01

    We have analysed the Mgii h&k resonance lines of IM Peg (KII-III) on 14 high resolution IUE LWR spectra and compared the results coming from visual spectroscopic and UBV(RI)_C photometric data. The `clean' spectra (free from interstellar absorption) were modelled using a convolution of the rotational profile with a Gaussian profile, that represents macroturbulence and broadenings of other origin, the former dominating. Significant variations in the h&k line fluxes and widths were found throughout the orbital phase range. A line broadening effect is found at maximum spot visibility both in the k and h lines. The Mgii line widths increase linearly with the flux of the transition region lines as a function of rotational phase. Anticorrelations as a function of phase were found between the Mgii line fluxes and the higher temperature lines. The k line is broader than the h line, correlated with a slope greater than unity, in keeping with a greater radiation transfer effect in the k line, and a non-optically thin medium at all phases. We observe a systematic asymmetry in the ratio of the h to k line profiles at all phases. The spectral diagnostics thus suggest the appearance of a plage region on the stellar disc. We obtained new orbital elements of the IM Peg system, deriving a small, but non-zero eccentricity. The authors would like to dedicate this paper to their late referee, Dr. P.B. Byrne.

  1. Galaxy emission line classification using three-dimensional line ratio diagrams

    SciTech Connect

    Vogt, Frédéric P. A.; Dopita, Michael A.; Kewley, Lisa J.; Sutherland, Ralph S.; Scharwächter, Julia; Basurah, Hassan M.; Ali, Alaa; Amer, Morsi A.

    2014-10-01

    Two-dimensional (2D) line 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 emission line ratios really is a multi-dimensional problem. Here we exploit recent software developments to explore the potential of three-dimensional (3D) line ratio diagnostic diagrams. We introduce the ZQE diagrams, which are a specific set of 3D diagrams that separate the oxygen abundance and the 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.

  2. SOLAR TRANSITION REGION LINES OBSERVED BY THE INTERFACE REGION IMAGING SPECTROGRAPH: DIAGNOSTICS FOR THE O IV AND Si IV LINES

    SciTech Connect

    Dudík, J.; Del Zanna, G.; Mason, H. E.; Dzifčáková, E.; Golub, L.

    2014-01-01

    The formation of the transition region O IV and Si IV lines observable by the Interface Region Imaging Spectrograph (IRIS) is investigated for both Maxwellian and non-Maxwellian conditions characterized by a κ-distribution exhibiting a high-energy tail. The Si IV lines are formed at lower temperatures than the O IV lines for all κ. In non-Maxwellian situations with lower κ, the contribution functions are shifted to lower temperatures. Combined with the slope of the differential emission measure, it is possible for the Si IV lines to be formed at very different regions of the solar transition region than the O IV lines; possibly close to the solar chromosphere. Such situations might be discernible by IRIS. It is found that photoexcitation can be important for the Si IV lines, but is negligible for the O IV lines. The usefulness of the O IV ratios for density diagnostics independently of κ is investigated and it is found that the O IV 1404.78 Å/1399.77 Å ratio provides a good density diagnostics except for very low T combined with extreme non-Maxwellian situations.

  3. Millimeter emission lines in Orion A

    NASA Technical Reports Server (NTRS)

    Lovas, F. J.; Johnson, D. R.; Buhl, D.; Snyder, L. E.

    1976-01-01

    During the course of a search of Orion A for signals from three large organic molecules, several millimeter-wave lines from known interstellar molecules were observed. Results are reported for observations of methanol (CH3OH), methyl cyanide (CH3CN), methyl acetylene (CH3CCH), acetaldehyde (CH3CHO) and (Si-29)O. Emission signals from two hydrogen recombination lines (H41-alpha and H42-alpha) detected from the H II region of Orion A are also reported. Negative results were obtained for several millimeter-wave transitions of ethylene oxide, acetone, and cyclopropenone.

  4. Molecular Emission Line Formation in Prestellar Cores

    NASA Astrophysics Data System (ADS)

    Pavlyuchenkov, Ya.; Wiebe, D.; Shustov, B.; Henning, Th.; Launhardt, R.; Semenov, D.

    2008-12-01

    We investigate general aspects of molecular line formation under conditions typical of prestellar cores. Focusing on simple linear molecules, we study the formation of their rotational lines with radiative transfer simulations. We present a thermalization diagram to show the effects of collisions and radiation on the level excitation. We construct a detailed scheme (contribution chart) to illustrate the formation of emission-line profiles. This chart can be used as an efficient tool to identify which parts of the cloud contribute to a specific line profile. We show how molecular line characteristics for uniform model clouds depend on hydrogen density, molecular column density, and kinetic temperature. The results are presented in a two-dimensional plane to illustrate mutual effects of the physical factors. We also use a core model with a nonuniform density distribution and chemical stratification to study the effects of cloud contraction and rotation on spectral line maps. We discuss the main issues that should be taken into account when dealing with interpretation and simulation of observed molecular lines.

  5. UV line diagnostics of accretion disk winds in cataclysmic variables

    NASA Technical Reports Server (NTRS)

    Vitello, Peter; Shlosman, Isaac

    1992-01-01

    The IUE data base is used to analyze the UV line shapes of cataclysmic variables RW Sex, RW Tri, and V Sge. Observed lines are compared to synthetic line profiles computed using a model of rotating bi-conical winds from accretion disks. The wind model calculates the wind ionization structure self-consistently including photoionization from the disk and boundary layer and treats 3-D line radiation transfer in the Sobolev approximation. It is found that winds from accretion disks provide a good fit for reasonable parameters to the observed UV lines which include the P Cygni profiles for low inclination systems and pure emission at large inclination. Disk winds are preferable to spherical winds which originate on the white dwarf because they (1) require a much lower ratio of mass loss rate to accretion rate and are therefore more plausible energetically, (2) provide a natural source for a bi-conical distribution of mass outflow which produces strong scattering far above the disk leading to P Cygni profiles for low inclination systems, and pure line emission profiles at high inclination with the absence of eclipses in UV lines, and (3) produce rotation broadened pure emission lines at high inclination.

  6. Ultraviolet line diagnostics of accretion disk winds in cataclysmic variables

    NASA Technical Reports Server (NTRS)

    Vitello, Peter; Shlosman, Isaac

    1993-01-01

    The IUE data base is used to analyze the UV line shapes of the cataclysmic variables RW Sex, RW Tri, and V Sge. Observed lines are compared to synthetic line profiles computed using a model of rotating biconical winds from accretion disks. The wind model calculates the wind ionization structure self-consistently including photoionization from the disk and boundary layer and treats 3D line radiation transfer in the Sobolev approximation. It is found that winds from accretion disks provide a good fit for reasonable parameters to the observed UV lines which include the P Cygni profiles for low-inclination systems and pure emission at large inclination. Disk winds are preferable to spherical winds which originate on the white dwarf because they: (1) require a much lower ratio of mass-loss rate to accretion rate and are therefore more plausible energetically; (2) provide a natural source for a biconical distribution of mass outflow which produces strong scattering far above the disk leading to P Cygni profiles for low-inclination systems and pure line emission profiles at high inclination with the absence of eclipses in UV lines; and (3) produce rotation-broadened pure emission lines at high inclination.

  7. Line and continuum spectroscopy as diagnostic tools for gamma ray bursts

    SciTech Connect

    Liang, E.P.

    1990-12-01

    We review the theoretical framework of both line and continuum spectra formation in gamma ray bursts. These include the cyclotron features at 10's of keV, redshifted annihilation features at {approximately}400 keV, as well as other potentially detectable nuclear transition lines, atomic x-ray lines, proton cyclotron lines and plasma oscillation lines. By combining the parameters derived from line and continuum modeling we can try to reconstruct the location, geometry and physical conditions of the burst emission region, thereby constraining and discriminating the astrophysical models. Hence spectroscopy with current and future generations of detectors should provide powerful diagnostic tools for gamma ray bursters. 48 refs., 10 figs., 4 tabs.

  8. Linear Polarization Measurements of Chromospheric Emission Lines

    NASA Technical Reports Server (NTRS)

    Sheeley, N. R., Jr.; Keller, C. U.

    2003-01-01

    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 emission lines) 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 emission lines 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 lines tended to depolarize the scattered continuum radiation by amounts that ranged up to 0.2%. 2. Lines previously known to show scattering polarization just inside the limb (such as the Na I lambda5889 D2 and the He I lambda5876 D3 lines) 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 line, 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%) lines 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.

  9. Newly Identified Rydberg Emission Lines in Novae

    NASA Astrophysics Data System (ADS)

    Lynch, David K.; Rudy, R. J.; Bernstein, L. S.

    2008-09-01

    Newly Identified Rydberg Emission Lines in Novae David K. Lynch, Richard. J. Rudy (The Aerospace Corporation) & Lawrence S. Bernstein (Spectral Sciences, Inc.) Novae spectra in the near infrared frequently show a set of six emission lines that have not been positively identified (Williams, Longmore, & Geballe 1996, MNRAS, 279, 804; Lynch et al. 2001, AJ, 122, 2013; Rudy et al. 2002 ApJ, 573, 794; Lynch et al. 2004 Astron. J. 127, 1089-1097). These lines are at 0.8926, 1.1114, 1.1901, 1.5545, 2.0996 and 2.425 µm ± 0.005 µm. Krautter et al. (1984 A&A 137, 304) suggested that three of the lines were due to rydberg (hydrogenic) transitions in an unspecified atomic species that was in the 4th or 5th ionization stage (core charge = 4 & 5). We believe that Krautter et al.'s explanation is correct based on 4 additional lines that we have identified in the visible and near infrared spectrum of V723 Cassiopeiae. The observed Rydberg lines appear to originate from high angular momentum states with negligible quantum defects. The species cannot be determined with any certainty because in rydberg states, the outer electron sees a nucleus shielded by the inner electrons and together the inner atom appears to have a charge of +1, like hydrogen. As a result, the atom looks hydrogenic and species such as CV, NV, OV, MgV, SiV, etc. have their rydberg transitions at very similar wavelengths. All the lines represent permitted transitions, most likely formed by recombination. Atoms with core charges 4, 5 & 6 are rarely seen in the astrophysical environment because an extremely hot radiation field is necessary to ionize them. Thermonuclear runaways on the surface of a white dwarf can reach millions of degrees K, and thus there are enough X-ray photons available to achieve the necessary high ionization levels.

  10. Observations of southern emission-line stars

    NASA Technical Reports Server (NTRS)

    Henize, K. G.

    1976-01-01

    A catalog of 1929 stars showing H-alpha emission 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 emission-line stars equatorial (1900) and galactic coordinates, visual and photographic magnitudes, H-alpha emission 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 emission-line stars shows significant concentrations in the region of the small Sagittarius cloud and in the Carina region.

  11. CORA: Emission Line Fitting with Maximum Likelihood

    NASA Astrophysics Data System (ADS)

    Ness, Jan-Uwe; Wichmann, Rainer

    2011-12-01

    The advent of pipeline-processed data both from space- and ground-based observatories often disposes of the need of full-fledged data reduction software with its associated steep learning curve. In many cases, a simple tool doing just one task, and doing it right, is all one wishes. In this spirit we introduce CORA, a line fitting tool based on the maximum likelihood technique, which has been developed for the analysis of emission line spectra with low count numbers and has successfully been used in several publications. CORA uses a rigorous application of Poisson statistics. From the assumption of Poissonian noise we derive the probability for a model of the emission line spectrum to represent the measured spectrum. The likelihood function is used as a criterion for optimizing the parameters of the theoretical spectrum and a fixed point equation is derived allowing an efficient way to obtain line fluxes. As an example we demonstrate the functionality of the program with an X-ray spectrum of Capella obtained with the Low Energy Transmission Grating Spectrometer (LETGS) on board the Chandra observatory and choose the analysis of the Ne IX triplet around 13.5 Å.

  12. CORA - emission line fitting with Maximum Likelihood

    NASA Astrophysics Data System (ADS)

    Ness, J.-U.; Wichmann, R.

    2002-07-01

    The advent of pipeline-processed data both from space- and ground-based observatories often disposes of the need of full-fledged data reduction software with its associated steep learning curve. In many cases, a simple tool doing just one task, and doing it right, is all one wishes. In this spirit we introduce CORA, a line fitting tool based on the maximum likelihood technique, which has been developed for the analysis of emission line spectra with low count numbers and has successfully been used in several publications. CORA uses a rigorous application of Poisson statistics. From the assumption of Poissonian noise we derive the probability for a model of the emission line spectrum to represent the measured spectrum. The likelihood function is used as a criterion for optimizing the parameters of the theoretical spectrum and a fixed point equation is derived allowing an efficient way to obtain line fluxes. As an example we demonstrate the functionality of the program with an X-ray spectrum of Capella obtained with the Low Energy Transmission Grating Spectrometer (LETGS) on board the Chandra observatory and choose the analysis of the Ne IX triplet around 13.5 Å.

  13. BATMAN beam properties characterization by the beam emission spectroscopy diagnostic

    SciTech Connect

    Bonomo, F.; Ruf, B.; Schiesko, L.; Fantz, U.; Franzen, P.; Riedl, R.; Wünderlich, D.; Barbisan, M.; Pasqualotto, R.; Serianni, G.; Cristofaro, S.

    2015-04-08

    The ITER neutral beam heating systems are based on the production and acceleration of negative ions (H/D) up to 1 MV. The requirements for the beam properties are strict: a low core beam divergence (< 0.4 °) together with a low source pressure (≤ 0.3 Pa) would permit to reduce the ion losses along the beamline, keeping the stripping particle losses below 30%. However, the attainment of such beam properties is not straightforward. At IPP, the negative ion source testbed BATMAN (BAvarian Test MAchine for Negative ions) allows for deepening the knowledge of the determination of the beam properties. One of the diagnostics routinely used to this purpose is the Beam Emission Spectroscopy (BES): the H{sub α} light emitted in the beam is detected and the corresponding spectra are evaluated to estimate the beam divergence and the stripping losses. The BES number of lines of sight in BATMAN has been recently increased: five horizontal lines of sight providing a vertical profile of the beam permit to characterize the negative ion beam properties in relation to the source parameters. Different methods of H{sub α} spectra analysis are here taken into account and compared for the estimation of the beam divergence and the amount of stripping. In particular, to thoroughly study the effect of the space charge compensation on the beam divergence, an additional hydrogen injection line has been added in the tank, which allows for setting different background pressure values (one order of magnitude, from about 0.04 Pa up to the source pressure) in the beam drift region.

  14. Photoionization of Highly Charged Argon Ions and Their Diagnostic Lines

    NASA Astrophysics Data System (ADS)

    Nahar, Sultana N.

    2012-06-01

    %TEXT OF YOUR ABSTRACT Lines of highly charged He-like and Li-like ions in the ultraviolet and X-ray regions provide useful diagnostics for the physical and chemical conditions of the astrophysical as well as fusion plasmas. For example, Ar XVII lines in a Syfert galaxy have been measured by the X-ray space observatory Chandra. Results on photoionization of Ar XVI and Ar XVII obtained from relativistic Breit-Pauli R-matrix method and close-coupling approximation will be presented. Important features for level-specific photoionization for the diagnostic w, x, y, z lines of He-like Ar XVII in the ultraviolet region will be illustrated. Although monotonous decay dominates the low energy photoionization for these ions, strong resonances appear in the high energy region indicating higher recombination, inverse process of photoionization, at high temperature. The spectra of the well known 22 diagnostics dielectronic satellite lines of Li-like Ar XVI will be shown produced from the the KLL resonances in photoionization. Acknowledgement: Partially supported by DOE, NSF; Computational work was carried out at the Ohio Supercomputer Center

  15. Spectral diagnostics of high energy emission in lambda Eri

    NASA Technical Reports Server (NTRS)

    Smith, Myron

    1995-01-01

    Multi-line observations of the optical spectrum of lambda Eri demonstrates that rapidly varying, low-velocity emissions occur in several He I lines even when H alpha shows no emission. A peculiar aspect of the He I emissions is that the ratio 5876/6678 is = 1. A theory of helium line formation generally admits two common emission mechanisms. The first is recombination/cascades, which is well known to give a ratio of greater than or equal to 3. The second is a non-LTE effect that occurs in hot (O-type) photospheres when resonance He I 584 radiation becomes transparent and drives single lines along into the emission. To accommodate a ratio of 5876/6678 = 1 may require that both processes sometimes operate at the same time, presumably in separate localities near the surface of this star.

  16. NON-EQUILIBRIUM IONIZATION EFFECTS ON THE DENSITY LINE RATIO DIAGNOSTICS OF O IV

    SciTech Connect

    Olluri, K.; Gudiksen, B. V.; Hansteen, V. H.

    2013-04-10

    The dynamic timescales in the solar atmosphere are shorter than the ionization and recombination times of many ions used for line ratio diagnostics of the transition region and corona. The long ionization and recombination times for these ions imply that they can be found far from their equilibrium temperatures, and spectroscopic investigations require more care before being trusted in giving correct information on local quantities, such as density and temperature. By solving the full time-dependent rate equations for an oxygen model atom in the three-dimensional numerical model of the solar atmosphere generated by the Bifrost code, we are able to construct synthetic intensity maps and study the emergent emission. We investigate the method of electron density diagnostics through line ratio analysis of the O IV 140.1 nm to the 140.4 nm ratio, the assumptions made in carrying out the diagnostics, and the different interpretations of the electron density. The results show big discrepancies between emission in statistical equilibrium and emission where non-equilibrium (NEQ) ionization is treated. Deduced electron densities are up to an order of magnitude higher when NEQ effects are accounted for. The inferred electron density is found to be a weighted mean average electron density along the line of sight and has no relation to the temperature of emission. This study shows that numerical modeling is essential for electron density diagnostics and is a valuable tool when the ions used for such studies are expected to be out of ionization equilibrium. Though this study has been performed on the O IV ion, similar results are also expected for other transition region ions.

  17. Fe X Emission Lines in Solar and Stellar Spectra

    NASA Astrophysics Data System (ADS)

    Foster, V. J.; Mathioudakis, M.; Keenan, F. P.; Drake, J. J.; Widing, K. G.

    1996-12-01

    Theoretical electron density sensitive emission line ratios involving Fe X 3s23p5-3s23p43d transitions in the 170-190 Å wavelength range are compared with observational data for a solar active region and flares, obtained during the Skylab mission, and Cen and Procyon observations from the Extreme Ultraviolet Explorer (EUVE) satellite. Electron densities derived from the majority of the ratios are consistent for the events but are in poor agreement with the values of Ne estimated from diagnostic lines in other species observed in the spectra, casting doubt on the accuracy of the theoretical line ratio calculations and, hence, the atomic data of Mohan et al. used in their derivation. At low Ne, the present ratios are significantly different from those of Young et al., while the latter imply densities that are in somewhat better agreement with densities derived from other diagnostics. This would appear to indicate that the electron impact excitation rates of Bhatia & Doschek adopted by Young et al. are to be preferred over the Mohan et al. results.

  18. EVOLUTION OF [O III] {lambda}5007 EMISSION-LINE PROFILES IN NARROW EMISSION-LINE GALAXIES

    SciTech Connect

    Wang, J.; Mao, Y. F.; Wei, J. Y.

    2011-11-01

    The active galactic nucleus (AGN)-host co-evolution issue is investigated here by focusing on the evolution of the [O III] {lambda}5007 emission-line profile. A large sample of narrow emission-line galaxies is selected from the Max-Planck Institute for Astrophysics/Johns Hopkins University Sloan Digital Sky Survey DR7 catalog to simultaneously measure both the [O III] line profile and circumnuclear stellar population in an individual spectrum. By requiring that (1) the [O III] line signal-to-noise ratio is larger than 30 and (2) the [O III] line width is larger than the instrumental resolution by a factor of two, our sample is narrowed down to 2333 Seyfert galaxies/LINERs (AGNs), 793 transition galaxies, and 190 star-forming galaxies. In addition to the commonly used profile parameters (i.e., line centroid, relative velocity shift, and velocity dispersion), two dimensionless shape parameters, skewness and kurtosis, are used to quantify the line shape deviation from a pure Gaussian function. We show that the transition galaxies are systematically associated with narrower line widths and weaker [O III] broad wings than the AGNs, which implies that the kinematics of emission-line gas are different in the two kinds of objects. By combining the measured host properties and line shape parameters, we find that the AGNs with stronger blue asymmetries tend to be associated with younger stellar populations. However, a similar trend is not identified in the transition galaxies. The failure likely results from a selection effect in which the transition galaxies are systematically associated with younger stellar populations than the AGNs. The evolutionary significance revealed here suggests that both narrow-line region kinematics and outflow feedback in AGNs co-evolve with their host galaxies.

  19. Evolution of [O III] λ5007 Emission-line Profiles in Narrow Emission-line Galaxies

    NASA Astrophysics Data System (ADS)

    Wang, J.; Mao, Y. F.; Wei, J. Y.

    2011-11-01

    The active galactic nucleus (AGN)-host co-evolution issue is investigated here by focusing on the evolution of the [O III] λ5007 emission-line profile. A large sample of narrow emission-line galaxies is selected from the Max-Planck Institute for Astrophysics/Johns Hopkins University Sloan Digital Sky Survey DR7 catalog to simultaneously measure both the [O III] line profile and circumnuclear stellar population in an individual spectrum. By requiring that (1) the [O III] line signal-to-noise ratio is larger than 30 and (2) the [O III] line width is larger than the instrumental resolution by a factor of two, our sample is narrowed down to 2333 Seyfert galaxies/LINERs (AGNs), 793 transition galaxies, and 190 star-forming galaxies. In addition to the commonly used profile parameters (i.e., line centroid, relative velocity shift, and velocity dispersion), two dimensionless shape parameters, skewness and kurtosis, are used to quantify the line shape deviation from a pure Gaussian function. We show that the transition galaxies are systematically associated with narrower line widths and weaker [O III] broad wings than the AGNs, which implies that the kinematics of emission-line gas are different in the two kinds of objects. By combining the measured host properties and line shape parameters, we find that the AGNs with stronger blue asymmetries tend to be associated with younger stellar populations. However, a similar trend is not identified in the transition galaxies. The failure likely results from a selection effect in which the transition galaxies are systematically associated with younger stellar populations than the AGNs. The evolutionary significance revealed here suggests that both narrow-line region kinematics and outflow feedback in AGNs co-evolve with their host galaxies.

  20. Line Emission from Radiation-pressurized H II Regions. I. Internal Structure and Line Ratios

    NASA Astrophysics Data System (ADS)

    Yeh, Sherry C. C.; Verdolini, Silvia; Krumholz, Mark R.; Matzner, Christopher D.; Tielens, Alexander G. G. M.

    2013-05-01

    The emission line ratios [O III] λ5007/Hβ and [N II] λ6584/Hα have been adopted as an empirical way to distinguish between the fundamentally different mechanisms of ionization in emission-line galaxies. However, detailed interpretation of these diagnostics requires calculations of the internal structure of the emitting H II regions, and these calculations depend on the assumptions one makes about the relative importance of radiation pressure and stellar winds. In this paper, we construct a grid of quasi-static H II region models to explore how choices about these parameters alter H II regions' emission line ratios. We find that when radiation pressure is included in our models, H II regions reach a saturation point beyond which further increase in the luminosity of the driving stars does not produce any further increase in effective ionization parameter, and thus does not yield any further alteration in an H II region's line ratio. We also show that if stellar winds are assumed to be strong, the maximum possible ionization parameter is quite low. As a result of this effect, it is inconsistent to simultaneously assume that H II regions are wind-blown bubbles and that they have high ionization parameters; some popular H II region models suffer from this inconsistency. Our work in this paper provides a foundation for a companion paper in which we embed the model grids we compute here within a population synthesis code that enables us to compute the integrated line emission from galactic populations of H II regions.

  1. Emission line spectropolarimetry and circumstellar structures

    NASA Astrophysics Data System (ADS)

    Vink, Jorick S.

    2015-10-01

    We discuss the role of linear emission-line polarimetry in a wide set of stellar environments, involving the accretion disks around young pre-main sequence stars, to the aspherical outflows from O stars, luminous blue variables and Wolf-Rayet stars, just prior to explosion as a supernova or a gamma-ray burst. We predict subtle QU line signatures, such as single/double QU loops for un/disrupted disks. Whilst there is plenty of evidence for single QU loops, suggesting the presence of disrupted disks around young stars, current sensitivity (with S/N of order 1000) is typically not sufficient to allow for quantitative 3D Monte Carlo modeling. However, the detection of our predicted signatures is expected to become feasible with the massive improvement in sensitivity of extremely large mirrors.

  2. Passive optical diagnostic of Xe-propelled Hall thrusters. I. Emission cross sections

    SciTech Connect

    Chiu Yuhui; Austin, Brad L.; Williams, Skip; Dressler, Rainer A.; Karabadzhak, George F.

    2006-06-01

    This paper presents a set of xenon apparent emission excitation cross sections for emission lines that have diagnostic value in the analysis of Xe-propelled Hall thruster plasmas. Emission cross sections are presented for three excitation processes involving ground-state xenon atoms: e{sup -}+Xe, Xe{sup +}+Xe, and Xe{sup 2+}+Xe. The cross sections are derived from luminescence spectra produced at single-collision conditions. Apparent emission excitation cross sections are tabulated for 12 visible and 8 near-infrared lines for electron energies ranging from 10 to 70 eV. In case of the near-infrared lines, radiation trapping effects are accounted for by measuring the detailed pressure dependence of the apparent emission cross sections and extrapolating to zero pressure. A semiempirical expression for the pressure dependence is derived that allows zero-pressure extrapolation from threshold to 70 eV. Ion-induced cross sections are reported for the same emission lines at an energy per unit charge E/q of 300 eV, chosen for typical Hall thruster operating voltages. Radiation trapping effects are negligible for the ion emission excitation cross sections between 0.1 and 2.0 mTorr in the present luminescence experiment.

  3. The resonance lines of MG2 as diagnostics of the upper solar chromosphere

    NASA Technical Reports Server (NTRS)

    Avrett, Eugene H.

    1994-01-01

    The resonance lines of singly ionized magnesium, the MgII h&k lines at about 280 nm, are two of the small number of lines in the solar spectrum that are optically thick in the chromospheric part of the solar atmosphere. Potentially these lines contain information on the initial temperature rise that occurs at the top of the photosphere. Unfortunately, few good observations of the lines exist due to their wavelength near 280 nm the ultraviolet. However, a fair number of observations (on the order of 200) are available from the data base of the UltraViolet Polarimeter and Spectrometer (UVSP) instrument that flew on board of NASA's Solar Maximum Mission (SMM) satellite. In addition, this data base contains a number of spectra that include the Mg I resonance line at (lambda)285.2nm, just longward of the h&k lines. The neutral magnesium line is not as strong as its ionic counterparts and samples slightly lower parts of the atmosphere. Its width is a sensitive diagnostic of the ionization balance between neutral and singly ionized magnesium, which determines the opacity scale (and formation height) of other diagnostically important MgI lines like the 457.1 nm intercombination line, the magnesium b lines and the infrared MgI emission lines near 12 microns. Analysis of the observed line profiles shows that it is necessary to include the effects of partial frequency redistribution (PRD) in the formation of the line as in the case of the h&k lines. This implies that the core of the line is very sensitive to the way scattering is treated in the modeling of the line, and in turn this allows us to separate the uncertain effects in the atomic data (viz. the Van der Waals broadening) from the uncertainties in the underlying atmospheric model. The main objective of this research was to compare observed spectra of the magnesium resonance lines against theoretical line profiles calculated from recent models of the solar atmosphere by Fontenla et al., hereafter called FAL. These

  4. A NEW CALCULATION OF Ne IX LINE DIAGNOSTICS

    SciTech Connect

    Smith, Randall K.; Chen Guoxin; Kirby, Kate; Brickhouse, Nancy S.

    2009-07-20

    We describe the effect that new atomic calculations, including fully relativistic R-matrix calculations of collisional excitation rates and level-specific dielectronic and radiative recombination rates, have on line ratios from the astrophysically significant ion Ne IX. The new excitation rates systematically change some predicted Ne IX line ratios by 25% at temperatures at or below the temperature of maximum emissivity (4 x 10{sup 6} K), while the new recombination rates lead to systematic changes at higher temperatures. The new line ratios are shown to agree with observations of Capella and {sigma}{sup 2} CrB significantly better than older line ratios, showing that 25%-30% accuracy in atomic rates is inadequate for high-resolution X-ray observations from existing spectrometers.

  5. Line emission from H II blister models

    NASA Technical Reports Server (NTRS)

    Rubin, R. H.

    1984-01-01

    Numerical techniques to calculate the thermal and geometric properties of line emission from H II 'blister' regions are presented. It is assumed that the density distributions of the H II regions are a function of two dimensions, with rotational symmetry specifying the shape in three-dimensions. The thermal and ionization equilibrium equations of the problem are solved by spherical modeling, and a spherical sector approximation is used to simplify the three-dimensional treatment of diffuse ionizing radiation. The global properties of H II 'blister' regions near the edges of a molecular cloud are simulated by means of the geometry/density distribution, and the results are compared with observational data. It is shown that there is a monotonic increase of peak surface brightness from the i = 0 deg (pole-on) observational position to the i = 90 deg (edge-on) position. The enhancement of the line peak intensity from the edge-on to the pole-on positions is found to depend on the density, stratification, ionization, and electron temperature weighting. It is found that as i increases, the position of peak line brightness of the lower excitation species is displaced to the high-density side of the high excitation species.

  6. The Formation of IRIS Diagnostics. VII. The Formation of the OI 135.56 NM Line in the Solar Atmosphere

    NASA Astrophysics Data System (ADS)

    Lin, Hsiao-Hsuan; Carlsson, Mats

    2015-11-01

    The O i 135.56 nm line is covered by NASA's Interface Region Imaging Spectrograph (IRIS) small explorer mission which studies how the solar atmosphere is energized. We study here the formation and diagnostic potential of this line by means of non-local thermodynamic equilibrium modeling employing both 1D semi-empirical and 3D radiation magnetohydrodynamic models. We study the basic formation mechanisms and derive a quintessential model atom that incorporates essential atomic physics for the formation of the O i 135.56 nm line. This atomic model has 16 levels and describes recombination cascades through highly excited levels by effective recombination rates. The ionization balance O i/O ii is set by the hydrogen ionization balance through charge exchange reactions. The emission in the O i 135.56 nm line is dominated by a recombination cascade and the line is optically thin. The Doppler shift of the maximum emission correlates strongly with the vertical velocity in its line forming region, which is typically located at 1.0-1.5 Mm height. The total intensity of the line emission is correlated with the square of the electron density. Since the O i 135.56 nm line is optically thin, the width of the emission line is a very good diagnostic of non-thermal velocities. We conclude that the O i 135.56 nm line is an excellent probe of the middle chromosphere, and compliments other powerful chromospheric diagnostics of IRIS such as the Mg ii h & k lines and the C ii lines around 133.5 nm.

  7. A Diagnostic Test for Determining the Location of the GeV Emission in Powerful Blazars

    NASA Technical Reports Server (NTRS)

    Dotson, Amanda; Georganopoulos, Markos; Kazanas, Demosthenes; Perlman, Eric

    2011-01-01

    An issue currently under debate in the literature is how far from the black hole is the Fermi-observed GeV emission of powerful blazars emitted. Here we present a clear diagnostic tool for testing whether the Ge V emission site is located within the sub-pc broad emission line (BLR) region or further out in the few pc scale molecular torus (MT) environment. Within the BLR the scatteri takes place at the onset of the Klein-Nishina regime, causing the electron cooling time to become almost energy independent and as a result, the variation of high-energy emission is expected to be achromatic. Contrarily, if the emission site is located outside the BLR, the expected GeY variability is energy-dependent and with amplitude increasing with energy. We demonstrate this using time-dependent numerical simulations of blazar variability.

  8. Atomic line emission analyzer for hydrogen isotopes

    DOEpatents

    Kronberg, J.W.

    1993-03-30

    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 emission 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 lines 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.

  9. Atomic line emission analyzer for hydrogen isotopes

    DOEpatents

    Kronberg, J.W.

    1991-05-08

    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 emission 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 lines 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.

  10. Atomic line emission analyzer for hydrogen isotopes

    DOEpatents

    Kronberg, James W.

    1993-01-01

    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 emission 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 lines 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.

  11. FE-XIII Infrared / FE-XIV Green Line Ratio Diagnostics (P55)

    NASA Astrophysics Data System (ADS)

    Srivastava, A. K.; et al.

    2006-11-01

    aks.astro.itbhu@gmail.com We consider the first 27-level atomic model of Fe XIII (5.9 < log Te < 6.4 K) to estimate its ground level populations, taking account of electron as well as proton collisional excitations and de-excitations, radiative cascades, radiative excitations and de-excitations. Radiative cascade is important but the effect of dilution factor is negligible at higher electron densities. The 3 P1-3P0 and 3P2-3P1 transitions in the ground configuration 3s2 3p2 of Fe XIII result in two forbidden coronal emission lines in the infrared region, namely 10747 Å and 10798 Å., while the 5303 Å green line is formed in the 3s2 3p 2 2 ground configuration of Fe XIV as a result of P3 / 2 - P1 / 2 magnetic dipole transition. The line-widths of appropriate pair of forbidden coronal emission lines observed simultaneously can be useful diagnostic tool to deduce temperature and non-thermal velocity in the large scale coronal structures using intensity ratios of the lines as the temperature signature, instead of assuming ion temperature to be equal to the electron temperature. Since the line intensity ratios IG5303/IIR10747 and IG5303/IIR10798 have very week density dependence, they are ideal monitors of temperature mapping in the solar corona.

  12. An Intrinsic Baldwin Effect in the H Beta Broad Emission Line in the Spectrum of NGC 5548

    NASA Technical Reports Server (NTRS)

    Gilbert, Karoline M.; Peterson, Bradley M.

    2003-01-01

    We investigate the possibility of an intrinsic Baldwin effect (i.e., nonlinear emission-line response to continuum variations) in the broad HP emission line of the active galaxy NGC 5548 using crosscorrelation techniques to remove light-travel time effects from the data. We find a nonlinear relationship between the HP emission line and continuum fluxes that is in good agreement with theoretical predictions. We suggest that similar analysis of multiple lines might provide a useful diagnostic of physical conditions in the broad-line region.

  13. X-ray lines from MG VIII and SI X ions and their diagnostic use

    NASA Astrophysics Data System (ADS)

    Dwivedi, Bhola N.

    The solar X-ray emission lines from Mg VIII and Si X ions have been studied. The variation of the theoretical line-intensity ratios from Mg VIII and Si X as functions of electron density are found to be good density monitors of the emitting regions of solar plasma. The computed values of line intensity from these ions based on the Kopp and Orrall model have been used to derive the electron density of the quiet sun and coronal holes. Electron densities of 10 exp 9/cu cm and 4.6 x 10 exp 8/cu cm are estimated at the electron temperatures of 8 x 10 exp 5 K and 1.6 x 10 exp 6 K for the quiet sun whereas the respective values of 5.4 x 10 exp 8/cu cm and 1.7 x 10 exp 8/cu cm are obtained for the coronal holes. The line-intensity ratios studied here are independent of temperature variation and are therefore excellent candidates for electron-density diagnostics. However, observational data with improved spectral resolution is needed for using X-ray-line pairs studied for their diagnostic use.

  14. Atomic Data and Emission Line Intensities for CA VII

    NASA Technical Reports Server (NTRS)

    Landi, E.; Bhatia, A. K.

    2003-01-01

    In the present work we calculate energy levels, transition probabilities and electron-ion collisional excitation rates for the 3s(sup 2)3p(sup 2), 3s3p(sup 3) and 3s(sup 2)3p3d configurations of the silicon-like ion Ca VII. The total number of intermediate coupling levels considered is 27. Collision strengths are calculated at seven incident electron energies: 8, 10, 15, 20, 30,40 and 60 Ry, using the Distorted Wave approximation and a 5-configuration model. Excitation rate coefficients are calculated by assuming a Maxwellian distribution of velocities and are used to calculate level populations and line emissivities under the assumption of statistical equilibrium. Line intensity ratios are calculated and compared with observed values measured from SERTS and SOHO/CDS spectra. The diagnostic potential of Ca VII is demonstrated, with particular emphasis on the possibility to measure the Ne/Ca relative abundance through simultaneous observations of Ca VII and N VI lines. Ca VII proves to be an excellent tool for the study of the FIP effect in the solar transition region.

  15. IFU spectroscopy of 10 early-type galactic nuclei - II. Nuclear emission line properties

    NASA Astrophysics Data System (ADS)

    Ricci, T. V.; Steiner, J. E.; Menezes, R. B.

    2014-05-01

    Although it is well known that massive galaxies have central black holes, most of them accreting at low Eddington ratios, many important questions still remain open. Among them are the nature of the ionizing source, the characteristics and frequencies of the broad-line region and of the dusty torus. We report observations of 10 early-type galactic nuclei, observed with the Gemini Multi Object Spectrograph in integral field unit mode, installed on the Gemini South telescope, analysed with standard techniques for spectral treatment and compared with results obtained with principal component analysis Tomography (Paper I). We performed spectral synthesis of each spaxel of the data cubes and subtracted the stellar component from the original cube, leaving a data cube with emission lines only. The emission lines were decomposed in multi-Gaussian components. We show here that, for eight galaxies previously known to have emission lines, the narrow-line region can be decomposed in two components with distinct line widths. In addition to this, broad Hα emission was detected in six galaxies. The two galaxies not previously known to have emission lines show weak Hα+[N II] lines. All 10 galaxies may be classified as low-ionization nuclear emission regions in diagnostic diagrams and seven of them have bona fide active galactic nuclei with luminosities between 1040 and 1043 erg s-1. Eddington ratios are always <10-3.

  16. Diagnostics of the κ-distribution using Si III lines in the solar transition region

    NASA Astrophysics Data System (ADS)

    Dzifčáková, E.; Kulinová, A.

    2011-07-01

    Aims: The solar transition region satisfies the conditions for appearance of the non-thermal κ-distribution. We aim to prove the occurrence of the non-thermal κ-distribution in the solar transition region and diagnose its parameters. Methods: The intensity ratios of Si iii lines observed by SUMER in 1100-1320 Å region do not correspond to the line ratios computed under the assumption of the Maxwellian electron distribution. We computed a set of synthetic Si iii spectra for the electron κ-distributions with different values of the parameter κ. We had to include the radiation field in our calculations to explain the observed line ratios. We propose diagnostics of the parameter κ and other plasma parameters and analyze the effect of the different gradient of differential emission measures (DEM) on the presented calculations. Results: The used line ratios are sensitive to T, density and the parameter κ. All these parameters were determined from the SUMER observations for the coronal hole (CH), quiet Sun (QS) and active region (AR) using our proposed diagnostics. A strong gradient of DEM influences the diagnosed parameters of plasma. The essential contributions to the total line intensities do not correspond to single T but a wider range of T, and they originate in different atmospheric layers. The amount of the contributions from these atmospheric layers depends on the gradient of DEM and the shape of the electron distribution function. Conclusions: The κ-distribution is able to explain the observed Si iii line spectrum in the transition region. The degree of non-thermality increases with the activity of the solar region, it is lower for CH and higher for the AR. The DEM influences the diagnosed T and Ne but it has only little effect on the diagnostics of the parameter κ.

  17. Excitation of emission lines by fluorescence and recombination in IC 418

    NASA Astrophysics Data System (ADS)

    Escalante, Vladimir; Morisset, Cristophe; Georgiev, Leonid

    2012-08-01

    We predict intensities of lines of CII, NI, NII, OI and OII and compare them with a deep spectroscopic survey of IC 418 to test the effect of excitation of nebular emission lines by continuum fluorescence of starlight. Our calculations use a nebular model and a synthetic spectrum of its central star to take into account excitation of the lines by continuum fluorescence and recombination. The NII spectrum is mostly produced by fluorescence due to the low excitation conditions of the nebula, but many CII and OII lines have more excitation by fluorescence than recombination. In the neutral envelope, the NI permitted lines are excited by fluorescence, and almost all the OI lines are excited by recombination. Electron excitation produces the forbidden optical lines of OI, but continuum fluorescence excites most of the NI forbidden line intensities. Lines excited by fluorescence of light below the Lyman limit thus suggest a new diagnostic to explore the photodissociation region of a nebula.

  18. An objective prism survey of emission line galaxies

    NASA Astrophysics Data System (ADS)

    Liu, J.-Y.; Huang, Y.-W.; Feng, X.-C.

    1986-09-01

    The first list of emission line objects detected as part of an object prism survey of emission line galaxies begun in China in 1981 is presented. The instrument and observations are described, and the identification of emission-line galaxies is discussed. The spectral structural classification of the presented objects is addressed. On a dozen plates covering some 220 square degrees of sky, 50 emission line objects were detected, 47 of which are galaxies and the other three of which are planetary nebulae. Finding charts of the objects are presented.

  19. Alternative diagnostic diagrams and the `forgotten' population of weak line galaxies in the SDSS

    NASA Astrophysics Data System (ADS)

    Cid Fernandes, R.; Stasińska, G.; Schlickmann, M. S.; Mateus, A.; Vale Asari, N.; Schoenell, W.; Sodré, L.

    2010-04-01

    A numerous population of weak line galaxies (WLGs) is often left out of statistical studies on emission-line galaxies (ELGs) due to the absence of an adequate classification scheme, since classical diagnostic diagrams, such as [OIII]/Hβ versus [NII]/Hα (the BPT diagram), require the measurement of at least four emission lines. This paper aims to remedy this situation by transposing the usual divisory lines between star-forming (SF) galaxies and active galactic nuclei (AGN) hosts and between Seyferts and LINERs to diagrams that are more economical in terms of line quality requirements. By doing this, we rescue from the classification limbo a substantial number of sources and modify the global census of ELGs. More specifically, (1) we use the Sloan Digital Sky Survey Data Release 7 to constitute a suitable sample of 280000 ELGs, one-third of which are WLGs. (2) Galaxies with strong emission lines are classified using the widely applied criteria of Kewley et al., Kauffmann et al. and Stasińska et al. to distinguish SF galaxies and AGN hosts and Kewley et al. to distinguish Seyferts from LINERs. (3) We transpose these classification schemes to alternative diagrams keeping [NII]/Hα as a horizontal axis, but replacing Hβ by a stronger line (Hα or [OII]), or substituting the ionization-level sensitive [OIII]/Hβ ratio with the equivalent width of Hα (WHα). Optimized equations for the transposed divisory lines are provided. (4) We show that nothing significant is lost in the translation, but that the new diagrams allow one to classify up to 50 per cent more ELGs. (5) Introducing WLGs in the census of galaxies in the local Universe increases the proportion of metal-rich SF galaxies and especially LINERs. In the course of this analysis, we were led to make the following points. (i) The Kewley et al. BPT line for galaxy classification is generally ill-used. (ii) Replacing [OIII]/Hβ by WHα in the classification introduces a change in the philosophy of the distinction

  20. Lower hybrid emission diagnostics on the NASA Lewis bumpy torus

    NASA Technical Reports Server (NTRS)

    Mallavarpu, R.

    1977-01-01

    The feasibility of using RF emission near the lower hybrid frequency of the NASA Lewis Bumpy Torus plasma for diagnostic purposes is examined. The emission is detected using a spectrum analyzer and a 50 omega miniature coaxial antenna that is sensitive to the polarization of the incoming signal. The frequency shift of the lower hybrid emission peak is monitored as a function of the background pressure, electrode voltage, electrode ring configuration and the strength of the toroidal dc magnetic field. Simultaneous measurements of the average plasma density are made with a polarization diplexing microwave interferometer. Data derived from the experiment are discussed with reference to the following: (1) the strength of the dc magnetic field in the emitting region; (2) comparison of the lower hybrid plasma density with the average plasma density; and (3) validity of the cold plasma lower hybrid resonance formula in the high density operating regime of the bumpy torus plasma.

  1. Chemo-population multizone models for emission line evolution of star forming galaxies

    NASA Astrophysics Data System (ADS)

    Valle, G.; Shore, S. N.

    2007-02-01

    Aims:We apply the nonlinear chemo-population (CP) models for galactic star formation and abundance evolution to the prediction of emission line diagnostics. Methods: We interfaced the CP code with the photoionization code Cloudy. Using the self-consistently generated star forming rates and abundance histories we predict the time dependences of the nebular line emissivities from model H II regions. We also simulated some effects of collisions, stripping, and accretion events on the emission line diagnostics. Results: We find, despite using extremely simplified input fluxes (i.e. blackbodies scaled to a range of effective temperatures but without detailed model atmospheres or population synthesis), the models reproduce many features of the observations. In particular, we suggest that the line ratios for highly ionized species (e.g. [O III] vs. [N II]) are more sensitive to the galactic history, while the exclusively ionization diagnostics (e.g. [O II] vs. [O I]) are more sensitive to the underlying stellar population and the composite ultraviolet flux distribution. We discuss some reasons for this and conclude that a coupled treatment of the galactic population and chemical evolution is essential for interpretation of the data. We also find that collisional and stripped models cover a wider range in the diagnostic diagrams that provide clues to the environmental effects.

  2. Helium-Like Iron Line Temperature Diagnostics in Clusters of Galaxies

    NASA Technical Reports Server (NTRS)

    Swartz, Douglas A.; Sulkanen, Martin E.

    1993-01-01

    The emission complex around 6.7 keV, arising from He-like Fe lines and their dielectronic satellites, has been observed at low resolution in a number of clusters of galaxies. With sufficient spectral resolution as in, e.g., solar flare observations, the ratio, G = (x + y + z)/w, of the intercombination (x and y) and forbidden (z) to the resonance (w) lines arising from the n = 2 level of the He-like ion, is a sensitive temperature diagnostic. We examine this role for G in the context of spatially and spectrally resolved observations of clusters of galaxies. The temperature behavior of this ratio is strongly dependent on the spectral resolution. We introduce an alternative definition for G that includes the contribution of satellite lines and improves the temperature fidelity of this diagnostic. We find that deprojection of the observed value of G along a line of sight through the cluster can yield accurate temperature profiles for temperatures in the range 10(exp 7)-10(exp 8) K that do not suffer from the cluster model uncertainties inherent in deconvolution of broad-band X-ray surface brightness profiles.

  3. Enhanced line emission from laser-produced plasmas

    NASA Technical Reports Server (NTRS)

    Timmer, C.; Srivastava, S. K.; Hall, T. E.; Fucaloro, A. F.

    1991-01-01

    This communication reports the first systematic study on background gas-induced spectral-line-emission enhancement from laser-produced plasmas. Line emission from aluminum plasmas was enhanced by factors of up to 35 by the introduction of He, Ne, Xe, or N2. The enhancement has been attributed to three-body recombination.

  4. Emission spectroscopy for coal-fired cyclone furnace diagnostics.

    PubMed

    Wehrmeyer, Joseph A; Boll, David E; Smith, Richard

    2003-08-01

    Using a spectrograph and charge-coupled device (CCD) camera, ultraviolet and visible light emission spectra were obtained from a coal-burning electric utility's cyclone furnaces operating at either fuel-rich or fuel-lean conditions. The aim of this effort is to identify light emission signals that can be related to a cyclone furnace's operating condition in order to adjust its air/fuel ratio to minimize pollutant production. Emission spectra at the burner and outlet ends of cyclone furnaces were obtained. Spectra from all cyclone burners show emission lines for the trace elements Li, Na, K, and Rb, as well as the molecular species OH and CaOH. The Ca emission line is detected at the burner end of both the fuel-rich and fuel-lean cyclone furnaces but is not detected at the outlet ends of either furnace type. Along with the disappearance of Ca is a concomitant increase in the CaOH signal at the outlet end of both types of furnaces. The OH signal strength is in general stronger when viewing at the burner end rather than the exhaust end of both the fuel-rich and fuel-lean cyclone furnaces, probably due to high, non-equilibrium amounts of OH present inside the furnace. Only one molecular species was detected that could be used as a measure of air/fuel ratio: MgOH. It was detected at the burner end of fuel-rich cyclone furnaces but not detected in fuel-lean cyclone furnaces. More direct markers of air/fuel ratio, such as CO and O2 emission, were not detected, probably due to the generally weak nature of molecular emission relative to ambient blackbody emission present in the cyclone furnaces, even at ultraviolet wavelengths. PMID:14661846

  5. SIMPLE MODELS OF METAL-LINE ABSORPTION AND EMISSION FROM COOL GAS OUTFLOWS

    SciTech Connect

    Prochaska, J. Xavier; Rubin, Kate

    2011-06-10

    We analyze the absorption and emission-line profiles produced by a set of simple, cool gas wind models motivated by galactic-scale outflow observations. We implement Monte Carlo radiative transfer techniques that track the propagation of scattered and fluorescent photons to generate one-dimensional spectra and two-dimensional spectral images. We focus on the Mg II {lambda}{lambda}2796, 2803 doublet and Fe II UV1 multiplet at {lambda} {approx} 2600 A, but the results are applicable to other transitions that trace outflows (e.g., Na I, H I Ly{alpha}, Si II). By design, the resonance transitions show blueshifted absorption but one also predicts strong resonance and fine-structure line emission at roughly the systemic velocity. This line-emission 'fills in' the absorption, reducing the equivalent width by up to 50%, shifting the absorption-line centroid by tens of km s{sup -1}, and reducing the effective opacity near systemic. Analysis of cool gas outflows that ignores this line emission may incorrectly infer that the gas is partially covered, measure a significantly lower peak optical depth, and/or conclude that gas at systemic velocity is absent (e.g., an interstellar or slowly infalling component). Because the Fe II lines are connected by optically thin transitions to fine-structure levels, their profiles more closely reproduce the intrinsic opacity of the wind. Together these results naturally explain the absorption and emission-line characteristics observed for star-forming galaxies at z < 1. We also study a scenario promoted to describe the outflows of z {approx} 3 Lyman break galaxies and find profiles inconsistent with the observations due to scattered photon emission. Although line emission complicates the analysis of absorption-line profiles, the surface brightness profiles offer a unique means of assessing the morphology and size of galactic-scale winds. Furthermore, the kinematics and line ratios offer powerful diagnostics of outflows, motivating deep

  6. Simple Models of Metal-line Absorption and Emission from Cool Gas Outflows

    NASA Astrophysics Data System (ADS)

    Prochaska, J. Xavier; Kasen, Daniel; Rubin, Kate

    2011-06-01

    We analyze the absorption and emission-line profiles produced by a set of simple, cool gas wind models motivated by galactic-scale outflow observations. We implement Monte Carlo radiative transfer techniques that track the propagation of scattered and fluorescent photons to generate one-dimensional spectra and two-dimensional spectral images. We focus on the Mg II λλ2796, 2803 doublet and Fe II UV1 multiplet at λ ≈ 2600 Å, but the results are applicable to other transitions that trace outflows (e.g., Na I, H I Lyα, Si II). By design, the resonance transitions show blueshifted absorption but one also predicts strong resonance and fine-structure line emission at roughly the systemic velocity. This line-emission "fills in" the absorption, reducing the equivalent width by up to 50%, shifting the absorption-line centroid by tens of km s-1, and reducing the effective opacity near systemic. Analysis of cool gas outflows that ignores this line emission may incorrectly infer that the gas is partially covered, measure a significantly lower peak optical depth, and/or conclude that gas at systemic velocity is absent (e.g., an interstellar or slowly infalling component). Because the Fe II lines are connected by optically thin transitions to fine-structure levels, their profiles more closely reproduce the intrinsic opacity of the wind. Together these results naturally explain the absorption and emission-line characteristics observed for star-forming galaxies at z < 1. We also study a scenario promoted to describe the outflows of z ~ 3 Lyman break galaxies and find profiles inconsistent with the observations due to scattered photon emission. Although line emission complicates the analysis of absorption-line profiles, the surface brightness profiles offer a unique means of assessing the morphology and size of galactic-scale winds. Furthermore, the kinematics and line ratios offer powerful diagnostics of outflows, motivating deep, spatially extended spectroscopic

  7. Pulse-Heated Vertical Electron Cyclotron Emission Diagnostic

    NASA Astrophysics Data System (ADS)

    Voss, Keith Edward

    1995-01-01

    Determination of plasma parameters in tokamak experiments is of primary importance for learning to control and optimize fusion plasmas. Electron cyclotron emission (ECE) diagnostics play an important role in these experiments and are planned for future test reactors, since they require only simple collecting optics in the harsh reactor environment. A novel diagnostic system, which extracts information about plasma parameters by examining the ECE resulting from a perturbation of the plasma, was examined and applied on the PBX-M tokamak. This diagnostic uses a brief pulse of power from the lower hybrid current drive system to create a population of superthermal electrons. These electrons evolve according to the Fokker-Planck equation, which involves dependences on the magnetic field pitch, ion charge state, background density, and electric field. Coincident with the evolution of the electrons is the evolution of their ECE radiation. The diagnostic exploits the fact that the temporal changes in the radiation are dependent upon those parameters which affect the electrons. The analysis method, which compares measured experimental signal with simulated radiation (as functions of frequency and time) and determines most probable plasma parameter values, was computationally tested for effectiveness and robustness. The method was extended to include determination of parameters of the lower hybrid current drive power deposition. A measurement system, based on a grating polychromator, was assembled, tested, and calibrated, and pulse-heated vertical ECE data were collected from the PBX-M tokamak. A proof-of-principle test of the diagnostic yielded positive results, resulting in information about the lower hybrid current drive deposition location.

  8. Iron emission line from the spiral galaxy M 101

    NASA Astrophysics Data System (ADS)

    Yamauchi, Shigeo

    2016-06-01

    Archival Suzaku data of the face-on spiral galaxy M 101 were analyzed. An intense emission line at 6.72^{+0.10}_{-0.12}keV was detected in the central region. This line is identified with a K-line from He-like iron, which indicates the existence of a thin thermal plasma with a temperature of several keV. The iron line luminosity within the central 5'-radius region is estimated to be (2-12) × 1037 erg s-1. The origin of the iron emission line is discussed.

  9. Design of a beam emission spectroscopy diagnostic for negative ions radio frequency source SPIDER

    SciTech Connect

    Zaniol, B.; Pasqualotto, R.; Barbisan, M.

    2012-04-15

    A facility will be built in Padova (Italy) to develop, commission, and optimize the neutral beam injection system for ITER. The full scale prototype negative ion radio frequency source SPIDER, featuring up to 100 kV acceleration voltage, includes a full set of diagnostics, required for safe operation and to measure and optimize the beam performance. Among them, beam emission spectroscopy (BES) will be used to measure the line integrated beam uniformity, divergence, and neutralization losses inside the accelerator (stripping losses). In the absence of the neutralization stage, SPIDER beam is mainly composed by H{sup -} or D{sup -} particles, according to the source filling gas. The capability of a spectroscopic diagnostic of an H{sup -} (D{sup -}) beam relies on the interaction of the beam particles with the background gas particles. The BES diagnostic will be able to acquire the H{sub {alpha}} (D{sub {alpha}}) spectrum from up to 40 lines of sight. The system is capable to resolve stripping losses down to 2 keV and to measure beam divergence with an accuracy of about 10%. The design of this diagnostic is reported, with discussion of the layout and its components, together with simulations of the expected performance.

  10. A New Interpretation for the Variation in Starburst Galaxy Emission Line Spectra

    NASA Astrophysics Data System (ADS)

    Richardson, Chris T.; Allen, James T.; Baldwin, Jack A.; Hewett, Paul C.; Ferland, Gary J.; Meskhidze, Helen

    2015-01-01

    Starburst galaxies have been easily distinguished from AGN using diagnostic emission line ratio diagrams constraining their excitation mechanism. Previous modeling of the star forming (SF) galaxy sequence outlined on the BPT diagram has led to the interpretation that high metallicity SF galaxies and low ionization SF galaxies are synonymous. Here, we present a new interpretation. Using a large sample of low-z SDSS galaxies, we co-added similar spectra of pure star forming galaxies allowing many weaker emission lines to act as consistency checks on strong line diagnostics. For the first time, we applied a locally optimally-emitting cloud (LOC) model to understand the physical reason for the variation in starburst galaxy emission line spectra. We fit over twenty diagnostic diagrams constraining the excitation mechanism, SED, temperature, density, metallicity, and grain content, making this work far more constrained than previous studies. Our results indicate that low luminosity SF galaxies could simply have less concentrated regions of ionized gas compared to their high luminosity counterparts, but have similar metallicities, thus requiring reevaluation about underlying nature of star forming galaxies.

  11. Optical emission line monitor with background observation and cancellation

    DOEpatents

    Goff, D.R.; Notestein, J.E.

    1985-01-04

    A fiber optics based optical emission line monitoring system is provided in which selected spectral emission lines, such as the sodium D-line emission in coal combustion, may be detected in the presence of interferring background or blackbody radiation with emissions much greater in intensity than that of the emission line 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 emission line 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 emission line 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 emission of interest. This instrument can reduce the effects of interfering blackbody radiation by greater than 20 dB.

  12. Optical emission line monitor with background observation and cancellation

    DOEpatents

    Goff, David R.; Notestein, John E.

    1986-01-01

    A fiber optics based optical emission line monitoring system is provided in which selected spectral emission lines, such as the sodium D-line emission in coal combustion, may be detected in the presence of interferring background or blackbody radiation with emissions much greater in intensity than that of the emission line 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 emission line 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 emission line 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 emission of interest. This instrument can reduce the effects of interferring blackbody radiation by greater than 20 dB.

  13. The Mg 2 lines as diagnostic of PMS nature in Herbig Ae/Be stars

    NASA Technical Reports Server (NTRS)

    1994-01-01

    The main objective of this program was to observe some newly discovered and previously unobserved Herbig Ae/Be (HAeBe) stars with IUE. A previous archival study suggested that there was a full range of profiles in the Mg II lines for these objects; ranging from the double peak emission to the narrow absorption lines. It has been found that by studying the IUE data of main sequence B and classical Be stars that the P Cygni profiles in the Mg II lines in HAeBe stars are truly unique and are the signature of accelerating winds in their extended circumstellar material. The arguement, for the purposes of this proposal, that the structure of the Mg II lines was a superior diagnostic of the dynamical activity and ultimately the PMS nature of these objects. This program was a follow up study of several interesting intermediate-mass stars with the goal of classifying these objects based on the shape of their MG II lines. A list of publications resulting from this research is included.

  14. Emission lines in the long period Cepheid l Carinae

    NASA Technical Reports Server (NTRS)

    Boehm-Vitense, Erika; Love, Stanley G.

    1991-01-01

    For the Cepheid (l) Carinae with a pulsation period of 35.5 days we have studied the emission line fluxes as a function of pulsational phase in order to find out whether we see chromosphere and transition layer emission or whether we see emission due to an outward moving shock. All emission lines 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 line fluxes shows that these are not transition layer lines. During maximum light the large ratio of the C IV to C II line fluxes also suggests that we see emission from a shock with velocities greater than 100 km/sec such that C IV emission can be excited. With such velocities mass outflow appears possible. The variations seen in the Mg II line 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 emission in the O I line at 1300 angstrom, which is probably excited by resonance with Ly beta.

  15. The 22 GHz Water Maser Line: A New Diagnostic Tool for Extrasolar Planet Search

    NASA Astrophysics Data System (ADS)

    Cosmovici, Cristiano; Pogrebenko, Sergej; Montebugnoli, Stelio; Maccaferri, Giuseppe

    The impact of 21 nuclei of Comet Shoemaker-Levy with the atmosphere of Jupiter in July 1994, permitted the detection of the 22 GHz water MASER line for the first time in the Solar System. This emission line was originated by a water cloud released from cometary ices after the explosion of the nuclei in the upper atmosphere. Our measurements have shown that, under particular physical conditions, water MASER emission can be observed from planetary atmospheres. Thus water (and probably other molecules like SiO) MASER emission can be used as a powerful diagnostic tool for planetary search outside the Solar System, since comets are able to deliver huge amounts of water into planetary atmospheres, increasing the probability of life development. We therefore started a search program with the 32m dish of the Medicina Radiotelescope using a 132,000 multichannel spectrometer in order to cover Doppler shifts due to planetary rotation. In this paper we will illustrate the feasibility, the technique used, and the first selected targets for the search within 50 ly.

  16. Enterprise utilization of "always on-line" diagnostic study archive.

    PubMed

    McEnery, Kevin W; Suitor, Charles T; Thompson, Stephen K; Shepard, Jeffrey S; Murphy, William A

    2002-01-01

    To meet demands for enterprise image distribution, an "always on-line" image storage archive architecture was implemented before soft copy interpretation. It was presumed that instant availability of historical diagnostic studies would elicit a substantial utilization. Beginning November 1, 2000 an enterprise distribution archive was activated (Stentor, SanFrancisco, CA). As of August 8, 2001, 83,052 studies were available for immediate access without the need for retrieval from long-term archive. Image storage and retrieval logs for the period from June 12, 2001 to August 8, 2001 were analyzed. A total of 41,337 retrieval requests were noted for the 83,052 studies available as August 8, 2001. Computed radiography represented 16.8% of retrieval requests; digital radiography, 16.9%; computed tomography (CT), 44.5%; magnetic resonance (MR), 19.2%; and ultrasonography, 2.6%. A total of 51.5% of study retrievals were for studies less than 72 hours old. Study requests for cases greater than 100 days old represented 9.9% of all accessions, 9.7% of CT accessions, and 15.4% of MR accessions. Utilization of the archive indicates a substantial proportion of study retrievals for studies less than 72 hours after study completion. However, significant interest in historical CT and MR examinations was shown. PMID:12105703

  17. On-line diagnostic system for power generators

    SciTech Connect

    Skormin, V.A.; Goodenough, G.S.; Huber, R.K.

    1996-12-31

    A novel approach to diagnostics of a power generator is developed. It utilizes readily available data acquired by the existing computer-based monitoring/control system. Diagnostic procedures detect various trends in the generator data and interpret these trends in the generator data and interpret these trends as changes in the generator performance caused by incipient failures. Results of trend analyses, subjected to statistical validation, facilitate failure prediction and identification thus providing the justification for service when needed. The procedures are incorporated in a diagnostic system implemented in a PC interfaced with the existing VAX-based process monitoring and control system. The diagnostic system provides graphical display of the diagnostic messages.

  18. Emission lines in the long-period Cepheid l Carinae

    NASA Technical Reports Server (NTRS)

    Bohm-Vitense, Erika; Love, Stanley G.

    1994-01-01

    For the Cepheid l Carinae, with a pulsation period of 35.5 days, we have studied the emission-line fluxes as a function of pulsational phase in order to find out whether we see chromospheric and transition-layer emission due to an outward-moving shock. All emission lines show a steep increase in flux shortly before maximum light, suggestive of a shock moving through the surface layers. The large ratio of C IV to C II line fluxes shows that these are not transition-layer lines. During maximum light the large ratio of the large ratio of the C IV to C II line fluxes also suggests that we see emission from a shock with velocities greater than 100 km/s such that C IV emission can be excited. With such velocities mass outflow appears possible. The variations seen in the MG II line profiles show that there is an external absorption over a broad velocity band independent of the pulsation phase. We attribute this absorption to a circumstellar 'shell.' This 'shell' appears to be seen also as spatially extended emission in the O I line at 1300 A, which is probably excited by resonance with Ly beta.

  19. Coronal Physics and the Chandra Emission Line Project

    NASA Technical Reports Server (NTRS)

    Brickhouse, Nancy

    1999-01-01

    With the launch of the Chandra X-ray Observatory, high resolution X-ray spectroscopy of cosmic sources has begun. Early, deep observations of three stellar coronal sources will provide not only invaluable calibration data, but will also give us benchmarks for plasma spectral modeling codes. These codes are to interpret data from stellar coronae, galaxies and clusters of galaxies. supernova remnants and other astrophysical sources, but they have been called into question in recent years as problems with understanding moderate resolution ASCA and EUVE data have arisen. The Emission Line Project is a collaborative effort to improve the models, with Phase 1 being the comparison of models with observed spectra of Capella, Procyon, and HR, 1099. Goals of these comparisons are (1) to determine and verify accurate and robust diagnostics and (2) to identify and prioritize issues in fundamental spectroscopy which will require further theoretical and/or laboratory work. A critical issue in exploiting the coronal data for these purposes is to understand the extent to which common simplifying assumptions (coronal equilibrium, time-independence, negligible optical depth) apply. We will discuss recent advances in our understanding of stellar coronae in this context.

  20. Fine structure line emission from supergiants

    NASA Astrophysics Data System (ADS)

    Haas, Michael R.; Glassgold, Alfred E.; Tielens, Alexander G. G. M.

    We have detected (O I) 63 micron and (Si II) 35 micron emission from the oxygen-rich, M supergiants alpha Orionis (Betelgeuse), alpha Scorpii (Antares), and alpha Herculis (Rasalgethi). The measured fluxes indicate that the emission originates in dense, warm gas in the inner envelope or transition region where molecules and dust are expected to form and the acceleration of the wind occurs. Mass-loss rates are derived, evidence for time variability is presented, and results for other evolved stars are included.

  1. Fine structure line emission from supergiants

    NASA Technical Reports Server (NTRS)

    Haas, Michael R.; Glassgold, Alfred E.; Tielens, Alexander G. G. M.

    1995-01-01

    We have detected (O I) 63 micron and (Si II) 35 micron emission from the oxygen-rich, M supergiants alpha Orionis (Betelgeuse), alpha Scorpii (Antares), and alpha Herculis (Rasalgethi). The measured fluxes indicate that the emission originates in dense, warm gas in the inner envelope or transition region where molecules and dust are expected to form and the acceleration of the wind occurs. Mass-loss rates are derived, evidence for time variability is presented, and results for other evolved stars are included.

  2. The Diagnostic Potential of Transition Region Lines Undergoing Transient Ionization in Dynamic Events

    NASA Astrophysics Data System (ADS)

    Doyle, J. G.; Giunta, A.; Singh, A.; Madjarska, M. S.; Summers, H.; Kellett, B. J.; O'Mullane, M.

    2012-09-01

    We discuss the diagnostic potential of high cadence UV spectral data when transient ionization is considered. For this we use high cadence UV spectra taken during the impulsive phase of a solar flare (observed with instruments on-board the Solar Maximum Mission) which showed excellent correspondence with hard X-ray pulses. The ionization fraction of the transition region ion O v and, in particular, the contribution function for the O v 1371 Å line are computed within the Atomic Data and Analysis Structure, which is a collection of fundamental and derived atomic data and codes to manipulate them. Due to transient ionization, the O v 1371 Å line is enhanced in the first fraction of a second with the peak in the line contribution function occurring initially at a higher electron temperature than in ionization equilibrium. The rise time and enhancement factor depend mostly on the electron density. The fractional increase in the O v 1371 Å emissivity due to transient ionization can reach a factor of two-four and can explain the fast response in the line flux of transition regions ions during the impulsive phase of flares solely as a result of transient ionization. This technique can be used to diagnose the electron temperature and density of solar flares observed with the forthcoming Interface Region Imaging Spectrograph.

  3. Evaluation of thermal helium beam and line-ratio fast diagnostic on the National Spherical Torus Experiment-Upgrade

    NASA Astrophysics Data System (ADS)

    Muñoz Burgos, J. M.; Agostini, M.; Scarin, P.; Stotler, D. P.; Unterberg, E. A.; Loch, S. D.; Schmitz, O.; Tritz, K.; Stutman, D.

    2016-05-01

    A 1-D kinetic collisional radiative model with state-of-the-art atomic data is developed and employed to simulate line emission to evaluate the Thermal Helium Beam (THB) diagnostic on NSTX-U. This diagnostic is currently in operation on RFX-mod, and it is proposed to be installed on NSTX-U. The THB system uses the intensity ratios of neutral helium lines 667.8, 706.5, and 728.1 nm to derive electron temperature (eV) and density (cm-3) profiles. The purpose of the present analysis is to evaluate the applications of this diagnostic for determining fast ( ∽ 4 μs ) electron temperature and density radial profiles on the scrape-off layer and edge regions of NSTX-U that are needed in turbulence studies. The diagnostic is limited by the level of detection of the 728.1 nm line, which is the weakest of the three. This study will also aid in future design of a similar 2-D diagnostic system on the divertor.

  4. Evaluation of thermal helium beam and line-ratio fast diagnostic on the National Spherical Torus Experiment-Upgrade

    DOE PAGESBeta

    Munoz Burgos, Jorge M.; Agostini, Matteo; Scarin, Paolo; Stotler, Daren P.; Unterberg, Ezekial A.; Loch, Stuart D.; Schmitz, Oliver; Tritz, Kevin; Stutman, Dan

    2015-05-06

    A 1-D kinetic collisional radiative model (CRM) with state-of-the-art atomic data is developed and employed to simulate line emission to evaluate the Thermal Helium Beam (THB) diagnostic on NSTX-U. This diagnostic is currently in operation on RFX-mod, and it is proposed to be installed on NSTX-U. The THB system uses the intensity ratios of neutral helium lines 667.8, 706.5, and 728.1 nm to derive electron temperature (eV ) and density (cm–3) profiles. The purpose of the present analysis is to evaluate the applications of this diagnostic for determining fast (~4 μs) electron temperature and density radial profiles on the scrape-offmore » layer (SOL) and edge regions of NSTX-U that are needed in turbulence studies. The diagnostic is limited by the level of detection of the 728.1 nm line, which is the weakest of the three. In conclusion, this study will also aid in future design of a similar 2-D diagnostic systems on the divertor.« less

  5. Evaluation of thermal helium beam and line-ratio fast diagnostic on the National Spherical Torus Experiment-Upgrade

    SciTech Connect

    Munoz Burgos, Jorge M.; Agostini, Matteo; Scarin, Paolo; Stotler, Daren P.; Unterberg, Ezekial A.; Loch, Stuart D.; Schmitz, Oliver; Tritz, Kevin; Stutman, Dan

    2015-05-06

    A 1-D kinetic collisional radiative model (CRM) with state-of-the-art atomic data is developed and employed to simulate line emission to evaluate the Thermal Helium Beam (THB) diagnostic on NSTX-U. This diagnostic is currently in operation on RFX-mod, and it is proposed to be installed on NSTX-U. The THB system uses the intensity ratios of neutral helium lines 667.8, 706.5, and 728.1 nm to derive electron temperature (eV ) and density (cm–3) profiles. The purpose of the present analysis is to evaluate the applications of this diagnostic for determining fast (~4 μs) electron temperature and density radial profiles on the scrape-off layer (SOL) and edge regions of NSTX-U that are needed in turbulence studies. The diagnostic is limited by the level of detection of the 728.1 nm line, which is the weakest of the three. In conclusion, this study will also aid in future design of a similar 2-D diagnostic systems on the divertor.

  6. Spectral classification of emission-line galaxies

    NASA Technical Reports Server (NTRS)

    Veilleux, Sylvain; Osterbrock, Donald E.

    1987-01-01

    A revised method of classification of narrow line active galaxies and H II region-like galaxies is proposed. It involves the line ratios (O III) lambda 5007/H beta, (N II) lambda 6583/H alpha, (S II) (lambda lambda 6716 = 6731)/H alpha, and (O I) lambda 6300/H alpha. These line ratios take full advantage of the physical distinction between the two types of objects and minimize the effects of reddening correction and errors in the flux calibration. Large sets of internally consistent data are used including new previously unpublished measurements. Prediction of recent photoionization models by power law spectra and by hot stars are compared with the observations. The classification is based on the observational data interpreted on the basis of these models.

  7. Spectral classification of emission-line galaxies

    SciTech Connect

    Veilleux, S.; Osterbrock, D.E.

    1987-02-01

    A revised method of classification of narrow-line active galaxies and H II region-like galaxies is proposed. It involves the line ratios which take full advantage of the physical distinction between the two types of objects and minimize the effects of reddening correction and errors in the flux calibration. Large sets of internally consistent data are used, including new, previously unpublished measurements. Predictions of recent photoionization models by power-law spectra and by hot stars are compared with the observations. The classification is based on the observational data interpreted on the basis of these models. 63 references.

  8. Nebular and auroral emission lines of [Cl iii] in the optical spectra of planetary nebulae

    PubMed Central

    Keenan, Francis P.; Aller, Lawrence H.; Ramsbottom, Catherine A.; Bell, Kenneth L.; Crawford, Fergal L.; Hyung, Siek

    2000-01-01

    Electron impact excitation rates in Cl III, recently determined with the R-matrix code, are used to calculate electron temperature (Te) and density (Ne) emission line 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 line 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 line ratio calculations. However the [Cl iii] 8433.9 Å line is found to be frequently blended with a weak telluric emission 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 line fluxes. Similarly, the 8500.0 Å line, previously believed to be free of contamination by the Earth's atmosphere, is also shown to be generally blended with a weak telluric emission feature. The [Cl iii] transition at 8480.9 Å is found to be blended with the He i 8480.7 Å line, 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 lines. Finally, the diagnostic potential of the near-UV [Cl iii] lines at 3344 and 3354 Å is briefly discussed. PMID:10759562

  9. Nebular and auroral emission lines of [Cl III] in the optical spectra of planetary nebulae.

    PubMed

    Keenan, F P; Aller, L H; Ramsbottom, C A; Bell, K L; Crawford, F L; Hyung, S

    2000-04-25

    Electron impact excitation rates in Cl III, recently determined with the R-matrix code, are used to calculate electron temperature (T(e)) and density (N(e)) emission line ratios involving both the nebular (5517.7, 5537.9 A) and auroral (8433.9, 8480.9, 8500.0 A) 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 R(1) = I(5518 A)/I(5538 A) intensity ratio provides estimates of N(e) in excellent agreement with the values derived from other line ratios in the echelle spectra. This agreement indicates that R(1) is a reliable density diagnostic for planetary nebulae, and it also provides observational support for the accuracy of the atomic data adopted in the line ratio calculations. However the [Cl iii] 8433.9 A line is found to be frequently blended with a weak telluric emission feature, although in those instances when the [Cl iii] intensity may be reliably measured, it provides accurate determinations of T(e) when ratioed against the sum of the 5518 and 5538 A line fluxes. Similarly, the 8500.0 A line, previously believed to be free of contamination by the Earth's atmosphere, is also shown to be generally blended with a weak telluric emission feature. The [Cl iii] transition at 8480.9 A is found to be blended with the He i 8480.7 A line, except in planetary nebulae that show a relatively weak He i spectrum, where it also provides reliable estimates of T(e) when ratioed against the nebular lines. Finally, the diagnostic potential of the near-UV [Cl iii] lines at 3344 and 3354 A is briefly discussed. PMID:10759562

  10. The Impact of Diffuse Ionized Gas on Emission-line Ratios and Gas Metallicity Measurements

    NASA Astrophysics Data System (ADS)

    Zhang, Kai; Yan, Renbin; MaNGA Team

    2016-01-01

    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 emission line ratios, hence the gas-phase metallicity measurements and the interpretation of diagnostic diagrams. We demonstrate that emission line 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 line ratios change systematically with emission line 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 lines ([NII], [SII], [OII], [OI]). The contamination by DIG is responsible for a substantial portion of the scatter in metallicity measurements. At different surface brightness, line ratios and line 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-line 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 line ratio diagnostic diagrams, contamination by DIG moves HII regions towards composite or LINER-like regions.

  11. A collinear self-emission and laser-backlighting imaging diagnostic

    SciTech Connect

    Bott, S. C.; Collins, G. IV; Gunasekera, K.; Mariscal, D.; Beg, F. N.; Haas, D. M.; Veloso, F.; Blesener, I. C.; Cahill, A. D.; Hoyt, C. L.; Kusse, B. R.; Hammer, D. A.

    2012-08-15

    In this work we demonstrate a design for obtaining laser backlighting (e.g., interferometry) and time-resolved extreme ultraviolet self-emission images along the same line-of-sight. This is achieved by modifying a single optical component in the laser collection optics with apertures and pinhole arrangements suitable for single or multiple frame imaging onto a gated detector, such as a microchannel plate. Test results for exploding wire experiments show that machining of the optic does not affect the overall quality of the recovered laser images, and that, even with a multiple frame system, the area sacrificed to achieve collinear imaging is relatively small. The diagnostics can therefore allow direct correlation of laser and self-emission images and their derived quantities, such as electron density in the case of interferometry. Simple methods of image correlation are also demonstrated.

  12. Line Emission from Optically Thick RelativisticAccretion Tori

    SciTech Connect

    Fuerst, Steven V.; Wu, Kinwah; /Mullard Space Sci. Lab.

    2007-09-14

    We calculate line emission from relativistic accretion tori around Kerr black holes and investigate how the line profiles depend on the viewing inclination, spin of the central black hole, parameters describing the shape of the tori, and spatial distribution of line emissivity on the torus surface. We also compare the lines with those from thin accretion disks. Our calculations show that lines from tori and lines from thin disks share several common features. In particular, at low and moderate viewing inclination angles they both have asymmetric double-peaked profiles with a tall, sharp blue peak and a shorter red peak which has an extensive red wing. At high viewing inclination angles they both have very broad, asymmetric lines which can be roughly considered as single-peaked. Torus and disk lines may show very different red and blue line wings, but the differences are due to the models for relativistic tori and disks having differing inner boundary radii. Self-eclipse and lensing play some role in shaping the torus lines, but they are effective only at high inclination angles. If inner and outer radii of an accretion torus are the same as those of an accretion disk, their line profiles show substantial differences only when inclination angles are close to 90{sup o}, and those differences are manifested mostly at the central regions of the lines instead of the wings.

  13. Significant contribution of the Cerenkov line-like radiation to the broad emission lines of quasars

    SciTech Connect

    Liu, D. B.; You, J. H.; Chen, W. P.; Chen, L. E-mail: dliu@cfa.Harvard.edu

    2014-01-01

    The Cerenkov line-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 emission lines of quasars and Seyfert 1 galaxies. With this quasi-line emission mechanism, some long standing puzzles in the study of quasars could be resolved. In this paper, we calculate the power of the Cerenkov line-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 electrons is sufficiently high to allow effective operation of the quasi-line emission. We present a model calculation for the luminosity of the Cerenkov Lyα line of 3C 279, which is high enough to compare with observations. We therefore conclude that the broad line of quasars may be a blend of the Cerenkov emission line with the real line produced by the bound-bound transition. A new approach to the absorption of the Cerenkov line 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 line-like radiation is more convenient in applications.

  14. Modeling and simulation of a beam emission spectroscopy diagnostic for the ITER prototype neutral beam injector

    SciTech Connect

    Barbisan, M. Zaniol, B.; Pasqualotto, R.

    2014-11-15

    A test facility for the development of the neutral beam injection system for ITER is under construction at Consorzio RFX. It will host two experiments: SPIDER, a 100 keV H{sup −}/D{sup −} ion RF source, and MITICA, a prototype of the full performance ITER injector (1 MV, 17 MW beam). A set of diagnostics will monitor the operation and allow to optimize the performance of the two prototypes. In particular, beam emission spectroscopy will measure the uniformity and the divergence of the fast particles beam exiting the ion source and travelling through the beam line components. This type of measurement is based on the collection of the H{sub α}/D{sub α} emission resulting from the interaction of the energetic particles with the background gas. A numerical model has been developed to simulate the spectrum of the collected emissions in order to design this diagnostic and to study its performance. The paper describes the model at the base of the simulations and presents the modeled H{sub α} spectra in the case of MITICA experiment.

  15. ACCRETION DISK TEMPERATURES OF QSOs: CONSTRAINTS FROM THE EMISSION LINES

    SciTech Connect

    Bonning, E. W.; Shields, G. A.; Stevens, A. C.; Salviander, S. E-mail: shields@astro.as.utexas.edu E-mail: triples@astro.as.utexas.edu

    2013-06-10

    We compare QSO emission-line spectra to predictions based on theoretical ionizing continua of accretion disks. The observed line intensities do not show the expected trend of higher ionization with theoretical accretion disk temperature as predicted from the black hole mass and accretion rate. Consistent with earlier studies, this suggests that the inner disk does not reach temperatures as high as expected from standard disk theory. Modified radial temperature profiles, taking account of winds or advection in the inner disk, achieve better agreement with observation. The emission lines of radio-detected and radio-undetected sources show different trends as a function of the theoretically predicted disk temperature.

  16. An Examination of Strong-line Metallicity Diagnostics with Direct Gas-Phase Metallicities at Higher Redshifts

    NASA Astrophysics Data System (ADS)

    Ly, Chun; Rigby, Jane R.; Malkan, Matthew Arnold; Malhotra, Sangeeta

    2016-01-01

    The [OIII]λ4363 nebular emission line, which provides the most reliable determination of the gas metallicity by measuring the electron temperature of the gas, is intrinsically weak. As such, most metallicity studies at both low and high redshifts have utilized "strong-line" metallicity calibrations, such as [NII]λ6583/Hα or R23 = ([OII]+[OIII])/Hβ. However, there are growing concerns that these diagnostics may not be used for evolutionary studies due to differences in the physical conditions (e.g., density, ionization, abundance ratios) of the interstellar gas in galaxies. A clear demonstration for this concern is the offset on the Baldwin-Phillips-Terlevich diagnostic diagram ([OIII]λ5007/Hβ vs. [NII]λ6583/Hα) for high-z star-forming galaxies from local star-forming galaxies.To examine this issue, we investigate the accuracy that commonly-used strong-line diagnostics can explain the direct oxygen abundances. Here, we use a sample of ~100 low-mass galaxies at z=0.07 to 1.0 with detections of the [OIII]λ4363 emission line from Keck and MMT optical spectroscopy. These galaxies are pre-selected for their strong nebular emission lines from the Subaru Deep Field and the DEEP2 Survey. Utilizing the optical emission lines, we argue that "R23" is not a reliable diagnostic and that discrepancies from [OIII]λ4363-based metallicity cannot be explained simply by higher gas densities or higher ionization parameter. We do find that the [NII]-based metallicity diagnostics of Pettini & Pagel (2004) are in agreement with [OIII]λ4363-based metallicity at z~0.5. There is, however, a sub-population (25%) where [NII]-based estimates are overestimating the oxygen metallicities. We argue that enhanced nitrogen abundances, relative to oxygen, is responsible for this significant (~0.5 dex) offset in metallicity. We present preliminary results for a revised metallicity calibration that considers the N/O abundance ratio.

  17. The optical emission line spectrum of Mark 110

    NASA Astrophysics Data System (ADS)

    Véron-Cetty, M.-P.; Véron, P.; Joly, M.; Kollatschny, W.

    2007-11-01

    Aims:We analyse in detail the rich emission line spectrum of Mark 110 to determine the physical conditions in the nucleus of this object, a peculiar NLS1 without any detectable Fe II emission associated with the broad line region and with a λ5007/Hβ line ratio unusually large for a NLS1. Methods: We use 24 spectra obtained with the Marcario Low Resolution Spectrograph attached at the prime focus of the 9.2 m Hobby-Eberly telescope at the McDonald observatory. We fitted the spectrum by identifying all the emission lines (about 220) detected in the wavelength range 4200-6900 Å (at rest). Results: The narrow emission lines are probably produced in a region with a density gradient in the range 103-106 cm-3 with a rather high column density (5×1021 cm-2). In addition to a narrow line system, three major broad line systems with different line velocity and width are required. We confirm the absence of broad Fe II emission lines. We speculate that Mark 110 is in fact a BLS1 with relatively “narrow” broad lines but with a BH mass large enough compared to its luminosity to have a lower than Eddington luminosity. Based on observations obtained with the Hobby-Eberly Telescope, which is a joint project of the University of Texas at Austin, the Pennsylvania State University, Stanford University, Ludwig-Maximilians-Universität München, and Georg-August-Universität Göttingen. Table A.1 is only available in electronic form at http://www.aanda.org

  18. XMM study of the emission lines of the Z-Source GX 349+2

    NASA Astrophysics Data System (ADS)

    Iaria, Rosario

    2006-10-01

    We propose a 40 ks XMM observation of the Z source GX 349+2, to perform a detailed study of the iron K-shell features and other low energy features in this source. In particular this source is known to show a broad (0.7 keV FWHM) iron K_a line: several hypothesis were proposed to explain the width of these lines (relativistic and Doppler effects in an accretion disk, Compton scattering, line-blending), and we expect that the good energy resolution of XMM will be able to resolve the complex line shape and to constrain the various models proposed. Furthermore, since some emission lines were already observed in GX 349+2 with BeppoSAX below 3 keV, a proper study of these low energy features are an important diagnostic tool for the physical conditions of the emitting regions.

  19. Helium shells and faint emission lines from slitless flash spectra

    NASA Astrophysics Data System (ADS)

    Bazin, Cyril; Koutchmy, Serge

    2013-05-01

    At the time of the two last solar total eclipses of August 1st, 2008 in Siberia and July 11th, 2010 in French Polynesia, high frame rate CCD flash spectra were obtained. These eclipses occurred in quiet Sun period and after. The slitless flash spectra show two helium shells, in the weak Paschen α 4686 Å line of the ionized helium HeII and in the neutral helium HeI line at 4713 Å. The extensions of these helium shells are typically 3 Mm. In prominences, the extension of the interface with the corona is much more extended. The observations and analysis of these lines can properly be done only in eclipse conditions, when the intensity threshold reaches the coronal level, and the parasitic scattered light is virtually zero. Under the layers of 1 Mm above the limb, many faint low FIP lines were also seen in emission. These emission lines are superposed on the continuum containing absorption lines. The solar limb can be defined using the weak continuum appearing between the emission lines at the time of the second and third contact. The variations of the singly ionized iron line, the HeI and HeII lines and the continuum intensity are analyzed. The intensity ratio of ionized to neutral helium is studied for evaluating the ionization rate in low layers up to 2 Mm and also around a prominence.

  20. Helium shells and faint emission lines from slitless flash spectra

    PubMed Central

    Bazin, Cyril; Koutchmy, Serge

    2013-01-01

    At the time of the two last solar total eclipses of August 1st, 2008 in Siberia and July 11th, 2010 in French Polynesia, high frame rate CCD flash spectra were obtained. These eclipses occurred in quiet Sun period and after. The slitless flash spectra show two helium shells, in the weak Paschen α 4686 Å line of the ionized helium HeII and in the neutral helium HeI line at 4713 Å. The extensions of these helium shells are typically 3 Mm. In prominences, the extension of the interface with the corona is much more extended. The observations and analysis of these lines can properly be done only in eclipse conditions, when the intensity threshold reaches the coronal level, and the parasitic scattered light is virtually zero. Under the layers of 1 Mm above the limb, many faint low FIP lines were also seen in emission. These emission lines are superposed on the continuum containing absorption lines. The solar limb can be defined using the weak continuum appearing between the emission lines at the time of the second and third contact. The variations of the singly ionized iron line, the HeI and HeII lines and the continuum intensity are analyzed. The intensity ratio of ionized to neutral helium is studied for evaluating the ionization rate in low layers up to 2 Mm and also around a prominence. PMID:25685435

  1. Helium shells and faint emission lines from slitless flash spectra.

    PubMed

    Bazin, Cyril; Koutchmy, Serge

    2013-05-01

    At the time of the two last solar total eclipses of August 1st, 2008 in Siberia and July 11th, 2010 in French Polynesia, high frame rate CCD flash spectra were obtained. These eclipses occurred in quiet Sun period and after. The slitless flash spectra show two helium shells, in the weak Paschen α 4686 Å line of the ionized helium HeII and in the neutral helium HeI line at 4713 Å. The extensions of these helium shells are typically 3 Mm. In prominences, the extension of the interface with the corona is much more extended. The observations and analysis of these lines can properly be done only in eclipse conditions, when the intensity threshold reaches the coronal level, and the parasitic scattered light is virtually zero. Under the layers of 1 Mm above the limb, many faint low FIP lines were also seen in emission. These emission lines are superposed on the continuum containing absorption lines. The solar limb can be defined using the weak continuum appearing between the emission lines at the time of the second and third contact. The variations of the singly ionized iron line, the HeI and HeII lines and the continuum intensity are analyzed. The intensity ratio of ionized to neutral helium is studied for evaluating the ionization rate in low layers up to 2 Mm and also around a prominence. PMID:25685435

  2. Diagnostic beam absorber in Mu2e beam line

    SciTech Connect

    Rakhno, Igor; /Fermilab

    2011-03-01

    Star density, hadron flux, and residual dose distributions are calculated around the {mu}2e diagnostic beam absorber. Corresponding surface and ground water activation, and air activation are presented as well.

  3. Profiles of emission lines in Be stars.

    NASA Technical Reports Server (NTRS)

    Huang, S. S.

    1972-01-01

    Study of the broadening functions resulting from a gaseous ring in circular motion around a star according to Kepler's law. When the distribution in the gaseous ring has a circular symmetry in the equatorial plane, the broadening profile is related to the surface density distribution along the radius by an integral equation which can be transformed into the Abel integral equation and solved analytically. Profiles corresponding to gaseous rings with a uniform density distribution but different widths are used to illustrate the general properties of the profile broadened by the gaseous ring in circular motion. The emission profile has also been studied for cases in which the circular motion does not follow Kepler's law.

  4. Comparative electron temperature measurements of Thomson scattering and electron cyclotron emission diagnostics in TCABR plasmas

    SciTech Connect

    Alonso, M. P.; Figueiredo, A. C. A.; Berni, L. A.; Machida, M.

    2010-10-15

    We present the first simultaneous measurements of the Thomson scattering and electron cyclotron emission radiometer diagnostics performed at TCABR tokamak with Alfven wave heating. The Thomson scattering diagnostic is an upgraded version of the one previously installed at the ISTTOK tokamak, while the electron cyclotron emission radiometer employs a heterodyne sweeping radiometer. For purely Ohmic discharges, the electron temperature measurements from both diagnostics are in good agreement. Additional Alfven wave heating does not affect the capability of the Thomson scattering diagnostic to measure the instantaneous electron temperature, whereas measurements from the electron cyclotron emission radiometer become underestimates of the actual temperature values.

  5. Forbidden line emission from highly ionized atoms in tokamak plasmas

    NASA Technical Reports Server (NTRS)

    Feldman, U.; Doschek, G. A.; Bhatia, A. K.

    1982-01-01

    Considerable interest in the observation of forbidden spectral lines from highly ionized atoms in tokamak plasmas is related to the significance of such observations for plasma diagnostic applications. Atomic data for the elements Ti Cr, Mn, Fe, Ni, and Kr have been published by Feldman et al. (1980) and Bhatia et al. (1980). The present investigation is concerned with collisional excitation rate coefficients and radiative decay rates, which are interpolated for ions of elements between calcium, and krypton and for levels of the 2s2 2pk, 2s 2p(k+1), and 2p(k+2) configurations, and for the O I, N I, C I, B I, and Be I isoelectronic sequences. The provided interpolated atomic data can be employed to calculate level populations and relative line intensities for ions of the considered sequences, taking into account levels of the stated configurations. Important plasma diagnostic information provided by the forbidden lines includes the ion temperature

  6. Far-Infrared Line Emission from High Redshift Quasars

    NASA Technical Reports Server (NTRS)

    Benford, D. J.; Cox, P.; Hunter, T. R.; Malhotra, S.; Phillips, T. G.; Yun, M. S.

    2002-01-01

    Recent millimeter and submillimeter detections of line emission 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 lines 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+ emission &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+ line 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 emission in the N+ 205 micron line from the Cloverleaf quasar, H1413+117, and detected emission in CO J=7-6. The N+ emission is found to be below the amount predicted based on comparison to the only previous detection of this line, in the starburst galaxy M82.

  7. Package for Interactive Analysis of Line Emission

    NASA Technical Reports Server (NTRS)

    Kashyap, Vinay; Hunter, Paul (Technical Monitor)

    2005-01-01

    PINTofALE is an IDL based package to analyze high-resolution grating spectra. The first version was made available to the public on 3 February 2001. Since then we have carried out numerous changes and subsidiary releases. The current release is version 2.0 (released 6 Apr 2004), and we are preparing to release v2.1 within the next month. The changes include bug fixes, upgrades to handle higher versions of IDL and the CHIANTI database, enhancements in user-friendliness, handling of instrument response matrices, and the release of a Markov Chain Monte Carlo based DEM fitting routines. A detailed description of the package, together with fairly detailed documentation, example walk-throughs, and downloadable tar files, are available on-line from http://hea.harvard.edu/PINTofALE/ The website also lists papers that have used PINTofALE in their analysis.

  8. Quantifying correlations between galaxy emission lines and stellar continua

    NASA Astrophysics Data System (ADS)

    Beck, Róbert; Dobos, László; Yip, Ching-Wa; Szalay, Alexander S.; Csabai, István

    2016-03-01

    We analyse the correlations between continuum properties and emission line equivalent widths of star-forming and active galaxies from the Sloan Digital Sky Survey. Since upcoming large sky surveys will make broad-band observations only, including strong emission lines into theoretical modelling of spectra will be essential to estimate physical properties of photometric galaxies. We show that emission line equivalent widths can be fairly well reconstructed from the stellar continuum using local multiple linear regression in the continuum principal component analysis (PCA) space. Line reconstruction is good for star-forming galaxies and reasonable for galaxies with active nuclei. We propose a practical method to combine stellar population synthesis models with empirical modelling of emission lines. The technique will help generate more accurate model spectra and mock catalogues of galaxies to fit observations of the new surveys. More accurate modelling of emission lines is also expected to improve template-based photometric redshift estimation methods. We also show that, by combining PCA coefficients from the pure continuum and the emission lines, automatic distinction between hosts of weak active galactic nuclei (AGNs) and quiescent star-forming galaxies can be made. The classification method is based on a training set consisting of high-confidence starburst galaxies and AGNs, and allows for the similar separation of active and star-forming galaxies as the empirical curve found by Kauffmann et al. We demonstrate the use of three important machine learning algorithms in the paper: k-nearest neighbour finding, k-means clustering and support vector machines.

  9. Emission lines in the optical spectrum of 3 Cen A

    NASA Astrophysics Data System (ADS)

    Wahlgren, G. M.; Hubrig, S.

    2004-05-01

    Previously, weak emission lines had been detected at red wavelengths in the spectra of a limited sample of mid to late B type main sequence stars. A fuller description of the occurrence and origins of these lines has yet to be forwarded, in part due to the lack of observations detailing the spectral transitions involved. To address this deficiency, we present a line list of weak emission features found in the optical and near infrared spectral region of the chemically peculiar He-weak star 3 Cen A (HD 120709). Nearly 350 features, mostly associated with allowed transitions from high-excitation states of first ions, are catalogued along with identifications. Prominent among the emission lines are the spectra P II, Mn II, Fe II, Ni II and Cu II. Emission lines from Ca II, Si II and Hg II are also evident. Abundances are determined for several elements from synthetic spectrum fitting, with anomalies detected for the ions O I/II, P II/III and Si II/III. The LTE synthetic spectrum fitting also revealed that the low excitation 4s-4p transitions of Fe II predict an abundance that is greater than that determined from higher excitation 4d-4f transitions. Several of these latter transitions have upper energy levels that are found to be associated with emission lines. We also present empirical considerations for the excitation processes leading to the weak emission lines. Based on observations obtained at the European Southern Observatory, La Silla, Chile, No. 65.L-0316 and Paranal, Chile No. 266.D-5655. Tables 2 and 3 are only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/418/1073

  10. Line Emission from Radiation-pressurized H II Regions. II. Dynamics and Population Synthesis

    NASA Astrophysics Data System (ADS)

    Verdolini, Silvia; Yeh, Sherry C. C.; Krumholz, Mark R.; Matzner, Christopher D.; Tielens, Alexander G. G. M.

    2013-05-01

    Optical and infrared emission lines from H II regions are an important diagnostic used to study galaxies, but interpretation of these lines requires significant modeling of both the internal structure and dynamical evolution of the emitting regions. Most of the models in common use today assume that H II region dynamics are dominated by the expansion of stellar wind bubbles, and have neglected the contribution of radiation pressure to the dynamics, and in some cases also to the internal structure. However, recent observations of nearby galaxies suggest that neither assumption is justified, motivating us to revisit the question of how H II region line emission depends on the physics of winds and radiation pressure. In a companion paper we construct models of single H II regions including and excluding radiation pressure and winds, and in this paper we describe a population synthesis code that uses these models to simulate galactic collections of H II regions with varying physical parameters. We show that the choice of physical parameters has significant effects on galactic emission line ratios, and that in some cases the line ratios can exceed previously claimed theoretical limits. Our results suggest that the recently reported offset in line ratio values between high-redshift star-forming galaxies and those in the local universe may be partially explained by the presence of large numbers of radiation-pressure-dominated H II regions within them.

  11. Emission Line Assimetry in Active Galaxies: Mrk 533 and Mrk 110

    NASA Astrophysics Data System (ADS)

    Gavrilovic, N.

    2009-09-01

    In this work emission line asymmetries detected in two different types of Active Galactic Nuclei (AGN) - Seyfert 1 galaxy Mrk 110 and Seyfert 2 galaxy Mrk 533 were analyzed. Since emission lines in two galaxies arise in different emitting regions, detailed spectrum analysis gave the insight into kinematical properties of the Narrow Line and the Broad Line region (NLR and BLR) of this galaxies. We used several methods in the analysis procedure: (a) in order to analyse line profiles we performed profile decomposition into Gaussian components, (b) to study kinematical properties of the gas in the stellar disk, we used the model of "tilted-rings" (Begeman 1989), (c) to determine the sources of ionization of emitting region, we used the Veilleux and Osterbrock diagnostic diagram (Veilleux and Osterbrock 1987), (d) thermodynamical properties of the BLR were determined using the Boltzman plot method (Popović 2003). We showed that the red-shift and asymmetry of emission lines in Mrk 110 are probable caused by the strong gravitational field of the super massive black hole in the center of this galaxy. On the other hand, detailed analysis of 3D spectrophotometric observation of Mrk 533 made possible to map the outflow velocities from the very center of this galaxy, as well as shock waves in the circum-nuclear region, and to analyse the increase of the blue asymmetry with the increase of the outflow velocity (in more details see Smirnova et al. 2007).

  12. A study of diagnostic x-ray lines in heliumlike neon using an electron beam ion trap

    SciTech Connect

    Wargelin, B.J.

    1993-10-01

    Heliumlike ions play an extremely important role in X-ray astrophysics because of their emissivity and because the relative intensities of their emission lines can be used to infer physical characteristics of X-ray emitting plasmas, including temperature, electron density, and ionization balance. In order to properly apply these diagnostics, accurate atomic data are required, including cross sections for collisional excitation and ionization, radiative rates, and the wavelengths and strengths of satellite lines. Although theoretical atomic models have been created to estimate many of the rates and cross sections involved, very few experimental results are available for comparison with theoretical predictions. This thesis describes an experimental study of heliumlike neon using an electron beam ion trap, a device specifically designed to study X-ray emission from highly charged ions. Using a low-energy X-ray spectrometer designed and built for this experiment, electron impact excitation cross sections and dielectronic satellite strengths were measured for all significant n = 2{yields}1 emission lines in He-like and Li-like Ne over a range of energy extending from well below the direct excitation threshold of the lines to over fourteen times the threshold energy. The cross section for innershell ionization of Li-like Ne, which excites the He-like forbidden line, was also measured. In addition, the radiative and collisional depopulation rates of the metastable ls2s {sup 3}S{sub 1}, state, which form the basis of the He-like Ne density diagnostic, were determined. Experimental results were generally in agreement with theoretical predictions, although some significant differences were noted, particularly for the wavelengths and resonance strengths of dielectronic satellites.

  13. Near-Infrared Emission Lines of Nova Cassiopeiae 1995

    NASA Astrophysics Data System (ADS)

    Rudy, R. J.; Lynch, D. K.; Mazuk, S. M.; Venturini, C. C.; Puetter, R. C.

    2000-12-01

    The slow nova V 723 Cas (Nova Cas 1995) exhibits comparatively narrow emission features (FWHM 500 km sec-1) that make it ideal for classifying weak lines and lines 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 emission lines that were present. During the period encompassed by these observations Nova Cas reached only moderate excitation-the most energetic coronal lines were [S VIII] 9913 and [Al IX] 20444; lines such as [S IX] 12523 that are prominent in some novae were not detected. Additional coronal lines present include [Si VI] 19641, [Ca VIII] 23205, and [Si VII] 24807. New lines identified include features of [Fe V], [Fe VI]. These iron features are not coronal lines, 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 lines 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.

  14. MICROLENSING OF QUASAR BROAD EMISSION LINES: CONSTRAINTS ON BROAD LINE REGION SIZE

    SciTech Connect

    Guerras, E.; Mediavilla, E.; Kochanek, C. S.; Munoz, J. A.; Falco, E.; Motta, V.

    2013-02-20

    We measure the differential microlensing of the broad emission lines between 18 quasar image pairs in 16 gravitational lenses. We find that the broad emission lines are in general weakly microlensed. The results show, at a modest level of confidence (1.8{sigma}), that high ionization lines such as C IV are more strongly microlensed than low ionization lines such as H{beta}, indicating that the high ionization line emission regions are more compact. If we statistically model the distribution of microlensing magnifications, we obtain estimates for the broad line region size of r{sub s} = 24{sup +22} {sub -15} and r{sub s} = 55{sup +150} {sub -35} lt-day (90% confidence) for the high and low ionization lines, respectively. When the samples are divided into higher and lower luminosity quasars, we find that the line emission 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.

  15. SED and Emission Line Properties of Red 2MASS AGN

    NASA Astrophysics Data System (ADS)

    Kuraszkiewicz, Joanna; Wilkes, Belinda J.; Schmidt, Gary; Ghosh, Himel

    2009-09-01

    Radio and far-IR surveys, and modeling of the cosmic X-ray background suggest that a large population of obscured AGN has been missed by traditional, optical surveys. The Two Micron All-Sky Survey (2MASS) has revealed a large population (surface density comparable to that of optically selected AGN with Ks<14.5mag) of mostly nearby (median z=0.25), red, moderately obscured AGN, among which 75% are previously unidentified emission-line AGN, with 85% showing broad emission lines. We present the SED and emission line properties of 44 such red (J-Ks>2) 2MASS AGN observed with Chandra. They lie at z<0.37, span a full range of spectral types (Type 1, intermediate, Type 2),Ks-to-X-ray slopes, and polarization (<13%). Their IR-to-X-ray spectral energy distributions (SEDs) are red in the near-IR/opt/UV showing little or no blue bump. The optical colors are affected by reddening, host galaxy emission, redshift, and in few, highly polarized objects, also by scattered AGN light. The levels of obscuration obtained from optical, X-rays, and far-IR imply N_H emission line equivalent widths, suggest a predominance of inclined objects in which obscuration/inclination allows us to see and study weaker emission components which are generally swamped by the direct AGN light. PCA analysis of the IR-X-ray SED and emission line properties shows that, while obscuration/inclination is important, the dominant cause of variance in the sample (eigenvector 1) is the L/L_{edd} ratio (perhaps because the red near-IR selection limits the range of inclination/obscuration values in our sample). This analysis also distinguishes two sources of obscuration: the host galaxy and circumnuclear absorption.

  16. 40 CFR 1033.110 - Emission diagnostics-general requirements.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... equip your locomotives with a diagnostic system that will detect significant malfunctions in their... for in-use testing. Notify the owner/operator that the presence of this diagnostic system affects... engine operation. (d) Record and store in computer memory any diagnostic trouble codes showing...

  17. 40 CFR 1033.110 - Emission diagnostics-general requirements.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... equip your locomotives with a diagnostic system that will detect significant malfunctions in their... for in-use testing. Notify the owner/operator that the presence of this diagnostic system affects... engine operation. (d) Record and store in computer memory any diagnostic trouble codes showing...

  18. KPC-Scale Properties of Emission-line Galaxies

    NASA Astrophysics Data System (ADS)

    Hemmati, Shoubaneh; Mobasher, Bahram; Candels

    2015-01-01

    We perform a detailed -combined spectroscopic and photometric- study of resolved properties of galaxies at kpc scale and investigate how small-scale and global properties of galaxies are related. The sample consists of 119 galaxies to z~1.3 with the unique feature of having very high-resolution spectroscopic data from long exposure observations with the KECK/DEIMOS. Using HST/ACS and WFC3 data taken as part of the CANDELS project, we produce resolved rest-frame (U-V) color, stellar mass and star formation surface densities, stellar age and extinction maps and profiles along the galaxies rotation axes. We model the optical nebular emission lines using the high-resolution DEIMOS spectra and construct the optical line ratio profiles diagnostic of metallicity (R23) and nebular extinction (Ha/Hb). We find that the nebular dust extinction profile, inferred from Balmer decrement, is in agreement with the average extinction derived from the resolved SED modeling. Using the R23 metallicity profiles we examine, for the first time, the mass metallicity relation across galaxies and explore how this relation changes as a function of spatial position. We identify red and blue 'regions' of statistical significance within individual galaxies, using their rest-frame color maps. As expected, for any given galaxy, the red regions are found to have higher stellar mass surface densities and older ages compared to the blue regions. Furthermore, we quantify the spatial distribution of red and blue regions with respect to both redshift and stellar mass, finding that the stronger concentration of red regions toward the centers of galaxies is not a significant function of either redshift or stellar mass. We find that the 'main sequence' of star forming galaxies exists among both red and blue regions inside galaxies, with the median of blue regions forming a tighter relation with a slope of 1.1±0.1 and a scatter of ˜ 0.2 dex compared to red regions with a slope of 1.3 ± 0.1 and a scatter

  19. Measurement of coronal X-ray emission lines from Capella

    NASA Technical Reports Server (NTRS)

    Vedder, P. W.; Canizares, C. R.

    1983-01-01

    The Einstein Observatory's Focal Plane Crystal Spectrometer has detected X-ray emission lines due to O VIII, Fe XVII, and Fe XX, from the binary star system Capella. Line luminosities are well fitted by an emitting plasma at a single temperature of 6.29 + or - 0.01 - 0.03 million K, and a volume emission measure of about 8.6 x 10 to the 52nd/cu cm, corresponding to the low temperature component previously observed. A high temperature component is undetectable, since the observed lines are not produced in plasma at temperatures above about 20 million K. Nearly isothermal plasma would be expected if many of the magnetically confined coronal loops have similar sizes and pressures, and a second population of longer loops would be required to account for the hotter component. An alternative interpretation of the observed X-ray line emission and upper limit is that the plasma contains a continuous distribution of emission measure versus temperature that rises sharply to 3 million K and then falls by nearly a decade to 16 million. An extrapolation of the loop sizes suggested by this alternative to hotter, longer loops may also account for the higher temperature emission.

  20. Impurity Line Emissions in VUV Region of TCABR Tokamak

    SciTech Connect

    Machida, M.; Daltrini, A. M.; Severo, J. H. F.; Nascimento, I. C.; Sanada, E. K.; Elizondo, J. I.; Kuznetsov, Y. K.; Galvao, R. M. O.

    2008-04-07

    Spectral emissions in the vacuum ultraviolet region from 50 nm to 320 nm have been measured on TCABR tokamak using an one meter VUV spectrometer and a MCP coupled to a CCD detector. Among the 98 emissions classified, 37 are from first order diffraction, 29 are from second order, 24 are from third order, 7 from fourth order, and one from fifth order diffraction. Main impurity lines are OII to OVII, CII to CIV, NIII to N V, FVII, besides working gas plasma hydrogen Lyman lines.

  1. The formation of emission lines in quasars and Seyfert nuclei

    NASA Technical Reports Server (NTRS)

    Kwan, J.; Krolik, J. H.

    1981-01-01

    The photoionization and heating throughout a quasar emission-line cloud optically thick at the Lyman edge are calculated. Photoionization and collisional ionization from excited states of hydrogen are included, which maintain a substantial electron fraction after the exhaustion of Lyman continuum photons halts ground-state photoionization. Observed values are explained for Ly-alpha/H-beta, H-alpha/H-beta, P-alpha/H-alpha, He I 5876/H-beta, O I 8446/H-alpha, and Mg II 2798/H-beta. The dependence of line strengths on physical conditions is discussed, and plotting Fe II/4570/H-beta versus Balmer continuum/H-beta is suggested. Other observations are also suggested, and the degree of asymmetry is given between the forward and backward emission of lines from a finite slab to make possible the use of comparative line profile studies to elucidate cloud kinematics.

  2. THE FORMATION OF IRIS DIAGNOSTICS. II. THE FORMATION OF THE Mg II h and k LINES IN THE SOLAR ATMOSPHERE

    SciTech Connect

    Leenaarts, J.; Pereira, T. M. D.; Carlsson, M.; De Pontieu, B.; Uitenbroek, H. E-mail: tiago.pereira@astro.uio.no E-mail: bdp@lmsal.com

    2013-08-01

    NASA's Interface Region Imaging Spectrograph (IRIS) small explorer mission will study how the solar atmosphere is energized. IRIS contains an imaging spectrograph that covers the Mg II h and k lines as well as a slit-jaw imager centered at Mg II k. Understanding the observations requires forward modeling of Mg II h and k line formation from three-dimensional (3D) radiation-magnetohydrodynamic (RMHD) models. This paper is the second in a series where we undertake this modeling. We compute the vertically emergent h and k intensity from a snapshot of a dynamic 3D RMHD model of the solar atmosphere, and investigate which diagnostic information about the atmosphere is contained in the synthetic line profiles. We find that the Doppler shift of the central line depression correlates strongly with the vertical velocity at optical depth unity, which is typically located less than 200 km below the transition region (TR). By combining the Doppler shifts of the h and k lines we can retrieve the sign of the velocity gradient just below the TR. The intensity in the central line depression is anti-correlated with the formation height, especially in subfields of a few square Mm. This intensity could thus be used to measure the spatial variation of the height of the TR. The intensity in the line-core emission peaks correlates with the temperature at its formation height, especially for strong emission peaks. The peaks can thus be exploited as a temperature diagnostic. The wavelength difference between the blue and red peaks provides a diagnostic of the velocity gradients in the upper chromosphere. The intensity ratio of the blue and red peaks correlates strongly with the average velocity in the upper chromosphere. We conclude that the Mg II h and k lines are excellent probes of the very upper chromosphere just below the TR, a height regime that is impossible to probe with other spectral lines. They also provide decent temperature and velocity diagnostics of the middle chromosphere.

  3. UV resonance line dayglow emissions on earth and Jupiter

    NASA Technical Reports Server (NTRS)

    Gladstone, G. Randall

    1988-01-01

    The similarities and differnces between atomic resonance line emissions on earth and Jupiter are studied. For earth, the scattering of the conservative atomic oxygen triplet transition at 1304 A and the nonconservative atomic oxygen sextuplet at 989 A is considered. For Jupiter, the scattering of the conservative atomic hydrogen doublet at 1216 A and the nonconservative atomic hydrogen doublet at 1026 A are addressed. Models are presented for the intensities of the emission features as seen from a distance of several planetary radii, using the same observational geometry for both earth and Jupiter. Variations of the line-integrated emissions across the disk and near the limb of each planet are examined in detail. Line profiles for the emission near the limb and at disk-center are also studied. The models reveal the importance of including inhomogeneities and temperature variations of the atmosphere in scattering models, and indicate that outer planet emissions previously interpreted as 'electroglow' may be solely due to resonant scattering of solar emissions.

  4. Carbon recombination lines as a diagnostic of photodissociation regions

    NASA Technical Reports Server (NTRS)

    Natta, A.; Walmsley, C. M.; Tielens, A. G. G. M.

    1994-01-01

    We have observed the C91 alpha radio recombination line toward the Orion H II region. This narrow (approximately 3-5 km per sec full width at half maximum (FWHM)) line is spatially very extended (approximately 8 arcmin or 1 pc). These charateristics compare well with the observed characteristics of the C II fine structure line at 158 microns. Thus, the C91 alpha line originates in the predominantly neutral photodissociation regions separating the H II region from the molecular cloud. We have developed theoretical models for the C II radio recombination lines from photodissociation regions. The results show that the I(C91 alpha)/I(C158) intensity ratio is a sensitive function of the temperature and density of the emitting gas. We have also extended theoretical models for photodissociation regions to include the C II recombination lines. Comparison with these models show that, in the central portion of the Orion region, the C91 alpha line originates in dense (10(exp 6) per cu cm), warm (500-1000 K) gas. Even at large projected distances (approximately 1 pc), the inferred density is still high (10(exp 5) per cu cm) and implies extremely high thermal pressures. As in the case of the (C II) 158 microns line, the large extent of the C91 alpha line shows that (FUV) photons can penetrate to large distances from the illuminating source. The decline of the intensity of the incident radiation field with distance from Theta(sup 1) C seems to be dominated by geometrical dilution, rather than dust extinction. Finally, we have used our models to calculate the intensity of the 9850 A recombination line of C II. The physical conditions inferred from this line are in good agreement with those determined from the radio recombination and the far-infrared fine-structure lines. We show that the ratio of the 9850 A to the C91 alpha lines is a very good probe of very high density clumps.

  5. Emission lines of [K v] in the optical spectra of gaseous nebulae

    PubMed Central

    Keenan, Francis P.; Aller, Lawrence H.; Espey, Brian R.; Exter, Katrina M.; Hyung, Siek; Keenan, Michael T. C.; Pollacco, Don L.; Ryans, Robert S. I.

    2002-01-01

    Recent R-matrix calculations of electron impact excitation rates in K v are used to derive the nebular emission line ratio R = I(4122.6 Å)/I(4163.3 Å) as a function of electron density (Ne). This ratio is found to be very sensitive to changes in Ne over the density range 103 to 106 cm−3, but does not vary significantly with electron temperature, and hence in principle should provide an excellent optical Ne diagnostic for the high-excitation zones of nebulae. The observed value of R for the planetary nebula NGC 7027, measured from a spectrum obtained with the Hamilton Echelle spectrograph on the 3-m Shane Telescope, implies a density in excellent agreement with that derived from [Ne iv], formed in the same region of the nebula as [K v]. This observation provides observational support for the accuracy of the theoretical [K v] line ratios, and hence the atomic data on which they are based. However, the analysis of a high-resolution spectrum of the symbiotic star RR Telescopii, obtained with the University College London Echelle Spectrograph on the 3.9-m Anglo–Australian Telescope, reveals that the [K v] 4122.6 Å line in this object is badly blended with Fe ii 4122.6 Å. Hence, the [K v] diagnostic may not be used for astrophysical sources that show a strong Fe ii emission line spectrum. PMID:11904366

  6. Emission lines of [K V] in the optical spectra of gaseous nebulae.

    PubMed

    Keenan, Francis P; Aller, Lawrence H; Espey, Brian R; Exter, Katrina M; Hyung, Siek; Keenan, Michael T C; Pollacco, Don L; Ryans, Robert S I

    2002-04-01

    Recent R-matrix calculations of electron impact excitation rates in K v are used to derive the nebular emission line ratio R = I(4122.6 A)/I(4163.3 A) as a function of electron density (N(e)). This ratio is found to be very sensitive to changes in N(e) over the density range 10(3) to 10(6) cm(-3), but does not vary significantly with electron temperature, and hence in principle should provide an excellent optical N(e) diagnostic for the high-excitation zones of nebulae. The observed value of R for the planetary nebula NGC 7027, measured from a spectrum obtained with the Hamilton Echelle spectrograph on the 3-m Shane Telescope, implies a density in excellent agreement with that derived from [Ne iv], formed in the same region of the nebula as [K v]. This observation provides observational support for the accuracy of the theoretical [K v] line ratios, and hence the atomic data on which they are based. However, the analysis of a high-resolution spectrum of the symbiotic star RR Telescopii, obtained with the University College London Echelle Spectrograph on the 3.9-m Anglo-Australian Telescope, reveals that the [K v] 4122.6 A line in this object is badly blended with Fe ii 4122.6 A. Hence, the [K v] diagnostic may not be used for astrophysical sources that show a strong Fe ii emission line spectrum. PMID:11904366

  7. Spectropolarimetry of the molecular hydrogen line emission from OMC-1

    NASA Technical Reports Server (NTRS)

    Burton, Michael G.; Hough, J. H.; Axon, David J.; Hasegawa, T.; Tamura, M.

    1988-01-01

    Observations of the H2 v = 1-0 S(1) line at 35 km/s velocity resolution were obtained at several locations within OMC-1, including the molecular hydrogen reflection nebula. All line profiles are smooth and show no evidence for being composed of discrete components. The data are discussed with respect to a model for the H2 line formation in which the emission originates in discrete clumps moving at different velocities. It is suggested that the extended blue wing may come from fast-moving clumps embedded in a wind.

  8. The Subaru FMOS galaxy redshift survey (FastSound). II. The emission line catalog and properties of emission line galaxies

    NASA Astrophysics Data System (ADS)

    Okada, Hiroyuki; Totani, Tomonori; Tonegawa, Motonari; Akiyama, Masayuki; Dalton, Gavin; Glazebrook, Karl; Iwamuro, Fumihide; Ohta, Kouji; Takato, Naruhisa; Tamura, Naoyuki; Yabe, Kiyoto; Bunker, Andrew J.; Goto, Tomotsugu; Hikage, Chiaki; Ishikawa, Takashi; Okumura, Teppei; Shimizu, Ikkoh

    2016-06-01

    We present basic properties of ˜3300 emission line galaxies detected by the FastSound survey, which are mostly Hα emitters at z ˜ 1.2-1.5 in the total area of about 20 deg2, with the Hα flux sensitivity limit of ˜1.6 × 10-16 erg cm-2 s-1 at 4.5 σ. This paper presents the catalog of the FastSound emission lines and galaxies, which is open to the public. We also present basic properties of typical FastSound Hα emitters, which have Hα luminosities of 1041.8-1043.3 erg s-1, star formation rates (SFRs) of 20-500 M⊙ yr-1, and stellar masses of 1010.0-1011.3 M⊙. The 3D distribution maps for the four fields of Canada-France-Hawaii Telescope Legacy Survey (CFHTLS) W1-4 are presented, clearly showing large scale clustering of galaxies at the scale of ˜100-600 comoving Mpc. Based on 1105 galaxies with detections of multiple emission lines, we estimate that the contamination of non-Hα lines is about 4% in the single-line emission galaxies, which is mostly [O III]λ5007. This contamination fraction is also confirmed by the stacked spectrum of all the FastSound spectra, in which Hα, [N II]λλ6548,6583, [S II]λλ6717,6731, and [O I]λλ6300,6364 are seen.

  9. EQUIB: Atomic level populations and line emissivities calculator

    NASA Astrophysics Data System (ADS)

    Howarth, I. D.; Adams, S.; Clegg, R. E. S.; Ruffle, D. P.; Liu, X.-W.; Pritchet, C. J.; Ercolano, B.

    2016-03-01

    The Fortran program EQUIB solves the statistical equilibrium equation for each ion and yields atomic level populations and line emissivities for given physical conditions, namely electron temperature and electron density, appropriate to the zones in an ionized nebula where the ions are expected to exist.

  10. Infrared emission-line spectrum of Gamma Cassiopeiae

    SciTech Connect

    Hamann, F.; Simon, M.

    1987-07-01

    The near-IR spectrum of Gamma Cas contains emission lines of H I, He I, and Mg II. No lines of low-excitation species, such as are found in cool and dense environments, are detected. At the time of the observations,the observed Br-alpha and Br-gamma profiles were double-peaked, with V/R roughly 0.5 and FWHM roughly 260 km/s. The Br-gamma line profile varied significantly over the 4.5 month interval between the observations and those published by Chabaev and Maillard in 1985. The IR hydrogen line fluxes indicate that these lines are formed in a small, dense, optically thick region where the density of ionized gas declines sharply with distance from the star. Both the line profiles and fluxes are shown to be inconsistent with the predictions of standard stellar wind theory, but are in qualitative agreement with a rotating disk model such as was proposed in 1978 by Poeckert and Marlborough. The observations are discussed briefly in terms of their similarities and differences with the IR emission-line spectra of luminous young stellar objects. 40 references.

  11. The infrared emission-line spectrum of Gamma Cassiopeiae

    NASA Astrophysics Data System (ADS)

    Hamann, F.; Simon, M.

    1987-07-01

    The near-IR spectrum of Gamma Cas contains emission lines of H I, He I, and Mg II. No lines of low-excitation species, such as are found in cool and dense environments, are detected. At the time of the observations,the observed Br-alpha and Br-gamma profiles were double-peaked, with V/R roughly 0.5 and FWHM roughly 260 km/s. The Br-gamma line profile varied significantly over the 4.5 month interval between the observations and those published by Chabaev and Maillard in 1985. The IR hydrogen line fluxes indicate that these lines are formed in a small, dense, optically thick region where the density of ionized gas declines sharply with distance from the star. Both the line profiles and fluxes are shown to be inconsistent with the predictions of standard stellar wind theory, but are in qualitative agreement with a rotating disk model such as was proposed in 1978 by Poeckert and Marlborough. The observations are discussed briefly in terms of their similarities and differences with the IR emission-line spectra of luminous young stellar objects.

  12. Ethylene line emission from the North Pole of Jupiter

    NASA Technical Reports Server (NTRS)

    Kostiuk, Theodor; Espenak, F.; Romani, P.; Goldstein, J.

    1991-01-01

    A significant enhancement in infrared emission 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 emission line 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 emission 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 emission line 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 line shape (width) implied that the enhanced emission originated very high in the stratosphere.

  13. A line-of-sight electron cyclotron emission receiver for electron cyclotron resonance heating feedback control of tearing modes.

    PubMed

    Oosterbeek, J W; Bürger, A; Westerhof, E; de Baar, M R; van den Berg, M A; Bongers, W A; Graswinckel, M F; Hennen, B A; Kruijt, O G; Thoen, J; Heidinger, R; Korsholm, S B; Leipold, F; Nielsen, S K

    2008-09-01

    An electron cyclotron emission (ECE) receiver inside the electron cyclotron resonance heating (ECRH) transmission line has been brought into operation. The ECE is extracted by placing a quartz plate acting as a Fabry-Perot interferometer under an angle inside the electron cyclotron wave (ECW) beam. ECE measurements are obtained during high power ECRH operation. This demonstrates the successful operation of the diagnostic and, in particular, a sufficient suppression of the gyrotron component preventing it from interfering with ECE measurements. When integrated into a feedback system for the control of plasma instabilities this line-of-sight ECE diagnostic removes the need to localize the instabilities in absolute coordinates. PMID:19044409

  14. Searching for gas emission lines in Spitzer Infrared Spectrograph (IRS) spectra of young stars in Taurus

    NASA Astrophysics Data System (ADS)

    Baldovin-Saavedra, C.; Audard, M.; Güdel, M.; Rebull, L. M.; Padgett, D. L.; Skinner, S. L.; Carmona, A.; Glauser, A. M.; Fajardo-Acosta, S. B.

    2011-04-01

    Context. Our knowledge of circumstellar disks has traditionally been based on studies of dust. However, gas dominates the disk mass and its study is key to our understanding of accretion, outflows, and ultimately planet formation. The Spitzer Space Telescope provides access to gas emission lines in the mid-infrared, providing crucial new diagnostics of the physical conditions in accretion disks and outflows. Aims: We seek to identify gas emission lines in mid-infrared spectra of 64 pre-main-sequence stars in Taurus. Using line luminosities and other known star-disk-outflow parameters, we aim to identify correlations that will help to constrain gas heating, excitation mechanisms, and the line formation. Methods: We have based our study on Spitzer observations using the Infrared Spectrograph (IRS), mainly with the high-resolution modules. Line luminosities (or 3σ upper limits) have been obtained by fitting Gaussian profiles to the lines. We have further searched for correlations between the line luminosities and different parameters related to the star-disk system. Results: We have detected H2 (17.03, 28.22 μm) emission in 6 objects, [Ne II] (12.81 μm) emission in 18 objects, and [Fe II] (17.93, 25.99 μm) emission in 7 objects. [Ne II] detections are found primarily in Class II objects. The luminosity of the [Ne II] line (LNeII) is in general higher for objects known to drive jets than for those without known jets, but the two groups are not statistically distinguishable. LNeII is correlated with X-ray luminosity, but for Class II objects only. LNeII is also correlated with disk mass and accretion rate when the sample is divided into high and low accretors. Furthermore, we find correlations of LNeII with mid-IR continuum luminosity and with luminosity of the [O I] (6300 Å) line, the latter being an outflow tracer. L [FeII] correlates with Ṁacc. No correlations were found between LH2 and several tested parameters. Conclusions: Our study reveals a general trend

  15. Model for the intense molecular line emission from OMC-1

    SciTech Connect

    Draine, B.T.; Roberge, W.G.

    1982-08-15

    We present a model which attributes the observed H/sub 2/ and CO line emission OMC-1 to a magnetohydrodynamic shock propagating into magnetized molecular gas. By requiring the shock to reporoduce the observed line intensities, we determine the shock speed to be v/sub s/roughly-equal38 km s/sup -1/ and the preshock density and (transverse) magnetic field to be n/sub H/roughly-equal7 x 10/sup 5/ cm/sup -3/, B/sub O/roughly-equal1.5 milligauss. The model is compared to observations of H/sub 2/, CO, OH, O I, and C I in emission and of CO in absorption. The shock gas may be detectible in H I 21 cm emission.

  16. Electromagnetic plasma wave emissions from the auroral field lines

    NASA Technical Reports Server (NTRS)

    Gurnett, D. A.

    1977-01-01

    The most important types of auroral radio emissions are reviewed, both from a historical perspective as well as considering the latest results. Particular emphasis is placed on four types of electromagnetic emissions which are directly associated with the plasma on the auroral field lines. These emissions 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 lines 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.

  17. Nebular Line Emission in z 1 Spitzer Infrared-Luminous Galaxies

    NASA Astrophysics Data System (ADS)

    Krause, John; Papovich, C.; Finkelstein, S.; Willmer, C.; Egami, E.; Conselice, C.; Huang, J.; Koo, D.; Laird, E.; Le Floc'h, E.; Lotz, J.; Maia, M.; Marcillac, D.; Nandra, K.; Webb, T.; Weiner, B.

    2010-01-01

    We present near-infrared (IR) spectroscopic observations from the Multi-Object IR Camera and Spectrograph (MOIRCS) on the Subaru telescope of a sample of 21 IR-luminous galaxies in the approximate range 1 < z < 1.5. These galaxies were selected based on their Spitzer 24-micron flux densities (S(24 micron) > 0.1 mJy) and known spectroscopic redshifts from the All-Wavelength Extended Groth Strip International Survey (AEGIS). We measure rest-frame optical emission line fluxes for H-alpha and [NII], and also [OIII] and H-beta, where available. We use emission-line diagnostics to constrain the origin of the ionization in these objects: processes associated with star formation or AGN (including Seyferts and LINERs). The high-redshift galaxies in our sample have similar [NII] / H-alpha flux ratios compared to low-redshift (z 0.1) IR-luminous galaxies (Kim et al., 1995; Veilleux et al., 1995) for galaxies with implied IR luminosities of 11 < Log L(8-1000 micron) / L sol < 12. However, we find evidence that the IR-luminous galaxies in our sample with implied Log L(8-1000 micron) / L sol > 12 have lower [NII] / H-alpha ratios than low-redshift galaxies with comparable IR luminosity, implying the higher redshift IR-luminous galaxies may have a higher fraction of systems dominated by star formation. We also study the relation of our rest-frame optical emission-line diagnostics to other indicators of AGN activity, including the mid-IR colors and X-ray luminosities. In addition, we compare star-formation-rate indicators from our dust-corrected H-alpha emission line luminosities to those from the mid-to-far IR and compare these as a function of IR luminosity against the low-redshift sample.

  18. Spectrophotometry of emission-line stars in the magellanic clouds

    NASA Technical Reports Server (NTRS)

    Bohannan, Bruce

    1990-01-01

    The strong emission lines 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 lines do not provide an accurate measure of photospheric conditions. In the research funded by this grant, temperatures and gravities of emission-line 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.

  19. Laboratory Study of the Diagnostic Utility of the 3C/3D Line Ratio in Fe XVII

    NASA Technical Reports Server (NTRS)

    Brown, G. V.; Beiersdorfer, P.; Chen, H.; Chen, M., II; Reed, K. J.

    2002-01-01

    Fe XVII X-ray emission is present in a multitude of sources, such as the corona of the Sun, Capella, and Procyon. Two of the strongest lines observed in these spectra are the resonance and intercombination lines located at 15.01 and 15.26 A, respectively. As part of the laboratory astrophysics program at the electron beam ion traps EBIT-I & EBIT-II located at the Lawrence Livermore National Laboratory we have measured this line ratio for the case where the relative abundance of Fe XVI to Fe XVII is approx. 1. Our results show that an Fe XVI innershell satellite line coincides with the intercombination line and can significantly reduce the relative intensity, R, of the resonance to intercombination line. The fact that the apparent relative intensity of the resonance and intercombination line in Fe XVII is sensitive to the strength of an Fe XVI innershell satellite, and therefore, tho relative abundance of Fe XVI to Fe XVII, makes the line ratio a diagnostic of temperature, and explains the anomalously low ratios observed in the solar and stellar coronae.

  20. INVESTIGATING THE RELIABILITY OF CORONAL EMISSION MEASURE DISTRIBUTION DIAGNOSTICS USING THREE-DIMENSIONAL RADIATIVE MAGNETOHYDRODYNAMIC SIMULATIONS

    SciTech Connect

    Testa, Paola; De Pontieu, Bart; Martinez-Sykora, Juan; Hansteen, Viggo; Carlsson, Mats

    2012-10-10

    Determining the temperature distribution of coronal plasmas can provide stringent constraints on coronal heating. Current observations with the Extreme ultraviolet Imaging Spectrograph (EIS) on board Hinode and the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory provide diagnostics of the emission measure distribution (EMD) of the coronal plasma. Here we test the reliability of temperature diagnostics using three-dimensional radiative MHD simulations. We produce synthetic observables from the models and apply the Monte Carlo Markov chain EMD diagnostic. By comparing the derived EMDs with the 'true' distributions from the model, we assess the limitations of the diagnostics as a function of the plasma parameters and the signal-to-noise ratio of the data. We find that EMDs derived from EIS synthetic data reproduce some general characteristics of the true distributions, but usually show differences from the true EMDs that are much larger than the estimated uncertainties suggest, especially when structures with significantly different density overlap along the line of sight. When using AIA synthetic data the derived EMDs reproduce the true EMDs much less accurately, especially for broad EMDs. The differences between the two instruments are due to the: (1) smaller number of constraints provided by AIA data and (2) broad temperature response function of the AIA channels which provide looser constraints to the temperature distribution. Our results suggest that EMDs derived from current observatories may often show significant discrepancies from the true EMDs, rendering their interpretation fraught with uncertainty. These inherent limitations to the method should be carefully considered when using these distributions to constrain coronal heating.

  1. Cloudy 94 and Applications to Quasar Emission Line Regions

    NASA Technical Reports Server (NTRS)

    Ferland, Gary J.

    2000-01-01

    This review discusses the most recent developments of the plasma simulation code Cloudy and its application to the, emission-line 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 emission line source. Emission lines 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 emission line regions. Powerful selection effects, introduced by the atomic physics and line formation process, permit individual lines 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.

  2. K alpha line emission during solar X-ray bursts

    NASA Technical Reports Server (NTRS)

    Phillips, K. J. H.; Neupert, W. M.

    1973-01-01

    Calculations of K alpha line emission from S, Ar, Ca and Fe are presented. It is reported that on the basis of data for hard X-ray bursts, the flux during most impulsive, non-thermal events is likely to be weak, though for a few strong bursts, a flux of approximately 100 photons/cm/s may be expected. The amount of S K alpha emission particularly is sensitively dependent on the value of the lower energy bound of the non-thermal electron distribution, offering a possible means of determining this. Thermal K alpha emission is only significant for Fe ions. The calculated thermal K alpha radiation is much less than that observed during an intense soft X-ray burst. It is concluded that a detailed temperature structure for the emission source is required in order to explain the discrepancy.

  3. Time-dependent analysis of visible helium line-ratios for electron temperature and density diagnostic using synthetic simulations on NSTX-U

    DOE PAGESBeta

    Muñoz Burgos, J. M.; Barbui, T.; Schmitz, O.; Stutman, D.; Tritz, K.

    2016-07-11

    Helium line-ratios for electron temperature (Te) and density (ne) plasma diagnostic in the Scrape-Off-Layer (SOL) and Edge regions of tokamaks are widely used. Due to their intensities and proximity of wavelengths, the singlet 667.8 and 728.1 nm, and triplet 706.5 nm visible lines have been typically preferred. Time-dependency of the triplet line (706.5 nm) has been previously analyzed in detail by including transient effects on line-ratios during gas-puff diagnostic applications. In this work, several line-ratio combinations within each of the two spin systems are analyzed with the purpose of eliminating transient effects to extend the application of this powerful diagnosticmore » to high temporal resolution characterization of plasmas. The analysis is done using synthetic emission modeling and diagnostic for low electron density NSTX SOL plasma conditions by several visible lines. Quasi-static equilibrium, and time-dependent models are employed to evaluate transient effects of the atomic population levels that may affect the derived electron temperatures and densities as the helium gas-puff penetrates the plasma. Ultimately, the analysis of a wider range of spectral lines will help to extend this powerful diagnostic to experiments where the wavelength range of the measured spectra may be constrained either by limitations of the spectrometer, or by other conflicting lines from different ions.« less

  4. The Survey of Lines in M31 (SLIM): Origin of [CII] Emission

    NASA Astrophysics Data System (ADS)

    Kapala, Maria; Sandstrom, K.; Groves, B.; Croxall, K. V.; Dalcanton, J.; Gordon, K. D.; Krause, O.; Kreckel, K.; Leroy, A. K.; Rix, H.; Schinnerer, E.; Walter, F.

    2014-01-01

    The [CII] 158 micron line is typically the brightest far-IR emission line from star-forming galaxies. To use this line as a tracer of star-formation and a diagnostic of ISM conditions, we must understand which phases of the ISM and what gas heating sources are contributing to it. As a massive, nearby galaxy, Andromeda is ideal for studying [CII] because we can resolve individual star-forming regions in the galaxy, but it is representative of more distant galaxies. To address the origins of [CII], we have assembled a unique set of observations including: [CII] 158 micron and [OI] 63 micron lines from Herschel PACS; fully sampled optical integral field spectroscopy from PPAK on the Calar Alto 3.5m, and Herschel dust continuum mapping from 70-500 microns. These observations span a range of conditions across Andromeda. We present first results on how [CII] correlates with the far-IR continuum on ~50 pc scales. In particular, we find that star-forming regions in M31 do not exhibit a "[CII] line deficit" even in regions where the dust is very warm. Using the optical line emission, we determine the fraction of [CII] emission spatially associated with star-forming regions. Our method implies a high fraction ~40-75% of [CII] emission is coming from diffuse regions. These diffuse regions appear to dominated by the UV interstellar radiation field, which we infer from the Pan-Chromatic Hubble Andromeda Treasury data to be dominated by B stars. Our results suggest that studies using [CII] to trace the massive star-formation rate must take into account the the contribution of older stellar populations in heating the ISM gas.

  5. Rotation and emission lines in stars and accretion disks

    NASA Technical Reports Server (NTRS)

    Horne, Keith; Saar, Steven H.

    1991-01-01

    In the accretion disks of quiescent dwarf novae, Doppler mapping studies reveal that Balmer emission lines increase sharply toward the center of the disk, with surface brightnesses scaling roughly as R exp -3/2 varies as Omega(Kep). Similarly, among chromospherically active stars the H-alpha and Ca II H and K emission cores are stronger in the more rapidly rotating stars, with surface brightnesses scaling again roughly as Omega(rot). Since in both cases the emission lines scale linearly with the rotation frequency, it is proposed that the mechanism powering the emission lines in quiescent accretion disks is the same as that in chromospherically active stars, namely, the emergence of magnetic flux generated by the action of a dynamo, and its interaction with the atmosphere. If this empirical connection between disks and stars is in fact due to magnetic dynamos, the range of rotation rates available for testing dynamo theories expands from a factor of 1000 to 10 to the 7th.

  6. A transmission line bridge for the diagnostics of plasma channels

    NASA Astrophysics Data System (ADS)

    Pechacek, R. E.; Raleigh, M.; Greig, J. R.; Dwyer, T.; Ehrlich, J.

    1984-03-01

    This paper describes a device for measuring the average electrical conductivity of a long, narrow, cylindrical plasma. Interest in plasmas of this shape originates from two areas of study: the study of electron beam propagation through neutral gas, and the study of long straight electrical discharges for use as a communication antenna. Propagation of an electron beam through a neutral gas produces an ionized channel whose properties and evolution are very important to the propagation of the beam itself. Long straight electrical discharges are created in a channel that is ionized by a pulsed laser beam focused with a long focal length lens, and the properties of the plasma in this channel are important to the propagation of the electrical discharge along with channel. The properties of these plasmas are inferred from changes in the transmission properties of a transmission line placed close to and parallel to the plasma. In this paper an analysis is made of the relation between the bridge output voltage and the conductivity of the perturbing plasma for the case in which the conductivity is very low. In this case all perturbations on the bridge parameters are small, and linear approximations are appropriate. The usefulness of the bridge, however, extends to plasma well above this low conductivity range, although a different set of approximations may be necessary to make the analysis of the experiment tractable. A transmission line bridge is a device for measuring very small changes in the properties of transmission lines.

  7. Emission Line Profiles of Warped Disks in a Kerr Spacetime

    NASA Astrophysics Data System (ADS)

    Yang, X. L.; Wang, J. C.

    2013-11-01

    The computations of emission line profiles of a warped disk around a Kerr black hole are discussed in this paper, which can be divided into two parts. In the first part, the geodesic motion in a Kerr spacetime and its equations with integral forms are presented. The equations are solved with the Weierstrass' elliptic functions and integrals. Making use of the elliptic functions, the Boyer-Lindquist (B-L) coordinates and the affine parameter σ are expressed semi-analytically as the functions of the parameter p. Then a code named ynogk (Yunnan Observatory Geodesic Kerr) is introduced based on the above discussions to calculate the null geodesics fast in a Kerr spacetime. In the second part of the paper, as an application of ynogk, the emission line profiles of a warped disk are investigated in detail. Here the structure model of the disk is specified according to the results of Bardeen and Petterson in 1975, and the line profiles are computed with the ray-tracing method. Finally, the discussions and conclusions of the computing results are presented, which indicate that the line profiles are dependent mainly on the inclination and azimuthal angles of the observer and the index of emissivity, and have the three-horn even multiple-horn structures comparing to those of a standard thin accretion disk.

  8. Phenomenology of Broad Emission Lines in Active Galactic Nuclei

    NASA Astrophysics Data System (ADS)

    Sulentic, J. W.; Marziani, P.; Dultzin-Hacyan, D.

    Broad emission lines hold fundamental clues about the kinematics and structure of the central regions in AGN. In this article we review the most robust line profile properties and correlations emerging from the best data available. We identify fundamental differences between the profiles of radio-quiet and radio-loud sources as well as differences between the high- and low-ionization lines, especially in the radio-quiet majority of AGN. An Eigenvector 1 correlation space involving FWHM Hβ, W(FeIIopt)/W(Hβ), and the soft X-ray spectral index provides optimal discrimination between all principal AGN types (from narrow-line Seyfert 1 to radio galaxies). Both optical and radio continuum luminosities appear to be uncorrelated with the E1 parameters. We identify two populations of radio-quiet AGN: Population A sources (with FWHM(Hβ) <~ 4000 km s-1, generally strong FeII emission and a soft X-ray excess) show almost no parameter space overlap with radio-loud sources. Population B shows optical properties largely indistinguishable from radio-loud sources, including usually weak FeII emission, FWHM(Hβ) >~ 4000 km s-1 and lack of a soft X-ray excess. There is growing evidence that a fundamental parameter underlying Eigenvector 1 may be the luminosity-to-mass ratio of the active nucleus (L/M), with source orientation playing a concomitant role.

  9. THE TEMPERATURE DIAGNOSTIC PROPERTIES OF THE Mg I 457.1 nm LINE

    SciTech Connect

    Langangen, Oeystein; Carlsson, Mats

    2009-05-10

    We analyze the important formation processes for the Mg I 457.1 nm line. This line is an intercombination line and the source function is close to the local thermodynamic equilibrium (LTE) value. The strong coupling to the local temperature and the relatively high population of the lower level (the ground state of Mg I) makes this line an ideal candidate for temperature diagnostics in the lower chromosphere/temperature minimum region. Linking the temperature probed to an absolute physical height is nontrivial because of non-LTE (NLTE) ionization. We analyze the NLTE effects and find that photoionization from the lower energy levels together with cascading collisional recombination dominates the ionization balance. Taking properly into account the line blanketing in the UV is essential for obtaining the right photoionization rates. The identification of the main NLTE effects in the line allows us to construct a 'quintessential' model atom, ideal for computationally demanding tasks, e.g., full three-dimensional and/or time-dependent radiative transfer. Furthermore, we analyze the diagnostic potential to temperature of this line in solarlike atmospheres, by synthesizing the line from a series of parameterized atmospheric models. These models have been constructed with fixed effective temperature, but with a variable heat term in the energy equation to obtain a chromospheric temperature rise at different heights. We conclude that the line has a significant potential in the diagnostics of the lower chromosphere temperature structure, especially for cooler atmospheres, such as sunspots.

  10. Do the Line Widths of Coronal Emission Lines Increase with Height above the Limb?

    NASA Astrophysics Data System (ADS)

    Singh, Jagdev; Sakurai, Takashi; Ichimoto, Kiyoshi

    2006-03-01

    In our earlier studies we obtained off-the-limb spectroscopic observations in a number of forbidden emission lines ([Fe X-XIV]) to study the physical properties and their temporal variations in steady coronal structures. Short exposure times adopted in those observations permitted us to study the variation in line widths up to about 150" above the limb. With a view to investigating the variations in the parameters of coronal emission lines up to about 500", we made raster scans with exposure times that are longer than the earlier exposure times by a factor of about 10. We find that the FWHM of the [Fe XIV] 5303 Å line decreases up to 300''+/-50'' and then remains more or less the same up to 500", while that of the [Fe X] 6374 Å line increases up to about 250" and subsequently remains unchanged. The FWHMs of the [Fe XI] 7892 Å and [Fe XIII] 10747 Å lines show an intermediate behavior. Furthermore, the ratio of the FWHM of 6374 to 5303 Å increases from 0.93 at the limb to 1.18 at 200" above the limb. The nonvariability in the FWHM of emission lines after about 300" above the limb in steady coronal structures does not support the prevailing view that the nonthermal velocity increases with height due to either the coronal waves or the high-velocity solar wind. The present results indicate the inadequacy of the earlier coronal loop models. The observed variations in FWHM of the coronal emission lines with height above the limb can be explained by assuming the recent model of coronal loops proposed by Akiyama et al.

  11. Emission lines and shock waves in RR Lyrae stars

    NASA Astrophysics Data System (ADS)

    Gillet, D.; Fokin, A. B.

    2014-05-01

    Context. Emission lines observed in radially pulsating stars are thought to be produced by atoms de-exciting after being excited by a shock wave that is traveling into and then compressing, heating, and accelerating the atmospheric gas. Aims: With the help of recent observations, we examine the origin of all the different types of emission lines of hydrogen and helium that appear during a pulsation cycle. Methods: To analyze the physical origin of emission lines, we used the different models of atmospheric dynamics of RR Lyrae stars that have been calculated so far. Results: In contrast to a recent explanation, we propose that the redshifted emission component of Hα, which occurs near the pulsation phase 0.3, is produced by the main shock. In this case, the emission is the natural consequence of the large extension of the expanding atmosphere. Therefore, this (weak) emission should only be observed in RR Lyrae stars for which the main shock will propagate far enough from the photosphere. It appears as a P-Cygni type profile. We estimate the shock front velocity during the shock propagation in the atmosphere and show that it decreases by 40% when the Hα emitting-shock passes from the photospheric level to the upper atmosphere. The Hα P-Cygni profile observed in long-period Cepheids also seems to be caused by the main shock wave. Although to date He II has only been detected in some Blazhko stars, a comprehensive survey of RR Lyrae stars is necessary to confirm this trend, so we can say that the most intense shocks will only be observed in Blazhko stars. Conclusions: The development of a model of atmospheric pulsation that takes the effects of 2D and 3D convection into account, seems to be a necessary step to fully quantify the effects of shock waves on the atmospheric dynamics of radially pulsating stars.

  12. Plasma simulations of emission line regions in high energy environments

    NASA Astrophysics Data System (ADS)

    Richardson, Chris T.

    This dissertation focuses on understanding two different, but in each case extreme, astrophysical environments: the Crab Nebula and emission line galaxies. These relatively local objects are well constrained by observations and are test cases of phenomena seen at high-z where detailed observations are rare. The tool used to study these objects is the plasma simulation code known as Cloudy. The introduction provides a brief summary of relevant physical concepts in nebular astrophysics and presents the basic features and assumptions of Cloudy. The first object investigated with Cloudy, the Crab Nebula, is a nearby supernova remnant that previously has been subject to photoionization modeling to reproduce the ionized emission seen in the nebula's filamentary structure. However, there are still several unanswered questions: (1) What excites the H2 emitting gas? (2) How much mass is in the molecular component? (3) How did the H2 form? (4) What is nature of the dust grains? A large suite of observations including long slit optical and NIR spectra over ionized, neutral and molecular gas in addition to HST and NIR ground based images constrain a particularly bright region of H2 emission, Knot 51, which exhibits a high excitation temperature of ˜3000 K. Simulations of K51 revealed that only a trace amount of H2 is needed to reproduce the observed emission and that H2 forms through an uncommon nebular process known as associative detachment. The final chapters of this dissertation focus on interpreting the narrow line region (NLR) in low-z emission line galaxies selected by a novel technique known as mean field independent component analysis (MFICA). A mixture of starlight and radiation from an AGN excites the gas present in galaxies. MFICA separates galaxies over a wide range of ionization into subsets of pure AGN and pure star forming galaxies allowing simulations to reveal the properties responsible for their observed variation in ionization. Emission line ratios can

  13. Anisotropic alpha emission from on-line separated isotopes

    SciTech Connect

    Wouters, J.; Vandeplassche, D.; van Walle, E.; Severijns, N.; Vanneste, L.

    1986-05-05

    A systematic on-line nuclear-orientation study of heavy isotopes using anisotropic ..cap alpha.. emission is reported for the first time. The anisotrophies recorded for /sup 199/At, /sup 201/At, and /sup 203/At are remarkably pronounced and strongly varying. At lower neutron number the ..cap alpha.. particles are more preferentially emitted perpendicularly to the nuclear-spin direction. This may be interpreted in terms of the high sensitivity of the ..cap alpha..-emission probability to changes in the nuclear shape.

  14. Electromagnetic plasma wave emissions from the auroral field lines

    NASA Technical Reports Server (NTRS)

    Gurnett, D. A.

    1978-01-01

    The most important types of auroral radio emissions are reviewed. Particular attention is given to the following four types of electromagnetic emissions: auroral hiss, saucers, ELF noise bands, and auroral kilometric radiation. It is shown that the auroral hiss and auroral kilometric radiation are generated along the auroral field lines relatively close to the earth, at radial distances in the range of 2.5-5 earth radii, probably in direct association with auroral-particle acceleration by parallel electric fields. The auroral hiss appears to be generated by amplified Cerenkov radiation. Several mechanisms are proposed for the auroral kilometric radiation, usually involving the intermediate generation of electrostatic waves by the precipitating electrons.

  15. 40 CFR 1033.112 - Emission diagnostics for SCR systems.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... diagnostic system must monitor reductant quality and tank levels and alert operators to the need to refill... computer memory all incidents of engine operation with inadequate reductant injection or reductant...

  16. 40 CFR 1033.112 - Emission diagnostics for SCR systems.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... diagnostic system must monitor reductant quality and tank levels and alert operators to the need to refill... computer memory all incidents of engine operation with inadequate reductant injection or reductant...

  17. TYPING SUPERNOVA REMNANTS USING X-RAY LINE EMISSION MORPHOLOGIES

    SciTech Connect

    Lopez, L. A.; Ramirez-Ruiz, E.; Badenes, C.; Huppenkothen, D.; Jeltema, T. E.

    2009-11-20

    We present a new observational method to type the explosions of young supernova remnants (SNRs). By measuring the morphology of the Chandra X-ray line emission in 17 Galactic and Large Magellanic Cloud SNRs with a multipole expansion analysis (using power ratios), we find that the core-collapse SNRs are statistically more asymmetric than the Type Ia SNRs. We show that the two classes of supernovae can be separated naturally using this technique because X-ray line morphologies reflect the distinct explosion mechanisms and structure of the circumstellar material. These findings are consistent with recent spectropolarimetry results showing that core-collapse supernovae explosions are intrinsically more asymmetric.

  18. Emission line eclipse phenomena in nova DQ Herculis /1934/

    NASA Astrophysics Data System (ADS)

    Young, P.; Schneider, D. P.

    1980-06-01

    H-gamma, He II 4686 A, and H-beta emission lines were observed in DQ Her through an eclipse (phases 0.80-0.15). A total of 14 spectra with exposure times of 300 seconds were used to investigate phenomena in the eclispe of the emitting region by the red companion. The classical rotational disturbance of the He II 4686 A line is observed; it changes its velocity by over 600 km/s in 25 minutes during the eclipse. The eclipse duration is very long (0.11 of a cycle) and indicates a mass ratio near unity.

  19. K alpha line emission during solar X-ray bursts

    NASA Technical Reports Server (NTRS)

    Phillips, K. J. H.; Neupert, W. M.

    1973-01-01

    The expected flux of K alpha line emission from sulfur, argon, calcium, and iron is calculated during both thermal and nonthermal solar X-ray events. Such emission is shown to be weak during the course of most of the nonthermal hard X-ray bursts that Kane and Anderson (1970) have observed. If Compton backscattering is significant at high energies, the flux is reduced still further for disk flares, but it is noted that the strong, near-limb burst of June 26 would have produced about 100 photons /sq cm/sec of sulfur and iron K alpha emission. The impulsive hard X-ray bursts may in general be too short-lived for much K alpha emission. It may be noted that sulfur K alpha emission in particular depends sensitively on the lower-energy limit of the nonthermal electron spectrum, assuming such a sharply defined boundary exists. During soft X-ray bursts, when temperatures of a few 10 to the 7th power K are obtained, K alpha emission from certain iron ions, specifically Fe XVIII-XXIII, may be important.

  20. Low Luminosity Cataclysmic Variables and Fe Emission Lines of Galactic Ridge X-ray Emission

    NASA Astrophysics Data System (ADS)

    Xu, Xiaojie; Wang, Q. Daniel

    2015-08-01

    Cataclysmic variables (CVs) has been proposed to be one of the main contributors of the Galactic Ridge X-ray Emission (GRXE). However, previous studies on the spectra of local CVs suggested that the I6.7keV/I7.0keV line intensity ratios of CVs are not consistent with that of GRXE. Utilizing the archival Suzaku observations on local CVs, we confirm that luminous local CVs like intermediate polars, symbiotic stars and polars have lower I6.7keV/I7.0keV values, thus are unable to explain the Fe emission line ratios of GRXE. On the other hand, dimmer CVs like dwarf novae (DNe) have I6.7keV/I7.0keV values consitent with that of GRXE. Given the potential huge population, DNe could be one of the main resources of GRXE Fe line emission.

  1. Accretion disk corona line emission from X0614+091

    NASA Technical Reports Server (NTRS)

    Christian, D. J.; White, N. E.; Swank, J. H.

    1994-01-01

    The low-mass X-ray binary X0614+091 was observed on 3 days in 1979 with the Einstein Observatory solid state spectrometer and the monitor proportional counter. During the observation with the highest measured flux, corresponding to an X-ray luminosity of 8 x 10(exp 36) erg/s (in the 0.5-20 keV band for an assumed distance of 5 kpc), significant low-energy emission was detected, centered at 0.77 keV, possibly due to line emission for O VII-O VIII and Fe XVII-Fe XIX. The other observations, which were at fluxes lower by a factor of 2, are consistent with the presence of the emission feature. The equivalent width of the feature, 37 +/- 6 eV, is of the same order as equivalent widths previously reported for more luminous low-mass X-ray binaries using grating spectrometer data. The soft X-ray lines could be emitted by gas expected to arise in an accretion disk corona excited by the central source. But to explain the observed feature, most of the corona needs to contribute, or other sources of emission are required.

  2. Shock-induced polarized hydrogen emission lines in omicron Ceti

    NASA Astrophysics Data System (ADS)

    Fabas, N.; Lèbre, A.; Gillet, D.

    2012-05-01

    Hydrogen emission lines in Mira variable stars are a well-known phenomenon whose origin has been established as related to the propagation of radiative hypersonic shock waves throughout the stellar atmosphere. A polarimetric observation by McLean and Coyne [1] made on omicron Ceti (the prototype of Mira variable stars) has revealed the existence of linear polarization signatures associated with Balmer emission lines. However, the polarizing mechanism has never been properly explained so far. The study presented here is the first of its kind since it displays the results of a spectropolarimetric survey of omicron Ceti in the Balmer lines. The survey was made with the NARVAL spectropolarimeter (Telescope Bernard Lyot, France) in full Stokes mode. We did not just confirm the appearance of this polarization but we also and above all showed the temporal variation of the linear polarization in the lines. We conclude that the polarizing mechanism is definitely intrinsic to the shock wave propagation throughout the stellar atmosphere of Mira and give some leads about the nature of this mechanism.

  3. Morphological processing of ultraviolet emissions of electrical corona discharge for analysis and diagnostic use.

    PubMed

    Schubert, Matthew; Moore, Andrew J

    2016-03-01

    Electron cascades from electrical discharge produce secondary emissions from atmospheric plasma in the ultraviolet band. For a single point of discharge, these emissions exhibit a stereotypical discharge morphology, with latent information about the discharge location. Morphological processing can uncover the location and therefore have diagnostic utility. PMID:26974615

  4. Morphological Processing of Ultraviolet Emissions of Electrical Corona Discharge for Analysis and Diagnostic Use

    NASA Technical Reports Server (NTRS)

    Schubert, Matthew R.; Moore, Andrew J.

    2015-01-01

    Electron cascades from electrical discharge produce secondary emissions from atmospheric plasma in the ultraviolet band. For a single point of discharge, these emissions exhibit a stereotypical discharge morphology, with latent information about the discharge location. Morphological processing can uncover the location and therefore can have diagnostic utility.

  5. Search for an emission line of a gravitational wave background

    NASA Astrophysics Data System (ADS)

    Nishizawa, Atsushi; Seto, Naoki

    2015-06-01

    In light of the history of research on an electromagnetic wave spectrum, a sharp emission line of gravitational wave background (GWB) would be an interesting observational target. Here we study an efficient method to detect a line GWB by correlating data of multiple ground-based detectors. We find that the width of frequency bin for coarse graining is a critical parameter, and, with the commonly used value 0.25 Hz, the signal-to-noise ratio could be decreased by up to a factor of 6.6, compared with a finer width of 0.02 Hz. By reanalyzing the existing data with a smaller bin width, we might detect a precious line signal from the early Universe.

  6. Continuum and line emission of flares on red dwarf stars

    NASA Astrophysics Data System (ADS)

    Morchenko, E.; Bychkov, K.; Livshits, M.

    2015-06-01

    The emission spectrum has been calculated of a homogeneous pure hydrogen layer, which parameters are typical for a flare on a red dwarf. The ionization and excitation states were determined by the solution of steady-state equations taking into account the continuum and all discrete hydrogen levels. We consider the following elementary processes: electron-impact transitions, spontaneous and induced radiative transitions, and ionization by the bremsstrahlung and recombination radiation of the layer itself. The Biberman-Holstein approximation was used to calculate the scattering of line radiation. Asymptotic formulae for the escape probability are obtained for a symmetric line profile taking into account the Stark and Doppler effects. The approximation for the core of the H- α line by a Gaussian curve has been substantiated.

  7. ESTIMATION OF RELATIVISTIC ACCRETION DISK PARAMETERS FROM IRON LINE EMISSION

    SciTech Connect

    V. PARIEV; B. BROMLEY; W. MILLER

    2001-03-01

    The observed iron K{alpha} fluorescence lines in Seyfert I galaxies provide strong evidence for an accretion disk near a supermassive black hole as a source of the emission. Here we present an analysis of the geometrical and kinematic properties of the disk based on the extreme frequency shifts of a line profile as determined by measurable flux in both the red and blue wings. The edges of the line are insensitive to the distribution of the X-ray flux over the disk, and hence provide a robust alternative to profile fitting of disk parameters. Our approach yields new, strong bounds on the inclination angle of the disk and the location of the emitting region. We apply our method to interpret observational data from MCG-6-30-15 and find that the commonly assumed inclination 30{degree} for the accretion disk in MCG-6-30-15 is inconsistent with the position of the blue edge of the line at a 3{sigma} level. A thick turbulent disk model or the presence of highly ionized iron may reconcile the bounds on inclination from the line edges with the full line profile fits based on simple, geometrically thin disk models. The bounds on the innermost radius of disk emission indicate that the black hole in MCG-6-30-15 is rotating faster than 30% of theoretical maximum. When applied to data from NGC 4151, our method gives bounds on the inclination angle of the X-ray emitting inner disk of 50 {+-} 10{degree}, consistent with the presence of an ionization cone grazing the disk as proposed by Pedlar et al. (1993). The frequency extrema analysis also provides limits to the innermost disk radius in another Seyfert 1 galaxy, NGC 3516, and is suggestive of a thick disk model.

  8. Use of FUV auroral emissions as diagnostic indicators

    SciTech Connect

    Germany, G.A.; Torr, D.G.; Richards, P.G. ); Torr, M.R. )

    1994-01-01

    In an earlier study the authors modeled selected FUV auroral emissions (O I (1356 [angstrom]), N[sub 2] Lyman-Birge-Hopfield (LBH) (1464 [angstrom]), and LBH (1838 [angstrom])) to examine the sensitivity of these emissions and their ratios to likely changes in the neutral atmosphere. In this paper they extent that study to examine the dependence of these same emissions and their ratios on the shape of the energy distribution of the auroral electrons. In particular, they wish to determine whether changes in energy spectra might interfere with their determination of the characteristic energy. Modeled column-integrated emissions show relatively small (<30%) dependences on the shape and width of the incident energy spectrum, provided the average energy and total energy flux of the energy distribution are held constant. Long-wavelength FUV emissions, which are relatively unaffected by O[sub 2] absorption losses, exhibit virtually no dependence on the shape of the incident energy distribution. Changes in ratios of FUV short- to long-wavelength emissions as a function of characteristic energy are much larger than those due to changes in energy distribution. As a result, the determination of characteristic energy using these emission ratios is relatively unambiguous. They also examine the relative intensities of the aurora and the dayglow for various conditions. The intensities of modeled FUV auroral emissions relative to the dayglow emissions are presented as a function of solar zenith angle and incident energy flux. Under certain conditions (energy flux [le] 1 erg cm[sup [minus]2] s[sup [minus]1] and solar zenith angle [le]50[degrees]) the dayglow will be the limiting factor in the detection of weak auroras. 19 refs., 10 figs., 1 tab.

  9. The optically thick O III spectrum. I - Diagnostic ratios involving the intercombination lines

    NASA Technical Reports Server (NTRS)

    Kastner, S. O.; Bhatia, A. K.

    1989-01-01

    An escape-probability calculation of the optically thick O III spectrum is carried out to obtain the optical depth dependence of the intercombination doublet at 1663 A and of resonance lines between the 2p2, 2s2p3, and 2p4 configurations. The effect of optical depth on diagnostic ratios involving the intercombination lines is quantitatively established. The general question raised is whether such effects may occur in actual sources.

  10. A proposed new diagnostic for Herbig disc geometry. FWHM versus J of CO ro-vibrational lines

    NASA Astrophysics Data System (ADS)

    Hein Bertelsen, R. P.; Kamp, I.; van der Plas, G.; van den Ancker, M. E.; Waters, L. B. F. M.; Thi, W.-F.; Woitke, P.

    2016-05-01

    sources and their inner CO radius. Conclusions: The FWHM versus J is a potential new gas diagnostic for the inner disc with, for example, a constant FWHM versus J indicating the presence of a large gas hole or gap. Models and observations both indicate the potential of this new diagnostic. Our extended sample does not fully support the previous trend where group I discs have CO ro-vibrational emission lines with small FWHM. Instead, our CO ro-vibrational data from a handful of sources indicates different inner disc geometries for the gas and dust of these sources. Based on observations made with ESO Telescopes at the La Silla Paranal Observatory under programme ID 088.C-0898A and programme ID 084.C-1002(A).

  11. Performance Assessment of the C-Mod Multi-Spectral Line Polarization MSE (MSE-MSLP) Diagnostic

    NASA Astrophysics Data System (ADS)

    Scott, Steven; Mumgaard, Robert; Khoury, Matthew

    2015-11-01

    The accuracy of the Alcator C-Mod Motional Stark Effect (MSE) diagnostic is limited primarily by partially polarized background light that varies rapidly both in time (1 ms) and space - factor 10 variations are observed between adjacent spatial channels. ITER is likely to operate in a similar regime. Visible Bremsstrahlung, divertor molecular D2 emission, and glowing invessel structures generate unpolarized light that becomes partially polarized upon reflection. Because all three sources are broadband, the background light can be measured in real-time at wavelengths close to the MSE spectrum, thereby allowing the background to be interpolated in wavelength rather than in time. A 10-spatial-channel, 4-wavelength MSE-MSLP system has been developed using polarization polychromators that measure simultaneously the MSE pi- and sigma- lines as well as two nearby wavelengths that were chosen to avoid both the MSE spectrum and all known impurity lines on each sightline. Initial performance evaluation indicates that the background channel measurements faithfully track the background light in the pi- and sigma- lines. The improvement in accuracy of pitch-angle measurements and increased diagnostic flexibility over a wide range of plasma conditions will be reported. This work is supported by USDoE awards DE-FC02-99ER54512 and DE-AC02-09CH11466.

  12. The nuclear region of low luminosity flat radio spectrum sources. II. Emission-line spectra

    NASA Astrophysics Data System (ADS)

    Gonçalves, A. C.; Serote Roos, M.

    2004-01-01

    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 emission lines; 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 emission lines; we have analyzed the results in terms of diagnostic diagrams. Our analysis shows that 79% of the studied objects harbour a Low Ionization Nuclear Emission-line 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 emission-line 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

  13. Sodium D-line emission from Io - Comparison of observed and theoretical line profiles

    NASA Technical Reports Server (NTRS)

    Carlson, R. W.; Matson, D. L.; Johnson, T. V.; Bergstralh, J. T.

    1978-01-01

    High-resolution spectra of the D-line profiles have been obtained for Io's sodium emission cloud. These lines, 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 line profile data with theoretical line 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.

  14. EFFECTS OF AN ACCRETION DISK WIND ON THE PROFILE OF THE BALMER EMISSION LINES FROM ACTIVE GALACTIC NUCLEI

    SciTech Connect

    Flohic, Helene M. L. G.; Eracleous, Michael; Bogdanovic, Tamara E-mail: mce@astro.psu.edu

    2012-07-10

    We explore the connection between active galactic nuclei (AGNs) with single- and double-peaked broad Balmer emission lines by using models dealing with radiative transfer effects through a disk wind. Our primary goal is to assess the applicability of the Murray and Chiang model by making an extensive and systematic comparison of the model predictions with data. In the process, we also verify the original derivation and evaluate the importance of general relativistic effects. As the optical depth through the emission layer increases, the peaks of a double-peaked profile move closer and eventually merge, producing a single peak. The properties of the emission line profile depend as sensitively on the geometric parameters of the line-emitting portion of the disk as they do on the disk-wind parameters. Using a parameter range that encompasses the expected characteristics of the broad-line regions in AGNs, we construct a database of model profiles and measure a set of diagnostic properties. Comparisons of the model profiles with emission lines from a subset of Sloan digital Sky Survey quasars show that observed lines are consistent with moderately large optical depth in the disk wind and a range of disk inclinations i {approx}< 45 Degree-Sign . Including relativistic effects is necessary to produce the asymmetries of observed line profiles.

  15. Infrared coronal emission lines and the possibility of their maser emission in Seyfert nuclei

    NASA Technical Reports Server (NTRS)

    Greenhouse, Matthew A.; Feldman, Uri; Smith, Howard A.; Klapisch, Marcel; Bhatia, Anand K.; Bar-Shalom, Abi

    1993-01-01

    Energetic emitting regions have traditionally been studied via x-ray, UV and optical emission lines of highly ionized intermediate mass elements. Such lines are often referred to as 'coronal lines' 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 lines 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 lines 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 lines 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 line emission. In addition, they provide a means to probe heavily dust obscured emitting regions which are often inaccessible to optical or UV line 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 emission lines in AGN. We present a complete list of infrared (lambda greater than 1 micron) lines 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 lines 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

  16. CO line emission from shock waves in molecular clouds

    SciTech Connect

    Draine, B.T.; Roberge, W.G.

    1984-07-15

    Calculations are presented of the emission spectrum of rotationally and vibrationally excited carbon monoxide in shocked interstellar molecular clouds. The calculations are based upon hydrodynamical shock models that include the effects of magnetically driven ion-neutral streaming. They incorporate a variety of collision processes that produce excited CO molecules, including H/sub 2/--CO collisions. The effects of photon trapping on the emission and excitation are included by means of a Sobolev-like approximation. Intensities are given for lines emitted from levels with J< or =60, for C-type shocks with speeds v/sub s/ from 5 to 50 km s/sup -1/, in clouds with densities n/sub H/ between 10/sup 2/ and 10/sup 6/ H nuclei per cm/sup 3/. Population inversions are found amongst the lowest levels of CO for a range of shock speeds and preshock conditions. Maser emission may be observable in favorable cases. Emission from vibrationally excited levels of CO may be detectable from v/sub s/> or approx. =35 km s/sup -1/ shocks in n/sub d/H = 10/sup 6/ cm/sup -3/ clouds.

  17. Emission-line objects projected upon the galactic bulge.

    PubMed

    Herbig, G H

    1969-08-01

    Low-dispersion slit spectrograms have been obtained of 34 faint objects that lie in the direction of the galactic bulge and have the Halpha line in emission 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 emission, as well as four conventional Be stars, and six certain or possible planetary nebulae. PMID:16578699

  18. Measuring Redshifts of Emission-line Galaxies Using Ramp Filters

    NASA Astrophysics Data System (ADS)

    Lesser, Ryan William; Bohman, John; McNeff, Mathew; Holden, Marcus; Moody, Joseph; Joner, Michael D.; Barnes, Jonathan

    2016-01-01

    Photometric redshifts are routinely obtained for galaxies without emission using broadband photometry. It is possible in theory to derive reasonably accurate (< 200 km/sec) photometric redshift values for emission-line objects using "ramp" filters with a linearly increasing/decreasing transmission through the bandpass. To test this idea we have obtained a set of filters tuned for isolating H-alpha at a redshift range of 0-10,000 km/sec. These filters consist of two that vary close to linearly in transmission, have opposite slope, and cover the wavelength range from 655nm - 685nm, plus a Stromgren y and 697nm filter to measure the continuum. Redshifts are derived from the ratio of the ramp filters indices after the continuum has been subtracted out. We are finishing the process of obtaining photometric data on a set of about 100 galaxies with known redshift to calibrate the technique and will report on our results.

  19. Hybrid time dependent/independent solution for the He I line ratio temperature and density diagnostic for a thermal helium beam with applications in the scrape-off layer-edge regions in tokamaks

    SciTech Connect

    Munoz Burgos, J. M.; Schmitz, O.; Loch, S. D.; Ballance, C. P.

    2012-01-15

    Spectroscopic studies of line emission intensities and ratios offer an attractive option in the development of non-invasive plasma diagnostics. Evaluating ratios of selected He I line emission profiles from the singlet and triplet neutral helium spin systems allows for simultaneous measurement of electron density (n{sub e}) and temperature (T{sub e}) profiles. Typically, this powerful diagnostic tool is limited by the relatively long relaxation times of the {sup 3}S metastable term of helium that populates the triplet spin system, and on which electron temperature sensitive lines are based. By developing a time dependent analytical solution, we model the time evolution of the two spin systems. We present a hybrid time dependent/independent line ratio solution that improves the range of application of this diagnostic technique in the scrape-off layer (SOL) and edge plasma regions when comparing it against the current equilibrium line ratio helium model used at TEXTOR.

  20. The nature of faint emission-line galaxies

    NASA Technical Reports Server (NTRS)

    Smetanka, John J.

    1993-01-01

    One of the results of faint galaxy redshift surveys is the increased fraction of galaxies which have strong emission-line spectra. These faint surveys find that roughly 50 percent of the galaxies have an equivalent width of (OII), W sub 3727, greater than 20 A while this fraction is less than 20 percent in the DARS survey. This has been interpreted as evidence for strong evolution in the galaxy population at redshifts less than 0.5. In order to further investigate the properties of the galaxies in faint redshift surveys, two important factors must be addressed. The first is the observed correlation between color, luminosity, and W sub 3727. There is a correlation between color and the strength of emission lines, bluer galaxies having stronger emission features, as evident for Markarian galaxies and for galaxies in Kennicutt's spectrophotometric atlas. This correlation also applies galaxies in faint redshift surveys. In addition, low luminosity galaxies have a larger average W sub 3727 (and bluer colors) than higher luminosity galaxies. This is illustrated for Kennicutt's low z late-type galaxies, for the Durham Faint Surveys, and for galaxies in SA68. The second factor which must be incorporated into any interpretation of the faint emission galaxies is the different luminosity functions for galaxies depending on color. This is usually modeled by varying M* for different color classes (or morphological types); however, the shape of the luminosity function is different for galaxies with different colors. Low luminosity, blue galaxies have a much larger number density than low luminosity, red galaxies. Furthermore, the low luminosity end of the blue galaxy luminosity function is not well fit by a Schechter function. These two factors have been included in a very simple, no-evolution, model for the galaxy population. This model uses the luminosity functions from Shanks (1990) and spectral energy distributions (SED's) from Bruzual (1988). W sub 3727 is predicted using

  1. First results from EBW emission diagnostics on COMPASS

    SciTech Connect

    Zajac, J.; Preinhaelter, J.; Aftanas, M.; Bilkova, P.; Boehm, P.; Fuchs, V.; Weinzettl, V.; Zacek, F.; Nanobashvili, S.

    2012-10-15

    COMPASS tokamak shots at low magnetic field feature overdense plasmas during the extended current flat-top phase. The first harmonic of the electron cyclotron emission is completely cutoff for O and X modes and so the emission caused by electron Bernstein waves (EBWs) propagating obliquely with respect to the magnetic field and undergoing so called EBW-X-O conversion process can be observed. We perform an angular scan of the EBW emission during a set of comparable shots in order to determine the optimum antenna direction. A weak dependence of the radiative temperature on the antenna angles indicates an influence of multiple reflections from the vessel wall. The low temperature at the mode conversion region is responsible for the collisional damping of EBW, which can explain several times lower measured radiative temperature than the electron temperature measured by the Thomson scattering system.

  2. Narrowband emission line imaging spectrometry using Savart plates

    NASA Astrophysics Data System (ADS)

    Maione, Bryan; Brickson, Leandra; Kudenov, Michael; Escuti, Michael

    2016-05-01

    Polarization spatial heterodyne interferometry (PSHI) allows for the development of compact, vibration insensitive, high spectral resolution sensors. Introducing the imaging qualities of a lenslet array extends the advantages of PSHI to imaging interferometers. The use of Savart plates enables a birefringent interferometer that obtains higher spectral resolution with fewer optical aberrations when compared to alternative designs. In this paper, we describe the design, construction, calibration and validation of a narrowband emission line imaging spectrometer (NELIS), based on Savart plates and liquid crystal polarization gratings, along with its associated theoretical model. This sensor is advantageous for spectral imaging in the areas of remote sensing, biomedical imaging and machine vision.

  3. A displaced-line velocity diagnostic and its application in a visualization engine

    NASA Astrophysics Data System (ADS)

    Bates, S. C.

    1989-04-01

    A technique for measuring three-dimensional velocity by imaging the displacement of a marked fluid line is described, together with its use in an automotive visualization engine. In a flow seeded with 2 3 μ phosphorescing particles, a line is excited by a UV laser beam, deformed by the local velocity field, and detected by stereo low-light-level video cameras. The derivation of velocity from digitized images is discussed and capabilities of the diagnostic are assessed. Some image data taken in the engine are shown and quantitative two-component velocity plots along the line are presented.

  4. The stability of QSO/AGN broad emission line clouds

    NASA Astrophysics Data System (ADS)

    Krinsky, I. S.; Puetter, R. C.

    1992-08-01

    Results of a numerical linear stability analysis of QSO/AGN emission-line clouds (ELCs) embedded within a confining hot intercloud medium (HIM) are reported. A first-order linear perturbation analysis reveals two important ionstabilities. The first instability is thermal in nature and arises in the interface region between the HIM and the ELC where thermal convection dominates gas heating; the growth time of the instability is approximately 1000 s, resulting in an ELC evaporation time of about 10 yr. The second instability is dynamic in nature, with the sound wave amplitude growing in response to radiative forces. The growth time of this instability is about 10 exp 6 s and essentially independent of the wavelength. The results suggest that if QSO/AGN ELCs have properties similar to those of the standard ELC model, then the broad-line region is in a constant state of flux in which ELCs continually form, are destroyed, and then re-formed.

  5. Design of a portable optical emission tomography system for microwave induced compact plasma for visible to near-infrared emission lines

    NASA Astrophysics Data System (ADS)

    Rathore, Kavita; Munshi, Prabhat; Bhattacharjee, Sudeep

    2016-03-01

    A new non-invasive diagnostic system is developed for Microwave Induced Plasma (MIP) to reconstruct tomographic images of a 2D emission 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. Emission profile depends on two crucial parameters, namely, the electron temperature and density (over the entire spatial extent) of the plasma system. Emission tomography provides basic understanding of plasmas and it is very useful to monitor internal structure of plasma phenomena without disturbing its actual processes. This paper presents development of a compact, modular, and versatile Optical Emission 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 emission 750 nm, 772 nm, and 811 nm lines and hydrogen emission Hα (656 nm) and Hβ (486 nm) lines. Convolution back projection algorithm is used to obtain the tomographic images of plasma emission line. The paper mainly focuses on (a) design of OET system in detail and (b) study of emission profile for 750 nm argon emission lines to validate the system design.

  6. Design of a portable optical emission tomography system for microwave induced compact plasma for visible to near-infrared emission lines.

    PubMed

    Rathore, Kavita; Munshi, Prabhat; Bhattacharjee, Sudeep

    2016-03-01

    A new non-invasive diagnostic system is developed for Microwave Induced Plasma (MIP) to reconstruct tomographic images of a 2D emission 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. Emission profile depends on two crucial parameters, namely, the electron temperature and density (over the entire spatial extent) of the plasma system. Emission tomography provides basic understanding of plasmas and it is very useful to monitor internal structure of plasma phenomena without disturbing its actual processes. This paper presents development of a compact, modular, and versatile Optical Emission 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 emission 750 nm, 772 nm, and 811 nm lines and hydrogen emission H(α) (656 nm) and H(β) (486 nm) lines. Convolution back projection algorithm is used to obtain the tomographic images of plasma emission line. The paper mainly focuses on (a) design of OET system in detail and (b) study of emission profile for 750 nm argon emission lines to validate the system design. PMID:27036771

  7. Laboratory Study of the Diagnostic Utility of the 3C/3D Line Ratio in Fe XVII

    NASA Astrophysics Data System (ADS)

    Brown, G. V.; Beiersdorfer, P.; Chen, H.; Chen, M. H.; Reed, K. J.

    2002-11-01

    Fe XVII x-ray emission is present in a multitude of sources observed by XMM- Newton and the Chandra X-Ray Observatory, such as, the corona of the Sun, Capella, HR1099, and Eta Pup. Two of the strongest lines observed in these spectra are the resonance and intercombination lines located at 15.01 and 15.26 Å, respectively. After being resolved in the Sun [1], calculations of the relative intensity, R, of these lines have varied by nearly a factor of two. As part of the laboratory astrophysics program at the electron beam ion traps ebit-i & ebit-ii located at the Lawrence Livermore National Laboratory we have measured this line ratio and found it to be significantly lower than most calculations [2]. However, our ratio is still higher than many of the ratios measured in the corona of the Sun. To address this discrepancy we have measured R as a function of the relative abundance of sodium-like Fe XVI [3]. Our results show that an Fe XVI innershell satellite line coincides with the intercombination line and can significantly reduce the apparent R. We measure R = 1.90 & ± 0.11 when the relative abundance of Fe XVI to Fe XVII is ~ 1. This explains the anomalously low ratios observed in the solar and stellar coronae previously believed to be the result of resonant scattering. The fact that the apparent relative intensity of the resonance and intercombination line in Fe XVII is sensitive to the strength of an Fe XVI innershell satellite, and therefore, the relative abundance of Fe XVI to Fe XVII, makes the line ratio a diagnostic of temperature. Work by the University of California, LLNL was performed under Contract No. W-7405-Eng-48 and supported by NASA SARA P.O. No. S-03958G and Smithsonian-CXO award No. EL9-1015A.

  8. New Strong-line Abundance Diagnostics for H II Regions: Effects of κ-distributed Electron Energies and New Atomic Data

    NASA Astrophysics Data System (ADS)

    Dopita, Michael A.; Sutherland, Ralph S.; Nicholls, David C.; Kewley, Lisa J.; Vogt, Frédéric P. A.

    2013-09-01

    Recently, Nicholls et al., inspired by in situ observations of solar system astrophysical plasmas, suggested that the electrons in H II regions are characterized by a κ-distribution of energies rather than a simple Maxwell-Boltzmann distribution. Here, we have collected together new atomic data within a modified photoionization code to explore the effects of both the new atomic data and the κ-distribution on the strong-line techniques used to determine chemical abundances in H II regions. By comparing the recombination temperatures (T rec) with the forbidden line temperatures (T FL), we conclude that κ ~ 20. While representing only a mild deviation from equilibrium, this result is sufficient to strongly influence abundances determined using methods that depend on measurements of the electron temperature from forbidden lines. We present a number of new emission line ratio diagnostics that cleanly separate the two parameters determining the optical spectrum of H II regions—the ionization parameter q or \\cal {U} and the chemical abundance, 12+log(O/H). An automated code to extract these parameters is presented. Using the homogeneous data set from van Zee et al., we find self-consistent results between all of these different diagnostics. The systematic errors between different line ratio diagnostics are much smaller than those found in the earlier strong-line work. Overall, the effect of the κ-distribution on the strong-line abundances derived solely on the basis of theoretical models is rather small.

  9. A recalibration of strong-line oxygen abundance diagnostics via the direct method and implications for the high-redshift universe

    NASA Astrophysics Data System (ADS)

    Brown, Jonathan S.; Martini, Paul; Andrews, Brett H.

    2016-05-01

    We use direct method oxygen abundances in combination with strong optical emission lines, stellar masses (M⋆), and star formation rates (SFRs) to recalibrate the N2, O3N2, and N2O2 oxygen abundance diagnostics. We stack spectra of ˜200 000 star-forming galaxies from the Sloan Digital Sky Survey in bins of M⋆ and SFR offset from the star-forming main sequence ( {Δ log (SSFR)}) to measure the weak emission lines needed to apply the direct method. All three new calibrations are reliable to within ±0.10 dex from log (M⋆/M⊙) ˜ 7.5-10.5 and up to at least 200 M⊙ yr-1 in SFR. The N2O2 diagnostic is the least subject to systematic biases. We apply the diagnostics to galaxies in the local Universe and investigate the M⋆-Z-SFR relation. The N2 and O3N2 diagnostics suggest the SFR dependence of the M⋆-Z-SFR relation varies with both M⋆ and {Δ log (SSFR)}, whereas the N2O2 diagnostic suggests a nearly constant dependence on SFR. We apply our calibrations to a sample of high-redshift galaxies from the literature, and find them to be metal-poor relative to local galaxies with similar M⋆ and SFR. The calibrations do reproduce direct method abundances of the local analogues. We conclude that the M⋆-Z-SFR relation evolves with redshift.

  10. Far-Infrared Water Line Emissions from Circumstellar Outflows

    NASA Technical Reports Server (NTRS)

    Chen, Wesley; Neufeld, David A.

    1995-01-01

    We have modeled the far-infrared water line emission expected from circumstellar outflows from oxygen-rich late-type stars, as a function of the mass-loss rate and the terminal outflow velocity. For each mass-loss rate and terminal outflow velocity considered, we computed self-consistently the gas density, temperature, outflow velocity, and water abundance as a function of distance from the star. We then used an escape probability method to solve for the equilibrium level populations of 80 rotational states of water and thereby obtained predictions for the luminosity of a large number of far-infrared rotational transitions of water. In common with previous models, our model predicts that water will be copiously produced in the warm circumstellar gas and that water rotational emission will dominate the radiative cooling. However, our use of a realistic radiative cooling function for water leads to a lower gas temperature than that predicted in previous models. Our predictions for the far-infrared water line luminosities are consequently significantly smaller than those obtained in previous studies. Observations to be carried out by the Infrared Space Observatory will provide a crucial test of the models presented here.

  11. NIR spectroscopy of Palomar emission-line galaxies

    NASA Astrophysics Data System (ADS)

    Mason, Rachel; Alonso-Herrero, Almudena; Bluck, Asa; Colina, Luis; Diaz, Ruben; Diaz-Santos, Tanio; Flohic, Helene; Gomez, Percy; Gonzalez-Martin, Omaira; Ho, Luis; Jorgensen, Inger; Lemoine-Busserolle, Marie; Levenson, Nancy; Lira, Paulina; McDermid, Richard; Perlman, Eric; Rodriguez-Ardila, Alberto; Riffel, Rogerio; Schiavon, Ricardo; Ramos Almeida, Cristina; Thanjavur, Karun; Winge, Claudia

    2012-02-01

    We propose GNIRS cross-dispersed spectroscopy of 60 Seyferts and LINERs from the Palomar galaxy sample. The spectra will advance our knowledge of AGN physics and lifecycles by demonstrating whether the accretion disk and nuclear dust properties change as a function of accretion rate, as predicted by theoretical models. They will be used to investigate the contribution of evolved stars to the line emission in LINERs, with implications for AGN demographics, and to make new stellar kinematic measurements for black hole mass estimates. The number and variety of spectral features that will appear in the data are expected to enable a wide range of science besides that highlighted in this proposal. For this reason, we plan a reduced proprietary period and to make the reduced spectra available to the community. We anticipate applying for time to observe the remaining emission-line galaxies in the (near-complete) Palomar sample over the next few semesters. The targets are distributed throughout the northern sky, making Gemini's queue mode ideal for this work. The fairly short observations are easily scheduled and can be carried out in suboptimal observing conditions.

  12. Design of a correlation electron cyclotron emission diagnostic for Alcator C-Moda)

    NASA Astrophysics Data System (ADS)

    Sung, C.; White, A. E.; Irby, J. H.; Leccacorvi, R.; Vieira, R.; Oi, C. Y.; Peebles, W. A.; Nguyen, X.

    2012-10-01

    A correlation electron cyclotron emission (CECE) diagnostic has been installed in Alcator C-Mod. In order to measure electron temperature fluctuations, this diagnostic uses a spectral decorrelation technique. Constraints obtained with nonlinear gyrokinetic simulations guided the design of the optical system and receiver. The CECE diagnostic is designed to measure temperature fluctuations which have kθ ≤ 4.8 cm-1 (kθρs < 0.5) using a well-focused beam pattern. Because the CECE diagnostic is a dedicated turbulence diagnostic, the optical system is also flexible, which allows for various collimating lenses and antenna to be used. The system overview and the demonstration of its operability as designed are presented in this paper.

  13. Design of a correlation electron cyclotron emission diagnostic for Alcator C-Mod

    SciTech Connect

    Sung, C.; White, A. E.; Irby, J. H.; Leccacorvi, R.; Vieira, R.; Oi, C. Y.; Peebles, W. A.; Nguyen, X.

    2012-10-15

    A correlation electron cyclotron emission (CECE) diagnostic has been installed in Alcator C-Mod. In order to measure electron temperature fluctuations, this diagnostic uses a spectral decorrelation technique. Constraints obtained with nonlinear gyrokinetic simulations guided the design of the optical system and receiver. The CECE diagnostic is designed to measure temperature fluctuations which have k{sub {theta}}{<=} 4.8 cm{sup -1} (k{sub {theta}}{rho}{sub s} < 0.5) using a well-focused beam pattern. Because the CECE diagnostic is a dedicated turbulence diagnostic, the optical system is also flexible, which allows for various collimating lenses and antenna to be used. The system overview and the demonstration of its operability as designed are presented in this paper.

  14. Design of a correlation electron cyclotron emission diagnostic for Alcator C-Mod.

    PubMed

    Sung, C; White, A E; Irby, J H; Leccacorvi, R; Vieira, R; Oi, C Y; Peebles, W A; Nguyen, X

    2012-10-01

    A correlation electron cyclotron emission (CECE) diagnostic has been installed in Alcator C-Mod. In order to measure electron temperature fluctuations, this diagnostic uses a spectral decorrelation technique. Constraints obtained with nonlinear gyrokinetic simulations guided the design of the optical system and receiver. The CECE diagnostic is designed to measure temperature fluctuations which have k(θ) ≤ 4.8 cm(-1) (k(θ)ρ(s) < 0.5) using a well-focused beam pattern. Because the CECE diagnostic is a dedicated turbulence diagnostic, the optical system is also flexible, which allows for various collimating lenses and antenna to be used. The system overview and the demonstration of its operability as designed are presented in this paper. PMID:23126971

  15. Star formation rates and chemical abundances of emission-line galaxies in intermediate-redshift clusters

    NASA Astrophysics Data System (ADS)

    Mouhcine, M.; Bamford, S. P.; Aragón-Salamanca, A.; Nakamura, O.; Milvang-Jensen, B.

    2006-06-01

    We examine the evolutionary status of luminous, star-forming galaxies in intermediate-redshift clusters by considering their star formation rates (SFRs) and the chemical and ionization properties of their interstellar emitting gas. Our sample consists of 17 massive, star-forming, mostly disc galaxies with MB<~-20, in clusters with redshifts in the range 0.31 <~z<~ 0.59, with a median of = 0.42. We compare these galaxies with the identically selected and analysed intermediate-redshift field sample of Mouhcine et al., and with local galaxies from the Nearby Field Galaxy Survey of Jansen et al. From our optical spectra, we measure the equivalent widths of [OII]λ3727, Hβ and [OIII]λ5007 emission lines to determine diagnostic line ratios, oxygen abundances and extinction-corrected SFRs. The star-forming galaxies in intermediate-redshift clusters display emission-line equivalent widths which are, on average, significantly smaller than measured for field galaxies at comparable redshifts. However, a contrasting fraction of our cluster galaxies have equivalent widths similar to the highest observed in the field. This tentatively suggests a bimodality in the SFRs per unit luminosity for galaxies in distant clusters. We find no evidence for further bimodalities, or differences between our cluster and field samples, when examining additional diagnostics and the oxygen abundances of our galaxies. This maybe because no such differences exist, perhaps because the cluster galaxies which still display signs of star formation have recently arrived from the field. In order to examine this topic with more certainty, and to further investigate the way in which any disparity varies as a function of cluster properties, larger spectroscopic samples are needed.

  16. Comprehensive, nonintercepting electron-beam diagnostics using spontaneous emission

    SciTech Connect

    Lumpkin, A.H.

    1989-01-01

    Characterization and optimization of electron-beam parameters are important aspects of optimizing free-electron laser (FEL) performance. The visible spontaneous emission ({lambda}{approximately}650 nm) from the 5-meter long undulator of the Boeing FEL experiment can be characterized in sufficient detail with a streak/spectrometer to deduce time-resolved electron-beam spatial position and profile, micropulse duration, and energy. 7 refs., 13 figs., 2 tabs.

  17. Asymmetries in coronal spectral lines and emission measure distribution

    SciTech Connect

    Tripathi, Durgesh; Klimchuk, James A.

    2013-12-10

    It has previously been argued that (1) spicules do not provide enough pre-heated plasma to fill the corona, and (2) even if they did, additional heating would be required to keep the plasma hot as it expands upward. Here we address whether spicules play an important role by injecting plasma at cooler temperatures (<2 MK), which then gets heated to coronal values at higher altitudes. We measure red-blue asymmetries in line profiles formed over a wide range of temperatures in the bright moss areas of two active regions. We derive emission measure distributions from the excess wing emission. We find that the asymmetries and emission measures are small and conclude that spicules do not inject an important (dominant) mass flux into the cores of active regions at temperatures >0.6 MK (log T > 5.8). These conclusions apply not only to spicules but also to any process that suddenly heats and accelerates chromospheric plasma (e.g., a chromospheric nanoflare). The traditional picture of coronal heating and chromospheric evaporation appears to remain the most likely explanation of the active region corona.

  18. Investigation of Nuclear Gamma Ray Line Emission Associated with Lightning

    NASA Astrophysics Data System (ADS)

    Boggs, S. E.; Millan, R. M.; Eack, K.; Aulich, G. D.

    2005-12-01

    The first conclusive observations of X-rays associated with thunderstorm activity were made in the 1980's and the prompt emission has been interpreted as bremsstrahlung produced by lightning-accelerated electrons. In 2004, Greenfield et al. reported the first detection of delayed gamma ray emission, with flux peaking 70 minutes after a lightning stroke and decaying exponentially over 50 minutes. They suggested the delayed gamma rays are a result of nuclear reactions in the atmosphere, creating excited Chlorine-39 and decaying with a 56-minute half-life. These results are compelling, but inconclusive; instrumentation capable of measuring the energy spectrum with high precision is necessary to confirm the existence of nuclear line emission associated with lightning. During June-September 2005, we used a spare RHESSI 7 cm-diameter segmented coaxial germanium spectrometer to continuously monitor gamma radiation on South Baldy Peak (10,800 ft) in New Mexico. The detector monitors gamma rays between ~18 keV-10 MeV with an energy resolution of ~2 keV@835 keV. South Baldy is the site of Langmuir Lab and was chosen to take advantage of other lightning research instrumentation located there, including New Mexico Tech's 3D Lightning Mapping Array (LMA) which can determine the location of a lightning stroke to within about 50m. We describe the experiment and present the initial results.

  19. Outflow and hot dust emission in broad absorption line quasars

    SciTech Connect

    Zhang, Shaohua; Zhou, Hongyan; Wang, Huiyuan; Wang, Tinggui; Xing, Feijun; Jiang, Peng; Zhang, Kai E-mail: whywang@mail.ustc.edu.cn

    2014-05-01

    We have investigated a sample of 2099 broad absorption line (BAL) quasars with z = 1.7-2.2 built from the Sloan Digital Sky Survey Data Release Seven and the Wide-field Infrared Survey. This sample is collected from two BAL quasar samples in the literature and is refined by our new algorithm. Correlations of outflow velocity and strength with a hot dust indicator (β{sub NIR}) and other quasar physical parameters—such as an Eddington ratio, luminosity, and a UV continuum slope—are explored in order to figure out which parameters drive outflows. Here β{sub NIR} is the near-infrared continuum slope, which is a good indicator of the amount of hot dust emission relative to the accretion disk emission. We confirm previous findings that outflow properties moderately or weakly depend on the Eddington ratio, UV slope, and luminosity. For the first time, we report moderate and significant correlations of outflow strength and velocity with β{sub NIR} in BAL quasars. It is consistent with the behavior of blueshifted broad emission lines in non-BAL quasars. The statistical analysis and composite spectra study both reveal that outflow strength and velocity are more strongly correlated with β{sub NIR} than the Eddington ratio, luminosity, and UV slope. In particular, the composites show that the entire C IV absorption profile shifts blueward and broadens as β{sub NIR} increases, while the Eddington ratio and UV slope only affect the high and low velocity part of outflows, respectively. We discuss several potential processes and suggest that the dusty outflow scenario, i.e., that dust is intrinsic to outflows and may contribute to the outflow acceleration, is most likely.

  20. Quasi-separatrix layers and three-dimensional reconnection diagnostics for line-tied tearing modes

    NASA Astrophysics Data System (ADS)

    Richardson, Andrew S.; Finn, John M.

    2011-10-01

    In three-dimensional magnetic configurations for a plasma in which no closed field line or magnetic null exists, no magnetic reconnection can occur, by the strictest definition of reconnection. A finitely long pinch with line-tied boundary conditions, in which all the magnetic field lines start at one end of the system and proceed to the opposite end, is an example of such a system. Nevertheless, for a long system of this type, the physical behavior in resistive magnetohydrodynamics (MHD) essentially involves reconnection. This has been explained in terms comparing the geometric and tearing widths. The concept of a quasi-separatrix layer was developed for such systems. We study a model for a line-tied system in which the corresponding periodic system has an unstable tearing mode. We analyze this system in terms of two magnetic field line diagnostics, the squashing factor and the electrostatic potential difference, which has been used in kinematic reconnection studies. We discuss the physical and geometric significance of these two diagnostics and compare them in the context of discerning tearing-like behavior in line-tied modes.

  1. Quasi-separatrix layers and three-dimensional reconnection diagnostics for line-tied tearing modes

    NASA Astrophysics Data System (ADS)

    Richardson, A. S.; Finn, J. M.

    2012-05-01

    In three-dimensional magnetic configurations for a plasma in which no closed field line or magnetic null exists, no magnetic reconnection can occur, by the strictest definition of reconnection. A finitely long pinch with line-tied boundary conditions, in which all the magnetic field lines start at one end of the system and proceed to the opposite end, is an example of such a system. Nevertheless, for a long system of this type, the physical behavior in resistive magnetohydrodynamics (MHD) essentially involves reconnection. This has been explained in terms comparing the geometric and tearing widths [1,2]. The concept of a quasi-separatrix layer [3,4] was developed for such systems. In this paper we study a model for a line-tied system in which the corresponding periodic system has an unstable tearing mode. We analyze this system in terms of two magnetic field line diagnostics, the squashing factor[5-7] and the electrostatic potential difference [8,9] which has been used in kinematic reconnection studies. We discuss the physical and geometric significance of these two diagnostics and compare them in the context of discerning tearing-like (reconnection-like) behavior in line-tied modes.

  2. Self-calibrating magnetic field diagnostics in beam emission spectroscopy

    SciTech Connect

    Voslamber, D.

    1995-04-01

    Magnetic field diagnostics in tokamaks using the motional Stark effect in fast neutral beams have been based on two kinds of polarimetry which we call ``static`` and ``dynamic.`` A detailed analysis shows that static polarimetry presents a number of advantages over dynamic polarimetry, provided it is made complete in the sense that a sufficient number of polarization analyzers are installed and different parts of the spectrum are explored to yield full information on the set of unknowns inherent in the problem. A detailed scheme of complete static polarimetry is proposed, including the case where an in-vessel mirror with changing characteristics (coating by impurities) is placed in front of the optical detection system. The main merit of this scheme relies on the fact that it is self-calibrating with respect to both the characteristics of the mirror and the transmission of the different polarization channels, the latter item implying that it is uniquely based on relative measurements of spectra. Further advantages are a greater flexibility with regard to different kinds of diagnostics and the circumstance that the technical equipment is less involved. The above scheme is based on a detection system of moderate etendue exploiting a large spectral domain, which is the regime where static polarimetry usually operates. It is also possible, however, to work with large etendue and a small spectral domain, such as commonly adopted in dynamic polarimetry. Using such a regime, static polarimetry loses the advantages mentioned above but gains, as a new advantage, the benefit of a comparatively lower level of photon noise. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.

  3. Infrared coronal emission lines and the possibility of their laser emission in Seyfert nuclei

    NASA Technical Reports Server (NTRS)

    Greenhouse, Matthew A.; Feldman, Uri; Smith, Howard A.; Klapisch, Marcel; Bhatia, Anand K.; Bar-Shalom, Avi

    1993-01-01

    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 emission lines, together with a table with a complete line 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 lines is presented, and the relationship of IR and optical coronal lines 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 lines. Several IR coronal line 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 lines are suggested.

  4. Flux-Calibrated Emission-Line Imaging of Extended Sources Using GTC/OSIRIS Tunable Filters

    NASA Astrophysics Data System (ADS)

    Mayya, Y. D.; Rosa González, D.; Vega, O.; Méndez-Abreu, J.; Terlevich, R.; Terlevich, E.; Bertone, E.; Rodríguez-Merino, L. H.; Muñoz-Tuñón, C.; Rodríguez-Espinosa, J. M.; Sánchez Almeida, J.; Aguerri, J. A. L.

    2012-08-01

    We investigate the utility of the tunable filters (TFs) for obtaining flux-calibrated emission-line maps of extended objects such as galactic nebulae and nearby galaxies using the Optical System for Imaging and low Resolution Integrated Spectroscopy (OSIRIS) at the 10.4-m Gran Telescopio Canarias (GTC). Despite the relatively large field of view (FoV) of OSIRIS (8' × 8'), the change in wavelength across the field (~80 Å) and the long tail of the TF spectral response function are hindrances for obtaining accurate flux-calibrated emission-line maps of extended sources. The purpose of this article is to demonstrate that emission-line maps useful for diagnostics of nebulae can be generated over the entire FoV of OSIRIS if we make use of theoretically well-understood characteristics of TFs. We have successfully generated the flux-calibrated images of the nearby large late-type spiral galaxy M101 in the emission lines of Hα, [N II]λ6583, [S II]λ6716 and [S II]λ6731. We find that the present uncertainty in setting the central wavelength of TFs (~1 Å) is the biggest source of error in the emission-line fluxes. By comparing the Hα fluxes of H II regions in our images with the fluxes derived from Hα images obtained using narrow-band filters, we estimate an error of ~11% in our fluxes. The flux-calibration of the images was carried out by fitting the Sloan Digital Sky Survey (SDSS) griz magnitudes of in-frame stars with the stellar spectra from the SDSS spectral database. This method resulted in an accuracy of 3% in flux-calibration of any narrow-band image, which is as good as, if not better than, what has been feasible using the observations of spectrophotometric standard stars. Thus time-consuming calibration images need not be taken. A user-friendly script under the IRAF environment was developed and is available on request. Based on observations made with the Gran Telescopio Canarias (GTC), installed in the Spanish Observatorio del Roque de los Muchachos of the

  5. Iron and helium emission lines in classical T Tauri stars

    NASA Astrophysics Data System (ADS)

    Beristain, Georgina

    Results are presented for the He emission in 31 CTTS from the Taurus-Auriga molecular cloud spanning two orders of magnitude in the mass accretion rate, and for the Fe emission in DR Tau, based on a series of high resolution echelle spectra. The He lines admit a description in terms of a narrow component ( NC) and a broad component (BC). The NC has FWHM between 32-55 km/s and centroid velocities near zero km/s or moderately redshifted, consistent with an origin in the postshock region of the magnetospheric accretion model. The BC, with FWHM between 128 and 287 km/s and centroid velocities between -93 and +35 km/s, includes a wind and an accretion component; we argue the BC is predominantly formed in the wind. Estimates of the wind and accretion component equivalent widths are oppositely related to the NC, so the NC equivalent width increases with the accretion component but decreases as the wind component increases. The NC is undetectable where profiles appear dominated by the wind, requiring a source of veiling other than the accretion shock to account for the observed continuum excess. Intensity ratios indicate that physical conditions are nearly uniform in the NC but span a range in the BC. For DR Tau, the range of morphologies in 62 unblended Fe I and Fe II lines can be resolved in terms of a narrow component (NC) that dominates the weakest lines, and a broad component (BC) that dominates the strongest lines. The (NC) has FWHM ~20 km/s and centroid velocity near zero km/s. The (BC) has FWHM ~100 km/s, and a tendency to be blueshifted by <=10 km/s. Estimates of iron line opacities τ and column densities N yield τNC ~ 3 × τBC, NFeI >~ 1017 - 1018 cm-2 , and NFeII >~ 1018 - 1019 cm-2 for the BC. Estimates of kinetic temperature for iron suggest that the NC gas is hotter than the BC by several thousand degrees. For iron, the NC is consistent with an origin in the postshock gas while the BC may originate in the inner accretion disk close to the corotation radius.

  6. 40 CFR 1060.515 - How do I test EPA Nonroad Fuel Lines and EPA Cold-Weather Fuel Lines for permeation emissions?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... and EPA Cold-Weather Fuel Lines for permeation emissions? 1060.515 Section 1060.515 Protection of... Nonroad Fuel Lines and EPA Cold-Weather Fuel Lines for permeation emissions? Measure emission as follows for EPA Nonroad Fuel Lines and EPA Cold-Weather Fuel Lines: (a) Prior to permeation testing, use...

  7. 40 CFR 1060.515 - How do I test EPA Nonroad Fuel Lines and EPA Cold-Weather Fuel Lines for permeation emissions?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... and EPA Cold-Weather Fuel Lines for permeation emissions? 1060.515 Section 1060.515 Protection of... Nonroad Fuel Lines and EPA Cold-Weather Fuel Lines for permeation emissions? Measure emission as follows for EPA Nonroad Fuel Lines and EPA Cold-Weather Fuel Lines: (a) Prior to permeation testing, use...

  8. 40 CFR 1060.515 - How do I test EPA Nonroad Fuel Lines and EPA Cold-Weather Fuel Lines for permeation emissions?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... and EPA Cold-Weather Fuel Lines for permeation emissions? 1060.515 Section 1060.515 Protection of... Nonroad Fuel Lines and EPA Cold-Weather Fuel Lines for permeation emissions? Measure emission as follows for EPA Nonroad Fuel Lines and EPA Cold-Weather Fuel Lines: (a) Prior to permeation testing, use...

  9. 40 CFR 1060.515 - How do I test EPA Nonroad Fuel Lines and EPA Cold-Weather Fuel Lines for permeation emissions?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... and EPA Cold-Weather Fuel Lines for permeation emissions? 1060.515 Section 1060.515 Protection of... Nonroad Fuel Lines and EPA Cold-Weather Fuel Lines for permeation emissions? Measure emission as follows for EPA Nonroad Fuel Lines and EPA Cold-Weather Fuel Lines: (a) Prior to permeation testing, use...

  10. 40 CFR 1060.515 - How do I test EPA Nonroad Fuel Lines and EPA Cold-Weather Fuel Lines for permeation emissions?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... and EPA Cold-Weather Fuel Lines for permeation emissions? 1060.515 Section 1060.515 Protection of... Nonroad Fuel Lines and EPA Cold-Weather Fuel Lines for permeation emissions? Measure emission as follows for EPA Nonroad Fuel Lines and EPA Cold-Weather Fuel Lines: (a) Prior to permeation testing, use...

  11. Hα Monitoring of Early-Type Emission Line Stars

    NASA Astrophysics Data System (ADS)

    Souza, Steven P.; Boettcher, E.; Wilson, S.; Hosek, M.

    2011-05-01

    We have begun a narrowband imaging program to monitor Hα emission in early-type stars in young open clusters and associations. A minority of early-type stars, particularly Be stars, show Hα in emission due to extended atmospheres and non-equilibrium conditions. Emission 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 emission line 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.

  12. Spectral Catalogue of Kr Optical Lines for the Development of Diagnostics for Fusion Plasmas

    SciTech Connect

    Hui, C.; Beiersdorfer, P.; Harris, C.L.; Utter, S.B.; Wong, K.L.

    2000-06-14

    We made an inventory of krypton spectra over the wavelength range 3700-6000 {angstrom} for the development of fusion plasma diagnostics. The measurements were performed using a Steinheil prism spectrometer on the LLNL low energy electron beam ion trap (EBIT II). With the electron energy from 150 eV to 17000 eV, we recorded low ionization stages together with a number of magnetic dipole transitions from higher charge states. In total, we observed over 80 lines, of which about 70% of the lines have not been listed in the literature. This measurement established a baseline for future extension using spectrometers with very high resolution. As an example, we present the Kr spectra from 3770 {angstrom} to 3900 {angstrom} measured with a transmission grating spectrometer that has a resolving power of about 15000. Among the 41 lines observed, only 6 lines have been listed in the databases.

  13. Spectral catalog of Kr optical lines for the development of diagnostics for fusion plasmas

    NASA Astrophysics Data System (ADS)

    Chen, H.; Beiersdorfer, P.; Harris, C. L.; Utter, S. B.; Wong, K. L.

    2001-01-01

    We made an inventory of krypton spectra over the wavelength range 3700-6000 Å for the development of fusion plasma diagnostics. The measurements were performed using a prism spectrometer on the Lawrence Livermore National Laboratory low energy electron beam ion trap (EBIT II). With the electron energy from 150 to 17 000 eV, we recorded low ionization stages together with a number of magnetic dipole transitions from higher charge states. In total, we observed over 80 lines, of which about 70% of the lines have not been listed in the literature. This measurement established a baseline for future extension using spectrometers with very high resolution. As an example, we present the Kr spectra from 3770 to 3900 Å measured with a transmission grating spectrometer that has a resolving power of about 15 000. Among the 41 lines observed, only six lines have been listed in the databases.

  14. On-Line Texture Diagnostics for Coated Conductor Manufacture. Final Report

    SciTech Connect

    White, M. K.

    2002-12-30

    This Phase I project was undertaken to assess the feasibility of implementing a particular diagnostic method for characterizing the crystallographic texture of high temperature superconductor (HTS) coated conductors on-line during their reel-to-reel continuous manufacture. Key factors in this technique were the use of an area detector to greatly reduce scan time, an x-ray mirror to enhance incident beam brightness, and an automation scheme for diffractometer control, tape motion control, and calculation and output of texture characterizations.

  15. 40 CFR 1060.510 - How do I test EPA Low-Emission Fuel Lines for permeation emissions?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Lines for permeation emissions? 1060.510 Section 1060.510 Protection of Environment ENVIRONMENTAL... NONROAD AND STATIONARY EQUIPMENT Test Procedures § 1060.510 How do I test EPA Low-Emission Fuel Lines for... incorporated by reference in § 1060.810....

  16. EXTENDED NARROW-LINE EMISSION IN THE BRIGHT SEYFERT 1.5 GALAXY HE 2211-3903

    SciTech Connect

    Scharwaechter, J.; Dopita, M. A.; Zuther, J.; Fischer, S.; Eckart, A.; Komossa, S.

    2011-08-15

    Extended narrow-line regions (ENLRs) and extended emission-line regions have been the focus of integral field spectroscopy aiming at the inner kiloparsecs of nearby Seyfert galaxies as well as the larger environment of high-redshift QSOs. Based on observations with the Wide Field Spectrograph at the 2.3 m telescope of the Australian National University, we present spatially resolved emission-line diagnostics of the bright Seyfert 1.5 galaxy HE 2211-3903 which is drawn from a sample of the brightest Seyfert galaxies at z < 0.06 with luminosities around the classical Seyfert/QSO demarcation. In addition to the previously known spiral arms of HE 2211-3903, the emission-line maps reveal a large-scale ring with a radius of about 6 kpc which is connected to the active galactic nucleus (AGN) through a bar-like structure. The overall gas kinematics indicates a disk rotation pattern. The emission-line ratios show Seyfert-type, H II region-type, and composite classifications, while there is no strong evidence of LINER-type ratios. Shock ionization is likely to be negligible throughout the galaxy. The composite line ratios are explained via a mixing line between AGN and H II region photoionization. Composite line ratios are predominantly found in between the H II regions in the circum-nuclear region, the bar-like structure to the east of the nucleus, and the eastern half of the ring, suggesting AGN photoionization of the low-density interstellar medium in an ENLR on galaxy scales. The line ratios in the nucleus indicate N enrichment, which is discussed in terms of chemical enrichment by Wolf-Rayet and asymptotic giant branch stars during past and ongoing nuclear starburst activity.

  17. A versatile apparatus for on-line emission channeling experiments

    SciTech Connect

    Silva, M. R.; Wahl, U.; Correia, J. G.; Unidade de Física e Aceleradores, IST Amorim, L. M.; Pereira, L. M. C.

    2013-07-15

    The concept and functionality of an apparatus dedicated to emission channeling experiments using short-lived isotopes on-line at ISOLDE/CERN is described. The setup is assembled in two functional blocks – (a) base stand including beam collimation, implantation and measurement chamber, cryogenic extension, and vacuum control system and (b) Panmure goniometer extension including maneuvering cradle and sample heating furnace. This setup allows for in situ implantation and sample analysis in the as-implanted state and upon cooling down to 50 K and during annealing up to 1200 K. The functionality of the setup will be illustrated with the example of establishing the lattice location of {sup 56}Mn probes implanted into GaAs.

  18. A Laser-Based Diagnostic for Tracing Magnetic Field Lines in Spheromks and Other Self-Organized Magnetically Confined Plamas

    SciTech Connect

    McLean, H S; Hill, D N; Ryutov, D D; Chen, H

    2002-07-06

    We are in the process of testing a new technique for measuring the magnetic field-line topology in magnetically confined plasmas. The basic idea behind the FLIRT (Field LIne TRacing) diagnostic is to use a high powerful short pulse laser to launch a burst of energetic ({approx}100keV) electrons from a target passing through the plasma of interest; these electrons then generally follow field lines until they strike a solid surface, where a burst of x-rays is produced and then detected. The field line connection length can be determined from the time delay between the laser pulse and the burst of x-rays. The topology of the field lines can be inferred by measuring the connection length as a function of initial target location inside the plasma. Measuring the spatial distribution of the x-ray production will provide further information on the field topology, including the effects of magnetic field fluctuations and stochasticity. The work will eventually include testing the appropriate x-ray detectors, measuring the background x-ray emission in a spheromak plasma, measuring the energetic electron production by a short-pulse high power laser, and making preliminary measurements of the edge field line topology in the Sustained Spheromak Physics Experiment (SSPX) using a newly-designed pulsed electron beam source as a prototype for a laser-based source. This technique may have broad application to a variety of plasma configurations and provide physics data applicable to a wide range of plasma physics problems.

  19. Searching for emission-line galaxies: The UCM survey

    NASA Technical Reports Server (NTRS)

    Gallego, J.; Zamorano, J.; Rego, M.; Vitores, A.

    1993-01-01

    We are carrying out a long-term project with the main purposes of finding and analyzing low metallicity galaxies. A very small number of very low metallicity galaxies is known up to now. However these ojbects are particularly interesting since they are excellent candidates to 'young galaxies' in evolutionary sense as POX186 (Kunth, Maurogordato & Vigroux, 1988). Since the interstellar matter in these objects is only weakly contaminated by stellar evolution, their study could provide valuable information about the primordial helium abundance and therefore it could place constraints on the different Big-Bang models. The instrumental set up of our survey is an objective-prism used with the Schmidt telescope at Calar Alto Observatory. By using hypersensitized IIIaF emulsion and RG630 filter low resolution spectra in the H alpha region of objects in a wide field is obtained (Rego et al. 1989, Zamorano et al. 1990). Surveys carried out in the past two decades at optical blue wavelengths have also produced large samples of emission-line galaxies (ELGs), for example MacAlpine & Willians 1981 and reference therein, Wasilewski 1983, Salzer and MacAlpine 1988, or Smith et al. 1976. Relying primarily on objective-prism plates taken in the blue, these surveys have found over 3000 blue/emission-line galaxies so far. A significant number of star-forming galaxies are missed by optical surveys in the blue because of their low-excitation spectra (MacAlpine and Willians 1981, Markarian et al. 1981 and references therein) or their low metallicity (Kunth and Sargent, 1986).

  20. Massive Emission-Line Stars in Nearby Galaxies

    NASA Astrophysics Data System (ADS)

    Lim, P. L.; Holtzman, J. A.; Walterbos, R. A. M.

    2003-12-01

    The evolution of massive stars is still poorly understood because of critical effects of mass loss during the post-main sequence phase. Of particular relevance is the Luminous Blue Variable phase, during which high mass loss may occur over a brief period. It would be useful to know the mass range of stars that enter this phase, and the life time of the phase. For that, better estimates of the numbers of LBVs in different environments is crucial. In a study of M31, we detected candidate LBVs as luminous stars with strong Hα emission-lines and no nebular [SII] emission. (King, N.L., Walterbos, R.A.M., & Braun, R., 1998, ApJ, 507:210-220). HST's sensitivity offers the capability to identify these candidate LBVs in galaxies beyond the Local Group. We identify massive Hα emmision-line stars in nearby spiral galaxies within 10 Mpc, using data from the HST WFPC2 archive. We obtained stellar photometry in Hα (F656N) and various broadband filters, with methods developed for the HST Local Group Stellar Photometry archive (Holtzman, J., Afonso, C., & Dolphin, A., 2003, ApJS, submitted). We identify candidates based on the amount of Hα excess in two-color plots. We also require an absolute magnitude MV ≤ -5, and photometry fit parameters consistent with point source characteristics. Candidates are inspected visually on the images for verification purpose. We find promising candidates in several nearby galaxies. We will present a catalog of the objects, and discuss their properties and the environments in which they are found. Support for this work was provided by NASA through grant numbers AR-08372.01-97A and HST-AR-08749.01-A from the Space Telescope Science Institute, which is operated by AURA, Inc. under NASA contract NAS5-26555.

  1. Quasar emission lines, radio structures and radio unification

    NASA Astrophysics Data System (ADS)

    Jackson, Neal; Browne, I. W. A.

    2013-02-01

    Unified schemes of radio sources, which account for different types of radio active galactic nucleus in terms of anisotropic radio and optical emission, together with different orientations of the ejection axis to the line of sight, have been invoked for many years. Recently, large samples of optical quasars, mainly from the Sloan Digital Sky Survey (SDSS), together with large radio samples, such as Faint Images of the Radio Sky at Twenty cm (FIRST), have become available. These hold the promise of providing more stringent tests of unified schemes but, compared to previous samples, lack high-resolution radio maps. Nevertheless, they have been used to investigate unified schemes, in some cases yielding results which appear inconsistent with such theories. Here we investigate using simulations how the selection effects to which such investigations are subject can influence the conclusions drawn. In particular, we find that the effects of limited resolution do not allow core-dominated radio sources to be fully represented in the samples, that the effects of limited sensitivity systematically exclude some classes of sources and the lack of deep radio data make it difficult to decide to what extent closely separated radio sources are associated. Nevertheless, we conclude that relativistic unified schemes are entirely compatible with the current observational data. For a sample selected from SDSS and FIRST which includes weak-cored triples we find that the equivalent width of the [O III] emission line decreases as core dominance increases, as expected, and also that core-dominated quasars are optically brighter than weak-cored quasars.

  2. Electron density diagnostics for gaseous nebulae involving the O IV intercombination lines near 1400 A

    NASA Technical Reports Server (NTRS)

    Keenan, F. P.; Conlon, E. S.; Bowden, D. A.; Feibelman, W. A.; Pradhan, A. K.

    1993-01-01

    The Bloom and Pradhan (1992) results on the excitation rates for transitions in O IV matrix are used to derive emission-line ratios near 1400 A, applicable to gaseous nebulae. The results are compared with the values measured from high-resolution spectra obtained by the IUE satellite.

  3. Chromatic-free spatially resolved optical emission spectroscopy diagnostics for microplasma

    NASA Astrophysics Data System (ADS)

    Zhu, Li-Guo; Chen, Wen-Cong; Zhu, Xi-Ming; Pu, Yi-Kang; Li, Ze-Ren

    2009-02-01

    A chromatic-free spatially resolved diagnostic system for microplasma measurement is proposed and demonstrated, which consists of an optical chromatic-free microscope mirror system, an electron multiplying charge coupled device (EMCCD), and bandpass filters. The diagnostic system free of chromatic aberrations with a spatial resolution of about 6 μm is achieved. The factors that limit the resolution of this diagnostic system have been analyzed, which are optical diffraction, the pixel size of the EMCCD, and the thickness of the microplasma. In this paper, the optimal condition for achieving a maximum resolution power has been analyzed. With this diagnostic system, we revealed the spatial nonuniformity of a microwave atmospheric-pressure argon microplasma. Furthermore, the spatial distribution of the time-averaged effective electron temperature has been estimated from the intensity distributions of 750.4 and 415.8 nm emissions.

  4. Cataloguing Emission Line Spectra from Fe VII-Fe XXIV in the Extreme Ultraviolet

    NASA Technical Reports Server (NTRS)

    Lepson, J. K.; Beiersdorfer, P.; Brown, G. V.; Kahn, D. A.; Liedahl, D. A.; Mauche, C. W.; Utter, S. B.

    2000-01-01

    Detailed laboratory astrophysics measurements are, in progress to produce spectral tables for the Fe VII Fe XXIV line emission in the EUV wavelength band. Results for Fe XIII are presented that update line lists used in the Chandra Emission Line Project.

  5. 40 CFR 1060.510 - How do I test EPA Low-Emission Fuel Lines for permeation emissions?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 33 2014-07-01 2014-07-01 false How do I test EPA Low-Emission Fuel Lines for permeation emissions? 1060.510 Section 1060.510 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EVAPORATIVE EMISSIONS FROM NEW AND...

  6. 40 CFR 1060.510 - How do I test EPA Low-Emission Fuel Lines for permeation emissions?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 34 2013-07-01 2013-07-01 false How do I test EPA Low-Emission Fuel Lines for permeation emissions? 1060.510 Section 1060.510 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EVAPORATIVE EMISSIONS FROM NEW AND...

  7. 40 CFR 1060.510 - How do I test EPA Low-Emission Fuel Lines for permeation emissions?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 32 2010-07-01 2010-07-01 false How do I test EPA Low-Emission Fuel Lines for permeation emissions? 1060.510 Section 1060.510 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EVAPORATIVE EMISSIONS FROM NEW AND...

  8. 40 CFR 1060.510 - How do I test EPA Low-Emission Fuel Lines for permeation emissions?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 34 2012-07-01 2012-07-01 false How do I test EPA Low-Emission Fuel Lines for permeation emissions? 1060.510 Section 1060.510 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EVAPORATIVE EMISSIONS FROM NEW AND...

  9. The Analysis of Emission Lines; A Meeting in Honour of the 70th Birthdays of D. E. Osterbrock and M. J. Seaton

    NASA Technical Reports Server (NTRS)

    Williams, Robert (Editor); Livio, Mario (Editor); Dufour, Reginald J.

    1994-01-01

    A review of the field of astronomical spectroscopy with emphasis on emission lines 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 emission-line objects to date (mid-1994). A discussion of the major diagnostic UV emission lines 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 emission-line spectroscopy of nebulae and active galaxies.

  10. SPITZER IRAC COLOR DIAGNOSTICS FOR EXTENDED EMISSION IN STAR-FORMING REGIONS

    SciTech Connect

    Ybarra, Jason E.; Tapia, Mauricio; Román-Zúñiga, Carlos G.; Lada, Elizabeth A.

    2014-10-20

    The infrared data from the Spitzer Space Telescope are an invaluable tool for identifying physical processes in star formation. In this study, we calculate the Infrared Array Camera (IRAC) color space of UV fluorescent H{sub 2} and polycyclic aromatic hydrocarbon (PAH) emission in photodissociation regions (PDRs) using the Cloudy code with PAH opacities from Draine and Li. We create a set of color diagnostics that can be applied to study the structure of PDRs and to distinguish between FUV-excited and shock-excited H{sub 2} emission. To test this method, we apply these diagnostics to Spitzer IRAC data of NGC 2316. Our analysis of the structure of the PDR is consistent with previous studies of the region. In addition to UV excited emission, we identify shocked gas that may be part of an outflow originating from the cluster.

  11. Spectroscopic Diagnostics of Solar Magnetic Flux Ropes Using Iron Forbidden Line

    NASA Astrophysics Data System (ADS)

    Cheng, X.; Ding, M. D.

    2016-05-01

    In this Letter, we present Interface Region Imaging Spectrograph Fe xxi 1354.08 Å forbidden line emission of two magnetic flux ropes (MFRs) that caused two fast coronal mass ejections with velocities of ≥1000 km s‑1 and strong flares (X1.6 and M6.5) on 2014 September 10 and 2015 June 22, respectively. The extreme-ultraviolet images at the 131 and 94 Å passbands provided by the Atmospheric Imaging Assembly on board Solar Dynamics Observatory reveal that both MFRs initially appear as suspended hot channel-like structures. Interestingly, part of the MFRs is also visible in the Fe xxi 1354.08 forbidden line, even prior to the eruption, e.g., for the SOL2014-09-10 event. However, the line emission is very weak and that only appears at a few locations but not the whole structure of the MFRs. This implies that the MFRs could be comprised of different threads with different temperatures and densities, based on the fact that the formation of the Fe xxi forbidden line requires a critical temperature (˜11.5 MK) and density. Moreover, the line shows a non-thermal broadening and a blueshift in the early phase. It suggests that magnetic reconnection at that time has initiated; it not only heats the MFR and, at the same time, produces a non-thermal broadening of the Fe xxi line but also produces the poloidal flux, leading to the ascension of the MFRs.

  12. A catalog of early-type emission-line stars and Hα line profiles from LAMOST DR2

    NASA Astrophysics Data System (ADS)

    Hou, Wen; Luo, A.-Li; Hu, Jing-Yao; Yang, Hai-Feng; Du, Chang-De; Liu, Chao; Lee, Chien-De; Lin, Chien-Cheng; Wang, Yue-Fei; Zhang, Yong; Cao, Zi-Huang; Hou, Yong-Hui

    2016-09-01

    We present a catalog including 11 204 spectra of 10 436 early-type emission-line stars from LAMOST DR2, among which 9752 early-type emission-line spectra are newly discovered. For these early-type emission-line stars, we discuss the morphological and physical properties of their low-resolution spectra. In this spectral sample, the Hα emission profiles display a wide variety of shapes. Based on the Hα line profiles, these spectra are categorized into five distinct classes: single-peak emission, single-peak emission in absorption, double-peak emission, double-peak emission in absorption, and P-Cygni profiles. To better understand what causes the Hα line profiles, we divide these objects into four types from the perspective of physical classification, which include classical Be stars, Herbig Ae/Be stars, close binaries and spectra contaminated by HΠ regions. The majority of Herbig Ae/Be stars and classical Be stars are identified and separated using a (H-K, K-W1) color-color diagram. We also discuss 31 binary systems that are listed in the SIMBAD on-line catalog and identify 3600 spectra contaminated by HΠ regions after cross-matching with positions in the Dubout-Crillon catalog. A statistical analysis of line profiles versus classifications is then conducted in order to understand the distribution of Hα profiles for each type in our sample. Finally, we also provide a table of 172 spectra with Fe Π emission lines and roughly calculate stellar wind velocities for seven spectra with P-Cygni profiles.

  13. Infrared Dual-line Hanle diagnostic of the Coronal Vector Magnetic Field

    NASA Astrophysics Data System (ADS)

    Dima, Gabriel; Kuhn, Jeffrey; Berdyugina, Svetlana

    2016-04-01

    Measuring the coronal vector magnetic field is still a major challenge in solar physics. This is due to the intrinsic weakness of the field (e.g. ~4G at a height of 0.1Rsun above an active region) and the large thermal broadening of coronal emission lines. We propose using concurrent linear polarization measurements of near-infrared forbidden and permitted lines together with Hanle effect models to calculate the coronal vector magnetic field. In the unsaturated Hanle regime both the direction and strength of the magnetic field affect the linear polarization, while in the saturated regime the polarization is insensitive to the strength of the field. The relatively long radiative lifetimes of coronal forbidden atomic transitions implies that the emission lines are formed in the saturated Hanle regime and the linear polarization is insensitive to the strength of the field. By combining measurements of both forbidden and permitted lines, the direction and strength of the field can be obtained. For example, the SiX 1.4301 um line shows strong linear polarization and has been observed in emission over a large field-of-view (out to elongations of 0.5 Rsun. Here we describe an algorithm that combines linear polarization measurements of the SiX 1.4301 um forbidden line with linear polarization observations of the HeI 1.0830 um permitted coronal line to obtain the vector magnetic field. To illustrate the concept we assume the emitting gas for both atomic transitions is located in the plane of the sky. The further development of this method and associated tools will be a critical step towards interpreting the high spectral, spatial and temporal infrared spectro-polarimetric measurements that will be possible when the Daniel K. Inouye Solar Telescope (DKIST) is completed in 2019.

  14. Spatial calibration of a tokamak neutral beam diagnostic using in situ neutral beam emission.

    PubMed

    Chrystal, C; Burrell, K H; Grierson, B A; Pace, D C

    2015-10-01

    Neutral beam injection is used in tokamaks to heat, apply torque, drive non-inductive current, and diagnose plasmas. Neutral beam diagnostics need accurate spatial calibrations to benefit from the measurement localization provided by the neutral beam. A new technique has been developed that uses in situ measurements of neutral beam emission to determine the spatial location of the beam and the associated diagnostic views. This technique was developed to improve the charge exchange recombination (CER) diagnostic at the DIII-D tokamak and uses measurements of the Doppler shift and Stark splitting of neutral beam emission made by that diagnostic. These measurements contain information about the geometric relation between the diagnostic views and the neutral beams when they are injecting power. This information is combined with standard spatial calibration measurements to create an integrated spatial calibration that provides a more complete description of the neutral beam-CER system. The integrated spatial calibration results are very similar to the standard calibration results and derived quantities from CER measurements are unchanged within their measurement errors. The methods developed to perform the integrated spatial calibration could be useful for tokamaks with limited physical access. PMID:26520957

  15. Spatial calibration of a tokamak neutral beam diagnostic using in situ neutral beam emission

    SciTech Connect

    Chrystal, C.; Burrell, K. H.; Pace, D. C.; Grierson, B. A.

    2015-10-15

    Neutral beam injection is used in tokamaks to heat, apply torque, drive non-inductive current, and diagnose plasmas. Neutral beam diagnostics need accurate spatial calibrations to benefit from the measurement localization provided by the neutral beam. A new technique has been developed that uses in situ measurements of neutral beam emission to determine the spatial location of the beam and the associated diagnostic views. This technique was developed to improve the charge exchange recombination (CER) diagnostic at the DIII-D tokamak and uses measurements of the Doppler shift and Stark splitting of neutral beam emission made by that diagnostic. These measurements contain information about the geometric relation between the diagnostic views and the neutral beams when they are injecting power. This information is combined with standard spatial calibration measurements to create an integrated spatial calibration that provides a more complete description of the neutral beam-CER system. The integrated spatial calibration results are very similar to the standard calibration results and derived quantities from CER measurements are unchanged within their measurement errors. The methods developed to perform the integrated spatial calibration could be useful for tokamaks with limited physical access.

  16. Spatial calibration of a tokamak neutral beam diagnostic using in situ neutral beam emission

    NASA Astrophysics Data System (ADS)

    Chrystal, C.; Burrell, K. H.; Grierson, B. A.; Pace, D. C.

    2015-10-01

    Neutral beam injection is used in tokamaks to heat, apply torque, drive non-inductive current, and diagnose plasmas. Neutral beam diagnostics need accurate spatial calibrations to benefit from the measurement localization provided by the neutral beam. A new technique has been developed that uses in situ measurements of neutral beam emission to determine the spatial location of the beam and the associated diagnostic views. This technique was developed to improve the charge exchange recombination (CER) diagnostic at the DIII-D tokamak and uses measurements of the Doppler shift and Stark splitting of neutral beam emission made by that diagnostic. These measurements contain information about the geometric relation between the diagnostic views and the neutral beams when they are injecting power. This information is combined with standard spatial calibration measurements to create an integrated spatial calibration that provides a more complete description of the neutral beam-CER system. The integrated spatial calibration results are very similar to the standard calibration results and derived quantities from CER measurements are unchanged within their measurement errors. The methods developed to perform the integrated spatial calibration could be useful for tokamaks with limited physical access.

  17. Observing Infrared Emission Lines of Neutron-Capture Species in Planetary Nebulae: New Detections with IGRINS

    NASA Astrophysics Data System (ADS)

    Dinerstein, Harriet L.; Sterling, N. C.; Kaplan, Kyle F.; Bautista, Manuel A.

    2015-08-01

    As the former envelopes of evolved stars, planetary nebulae (PNe) present an opportunity to study slow neutron-capture reactions (the “s-process”) during the AGB. Such studies differ from those of AGB stars in two ways. First, PNe represent the end point of self-enrichment and dredge-up in the star and most of its mass return to the ISM, enabling us to infer the nucleosynthetic yield of a specific element. Second, some s-process products are observable in PNe but difficult or impossible to observe in cool stars. These include some species with nuclear charge Z in the 30’s for which the major synthesis sites are uncertain. Optical emission lines of trans-iron species have been observed in some PNe, but are faint and can suffer from blending with lines of more abundant elements (Péquignot & Baluteau 1994, A&A, 283, 593; Sharpee et al. 2007, ApJ, 659, 1265). Observing infrared transitions from low energy states has proven to be a fruitful alternate approach. We used K-band lines of Se (Z=34) and Kr (Z=36) to study the demographics of their abundances in a large sample of Milky Way PNe (Dinerstein 2001, ApJ, 550, L223; Sterling & Dinerstein 2008, ApJ, 174, 158; Sterling, Porter, & Dinerstein 2015, submitted). An L-band emission line of Zn identified by Dinerstein & Geballe (2001, ApJ, 562, 515) and further observed by Smith, Zijlstra, & Dinerstein 2014 (MNRAS, 441, 3161), can be used as a tracer of the Fe-group, enabling determinations of the key stellar population diagnostic ratio [alpha/Fe] in PNe (see poster by Dinerstein et al., Focus Meeting 4). Using IGRINS, a high spectral resolution H and K band spectrometer (Park & Jaffe et al. 2014, Proc SPIE, 9147), we have discovered several new lines not previously reported in any astronomical object. Our detection of an H-band line of Rb (Z=37) confirms previous claims of optical Rb detections and indicates enrichment by a factor of ~4 in the PN NGC 7027 (Sterling, Dinerstein, Kaplan, & Bautista, in preparation

  18. On-line experimental validation of a model-based diagnostic algorithm dedicated to a solid oxide fuel cell system

    NASA Astrophysics Data System (ADS)

    Polverino, Pierpaolo; Esposito, Angelo; Pianese, Cesare; Ludwig, Bastian; Iwanschitz, Boris; Mai, Andreas

    2016-02-01

    In the current energetic scenario, Solid Oxide Fuel Cells (SOFCs) exhibit appealing features which make them suitable for environmental-friendly power production, especially for stationary applications. An example is represented by micro-combined heat and power (μ-CHP) generation units based on SOFC stacks, which are able to produce electric and thermal power with high efficiency and low pollutant and greenhouse gases emissions. However, the main limitations to their diffusion into the mass market consist in high maintenance and production costs and short lifetime. To improve these aspects, the current research activity focuses on the development of robust and generalizable diagnostic techniques, aimed at detecting and isolating faults within the entire system (i.e. SOFC stack and balance of plant). Coupled with appropriate recovery strategies, diagnosis can prevent undesired system shutdowns during faulty conditions, with consequent lifetime increase and maintenance costs reduction. This paper deals with the on-line experimental validation of a model-based diagnostic algorithm applied to a pre-commercial SOFC system. The proposed algorithm exploits a Fault Signature Matrix based on a Fault Tree Analysis and improved through fault simulations. The algorithm is characterized on the considered system and it is validated by means of experimental induction of faulty states in controlled conditions.

  19. The beam diagnostic instruments in Beijing radioactive ion-beam facilities isotope separator on-line

    SciTech Connect

    Ma, Y. Cui, B.; Ma, R.; Tang, B.; Chen, L.; Huang, Q.; Jiang, W.

    2014-02-15

    The beam diagnostic instruments for Beijing Radioactive Ion-beam Facilities Isotope Separator On-Line are introduced [B. Q. Cui, Z. H. Peng, Y. J. Ma, R. G. Ma, B. Tang, T. Zhang, and W. S. Jiang, Nucl. Instrum. Methods 266, 4113 (2008); T. J. Zhang, X. L. Guan, and B. Q. Cui, in Proceedings of APAC 2004, Gyeongju, Korea, 2004, http://www.jacow.org , p. 267]. For low intensity ion beam [30–300 keV/1 pA–10 μA], the beam profile monitor, the emittance measurement unit, and the analyzing slit will be installed. For the primary proton beam [100 MeV/200 μA], the beam profile scanner will be installed. For identification of the nuclide, a beam identification unit will be installed. The details of prototype of the beam diagnostic units and some experiment results will be described in this article.

  20. On the sodium D line emission in the terrestrial nightglow

    NASA Astrophysics Data System (ADS)

    Plane, John; Oetjen, Hilke; de Miranda, Marcelo; Saiz-Lopez, Alfonso; Gausa, Michael; Williams, Bifford

    2012-01-01

    Emission from atomic Na, consisting of a doublet of lines at 589.0 and 589.6 nm, is a prominent feature of the earth’s nightglow. A large data-base of measurements of the relative intensities of the D lines (RD) was gathered at three locations: the ALOMAR observatory, Andenes (Norway, 69°N), Kuujjuarapik (Canada, 55°N) and the Danum Valley (Borneo, 8°N). RD varies between 1.5 and 2.0, with an average value of 1.67. These results were interpreted using a theoretical model of the Na nightglow which involves initial production of electronically excited NaO(A2Σ) from the reaction between Na and O3, followed either by reaction with O to generate Na(2PJ) with a branching ratio of 1/6 and a J=3/2 to 1/2 propensity of 2.0, or quenching of NaO(A) to NaO(X2Π) by O2. The resulting NaO(X) then reacts with O to generate Na(2PJ) with a branching ratio of 1/6 and a J=3/2 to 1/2 propensity of 1.5. These branching ratios and spin-orbit propensities are derived from statistical correlation of the electronic potential energy surfaces connecting the reactants NaO(A)+O and NaO(X)+O with the products Na+O2, through the Na+O2- ion-pair intermediate. A fit of this statistical model to the results of an earlier laboratory study (Slanger et al., 2005), where RD was measured as a function of the ratio [O]/[O2], indicates that the rate coefficient for the quenching of NaO(A) by O2 is around 1×10-11 cm3 molecule-1 s-1. The statistical model is also in good accord with recent high resolution observations of the Na D line widths (Harrell et al., 2010). An atmospheric model is then used to show that gravity wave-driven perturbations to the Na layer can account for the observed variability of RD.

  1. Time Variability of Molecular Line Emission in IRC +10216

    NASA Astrophysics Data System (ADS)

    Teyssier, D.; Cernicharo, J.; Quintana-Lacaci, G.; Agúndez, M.; Barlow, M. J.; Daniel, F.; De Beck, E.; Decin, L.; Garcia Lario, P.; Groenewegen, M. A. T.; Neufeld, D. A.; Pearson, J. C.

    2015-08-01

    We present the results of monitoring the molecular emission of the C-rich AGB star IRC+10216 over 3 years with the Herschel Space Observatory. Observations of rotational transitions of various vibrational levels of CO, 13CO, CS, CCH, H2O, SiO, SiS, SiC2, HCN and HNC have been collected with the HIFI, PACS and SPIRE instruments over multiple epochs. The intensity monitoring shows strong and periodic variations of most of the observed molecules, often with differential behavior depending on the transition level (larger variation at higher J), and generally enhanced modulations in the vibrational modes of some of these molecules (e.g. HCN). These results show that the effect of IR pumping through the different vibrational levels on the emergent line profiles of a given transition can be really significant. This implies that the IR radiation field of the circumstellar envelope and its time variation has to be taken into account in any radiative transfer model in order to derive accurately the physico-chemical structure of the envelope.

  2. Feasibility study for a correlation electron cyclotron emission turbulence diagnostic based on nonlinear gyrokinetic simulations

    NASA Astrophysics Data System (ADS)

    White, A. E.; Howard, N. T.; Mikkelsen, D. R.; Greenwald, M.; Candy, J.; Waltz, R. E.

    2011-11-01

    This paper describes the use of nonlinear gyrokinetic simulations to assess the feasibility of a new correlation electron cyclotron emission (CECE) diagnostic that has been proposed for the Alcator C-Mod tokamak (Marmar et al 2009 Nucl. Fusion 49 104014). This work is based on a series of simulations performed with the GYRO code (Candy and Waltz 2003 J. Comput. Phys. 186 545). The simulations are used to predict ranges of fluctuation level, peak poloidal wavenumber and radial correlation length of electron temperature fluctuations in the core of the plasma. The impact of antenna pattern and poloidal viewing location on measurable turbulence characteristics is addressed using synthetic diagnostics. An upper limit on the CECE sample volume size is determined. The modeling results show that a CECE diagnostic capable of measuring transport-relevant, long-wavelength (kθρs < 0.5) electron temperature fluctuations is feasible at Alcator C-Mod.

  3. Adaptive-array Electron Cyclotron Emission diagnostics using data streaming in a Software Defined Radio system

    NASA Astrophysics Data System (ADS)

    Idei, H.; Mishra, K.; Yamamoto, M. K.; Hamasaki, M.; Fujisawa, A.; Nagashima, Y.; Hayashi, Y.; Onchi, T.; Hanada, K.; Zushi, H.; the QUEST team

    2016-04-01

    Measurement of the Electron Cyclotron Emission (ECE) spectrum is one of the most popular electron temperature diagnostics in nuclear fusion plasma research. A 2-dimensional ECE imaging system was developed with an adaptive-array approach. A radio-frequency (RF) heterodyne detection system with Software Defined Radio (SDR) devices and a phased-array receiver antenna was used to measure the phase and amplitude of the ECE wave. The SDR heterodyne system could continuously measure the phase and amplitude with sufficient accuracy and time resolution while the previous digitizer system could only acquire data at specific times. Robust streaming phase measurements for adaptive-arrayed continuous ECE diagnostics were demonstrated using Fast Fourier Transform (FFT) analysis with the SDR system. The emission field pattern was reconstructed using adaptive-array analysis. The reconstructed profiles were discussed using profiles calculated from coherent single-frequency radiation from the phase array antenna.

  4. Line broadening of Mg X 609 and 625 A coronal emission lines observed above the solar limb

    NASA Technical Reports Server (NTRS)

    Hassler, Donald M.; Rottman, Gary J.; Shoub, Edward C.; Holzer, Thomas E.

    1990-01-01

    A University of Colorado sounding rocket experiment on March 17, 1988, provided high-resolution EUV spectra along a solar diameter and out to 1.2 solar radius with spatial resolution of 20 x 60 arcsec. Each spectrum contains transition region and coronal emission lines in the wavelength range 605-635 A and 1210-1270 A, including the emission lines Mg X 609 and 625 A, Fe XII 1242 A, O V 629 A, N V 1238 and 1242 A, corresponding to a wide range of temperatures of formation. Increased line broadening is observed above the limb for all lines, and this effect is illustrated by presenting observed line widths as a function of height above the limb for the higher temperature lines Mg X 609 and 625 A. On the basis of calculations, the most likely cause of the increased broadening above the limb appears to be the presence of hydromagnetic waves in the corona.

  5. Investigating Possible Departures from Maxwellian Energy Distributions in Nebulae using High-Resolution Emission Line Spectra

    NASA Astrophysics Data System (ADS)

    Turbyfill, Amanda; Dinerstein, H. L.; Sterling, N. C.

    2014-01-01

    The derivation of ionic abundance ratios from collisionally excited emission lines in gaseous nebulae requires knowledge of the physical state of the gas, particularly the electron kinetic temperature, Te, to which the resulting abundances are highly sensitive. A long-standing problem in nebular analyses has been pervasive discrepancies among values of Te obtained from different diagnostic ratios for a single nebula. Recently, Nicholls et al. (2012, ApJ, 752, 148) have suggested that the nebular electrons may not obey an equilibrium Maxwell-Boltzmann (M-B) energy distribution, but instead follow a “κ distribution” seen in many solar system plasmas, a family of distributions for which the M-B distribution is the limiting case where κ → ∞. The high-energy tail of supra-thermal electrons in κ distributions have a disproportionate effect on strongly energy dependent quantities, such as Te diagnostics, for even modest departures from M-B distributions. We apply prescriptions given by Nicholls et al. (2013, ApJS, 207, 21) to high-resolution (R=36,700) optical spectra of 10 planetary nebulae obtained with the 2d-coudé echelle spectrograph on the 2.7 m Harlan J. Smith Telescope at McDonald Observatory. The advantages of these data include their broad spectral coverage and sufficiently high spectral resolution to separate blended lines and assess possible atmospheric absorption issues. The line fluxes were obtained using ROBOSPECT, an automated spectral line measurement package developed by Waters & Hollek (2013, PASP, 125, 1164). We solve both for Te under the assumption of M-B distributions, and the parameters of κ distributions consistent with the data. Our goal is to test whether the κ distribution hypothesis provides a better fit to the observed line ratios. Finally, we discuss effects on the derived ionic abundances under this alternate description of the particle energy distributions. This research was supported by NSF grant AST 0708245 and the John W

  6. Physical Properties of Emission-Line Galaxies at 2 from Near-Infrared Spectroscopy with Magellan FIRE

    NASA Astrophysics Data System (ADS)

    Masters, Daniel C.; McCarthy, P. J.; Malkan, M. A.; Siana, B. D.; Scarlata, C.; Hathi, N. P.; Atek, H.; Henry, A. L.; WISP Team

    2014-01-01

    We present results from near-infrared spectroscopy with Magellan FIRE of 26 strong emission-line galaxies at 2.2 and 1.5. The sample was selected from the WFC3 Infrared Spectroscopic Parallels (WISP) survey, which uses the near-infrared grism capability of the Hubble Space Telescope Wide Field Camera 3 to detect emission-line galaxies over 0.5 < z < 2.3. High-resolution ( 5000) follow-up spectroscopy with Magellan FIRE over 1.0--2.5 microns resolves important rest-frame optical emission lines, allowing us to measure physical properties such as dust obscuration, metal abundance, star formation rate, ionization parameter, and emission line kinematics. We also analyze the properties of composite spectra derived from the FIRE-observed sample. With this relatively large sample of rest-frame optical spectra we can make statistical inferences about the population of emission-line galaxies at 2. We find that the galaxies are low metallicity ( 1/5-1/2 Z_solar) as determined from the R23 calibration. The galaxies are low dust extinction on average (E(B-V 0.2) but with significant scatter. The dust-corrected H-alpha star formation rates range from ~10--150 M_sun yr^-1 with a mean of 50 M_su yr^-1. The average ionization parameter for the sample, log U ~ -2.5, is higher than typically found for star-forming galaxies in the local universe but consistent with those found in more intense starbursting regions in galaxies such as M82. Emission line velocity dispersions are measured to be 71 +- 38 km s^-1, in good agreement with other studies that have probed the H-alpha kinematics of star-forming galaxies at similar redshift. The galaxies are compact, with half-light radii of < 2 kpc, and ~50% show evidence for multiple structures or asymmetries in the WFC3 imaging. Based on the line velocity dispersions and the location of the galaxies on BPT diagnostic plots, there is little evidence for significant AGN contribution to most emission-line galaxies at 2.

  7. On the physical association of the peculiar emission: Line stars HD 122669 and HD 122691

    NASA Technical Reports Server (NTRS)

    Garrison, R. F.; Hiltner, W. A.; Sanduleak, N.

    1975-01-01

    Spectroscopic and photometric observations indicate a physical association between the peculiar early-type emission-line stars HD 122669 and HD 122691. The latter has undergone a drastic change in the strength of its emission lines during the past twenty years. There is some indication that both stars vary with shorter time scales.

  8. On the physical association of the peculiar emission-line stars HD 122669 and HD 122691

    NASA Technical Reports Server (NTRS)

    Garrison, R. F.; Hiltner, W. A.; Sanduleak, N.

    1975-01-01

    Spectroscopic and photometric observations indicate a physical association between the peculiar early-type emission-line stars HD 122669 and HD 122691. The latter has undergone a drastic change in the strength of its emission lines during the past 20 years. There is some indication that both stars vary with shorter time scales.

  9. Discovery of iron line emission in the Hercules X-1 low state spectrum with HEAO-1

    NASA Technical Reports Server (NTRS)

    Pravdo, S. H.; Boldt, E. A.; Holt, S. S.; Rothschild, R. E.; Serlemitsos, P. J.

    1978-01-01

    The line energy, equivalent width, binary phase dependence, and intrinsic width of the iron line emission feature observed in the low state sepctrum of Hercules X-1 are examined. Deductions are made concerning secondary X-ray emission from this binary system.

  10. Spectropolarimetric test of the relativistic disk model for the broad emission lines of active galactic nuclei

    NASA Technical Reports Server (NTRS)

    Chen, Kaiyou; Halpern, Jules P.

    1990-01-01

    Previously, it was claimed that the broad emission lines of the radio galaxy Arp 102B can be fitted by the line profile from a simple relativistic Keplerian thin disk. It was argued that the lines originating from the relativistic accretion disk could be polarized due to electron scattering, which is likely to be the dominant opacity in the line-emitting region of Arp 102B. In the present work, the expected polarization properties of these broad emission lines are calculated. The percentage of polarization depends strongly on the inclination angle. For some angles, the red peak of the polarized, double-peaked line profile can be higher than the blue peak. This is in contrast to the total line profile, in which the blue peak is always higher than the red one. Spectropolarimetric observations could, therefore, provide an independent test of the relativistic disk model for the broad emission lines of Arp 102B and other active galactic nuclei.

  11. The link between broad emission line fluctuations and non-thermal emission from the inner AGN jet

    NASA Astrophysics Data System (ADS)

    León-Tavares, J.; Chavushyan, V.; Lobanov, A.; Valtaoja, E.; Arshakian, T. G.

    2015-03-01

    AGN reverberate when the broad emission lines respond to changes of the ionizing thermal continuum emission. Reverberation measurements have been commonly used to estimate the size of the broad-line region (BLR) and the mass of the central black hole. However, reverberation mapping studies have been mostly performed on radio-quiet sources where the contribution of the jet can be neglected. In radio-loud AGN, jets and outflows may affect substantially the relation observed between the ionizing continuum and the line emission. To investigate this relation, we have conducted a series of multi-wavelength studies of radio-loud AGN, combining optical spectral line monitoring with regular VLBI observations. Our results suggest that at least a fraction of the broad-line emitting material can be located in a sub-relativistic outflow ionized by non-thermal continuum emission generated in the jet at large distances (> 1 pc) from the central engine of AGN. This finding may have a strong impact on black hole mass estimates based on measured widths of the broad emission lines and on the gamma-ray emission mechanisms.

  12. Agent-based station for on-line diagnostics by self-adaptive laser Doppler vibrometry.

    PubMed

    Serafini, S; Paone, N; Castellini, P

    2013-12-01

    A self-adaptive diagnostic system based on laser vibrometry is proposed for quality control of mechanical defects by vibration testing; it is developed for appliances at the end of an assembly line, but its characteristics are generally suited for testing most types of electromechanical products. It consists of a laser Doppler vibrometer, equipped with scanning mirrors and a camera, which implements self-adaptive bahaviour for optimizing the measurement. The system is conceived as a Quality Control Agent (QCA) and it is part of a Multi Agent System that supervises all the production line. The QCA behaviour is defined so to minimize measurement uncertainty during the on-line tests and to compensate target mis-positioning under guidance of a vision system. Best measurement conditions are reached by maximizing the amplitude of the optical Doppler beat signal (signal quality) and consequently minimize uncertainty. In this paper, the optimization strategy for measurement enhancement achieved by the down-hill algorithm (Nelder-Mead algorithm) and its effect on signal quality improvement is discussed. Tests on a washing machine in controlled operating conditions allow to evaluate the efficacy of the method; significant reduction of noise on vibration velocity spectra is observed. Results from on-line tests are presented, which demonstrate the potential of the system for industrial quality control. PMID:24387408

  13. Agent-based station for on-line diagnostics by self-adaptive laser Doppler vibrometry

    NASA Astrophysics Data System (ADS)

    Serafini, S.; Paone, N.; Castellini, P.

    2013-12-01

    A self-adaptive diagnostic system based on laser vibrometry is proposed for quality control of mechanical defects by vibration testing; it is developed for appliances at the end of an assembly line, but its characteristics are generally suited for testing most types of electromechanical products. It consists of a laser Doppler vibrometer, equipped with scanning mirrors and a camera, which implements self-adaptive bahaviour for optimizing the measurement. The system is conceived as a Quality Control Agent (QCA) and it is part of a Multi Agent System that supervises all the production line. The QCA behaviour is defined so to minimize measurement uncertainty during the on-line tests and to compensate target mis-positioning under guidance of a vision system. Best measurement conditions are reached by maximizing the amplitude of the optical Doppler beat signal (signal quality) and consequently minimize uncertainty. In this paper, the optimization strategy for measurement enhancement achieved by the down-hill algorithm (Nelder-Mead algorithm) and its effect on signal quality improvement is discussed. Tests on a washing machine in controlled operating conditions allow to evaluate the efficacy of the method; significant reduction of noise on vibration velocity spectra is observed. Results from on-line tests are presented, which demonstrate the potential of the system for industrial quality control.

  14. Therapeutic and diagnostic set for irradiation the cell lines in low level laser therapy

    NASA Astrophysics Data System (ADS)

    Gryko, Lukasz; Zajac, Andrzej; Gilewski, Marian; Szymanska, Justyna; Goralczyk, Krzysztof

    2014-05-01

    In the paper is presented optoelectronic diagnostic set for standardization the biostimulation procedures performed on cell lines. The basic functional components of the therapeutic set are two digitally controlled illuminators. They are composed of the sets of semiconductor emitters - medium power laser diodes and high power LEDs emitting radiation in wide spectral range from 600 nm to 1000 nm. Emitters are coupled with applicator by fibre optic and optical systems that provides uniform irradiation of vessel with cell culture samples. Integrated spectrometer and optical power meter allow to control the energy and spectral parameters of electromagnetic radiation during the Low Level Light Therapy procedure. Dedicated power supplies and digital controlling system allow independent power of each emitter . It was developed active temperature stabilization system to thermal adjust spectral line of emitted radiation to more efficient association with absorption spectra of biological acceptors. Using the set to controlled irradiation and allowing to measure absorption spectrum of biological medium it is possible to carry out objective assessment the impact of the exposure parameters on the state cells subjected to Low Level Light Therapy. That procedure allows comparing the biological response of cell lines after irradiation with radiation of variable spectral and energetic parameters. Researches were carried out on vascular endothelial cell lines. Cells proliferations after irradiation of LEDs: 645 nm, 680 nm, 740 nm, 780 nm, 830 nm, 870 nm, 890 nm, 970 nm and lasers 650 nm and 830 nm were examined.

  15. Molecular Gas Kinematics and Line Diagnostics in Early-type Galaxies: NGC 4710 & NGC 5866

    NASA Astrophysics Data System (ADS)

    Topal, Selçuk; Bureau, Martin; Davis, Timothy A.; Krips, Melanie; Young, Lisa M.; Crocker, Alison F.

    2016-09-01

    We present interferometric observations of CO lines (12CO(1-0, 2-1) and 13CO(1-0, 2-1)) and dense gas tracers (HCN(1-0), HCO+(1-0), HNC(1-0) and HNCO(4-3)) in two nearby edge-on barred lenticular galaxies, NGC 4710 and NGC 5866, with most of the gas concentrated in a nuclear disc and an inner ring in each galaxy. We probe the physical conditions of a two-component molecular interstellar medium in each galaxy and each kinematic component by using molecular line ratio diagnostics in three complementary ways. First, we measure the ratios of the position-velocity diagrams of different lines, second we measure the ratios of each kinematic component's integrated line intensities as a function of projected position, and third we model these line ratios using a non-local thermodynamic equilibrium radiative transfer code. Overall, the nuclear discs appear to have a tenuous molecular gas component that is hotter, optically thinner and with a larger dense gas fraction than that in the inner rings, suggesting more dense clumps immersed in a hotter more diffuse molecular medium. This is consistent with evidence that the physical conditions in the nuclear discs are similar to those in photo-dissociation regions. A similar picture emerges when comparing the observed molecular line ratios with those of other galaxy types. The physical conditions of the molecular gas in the nuclear discs of NGC 4710 and NGC 5866 thus appear intermediate between those of spiral galaxies and starbursts, while the star formation in their inner rings is even milder.

  16. Polarized Line Profiles as Diagnostics of Circumstellar Geometry in Type IIn Supernovae

    NASA Astrophysics Data System (ADS)

    Hoffman, J. L.; Nugent, P.; Leonard, D. C.; Filippenko, A. V.

    2005-12-01

    Supernovae of type IIn possess spectral signatures that indicate an intense interaction between the supernova ejecta and surrounding dense circumstellar material, presumably cast off by the star in pre-explosion mass-loss episodes. Studying this interaction can yield clues to the nature of Type IIn progenitors and their mass loss history. In particular, polarization spectra of Type IIn's show complex line polarization and position angle features that arise from a combination of geometrical and optical effects. We investigate ways in which polarized H alpha line profiles can be produced at early times in the evolution of a Type IIn supernova by modeling the transfer of the photospheric H alpha line through circumstellar shells with various geometrical configurations and optical characteristics. Electron scattering combined with hydrogen absorption, thermal emission, and resonance line effects produces a variety of polarized line shapes. We compare our results with high-quality spectropolarimetric observations of Type IIn supernovae, and show how they can be used to constrain the characteristics of the circumstellar material in these objects. J.L. Hoffman is supported by an NSF Astronomy & Astrophysics Postdoctoral Fellowship under award AST-0302123. This research uses the resources of the National Energy Research Scientific Computing Center, which is supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC03-76SF00098.

  17. Measurements of Spatial Line Emission Profiles in the Main Scrape-Off Layer of the DIII-D Tokamak

    SciTech Connect

    Groth, M; Ellis, R; Brooks, N; Fenstermacher, M; Lasnier, C; Meyer, W; Moller, J

    2009-06-05

    A video camera system is described that measures the spatial distribution of visible line emission emitted from the main scrape-off layer (SOL) of plasmas in the DIII-D tokamak. A wide-angle lens installed on an equatorial port and an in-vessel mirror which intercepts part of the lens view provide simultaneous tangential views of the SOL on the low-field and high-field sides of the plasma's equatorial plane. Tomographic reconstruction techniques are used to calculate the 2-D poloidal profiles from the raw data, and 1-D poloidal profiles simulating chordal views of other optical diagnostics from the 2-D profiles. The 2-D profiles can be compared with SOL plasma simulations; the 1-D profiles with measurements from spectroscopic diagnostics. Sample results are presented which elucidate carbon transport in plasmas with toroidally uniform injection of methane and argon transport in disruption mitigation experiments with massive gas jet injection.

  18. Spectroscopic survey of emission-line stars - I. B[e] stars

    NASA Astrophysics Data System (ADS)

    Aret, A.; Kraus, M.; Šlechta, M.

    2016-02-01

    Emission-line stars are typically surrounded by dense circumstellar material, often in form of rings or disc-like structures. Line emission from forbidden transitions trace a diversity of density and temperature regimes. Of particular interest are the forbidden lines of [O I] λλ6300, 6364 and [Ca II] λλ7291, 7324. They arise in complementary, high-density environments, such as the inner-disc regions around B[e] supergiants. To study physical conditions traced by these lines and to investigate how common they are, we initiated a survey of emission-line stars. Here, we focus on a sample of nine B[e] stars in different evolutionary phases. Emission of the [O I] lines is one of the characteristics of B[e] stars. We find that four of the objects display [Ca II] line emission: for the B[e] supergiants V1478 Cyg and 3 Pup, the kinematics obtained from the [O I] and [Ca II] line profiles agrees with a Keplerian rotating disc scenario; the forbidden lines of the compact planetary nebula OY Gem display no kinematical broadening beyond spectral resolution; the luminous blue variable candidate V1429 Aql shows no [O I] lines, but the profile of its [Ca II] lines suggests that the emission originates in its hot, ionized circumbinary disc. As none of the B[e] stars of lower mass displays [Ca II] line emission, we conclude that these lines are more likely observable in massive stars with dense discs, supporting and strengthening the suggestion that their appearance requires high-density environments.

  19. Detection of fast electrons in pulsed argon inductively-coupled plasmas using the 420.1-419.8 nm emission line pair

    NASA Astrophysics Data System (ADS)

    Boffard, John B.; Wang, S.; Lin, Chun C.; Wendt, A. E.

    2015-12-01

    Pulsed rf plasmas exhibit many differences as compared to continuous wave plasmas with the same average power levels, including large temporal variations in the electron temperature, with a sharp spike when the power is applied and falling dramatically in the afterglow. We present a comparison of time-resolved measurements of the effective electron temperature in pulsed inductively-coupled plasmas by means of (i) optical emission spectroscopy (OES) using different sets of argon emission lines and (ii) Langmuir probe measurements. One OES diagnostic used six strong Ar(2{{\\text{p}}x}\\to 1{{\\text{s}}y} ) emission lines in the 700-800 nm wavelength range, the second used only the Ar 420.1-419.8 nm line pair. For pulsed plasmas with long afterglow periods, the line pair method reveals the presence of a significant number of hot electrons (E≥slant 22 eV) at the start of the pulse. Under these conditions, the metastable atom density is very low, and the diagnostic using the Ar(2{{\\text{p}}x}\\to 1{{\\text{s}}y} ) emission lines is ineffective for determining the electron temperature. For later parts of the pulse and pulsed plasmas with short periods (i.e. 10 μs), the metastable density is high and the two OES methods yield similar results which are also in agreement with probe measurements.

  20. The Diagnostic Accuracy of Purple Line in Prediction of Labor Progress in Omolbanin Hospital, Iran

    PubMed Central

    Kordi, Masoumeh; Irani, Morvarid; Tara, Fatemeh; Esmaily, Habibollah

    2014-01-01

    Background: Currently, vaginal examination is the gold standard for assessment of labor progress. The World Health Organization emphasizes that the number of vaginal examinations should be limited where it is necessary. Objectives: Therefore, this study aimed to determine the diagnostic accuracy of purple line in the prediction of labor progress. Patients and Methods: In this cross-sectional study, 350 women with a single pregnancy in vertex presentation and gestational age of 38-42 weeks without any medical disorder, admitted to government hospitals of Mashhad, were selected using convenience sampling. Vaginal examination and observation of the line each hour in the active phase of labor were measured. Abnormal progress of labor was defined as cervical dilatation less than 1 centimeter/hour in the active phase for two consecutive hours and fetal head descend less than 1cm/h or duration of more than two hours for nulliparous and one hour for multiparous In the second stage of labor. Data was analyzed by SPSS version 16 using chi -square test. Results: The purple line appeared in 75.3% of women during the active phase of labor. Appearance of the purple line in the prediction of labor progress had 90.2% sensitivity, 45.3% specificity, 88.1% positive predictive value, 51.0% negative predictive value in the first stage of labor and had 87.6% sensitivity, 52.4% specificity, 96.5% positive predictive value, 22.0% negative predictive value in the second stage of labor and has 68.57% sensitivity, 42.66% specificity, 85.32% positive predictive value, and 43.85% negative predictive value for the total labor. Conclusions: According to the appearance of the purple line in most of the cases and its high sensitivity and specificity, we can use it as a non-invasive complementary method for clinical assessment of labor progress. PMID:25763210

  1. Atomic emission lines in the near ultraviolet; hydrogen through krypton, section 1

    NASA Technical Reports Server (NTRS)

    Kelly, R. L.

    1979-01-01

    A compilation of spectra from the first 36 elements was prepared from published literature available through October 1977. In most cases, only those lines which were actually observed in emission or absorption are listed. The wavelengths included range from 2000 Angstroms to 3200 Angstroms with some additional lines up to 3500 Angstroms. Only lines of stripped atoms are reported; no molecular bands are included.

  2. Atomic emission lines in the near ultraviolet; hydrogen through krypton, section 2

    NASA Technical Reports Server (NTRS)

    Kelly, R. L.

    1979-01-01

    A compilation of spectra from the first 36 elements was prepared from published literature available through October 1977. In most cases, only those lines which were actually observed in emission or absorption are listed. The wavelengths included range from 2000 Angstroms to 3200 Angstroms with some additional lines up to 3500 Angstroms. Only lines of stripped atoms are reported; no molecular bands are included.

  3. Assessing molecular line diagnostics of triggered star formation using synthetic observations

    NASA Astrophysics Data System (ADS)

    Haworth, Thomas J.; Harries, Tim J.; Acreman, David M.; Rundle, David A.

    2013-06-01

    We investigate observational signatures of triggered star formation in bright rimmed clouds (BRCs) by using molecular line transfer calculations based on radiation-hydrodynamic radiatively driven implosion models. We find that for BRCs the separation in velocity between the line profile peak of an optically thick and an optically thin line is determined by both the observer viewing angle and the density of the shell driving into the cloud. In agreement with observations, we find that most BRC line profiles are symmetric and that asymmetries can be either red or blue, in contrast to the blue dominance expected for a collapsing cloud. Asymmetries in the line profiles arise when an optically thick line is dominated by the shell and an optically thin line is dominated by the cloud interior to the shell. The asymmetries are red or blue depending on whether the shell is moving towards or away from the observer, respectively. Using the known motions of the molecular gas in our models we rule out the `envelope expansion with core collapse' mechanism as the cause of the lack of blue-asymmetry in our simulated observations. We show that the absence of a strong photon-dominated region (PDR) around a BRC may not rule out the presence of triggered star formation: if the BRC line profile has a strong blue component then the shell is expected to be driving towards the observer, suggesting that the cloud is being viewed from behind and the PDR is obstructed. This could explain why BRCs such as SFO 80, 81 and 86 have a blue secondary peak and only a weak PDR inferred at 8 μm. Finally we also test the use of 12CO, 13CO and C18O as diagnostics of cloud mass, temperature and column density. We find that the inferred conditions are in reasonable agreement with those from the models. Calculating the cloud mass assuming spherical symmetry is shown to introduce an error of an order of magnitude whereas integrating the column density over a given region is found to introduce an error of

  4. KILOPARSEC-SCALE PROPERTIES OF EMISSION-LINE GALAXIES

    SciTech Connect

    Hemmati, Shoubaneh; Miller, Sarah H.; Mobasher, Bahram; Nayyeri, Hooshang; Ferguson, Henry C.; Koekemoer, Anton M.; Guo, Yicheng; Koo, David C.

    2014-12-20

    We perform a detailed study of the resolved properties of emission-line galaxies at kiloparsec scales to investigate how small-scale and global properties of galaxies are related. We use a sample of 119 galaxies in the GOODS fields. The galaxies are selected to cover a wide range in morphologies over the redshift range 0.2 < z < 1.3. High resolution spectroscopic data from Keck/DEIMOS observations are used to fix the redshift of all the galaxies in our sample. Using the HST/ACS and HST/WFC3 imaging data taken as a part of the CANDELS project, for each galaxy, we perform spectral energy distribution fitting per resolution element, producing resolved rest-frame U – V color, stellar mass, star formation rate (SFR), age, and extinction maps. We develop a technique to identify ''regions'' of statistical significance within individual galaxies, using their rest-frame color maps to select red and blue regions, a broader definition for what are called ''clumps'' in other works. As expected, for any given galaxy, the red regions are found to have higher stellar mass surface densities and older ages compared to the blue regions. Furthermore, we quantify the spatial distribution of red and blue regions with respect to both redshift and stellar mass, finding that the stronger concentration of red regions toward the centers of galaxies is not a significant function of either redshift or stellar mass. We find that the ''main sequence'' of star-forming galaxies exists among both red and blue regions inside galaxies, with the median of blue regions forming a tighter relation with a slope of 1.1 ± 0.1 and a scatter of ∼0.2 dex compared to red regions with a slope of 1.3 ± 0.1 and a scatter of ∼0.6 dex. The blue regions show higher specific SFRs (sSFRs) than their red counterparts with the sSFR decreasing since z ∼ 1, driven primarily by the stellar mass surface densities rather than the SFRs at a given resolution element.

  5. Kiloparsec-scale Properties of Emission-line Galaxies

    NASA Astrophysics Data System (ADS)

    Hemmati, Shoubaneh; Miller, Sarah H.; Mobasher, Bahram; Nayyeri, Hooshang; Ferguson, Henry C.; Guo, Yicheng; Koekemoer, Anton M.; Koo, David C.; Papovich, Casey

    2014-12-01

    We perform a detailed study of the resolved properties of emission-line galaxies at kiloparsec scales to investigate how small-scale and global properties of galaxies are related. We use a sample of 119 galaxies in the GOODS fields. The galaxies are selected to cover a wide range in morphologies over the redshift range 0.2 < z < 1.3. High resolution spectroscopic data from Keck/DEIMOS observations are used to fix the redshift of all the galaxies in our sample. Using the HST/ACS and HST/WFC3 imaging data taken as a part of the CANDELS project, for each galaxy, we perform spectral energy distribution fitting per resolution element, producing resolved rest-frame U - V color, stellar mass, star formation rate (SFR), age, and extinction maps. We develop a technique to identify "regions" of statistical significance within individual galaxies, using their rest-frame color maps to select red and blue regions, a broader definition for what are called "clumps" in other works. As expected, for any given galaxy, the red regions are found to have higher stellar mass surface densities and older ages compared to the blue regions. Furthermore, we quantify the spatial distribution of red and blue regions with respect to both redshift and stellar mass, finding that the stronger concentration of red regions toward the centers of galaxies is not a significant function of either redshift or stellar mass. We find that the "main sequence" of star-forming galaxies exists among both red and blue regions inside galaxies, with the median of blue regions forming a tighter relation with a slope of 1.1 ± 0.1 and a scatter of ~0.2 dex compared to red regions with a slope of 1.3 ± 0.1 and a scatter of ~0.6 dex. The blue regions show higher specific SFRs (sSFRs) than their red counterparts with the sSFR decreasing since z ~ 1, driven primarily by the stellar mass surface densities rather than the SFRs at a given resolution element.

  6. Evidence for a corona of beta Geminorum. [UV emission line

    NASA Technical Reports Server (NTRS)

    Gerola, H.; Shine, R.; Mcclintock, W.; Linsky, J. L.; Henry, R. C.; Moos, H. W.

    1974-01-01

    A spectrometer was used on the satellite Copernicus to observe a chromospheric L alpha emission from the K0 giant beta Gem at 1218.4 A. This emission appears to be in the corona at temperatures near 260,000 deg K, since the ion it is identified with requires 77.4 eV to be produced.

  7. LINE1 methylation levels in pre-diagnostic leukocyte DNA and future renal cell carcinoma risk

    PubMed Central

    Karami, Sara; Andreotti, Gabriella; Liao, Linda M; Pfeiffer, Ruth M; Weinstein, Stephanie J; Purdue, Mark P; Hofmann, Jonathan N; Albanes, Demetrius; Mannisto, Satu; Moore, Lee E

    2015-01-01

    Abstract Higher levels of LINE1 methylation in blood DNA have been associated with increased kidney cancer risk using post-diagnostically collected samples; however, this association has never been examined using pre-diagnostic samples. We examined the association between LINE1 %5mC and renal cell carcinoma (RCC) risk using pre-diagnostic blood DNA from the United States-based, Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial (PLCO) (215 cases/436 controls), and the Alpha-tocopherol, Beta-carotene Cancer Prevention Study (ATBC) of Finnish male smokers (191 cases/575 controls). Logistic regression adjusted for age at blood draw, study center, pack-years of smoking, body mass index, hypertension, dietary alcohol intake, family history of cancer, and sex was used to calculate odds ratios (ORs) and 95% confidence intervals (CIs) using cohort and sex-specific methylation categories. In PLCO, higher, although non-significant, RCC risk was observed for participants at or above median methylation level (M2) compared to those below the median (M1) (OR: 1.37, 95% CI: 0.96–1.95). The association was stronger in males (M2 vs. M1, OR: 1.54, 95% CI: 1.00–2.39) and statistically significant among male smokers (M2 vs. M1, OR: 2.60, 95% CI: 1.46–4.63). A significant interaction for smoking was also detected (P-interaction: 0.01). No association was found among females or female smokers. Findings for male smokers were replicated in ATBC (M2 vs. M1, OR: 1.31, 95% CI: 1.07–1.60). In a pooled analysis of PLCO and ATBC male smokers (281cases/755controls), the OR among subjects at or above median methylation level (M2) compared to those below the median (M1) was 1.89 (95% CI: 1.34–2.67, P-value: 3 x 10–4); a trend was also observed by methylation quartile (P-trend: 0.002). These findings suggest that higher LINE1 methylation levels measured prior to cancer diagnosis may be a biomarker of future RCC risk among male smokers. PMID:25647181

  8. Quality control agent: Self-adaptive laser vibrometry for on-line diagnostics

    NASA Astrophysics Data System (ADS)

    Serafini, S.; Paone, N.; Castellini, P.

    2012-06-01

    It is presented the development of a self-adaptive diagnostic system based on laser vibrometry for production line quality control. The vibration measurement system consists of a laser Doppler vibrometer, equipped with scanning mirrors and a smart camera, which implements self-adaptivity for compensating target mis-positioning under guidance by a vision system and for the achievement of the best condition for measurement by optimizing the Doppler signal level. This system is designed as a Quality Control Agent (QCA) and it is part of a Multi Agent System (MAS) that supervises all the production line. The QCA behavior is defined so to perform a minimization of measurement uncertainty during the on line tests; for this purpose the QCA exhibits a self-adaptive behavior. Best measurement conditions are defined in terms of amplitude of the optical Doppler beat signal (signal quality - SQ). In this paper, the optimization strategy for measurement enhancement achieved by the down-hill algorithm (Nelder-Mead algorithm) and its effect on signal quality improvement is discussed. Tests on a washing machine in controlled operating conditions allow to evaluate the efficacy of the method; significant reduction of noise on vibration velocity spectra is observed.

  9. Electron density diagnostics for gaseous nebulae involving the O 4 intercombination lines near 1400 A

    NASA Technical Reports Server (NTRS)

    Keenan, F. P.; Conlon, E. S.; Bowden, D. A.; Feibelman, W. A.; Pradhan, Anil K.

    1992-01-01

    Theoretical O IV electron density sensitive emission line ratios, determined using electron impact excitation rates calculated with the R-matrix code, are presented for R(sub 1) = I(1407.4 A)/I(1401.2 A), R(sub 2) = I(1404.8 A)/I(1401.2A), R(sub 3) = I(1399.8 A)/(1401.2 A), and R(sub 4) = I(1397.2 A)/I(1401.2 A). The observed values of R(sub 1)-R(sub 4), measured from high resolution spectra obtained with the International Ultraviolet Explorer (IUE) satellite, lead to electron densities that are compatible, and which are also in good agreement with those deduced from line ratios in other species. This provides observational support for the accuracy of the atomic data adopted in the present calculations.

  10. An atlas of Doppler emission-line tomography of cataclysmic variable stars

    NASA Technical Reports Server (NTRS)

    Kaitchuck, Ronald H.; Schlegel, Eric M.; Honeycutt, R. Kent; Horne, Keith; Marsh, T. R.; White, J. C., II; Mansperger, Cathy S.

    1994-01-01

    Doppler emission-line tomography is a technique similar to medical tomography. In this atlas the emission-line profiles of cataclysmic variable stars, seen at different orbital phases, are transformed into velocity space images. This transformation makes many of the complex line profile changes easier to interpret. The emission contributions of the disk and the s-wave are clearly separated in these images, and any emission from the stream and the secondary star can often be identified. In this atlas, Doppler tomograms of Hbeta, He I lambda 4471, and He II lambda 4686 emission lines of 18 cataclysmic variable stars are presented. The Doppler images provide insights into the individual systems and a better technique for measuring and radial velocity amplitude of the white dwarf.

  11. Cosmic rays and the emission line regions of active galactic nuclei

    NASA Technical Reports Server (NTRS)

    Ferland, G. J.; Mushotzky, R. F.

    1984-01-01

    The effects that the synchrotron emitting relativistic electrons could have on the emission line regions which characterize active nuclei are discussed. Detailed models of both the inner, dense, broad line region and the outer, lower density, narrow line region are presented, together with the first models of the optically emitting gas often found within extended radio lobes. If the relativistic gas which produces the synchrotron radio emission is mixed with the emission line region gas then significant changes in the emission line spectrum will result. The effects of the synchrotron emitting electrons on filaments in the Crab Nebula are discussed in an appendix, along with a comparison between the experimental calculations, which employ the mean escape probability formalism, and recent Hubbard and Puetter models.

  12. Emission line eclipse mapping of velocity fields in dwarf nova accretion discs

    NASA Astrophysics Data System (ADS)

    Makita, M.; Mineshige, S.

    2002-01-01

    We propose a new method, emission-line eclipse mapping, to map the velocity fields in an accretion disc. We apply the usual eclipse mapping technique to the light curves at each of 12-24 wavelengths across the line center to map the region with same line-of-sight velocity, from which we are able to plot the rotational velocity as a function of radius on the assumption of axisymmetric disc. We calculate time changes of the emission line profiles, assuming Keplerian rotation fields (vvarphi propto r-1/2) and the emissivity distribution of j propto r-3/2, and reconstruct emissivity profiles. The results show typically a `two-eye' pattern for high line-of-sight velocities and we can recover the relation, vvarphi propto d-1/2, where d is the separation of two lq eyes.'

  13. Electron Bernstein wave emission based diagnostic on National Spherical Torus Experiment (invited)

    SciTech Connect

    Diem, S. J.; Taylor, G.; Efthimion, P.; Kugel, H.; LeBlanc, B. P.; Caughman, J. B.; Wilgen, J.; Preinhaelter, J.; Urban, J.

    2008-10-15

    National Spherical Torus Experiment (NSTX) is a spherical tokamak (ST) that operates with n{sub e} up to 10{sup 20} m{sup -3} and B{sub T} less than 0.6 T, cutting off low harmonic electron cyclotron (EC) emission widely used for T{sub e} measurements on conventional aspect ratio tokamaks. The electron Bernstein wave (EBW) can propagate in ST plasmas and is emitted at EC harmonics. These properties suggest thermal EBW emission (EBE) may be used for local T{sub e} measurements in the ST. Practically, a robust T{sub e}(R,t) EBE diagnostic requires EBW transmission efficiencies of >90% for a wide range of plasma conditions. EBW emission and coupling physics were studied on NSTX with an obliquely viewing EBW to O-mode (B-X-O) diagnostic with two remotely steered antennas, coupled to absolutely calibrated radiometers. While T{sub e}(R,t) measurements with EBW emission on NSTX were possible, they were challenged by several issues. Rapid fluctuations in edge n{sub e} scale length resulted in >20% changes in the low harmonic B-X-O transmission efficiency. Also, B-X-O transmission efficiency during H modes was observed to decay by a factor of 5-10 to less than a few percent. The B-X-O transmission behavior during H modes was reproduced by EBE simulations that predict that EBW collisional damping can significantly reduce emission when T{sub e}<30 eV inside the B-X-O mode conversion (MC) layer. Initial edge lithium conditioning experiments during H modes have shown that evaporated lithium can increase T{sub e} inside the B-X-O MC layer, significantly increasing B-X-O transmission.

  14. Electron Bernstein Wave Emission Based Diagnostic on National Spherical Torus Experiment

    SciTech Connect

    Diem, S.; Taylor, G.; Caughman, John B; Efthimion, P. C.; Kugel, H.; LeBlanc, B; Preinhaelter, J.; Sabbagh, S. A.; Urban, J; Wilgen, John B

    2008-01-01

    National Spherical Torus Experiment (NSTX) is a spherical tokamak (ST) that operates with n(e) up to 10(20) m(-3) and B(T) less than 0.6 T, cutting off low harmonic electron cyclotron (EC) emission widely used for T(e) measurements on conventional aspect ratio tokamaks. The electron Bernstein wave (EBW) can propagate in ST plasmas and is emitted at EC harmonics. These properties suggest thermal EBW emission (EBE) may be used for local T(e) measurements in the ST. Practically, a robust T(e)(R,t) EBE diagnostic requires EBW transmission efficiencies of >90% for a wide range of plasma conditions. EBW emission and coupling physics were studied on NSTX with an obliquely viewing EBW to O-mode (B-X-O) diagnostic with two remotely steered antennas, coupled to absolutely calibrated radiometers. While T(e)(R,t) measurements with EBW emission on NSTX were possible, they were challenged by several issues. Rapid fluctuations in edge n(e) scale length resulted in >20% changes in the low harmonic B-X-O transmission efficiency. Also, B-X-O transmission efficiency during H modes was observed to decay by a factor of 5-10 to less than a few percent. The B-X-O transmission behavior during H modes was reproduced by EBE simulations that predict that EBW collisional damping can significantly reduce emission when T(e)< 30 eV inside the B-X-O mode conversion (MC) layer. Initial edge lithium conditioning experiments during H modes have shown that evaporated lithium can increase T(e) inside the B-X-O MC layer, significantly increasing B-X-O transmission.

  15. Electron Bernstein wave emission based diagnostic on National Spherical Torus Experiment (invited)

    SciTech Connect

    Diem, S.; Taylor, G.; Caughman, John B; Efthimion, P. C.; Kugel, H.; LeBlanc, B; Preinhaelter, J.; Sabbagh, S. A.; Urban, J

    2008-01-01

    National Spherical Torus Experiment (NSTX) is a spherical tokamak (ST) that operates with n(e) up to 10(20) m(-3) and B-T less than 0.6 T, cutting off low harmonic electron cyclotron (EC) emission widely used for T-e measurements on conventional aspect ratio tokamaks. The electron Bernstein wave (EBW) can propagate in ST plasmas and is emitted at EC harmonics. These properties suggest thermal EBW emission (EBE) may be used for local T-e measurements in the ST. Practically, a robust T-e(R,t) EBE diagnostic requires EBW transmission efficiencies of >90% for a wide range of plasma conditions. EBW emission and coupling physics were studied on NSTX with an obliquely viewing EBW to O-mode (B-X-O) diagnostic with two remotely steered antennas, coupled to absolutely calibrated radiometers. While T-e(R,t) measurements with EBW emission on NSTX were possible, they were challenged by several issues. Rapid fluctuations in edge n(e) scale length resulted in >20% changes in the low harmonic B-X-O transmission efficiency. Also, B-X-O transmission efficiency during H modes was observed to decay by a factor of 5-10 to less than a few percent. The B-X-O transmission behavior during H modes was reproduced by EBE simulations that predict that EBW collisional damping can significantly reduce emission when T-e < 30 eV inside the B-X-O mode conversion (MC) layer. Initial edge lithium conditioning experiments during H modes have shown that evaporated lithium can increase T-e inside the B-X-O MC layer, significantly increasing B-X-O transmission.

  16. Stability of narrow emission line clouds in active galactic nuclei

    SciTech Connect

    Mathews, W.G.; Veilleux, S.

    1989-01-01

    The effects of the lateral flow and Rayleigh-Taylor instabilities on clouds in the narrow-line region of active galaxies are considered using cloud densities and velocities based on observations. A simplified model for the lateral flow instability governed only by overpressures is discussed. The associated radiative acceleration is considered, and parameters describing the narrow-line region and the central nonstellar continuum are presented. It is shown that many otherwise acceptable narrow-line clouds are unstable to lateral flows, particularly if their column depths are small. It is argued that the most likely narrow-line clouds have column densities of about 10 to the 23rd/sq cm and that these clouds are accelerated by winds in the intercloud medium. Arguments are made against models in which narrow-line clouds move inward. 22 references.

  17. Skylab ultraviolet stellar spectra - Emission lines from the Beta Lyrae system

    NASA Technical Reports Server (NTRS)

    Kondo, Y.; Parsons, S. B.; Wray, J. D.; Benedict, G. F.; Henize, K. G.; Mccluskey, G. E.

    1976-01-01

    Observations of Beta Lyr with the Skylab S-019 ultraviolet objective-prism spectrograph show numerous emission lines in the region from 1400 to 2300 A. Some variations in line strength between phases 0.25 and 0.50 are seen, which probably explain the shallowness of the OAO-2 light curve at 1910 A. Many of the emission lines are probably due to intercombination transitions, thus confirming the concept that the emission is produced by collisional excitation in low-density clouds of hot gas.

  18. Laboratory Measurements of the X-ray Line Emission from Neon-like Fe XVII

    NASA Technical Reports Server (NTRS)

    Brown, G. V.; Beiersdorfer, P.; Chen, H.; Scofield, J. H.; Boyce, K. R.; Kelley, R. L.; Kilbourne, C. A.; Porter, F. S.; Gu, M. F.; Kahn, S. M.

    2006-01-01

    We have conducted a systematic study of the dominant x-ray line emission from Fe XVII. These studies include relative line intensities in the optically thin limit, intensities in the presence of radiation from satellite lines from lower charge states of iron, and the absolute excitation cross sections of some of the strongest lines. These measurements were conducted at the Lawrence Livermore National Laboratory electron beam ion trap facility using crystal spectrometers and a NASA-Goddard Space Flight Center microcalorimeter array.

  19. Diagnostic odyssey in severe neurodevelopmental disorders: toward clinical whole-exome sequencing as a first-line diagnostic test.

    PubMed

    Thevenon, J; Duffourd, Y; Masurel-Paulet, A; Lefebvre, M; Feillet, F; El Chehadeh-Djebbar, S; St-Onge, J; Steinmetz, A; Huet, F; Chouchane, M; Darmency-Stamboul, V; Callier, P; Thauvin-Robinet, C; Faivre, L; Rivière, J B

    2016-06-01

    The current standard of care for diagnosis of severe intellectual disability (ID) and epileptic encephalopathy (EE) results in a diagnostic yield of ∼50%. Affected individuals nonetheless undergo multiple clinical evaluations and low-yield laboratory tests often referred to as a 'diagnostic odyssey'. This study was aimed at assessing the utility of clinical whole-exome sequencing (WES) in individuals with undiagnosed and severe forms of ID and EE, and the feasibility of its implementation in routine practice by a small regional genetic center. We performed WES in a cohort of 43 unrelated individuals with undiagnosed ID and/or EE. All individuals had undergone multiple clinical evaluations and diagnostic tests over the years, with no definitive diagnosis. Sequencing data analysis and interpretation were carried out at the local molecular genetics laboratory. The diagnostic rate of WES reached 32.5% (14 out of 43 individuals). Genetic diagnosis had a direct impact on clinical management in four families, including a prenatal diagnostic test in one family. Our data emphasize the clinical utility and feasibility of WES in individuals with undiagnosed forms of ID and EE and highlight the necessity of close collaborations between ordering physicians, molecular geneticists, bioinformaticians and researchers for accurate data interpretation. PMID:26757139

  20. WFPC2 LRF Imaging of Emission-Line Nebulae in 3CR Radio Galaxies

    NASA Astrophysics Data System (ADS)

    Privon, G. C.; O'Dea, C. P.; Baum, S. A.; Axon, D. J.; Kharb, P.; Buchanan, C. L.; Sparks, W.; Chiaberge, M.

    2008-04-01

    We present Hubble Space Telescope WFPC2 Linear Ramp Filter images of high surface brightness emission lines (either [O II], [O III], or H α + [N II]) in 80 3CR radio sources. We overlay the emission-line images on high-resolution VLA radio images (eight of which are new reductions of archival data) in order to examine the spatial relationship between the optical and radio emission. We confirm that the radio and optical emission-line structures are consistent with weak alignment at low redshift (z < 0.6) except in the compact steep-spectrum (CSS) radio galaxies where both the radio source and the emission-line nebulae are on galactic scales and strong alignment is seen at all redshifts. There are weak trends for the aligned emission-line nebulae to be more luminous and for the emission-line nebula size to increase with redshift and/or radio power. The combination of these results suggests that there is a limited but real capacity for the radio source to influence the properties of the emission-line nebulae at these low redshifts (z < 0.6). Our results are consistent with previous suggestions that both mechanical and radiant energy are responsible for generating alignment between the radio source and emission-line gas. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 05-26555. These observations are associated with program 5957.

  1. Al-26: A galactic source of gamma ray line emission

    NASA Technical Reports Server (NTRS)

    Ramaty, R.; Lingenfelter, R. E.

    1976-01-01

    It is shown that Al26 is a very good candidate for producing a detectable gamma-ray line, and that this line is not only intense but also very narrow. By examining the chart of nuclides for other radioactive isotopes which could produce hiterto unnoticed gamma-ray lines following nucleosynthesis, it is found that for mass numbers less than 60, the isotopes Na22, Al26, K40, Ar42, Ti44, Sc46, Mn54, Co56, Co57, Co58, Co60 and Fe60 are the only ones with sufficiently long half lives (70) days to produce gamma rays in optically thin regions.

  2. Evidence for Supermassive Black Holes in Active Galactic Nuclei from Emission-Line Reverberation

    NASA Technical Reports Server (NTRS)

    Peterson, Bradley M.; Wandel, Amri

    2000-01-01

    Emission-line variability data for Seyfert 1 galaxies provide strong evidence for the existence of supermassive black holes in the nuclei of these galaxies and that the line-emitting gas is moving in the gravitational potential of that black hole. The time-delayed response of the emission lines to continuum variations is used to infer the size of the line-emitting region, which is then combined with measurements of the Doppler widths of the variable line components to estimate a virial mass. la the case of the best-studied galaxy, NGC 5548, various emission lines spanning an order of magnitude in distance from the central source show the expected V proportional to r(sup -l/2) correlation between distance and line width and are thus consistent with a single value for the mass. Two other Seyfert galaxies, NGC 7469 and 3C 390.3, show a similar relationship. We compute the ratio of luminosity to mass for these three objects and the narrow-line Seyfert I galaxy NGC 4051 and find that the gravitational force on the line-emitting gas is much stronger than radiation pressure. These results strongly support the paradigm of gravitationally bound broad emission line region clouds.

  3. Emission line tomography of the short period cataclysmic variables CC Scl and V2051 Oph

    NASA Astrophysics Data System (ADS)

    Longa-Peña, P.; Steeghs, D.; Marsh, T.

    2015-02-01

    We present time series spectroscopy of two short period cataclysmic variables, CC Scl and V2051 Oph, to test the efficiency of Doppler-tomography-based methods in constraining orbital parameters of evolved cataclysmic variables. We find that the Ca II triplet lines offer superior diagnostics, revealing emission components from the mass donors and sharp images of the accretion discs. Furthermore, we use Monte Carlo methods to estimate the uncertainties from ensembles of Doppler maps. We compare our new methods against traditional radial velocity methods and show that they offer a valid route towards system parameter determination. Our analysis of CC Scl suggests a low mass ratio of q = 0.08 ± 0.03 with a primary velocity of K1 = 37 ± 14 km s-1. This mass ratio is in between the pre- and post-period minimum status, however our K1 solution favours a post-period minimum system. Our derived parameters for V2051 Oph (q = 0.18 ± 0.05, K1 = 97 ± 10 km s-1) are in agreement with the eclipse solution (q = 0.19 ± 0.03), offering a direct validation of our methods.

  4. X-ray Emission and Absorption Lines During the SSS Phase of RS Ophiuchi

    NASA Astrophysics Data System (ADS)

    Schönrich, R. A.; Ness, J.-U.

    2008-12-01

    The high-resolution X-ray spectra of the sixth outburst of RS Ophiuchi revealed P Cygni-like line profiles. We use the column densities of selected isolated absorption lines to derive the nitrogen-to-oxygen abundance ratio. We next discuss the origin of the emission lines, which may originate from the shock, and the absorption and emission lines may thus have a different formation history. Finally, we discuss the correlation of high-amplitude variability detected during the early SSS phase with variability in the hardness ratio that follows the same pattern but is shifted by 1000~sec.

  5. Molecular line emission in asymmetric envelopes of evolved stars

    NASA Astrophysics Data System (ADS)

    Sanchez, Andres Felipe Perez

    2014-06-01

    Stars with initial masses of 0.8 < M⊙ < 9M⊙ eject most of their mass when evolving along the asymptotic giant branch (AGB) phase. The ejected material eventually cools down, which leads it to condensate and to form dust grains and molecular gas around the star, creating an extended circumstellar envelope (CSE). The mechanism responsible for the expansion of the dusty and dense CSEs is not completely understood. It is suggested that stellar radiation pressure on the dust particles can accelerate them outwards. Then, by collisional exchange of momentum, the dust particles drag along the molecular gas. However, this scenario cannot explain the onset of asymmetries in the CSEs observed towards more evolved sources such as post-AGB sources and Planetary nebulae. Part of the research in this thesis is focused on the study of the role that the stellar magnetic field plays on the formation of the collimated high-velocity outflows observed towards post-AGB sources. Polarized maser emission towards (post-)AGB stars has become an useful tool to determine the properties of the stellar magnetic fields permeating their CSEs. However, the polarization fraction detected can be affected by non-Zeeman effects. Here I present the results of our analysis of the polarization properties of SiO, H2O and HCN maser emission in the (sub-)millimetre wavelength range. The goal of this analysis is to determine whether polarized maser emission of these molecular species can be used as reliable tracer of the magnetic field from observations at (sub-)millimetre wavelengths. I also present the results of radio interferometric observations of both continuum and polarized maser emission towards post-AGB stars. The sources observed are characterized by H2O maser emission arising from their collimated, high-velocity outflows. The observations have been carried out with the Australian Telescope Compact Array aiming to detect both polarized maser emission and non-thermal radio continuum emission

  6. Diesel combustion and emissions formation using multiple 2-D imaging diagnostics

    SciTech Connect

    Dec, J.E.

    1997-12-31

    Understanding how emissions are formed during diesel combustion is central to developing new engines that can comply with increasingly stringent emission standards while maintaining or improving performance levels. Laser-based planar imaging diagnostics are uniquely capable of providing the temporally and spatially resolved information required for this understanding. Using an optically accessible research engine, a variety of two-dimensional (2-D) imaging diagnostics have been applied to investigators of direct-injection (DI) diesel combustion and emissions formation. These optical measurements have included the following laser-sheet imaging data: Mie scattering to determine liquid-phase fuel distributions, Rayleigh scattering for quantitative vapor-phase-fuel/air mixture images, laser induced incandescence (LII) for relative soot concentrations, simultaneous LII and Rayleigh scattering for relative soot particle-size distributions, planar laser-induced fluorescence (PLIF) to obtain early PAH (polyaromatic hydrocarbon) distributions, PLIF images of the OH radical that show the diffusion flame structure, and PLIF images of the NO radical showing the onset of NO{sub x} production. In addition, natural-emission chemiluminescence images were obtained to investigate autoignition. The experimental setup is described, and the image data showing the most relevant results are presented. Then the conceptual model of diesel combustion is summarized in a series of idealized schematics depicting the temporal and spatial evolution of a reacting diesel fuel jet during the time period investigated. Finally, recent PLIF images of the NO distribution are presented and shown to support the timing and location of NO formation hypothesized from the conceptual model.

  7. A Suzaku Observation of the Neutral Fe-line Emission from RCW 86

    NASA Technical Reports Server (NTRS)

    Ueno, Masaru; Sato, Rie; Kataoka, Jun; Bamba, Aya; Harrus, Ilana; Hiraga, Junko; Hughes, John P.; Kilbourne, Caroline A.; Koyama, Katsuji; Kokubun, Motohide; Nakajima, Hiroshi; Ozaki, Masanobu; Petre, Robert; Takahashi, Tadayuki; Tanaka, Takaaki; Tomida, Hiroshi; Yamaguchi, Hiroya

    2007-01-01

    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 emission line first detected with the Advanced Satellite for Cosmology and Astronomy (ASCA). The new data confirms the existence of the line, localizing it for the first time inside a low temperature emission region and not at the locus of the continuum hard X-ray emission. We also report the first detection of a 7.1 keV line that we interpret as the K(beta) emission from neutral or low-ionized iron. The Fe-K line 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) line is intrinsically broadened 47 (35-57) eV (99% error region). Cr-K line is also marginally detected, which is supporting the ejecta origin for the Fe-K line. By showing that the hard continuum above 3 keV has different spatial distribution from the Fe-K line, we confirmed it to be synchrotron X-ray emission.

  8. Observations of the 145.5 micron (OI) emission line in the Orion nebula

    NASA Technical Reports Server (NTRS)

    Stacey, G. J.; Smyers, S. D.; Kurtz, N. T.; Harwit, M.

    1982-01-01

    A first set of observations of the (OI) 3P to 3P1 (145.5 micron) transition was obtained. The line was observed both in a beam centered on the Trapezium, and in a 7 times wider beam encompassing most of the Orion Nebula. A wide beam map of the region was constructed which shows that most of the emission is confined to the central regions of the nebula. These observations may be compared with reported measurement of the 3P1 to 3P2 (63.2 micron) transition in Orion and are consistent with optically thin emission in the 145.5 micron line and self-adsorbed 63.2 micron emission lines. Mechanisms are discussed for the excitation of neutral oxygen. It is included that much of the observed emission originates in the thin, radio-recombination-line-emitting CII/HI envelope bordering on the HII region.

  9. Quantum degeneracy corrections to plasma line emission and to Saha equation

    NASA Astrophysics Data System (ADS)

    Molinari, V. G.; Mostacci, D.; Rocchi, F.; Sumini, M.

    2003-09-01

    The effect of quantum degeneracy on the electron collisional excitation is investigated, and its effects on line emission evaluated for applications to spectroscopy of dense, cold plasmas. A correction to Saha equation for weakly-degenerate plasmas is also presented.

  10. Theoretical quasar emission-line ratios. VII - Energy-balance models for finite hydrogen slabs

    NASA Technical Reports Server (NTRS)

    Hubbard, E. N.; Puetter, R. C.

    1985-01-01

    The present energy balance calculations for finite, isobaric, hydrogen-slab quasar emission line clouds incorporate probabilistic radiative transfer (RT) in all lines and bound-free continua of a five-level continuum model hydrogen atom. Attention is given to the line ratios, line formation regions, level populations and model applicability results obtained. H lines and a variety of other considerations suggest the possibility of emission line cloud densities in excess of 10 to the 10th/cu cm. Lyman-beta/Lyman-alpha line 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.

  11. First detection of line emission from the hot interstellar medium with solid state detectors

    NASA Technical Reports Server (NTRS)

    Schnopper, H. W.; Delvaille, J. P.; Rocchia, R.; Blondel, C.; Cheron, C.; Christy, J. C.; Ducros, R.; Koch, L.; Rothenflug, R.

    1981-01-01

    Previously reported enhanced soft X-ray emission from the North-Galactic Polar region supports the theory of a hot interstellar component. This paper reports the first detection of line emission from the hot interstellar component in the North-Galactic-Polar region. Measurements were made with solid state Si(Li) detectors aboard a spin-stabilized rocket launched from the White Sands Missile Range on March 22, 1980. Two features are clearly present in the low energy portion of the spectrum derived from the data. They correspond to emission lines from C V (300 eV) and C VI (360 eV), and from O VII (560 eV) and O VIII (650 eV). The detection of emission lines coming from these highly stripped ions is direct evidence for the thermal origin of the emission and confirms the presence of a hot (1-million K) component in the interstellar medium.

  12. Virilization of the Broad Line Region in Active Galactic Nuclei—connection between shifts and widths of broad emission lines

    NASA Astrophysics Data System (ADS)

    Jonić, S.; Kovačević-Dojčinović, J.; Ilić, D.; Popović, L. Č.

    2016-03-01

    We investigate the virilization of the emission lines {Hβ } and Mg II in the sample of 287 Type 1 Active Galactic Nuclei taken from the Sloan Digital Sky Survey database. We explore the connections between the intrinsic line shifts and full widths at different levels of maximal intensity. We found that: (i) {Hβ} seems to be a good virial estimator of black hole masses, and an intrinsic redshift of {Hβ} is dominantly caused by the gravitational effect, (ii) there is an anti-correlation between the redshift and width of the wings of the Mg II line, (iii) the broad Mg II line can be used as virial estimator only at 50 % of the maximal intensity, while the widths and intrinsic shifts of the line wings cannot be used for this purpose.

  13. Iron Emission Lines in the Spectra of Classical T Tauri Stars

    NASA Astrophysics Data System (ADS)

    Beristain, G.; Edwards, S.; Hartigan, P.

    1993-05-01

    The optical and infrared continuum emission excesses in classical T Tauri stars are frequently attributed to accretion disks with characteristic mass accretion rates of 10(-7) Msun yr(-1) . The spectra of classical T Tauri stars are also rich in emission lines, arising from both permitted and forbidden atomic species, which have been attributed to formation in regions as diverse as chromospheres, boundary layers, winds and collimated jets. We have conducted a high resolution spectroscopic survey of 48 T Tauri stars in the Tau-Aur star formation complex covering the wavelength range 3900{\\kern.2em Angstroms} to 7000{\\kern.2em Angstroms} with the aim of determining the origin of the various emission lines and report here on the most prominent metallic species present in the T Tauri spectra, Fe I and Fe II. From our spectra we have both 1) determined the level of optical continuum emission, expressed as the ratio of `veiling' to photospheric flux, and 2) extracted residual Fe emission line profiles, free of contamination from underlying photospheric features. We find that Fe I, II emission is seen only in T Tauri stars which have infrared and optical continuum emission excesses attributed to accretion disks; none of the `weak-line' T Tauri stars, with photospheric IR colors and no optical veiling, have detectable Fe emission. Correlations of Fe emission equivalent widths with both K-L and the ratio of veiling to photospheric flux, r, suggest that the Fe lines arise as a result of accretion related activity. DR Tau's rich emission line spectra permit study of the largest number of unblended Fe I,II profiles, for which we have spectra covering 5 different nights. Multiplet line ratios indicate the Fe lines are optically thick, and line luminosities imply emitting areas covering a few percent of the stellar surface. The lines are typically broad and symmetric, although inverse P Cygni structure in Fe II is seen on one night. For 4 nights, the Fe I and Fe II lines

  14. LZIFU: IDL emission line fitting pipeline for integral field spectroscopy data

    NASA Astrophysics Data System (ADS)

    Ho, I.-Ting

    2016-07-01

    LZIFU (LaZy-IFU) is an emission line fitting pipeline for integral field spectroscopy (IFS) data. Written in IDL, the pipeline turns IFS data to 2D emission line flux and kinematic maps for further analysis. LZIFU has been applied and tested extensively to various IFS data, including the SAMI Galaxy Survey, the Wide-Field Spectrograph (WiFeS), the CALIFA survey, the S7 survey and the MUSE instrument on the VLT.

  15. Search with Copernicus for ultraviolet emission lines in the planetary nebula NGC 3242

    NASA Technical Reports Server (NTRS)

    Schwartz, R. D.; Snow, T. P., Jr.; Upson, W. L., II

    1978-01-01

    The high-excitation planetary nebula NGC 3242 has been observed with the ultraviolet telescope-spectrometer aboard Copernicus. Wavelength intervals corresponding to the emission lines 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 emission-line fluxes from this object.

  16. Emission Line Spectra in the Soft X-ray Region 20 - 75 Angstroms

    NASA Technical Reports Server (NTRS)

    Lepson, J. K.; Beiersdorfer, P.; Chen, H.; Behar, E.; Kahn, S. M.

    2002-01-01

    As part of a project to complete a comprehensive catalogue of astrophysically relevant emission lines in support of new-generation X-ray observatories using the Lawrence Livermore electron beam ion traps EBIT-I and EDIT-II, emission lines of argon and sulfur in the soft X-ray and extreme ultraviolet region were studied. Observations of Ar IX through Ar XVI and S VII through S XIV between 20 and 75 Angstrom are presented to illustrate our work.

  17. Emission Line Spectra in the Soft X-Ray Region 20-75 (Angstrom)

    SciTech Connect

    Lepson, J K; Beiersdorfer, P; Chen, H; Behar, E; Kahn, S M

    2002-06-18

    As part of a project to complete a comprehensive catalogue of astrophysically relevant emission lines in support of new-generation X-ray observatories using the Lawrence Livermore electron beam ion traps EBIT-I and EBIT-II, we studied emission lines of argon and sulfur in the soft X-ray and extreme ultraviolet region. Here we present observations of Ar IX through Ar XVI and S VII through S XIV between 20 and 75 {angstrom} to illustrate our work.

  18. Improved Beam Diagnostic Spatial Calibration Using In-Situ Measurements of Beam Emission

    NASA Astrophysics Data System (ADS)

    Chrystal, C.; Burrell, K. H.; Pace, D. C.; Grierson, B. A.; Pablant, N. A.

    2014-10-01

    A new technique has been developed for determining the measurement geometry of the charge exchange recombination spectroscopy diagnostic (CER) on DIII-D. This technique removes uncertainty in the measurement geometry related to the position of the neutral beams when they are injecting power. This has been accomplished by combining standard measurements that use in-vessel calibration targets with spectroscopic measurements of Doppler shifted and Stark split beam emission to fully describe the neutral beam positions and CER views. A least squares fitting routine determines the measurement geometry consistent with all the calibration data. The use of beam emission measurements allows the position of the neutral beams to be determined in-situ by the same views that makeup the CER diagnostic. Results indicate that changes in the measurement geometry are required to create a consistent set of calibration measurements. However, changes in quantities derived from the geometry, e.g. ion temperature gradient and poloidal rotation, are small. Work supported by the US DOE under DE-FG02-07ER54917, DE-FC02-04ER54698, and DE-AC02-09H11466.

  19. Diagnostics of nitrogen plasma by trace rare-gas-optical emission spectroscopy

    SciTech Connect

    Qayyum, A.; Zeb, Shaista; Naveed, M.A.; Ghauri, S.A.; Zakaullah, M.; Waheed, A.

    2005-11-15

    Trace rare-gas-optical emission spectroscopy is carried out to characterize the nitrogen plasma as a function of discharge parameters. The functional dependence of N{sub 2}(C {sup 3}{pi}{sub u}) and N{sub 2}{sup +}(B {sup 2}{sigma}{sub u}{sup +}) excited states is monitored by measuring the emission intensities of the bandheads of second positive and first negative systems. The excited-state population density of N atoms and N{sub 2} molecules, extracted from their optical emission, is related to the ground-state population density after normalizing the changes for excitation cross section and electron energy distribution function by optical actinometry. The electron temperature is determined from the plasma-induced optical emission of trace rare gas by the line-to-line method. The obtained data may help us to adjust the optimum discharge conditions for the production of active species, which are considered to be important for the desired treatment of the samples.

  20. X-ray secondary heating and ionization in quasar emission-line clouds

    NASA Technical Reports Server (NTRS)

    Shull, J. M.; Van Steenberg, M. E.

    1985-01-01

    Accurate Monte Carlo computations of the X-ray secondary electron heating, ionization, and excitation of H and He gas in interstellar space and in quasar emission-line clouds, are presented. The fraction of energy deposited in each form is sensitive to the background ionization fraction, x = n(H+)/n(Htot), and can affect the temperature, ionization state, and line emissivities at large depths in X-ray photoionized clouds. Analytic fits are provided for these energy fractions over the range 0.0001-1 for primary electron energies up to many keV. In both broad-line and narrow-line clouds, emission lines sensitive to the energy budget and electron density may be strongly affected.

  1. Package for Interactive Analysis of Line Emission (Analysis of UV-X-Ray High-Resolution Emission Spectra)

    NASA Technical Reports Server (NTRS)

    Hunter, Paul (Technical Monitor); Kashyap, Vinay

    2004-01-01

    The Package for Interactive Analysis of Line Emission (PINTofALE) is a suite of IDL routines designed to carry out spectroscopic analysis of high-resolution X-ray spectra. The current version is 1.5, and will shortly be upgraded to v2. A detailed description of the package, together with detailed documentation, example walk-throughs, science threads, and downloadable tar files, are available on-line.

  2. Far-infrared line emission from the galaxy. Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Stacey, G. J.

    1985-01-01

    The diffuse 157.74 micron (CII) emission 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) emission profiles follow closely the nearby (12)CO (J=1to0) emission profiles. The (CII) emission 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 emission in other far-infrared (FIR) cooling lines. The (CII) line was found to be the dominant FIR emission line from the galaxy and the primary coolant for the warm neutral gas near the galactic plane. Other cooling lines predicted to be prominent in the galactic spectrum are discussed. The 145.53 micron (OI) emission line from the Orion nebula was also measured.

  3. Escape factors for Paschen 2p–1s emission lines in low-temperature Ar, Kr, and Xe plasmas

    NASA Astrophysics Data System (ADS)

    Zhu, Xi-Ming; Cheng, Zhi-Wen; Pu, Yi-Kang; Czarnetzki, Uwe

    2016-06-01

    Radiation trapping phenomenon is often observed when investigating low-temperature plasmas. Photons emitted from the upper excited states may be reabsorbed by the lower states before they leave the plasmas. In order to account for this effect in the modelling and optical diagnostics of plasmas, either an ‘escape factor’ of a function of the optical depth or a strict solution of the radiation transfer equation can be employed. However, the former is more convenient in comparison and thus is widely adopted. Previous literatures have provided several simple expressions of the escape factor for the uniform plasmas. The emission line profiles are assumed to be dominated by the Doppler broadening, and the line splitting due to the hyperfine structure is not considered. This kind of expression is only valid for small atoms, e.g. Ar in low-pressure uniform discharges. Actually, the excited state density in many of the low-temperature plasmas is non-uniform and the emission line profile can be significantly influenced by the collisional broadening at medium and high pressures. In these cases, a new escape factor equation should be calculated. In this work, we study the escape factor equations for the often used 2p–1s transitions (Paschen’s notation) of the Ar, Kr, and Xe atoms. Possible non-uniform density profiles are considered. In addition, we include the line splitting due to the hyperfine structure for Kr and Xe. For the low-pressure plasmas, an escape factor expression mainly based on the Gaussian line profile is given and particularly verified by an experiment in a low-pressure capacitive discharge. For the high-pressure plasmas, an equation based on the Voigt line profile is also calculated. In this way, the new escape factor expression is ready for use in the modelling of the Ar, Kr, and Xe plasmas from low to atmospheric pressure.

  4. An intelligent systems approach for on-line power plant efficiency, emisions, and maintenance diagnostics

    SciTech Connect

    Hunt, M.; Williams, S.; Hickok, K.

    1995-06-01

    The Fossil Thermal performance Advisor{sup TM} (FTPA{sup TM}), developed by New York State Electric & Gas Corporation (NYSEG) and personnel from DHR Technologies, Inc. (DHR), is an advanced, on-line Electronic Performance Support System (EPSS) that helps fossil power plant operators, performance engineers, and plant managers improve daily plant operations. The FTPA uses an intelligent systems approach to identify existing and potential heat rate, emissions, and maintenance-related problems early, and to provide recommendations to help plant staff reduce costs related to these problems. The FTPA has been installed in several plants throughout the United States and abroad, most recently at NYSEG`s Greenridge Station, Unit No. 4. Currently, another system is being installed at Portland General Electric`s Boardman Station. This paper examines advances in the FTPA architecture designed to significantly reduce installation costs while increasing the benefits provided by the FTPA for smaller pulverized coal units, such as Greenidge Unit No. 4.

  5. ESO089-G018 and ESO089-G019: long-slit spectroscopy of emission-line galaxies

    NASA Astrophysics Data System (ADS)

    da Rocha-Poppe, P. C.; Faúndez-Abans, M.; Fernandes-Martin, V. A.; Fernandes, I. F.; de Oliveira-Abans, M.; Rodrígues-Ardila, A.

    2010-03-01

    We present the first spectroscopic observations for the galaxies ESO089-G018 (hereafter G18, an Sb(?)-type galaxy seen nearly edge-on) and ESO089-G019 (hereafter G19, an SA(s): a peculiar galaxy), extracted from the sample of ring-shaped galaxies compiled in Faúndez-Abans & de Oliveira-Abans. The main goal of this work is to investigate the spectral classification using the three line-ratio diagrams, called diagnostic diagrams, of Veilleux & Osterbrock. However, in order to separate the different types of galaxies [HII galaxies, Seyfert 2 galaxies and low-ionization nuclear emission-line region galaxies (LINERs)] we have to used empirical boundaries between them. Based on the observed spectra, we suggest G18 is a `weak-[OI] LINER' or even a `transition object' or LINER/HII. In the case of G19, we see Hβ in absorption and no [OIII] lines, impeding the [OIII]/Hβ ratio to be estimated. However, other lines ratios have been evaluated for the discussion. We classify the nature of G19 as ambiguous, because of the difficulty in determining its ionizing source (narrow-line active galactic nuclei or HII galaxies) in different diagnostic diagrams. The errors in the fluxes were mostly caused by uncertainties in the placement of the continuum level. We have estimated nuclear redshift of z = 0.034 (G18) and z = 0.039 (G19), corresponding to a heliocentric velocity of 10246 and 11734kms-1, respectively. Some other physical parameters have been derived whenever possible. All spectra were reduced and analysed in a homogeneous way with the standard IRAF procedures. Based on observations carried out at Observatório do Pico dos Dias (OPD), which operated by the LNA/MCT, Brazil-MG. E-mail: paulopoppe@gmail.com

  6. Measurement of Plasma Ion Temperature and Flow Velocity from Chord-Averaged Emission Line Profile

    NASA Astrophysics Data System (ADS)

    Wei, Xu

    2011-06-01

    The distinction between Doppler broadening and Doppler shift has been analysed, the differences between Gaussian fitting and the distribution of chord-integral line shape have also been discussed. Local ion temperature and flow velocity have been derived from the chord-averaged emission line profile by a chosen-point Gaussian fitting technique.

  7. SOFT X-RAY EMISSION LINES OF S VII-S XIV IN PROCYON

    SciTech Connect

    Li, F.; Liang, G. Y.; Zhao, G. E-mail: gzhao@bao.ac.cn

    2013-01-01

    Observational data for cool star Procyon available from the Chandra Data Public Archive are co-added and analyzed with as high a signal-to-noise ratio as possible. The soft X-ray emission lines of highly charged sulfur ions (S VII-S XV) are investigated in the 30-80 A range. A collisional-radiative model is constructed to predict line emissivities of sulfur ions using updated excitation data from the R-matrix method. Theoretical line fluxes and line intensity ratios are calculated, and theoretical spectra are constructed with a Gaussian profile with a line width of 0.06 A. By comparing predicted emission lines with observed ones, several strong emission lines are identified for the first time. Some misassignments of lines in previous works are also corrected. By comparing our results with those from the Chianti (v6) model, this work provides insight into the completeness and accuracy of the atomic data of sulfur ions in the Chianti (v6) database.

  8. Emission-Line Eclipse Mapping of Velocity Fields in a Dwarf-Nova Accretion Disk

    NASA Astrophysics Data System (ADS)

    Makita, Makoto; Mineshige, Shin

    2002-06-01

    We propose a new method, emission-line eclipse mapping, to map the velocity fields of an accretion disk in position space. Quiescent dwarf novae usually exhibit double-peaked emission-line profiles because of disk rotation. Since a part of a disk having a different line-of-sight velocity is successively obscured by a companion in eclipsing systems, they show time-varying line profiles. We calculated the time changes of the emission-line profiles, assuming Keplerian rotation fields (vφ ~ r-1/2 with r being the distance from the disk center) and an emissivity distribution of j ~ r-3/2. We, then, applied the usual eclipse mapping technique to the light curves at each of 12-24 wavelengths across the line center to map the region with the same line-of-sight velocity. The reconstructed images typically exhibit a `two-eye' pattern for high line-of-sight velocities, and we can recover the relation, vφ ~ d-1/2, on the assumption of an axisymmetric disk, where d is the separation between the two `eyes'. We will be able to probe the Keplerian rotation law, the most fundamental assumption adopted in many disk models, by high-speed spectroscopic observations with 8-m class telescopes.

  9. Electron Density Measurements in the National Spherical Torus Experiment Detached Divertor Region Using Stark Broadening of Deuterium Infrared Paschen Emission Lines

    SciTech Connect

    Soukhanovskii, V A; Johnson, D W; Kaita, R; Roquemore, A L

    2007-04-27

    Spatially resolved measurements of deuterium Balmer and Paschen line emission have been performed in the divertor region of the National Spherical Torus Experiment using a commercial 0.5 m Czerny-Turner spectrometer. While the Balmer emission lines, Balmer and Paschen continua in the ultraviolet and visible regions have been extensively used for tokamak divertor plasma temperature and density measurements, the diagnostic potential of infrared Paschen lines has been largely overlooked. We analyze Stark broadening of the lines corresponding to 2-n and 3-m transitions with principle quantum numbers n = 7-12 and m = 10-12 using recent Model Microfield Method calculations (C. Stehle and R. Hutcheon, Astron. Astrophys. Supl. Ser. 140, 93 (1999)). Densities in the range (5-50) x 10{sup 19} m{sup -3} are obtained in the recombining inner divertor plasma in 2-6 MW NBI H-mode discharges. The measured Paschen line profiles show good sensitivity to Stark effects, and low sensitivity to instrumental and Doppler broadening. The lines are situated in the near-infrared wavelength domain, where optical signal extraction schemes for harsh nuclear environments are practically realizable, and where a recombining divertor plasma is optically thin. These properties make them an attractive recombining divertor density diagnostic for a burning plasma experiment.

  10. A Suzaku search for dark matter emission lines in the X-ray brightest galaxy clusters

    NASA Astrophysics Data System (ADS)

    Urban, O.; Werner, N.; Allen, S. W.; Simionescu, A.; Kaastra, J. S.; Strigari, L. E.

    2015-08-01

    We present the results of a search for unidentified emission lines in deep Suzaku X-ray spectra of the central regions of the X-ray brightest galaxy clusters: Perseus, Coma, Virgo and Ophiuchus. We analyse an optimized energy range (3.2-5.3 keV) that is relatively free of instrumental features, and a plasma emission model incorporating the abundances of elements with the strongest expected emission lines at these energies (S, Ar, Ca) as free parameters. For the Perseus Cluster core, employing this model, we find evidence for an additional emission feature at an energy E=3.51^{+0.02}_{-0.01} keV with a flux of 2.87_{-0.38}^{+0.33}× 10^{-7} photons s^{-1} cm^{-2} arcmin^{-2}. At slightly larger radii, we detect an emission line at 3.59 ± 0.02 keV with a flux of 4.8_{-1.4}^{+1.7}× 10^{-8} photons s^{-1} cm^{-2} arcmin^{-2}. The properties of these features are broadly consistent with previous claims, although the radial variation of the line strength appears in tension with dark matter (DM) decay model predictions. Assuming a decaying DM origin for these features allows us to predict the energies and detected line fluxes for the other clusters. We do not detect an emission feature at the predicted energy and line flux in the Coma, Virgo and Ophiuchus clusters. The formal 99.5 per cent upper limits on the line strengths in each cluster are well below the decaying DM model predictions, disfavouring a decaying DM interpretation. The results of further analysis suggest that systematic effects associated with modelling the spectra for the Perseus Cluster, details of the assumed ionization balance and errors in the predicted spectral line emissivities may be largely responsible for the ˜3.55 keV feature.

  11. Systematic QSO emission-line velocity shifts and new unbiased redshifts

    NASA Technical Reports Server (NTRS)

    Tytler, David; Fan, Xiao-Ming

    1992-01-01

    A novel method for determining mean line velocities which is an order of magnitude more accurate than past work is presented. Using a large sample of 518 lines from 160 QSOs, it is found that each UV emission line has a well-determined mean velocity, with a surprisingly small QSO-to-QSO dispersion of under 200 km/s. All correlations between emission-line velocities and QSO properties are found to be explained by just three basic correlations. Both N V and Mg II tend to be at less negative velocities in radio-quiet vs radio-loud QSOs, and C IV lines with small equivalent widths are at more negative velocities, probably because of the line asymmetry. The finding of Sargent et al. (1989) that the UV spectral index increases with UV luminosity is confirmed, but their claim that radio-loud and radio-quiet QSOs have different indices is not confirmed.

  12. PyNeb: a new tool for analyzing emission lines. I. Code description and validation of results

    NASA Astrophysics Data System (ADS)

    Luridiana, V.; Morisset, C.; Shaw, R. A.

    2015-01-01

    Analysis of emission lines 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 emission lines. 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 lines, PyNeb works by solving the equilibrium equations for an n-level atom; in the case of recombination lines, it works by interpolation in emissivity 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.

  13. The spatial distribution of ultraviolet line and continuum emission in Herbig-Haro objects

    NASA Technical Reports Server (NTRS)

    Lee, M. G.; Boehm, K. H.; Temple, S. D.; Raga, A. C.; Mateo, M. L.

    1988-01-01

    Archival IUE data and monochromatic CCD images in the optical range are used to compare the spatial distribution of UV and optical emission in HH 1, HH 2, HH 24, HH 32, HH 43, and HH 47. For all six objects, the observed UV radiation is shown to originate in the objects themselves. The results indicate that the C IV and semiforbidden emission-line regions are small. Although the continuum in the IUE short-wavelength range displays a distribution that is broader than that of any measured line emission in the UV or optical range, the continuum distribution in the IUE long-wavelength range is quite narrow.

  14. Modeling X-ray emission line profiles from massive star winds - A review

    NASA Astrophysics Data System (ADS)

    Ignace, Richard

    2016-09-01

    The Chandra and XMM-Newton X-ray telescopes have led to numerous advances in the study and understanding of astrophysical X-ray sources. Particularly important has been the much increased spectral resolution of modern X-ray instrumentation. Wind-broadened emission lines have been spectroscopically resolved for many massive stars. This contribution reviews approaches to the modeling of X-ray emission line profile shapes from single stars, including smooth winds, winds with clumping, optically thin versus thick lines, and the effect of a radius-dependent photoabsorption coefficient.

  15. Temperature measurement of wood flame based on the double line method of atomic emission spectra

    NASA Astrophysics Data System (ADS)

    Hao, Xiaojian; Liu, Zhenhua; Sang, Tao

    2016-01-01

    Aimed at the testing requirement of the transient high temperature in explosion field and the bore of barrel weapon, the temperature measurement system of double line of atomic emission spectrum was designed, the method of flame spectrum testing system were used for experimental analysis. The experimental study of wood burning spectra was done with flame spectrum testing system. The measured spectra contained atomic emission spectra of the elements K, Na, and the excitation ease of two kinds atomic emission spectra was analyzed. The temperature was calculated with two spectral lines of K I 766.5nm and 769.9nm. The results show that, compared with Na, the excitation temperature of K atomic emission spectra is lower. By double line method, the temperature of wood burning is 1040K, and error is 3.7%.

  16. Classification of Spectra of Emission-line Stars Using Feature Extraction Based on Wavelet Transform

    NASA Astrophysics Data System (ADS)

    Bromová P.; Bařina, D.; Škoda, P.; Vážný, J.; Zendulka, J.

    2014-05-01

    Our goal is to automatically identify spectra of emission (Be) stars in large archives and classify their types based on a typical shape of the Hα emission line. Due to the length of spectra, of the original data is very time-consuming. In order to lower computational requirements and enhance the separability of the classes, we have to find a reduced representation of spectral features, however conserving most of the original information content. As the Be stars show a number of different shapes of emission lines, it is not easy to construct simple criteria (like e.g. Gaussian fits) to distinguish the emission lines in an automatic manner. We proposed to perform the wavelet transform of the spectra, calculate statistical metrics from the wavelet coefficients, and use them as feature vectors for classification. In this paper, we compare different wavelet transforms, different wavelets, and different statistical metrics in an attempt to identify the best method.

  17. Error Estimates for Emission Lines in the Hydrogen and Helium Isosequences

    NASA Astrophysics Data System (ADS)

    Smith, R. K.; Brickhouse, N. S.

    2000-05-01

    Emission lines from hydrogen and helium isosequence are among the strongest in X-ray spectra; they will soon be used to measure the temperature, density, and equilibrium state of collisionally excited, astrophysical plasmas. We have created a new plasma code, APEC, which calculates the emission from such a plasma. APEC calculates the line emission from the direct electron and proton excitation rate and the radiative and dielectronic recombination rate. We show how different collisional plasma codes give varying emissivities for some strong lines of O VII and Fe XXVI, where direct excitation is the primary effect. This variation is partly due to simple differences in the plasma code. However, the primary reason is that much work remains to be done on experimental and theoretical calculations of the atomic rates. Large (~ 50%) differences exist even for excitation rates for hydrogenic ions.

  18. Relation between Starlight and Nebular Emission Lines of Star-Forming Galaxies

    NASA Astrophysics Data System (ADS)

    Lu, Hong-Lin; Zhou, Hong-Yan; Wang, Ting-Gui; Zhuang, Zhen-Quan; Dong, Xiao-Bo; Wang, Jun-Xian; Li, Cheng

    2005-06-01

    We present an exercise that intends to establish a relationship between the strength of nebular emission lines and optical stellar features in the spectrum of a galaxy. After accurately subtracting the stellar continuum and the underlying stellar absorption, we made reliable measurements of the emission lines of all the galaxies in the Sloan Digital Sky Survey Data Release 2 (SDSS DR2). More than 4000 star-forming galaxies with high S/N ratio of both the stellar spectrum and the emission lines are selected. These galaxy spectra are fitted with the 10 PCs of Yip et al., after all the emission line regions have been filtered out. We find that the flux of hydrogen Balmer emission lines, Hα and Hβ can be well recovered from the PCs, while the metal lines are not well reproduced. The fluxes of Hα and Hβ measured from the PC-reconstructed spectra and from the observed spectra agree well with an rms scatter of only ~0.1 dex. This result suggests that, with moderate spectral resolution and S/N ratio, the optical stellar spectrum of a galaxy can serve as an indicator of star formation rate.

  19. P-MaNGA Galaxies: emission-lines properties - gas ionization and chemical abundances from prototype observations

    NASA Astrophysics Data System (ADS)

    Belfiore, F.; Maiolino, R.; Bundy, K.; Thomas, D.; Maraston, C.; Wilkinson, D.; Sánchez, S. F.; Bershady, M.; Blanc, G. A.; Bothwell, M.; Cales, S. L.; Coccato, L.; Drory, N.; Emsellem, E.; Fu, H.; Gelfand, J.; Law, D.; Masters, K.; Parejko, J.; Tremonti, C.; Wake, D.; Weijmans, A.; Yan, R.; Xiao, T.; Zhang, K.; Zheng, T.; Bizyaev, D.; Kinemuchi, K.; Oravetz, D.; Simmons, A.

    2015-05-01

    MaNGA (Mapping Nearby Galaxies at Apache Point Observatory) is a 6-yr Sloan Digital Sky Survey (SDSS-IV) survey that will obtain spatially resolved spectroscopy from 3600 to 10 300 Å for a representative sample of over 10 000 nearby galaxies. In this paper, we present the analysis of nebular emission-line properties using observations of 14 galaxies obtained with P-MaNGA, a prototype of the MaNGA instrument. By using spatially resolved diagnostic diagrams, we find extended star formation in galaxies that are centrally dominated by Seyfert/LINER-like emission, which illustrates that galaxy characterizations based on single fibre spectra are necessarily incomplete. We observe extended low ionization nuclear emission-line regions (LINER)-like emission (up to 1Re) in the central regions of three galaxies. We make use of the Hα equivalent width [EW(Hα)] to argue that the observed emission is consistent with ionization from hot evolved stars. We derive stellar population indices and demonstrate a clear correlation between Dn(4000) and EW(HδA) and the position in the ionization diagnostic diagram: resolved galactic regions which are ionized by a Seyfert/LINER-like radiation field are also devoid of recent star formation and host older and/or more metal-rich stellar populations. We also detect extraplanar LINER-like emission in two highly inclined galaxies, and identify it with diffuse ionized gas. We investigate spatially resolved metallicities and find a positive correlation between metallicity and star formation rate surface density. We further study the relation between N/O versus O/H on resolved scales. We find that, at given N/O, regions within individual galaxies are spread towards lower metallicities, deviating from the sequence defined by galactic central regions as traced by Sloan 3-arcsec fibre spectra. We suggest that the observed dispersion can be a tracer for gas flows in galaxies: infalls of pristine gas and/or the effect of a galactic fountain.

  20. BAT AGN spectroscopic survey-II. X-ray emission and high-ionization optical emission lines

    NASA Astrophysics Data System (ADS)

    Berney, Simon; Koss, Michael; Trakhtenbrot, Benny; Ricci, Claudio; Lamperti, Isabella; Schawinski, Kevin; Baloković, Mislav; Crenshaw, D. Michael; Fischer, Travis; Gehrels, Neil; Harrison, Fiona; Hashimoto, Yasuhiro; Ichikawa, Kohei; Mushotzky, Richard; Oh, Kyuseok; Stern, Daniel; Treister, Ezequiel; Ueda, Yoshihiro; Veilleux, Sylvain; Winter, Lisa

    2015-12-01

    We investigate the relationship between X-ray and optical line emission in 340 nearby (z ≃ 0.04) AGN selected above 10 keV using Swift BAT. We find a weak correlation between the extinction corrected [O III] and hard X-ray luminosity (L_[O III]^{int} ∝ L_{14-195}) with a large scatter (RPear = 0.64, σ = 0.62 dex) and a similarly large scatter with the intrinsic 2-10 keV to [O III] luminosities (RPear = 0.63, σ = 0.63 dex). Correlations of the hard X-ray fluxes with the fluxes of high-ionization narrow lines ([O III], He II, [Ne III] and [Ne V]) are not significantly better than with the low-ionization lines (H α, [S II]). Factors like obscuration or physical slit size are not found to be a significant part of the large scatter. In contrast, the optical emission lines show much better correlations with each other (σ = 0.3 dex) than with the X-ray flux. The inherent large scatter questions the common usage of narrow emission lines as AGN bolometric luminosity indicators and suggests that other issues such as geometrical differences in the scattering of the ionized gas or long-term AGN variability are important.

  1. Characterizing ICF Neutron Diagnostics on the nTOF line at SUNY Geneseo

    NASA Astrophysics Data System (ADS)

    Simone, Angela; Padalino, Stephen; Turner, Ethan; Ginnane, Mary Kate; Dubois, Natalie; Fletcher, Kurtis; Giordano, Michael; Lawson-Keister, Patrick; Harrison, Hannah; Visca, Hannah; Sangster, Craig; Regan, Sean

    2014-10-01

    Charged particle beams from the Geneseo 1.7 MV tandem Pelletron accelerator produce nuclear reactions that emit neutrons in the range of 0.5 to 17.9 MeV via the d(d,n)3He and 11B(d,n)12C reactions. The neutron energy and flux can be adjusted by controlling the accelerator beam current and potential. This adjustable neutron source makes it possible to calibrate ICF and HEDP neutron scintillator diagnostics. However, gamma rays which are often present during an accelerator-based calibration are difficult to differentiate from neutron signals in scintillators. To identify neutrons from gamma rays and to determine their energy, a permanent neutron time-of-flight (nTOF) line is being constructed. By detecting the scintillator signal in coincidence with an associated charged particle (ACP) produced in the reaction, the identity of the neutron can be known and its energy determined by time of flight. Using a 100% efficient surface barrier detector to count the ACPs, the absolute efficiency of the scintillator as a function of neutron energy can be determined. This is done by determining the ratio of the ACP counts in the singles spectrum to coincidence counts for matched solid angles of the SBD and scintillator. Funded in part by a LLE contract through the DOE.

  2. Beyond Zeeman spectroscopy: Magnetic-field diagnostics with Stark-dominated line shapes

    SciTech Connect

    Tessarin, S.; Mikitchuk, D.; Doron, R.; Stambulchik, E.; Kroupp, E.; Maron, Y.; Hammer, D. A.; Jacobs, V. L.; Seely, J. F.; Oliver, B. V.; Fisher, A.

    2011-09-15

    A recently suggested spectroscopic approach for magnetic-field determination in plasma is employed to measure magnetic fields in an expanding laser-produced plasma plume in an externally applied magnetic field. The approach enables the field determination in a diagnostically difficult regime for which the Zeeman-split patterns are not resolvable, as is often encountered under the conditions characteristic of high-energy-density plasmas. Here, such conditions occur in the high-density plasma near the laser target, due to the dominance of Stark broadening. A pulsed-power system is used to generate magnetic fields with a peak magnitude of 25 T at the inner-electrode surface in a coaxial configuration. An aluminum target attached to the inner electrode surface is then irradiated by a laser beam to produce the expanding plasma that interacts with the applied azimuthal magnetic field. A line-shape analysis of the Al III 4s-4p doublet (5696 and 5722 A) enables the simultaneous determination of the magnetic field and the electron density. The measured magnetic fields are generally found to agree with those expected in a vacuum based on the pulsed-power system current. Examples of other transitions that can be used to diagnose a wide range of plasma and magnetic field parameters are presented.

  3. EMAT weld inspection and weld machine diagnostic system for continuous coil processing lines

    NASA Astrophysics Data System (ADS)

    Latham, Wayne M.; MacLauchlan, Daniel T.; Geier, Dan P.; Lang, Dennis D.

    1996-11-01

    Weld breaks of steel coil during cold rolling and continuous pickling operations are a significant source of lost productivity and product yield. Babcock and Wilcox Innerspec Technologies has developed a weld process control system which monitors the key variables of the welding process and determines the quality of the welds generated by flash butt welding equipment. This system is known as the Temate 2000 Automated Flash Butt Weld Inspection and Weld Machine Diagnostic System. The Temate 2000 system utilizes electro- magnetic acoustic transducer (EMAT) technology as the basis for performing on-line, real-time, nondestructive weld quality evaluation. This technique accurately detects voids, laps, misalignment and over/under trim conditions in the weld. Results of the EMAT weld inspection are immediately presented to the weld machine operator for disposition. Welding process variables such as voltage, current, platen movements and upset pressures are monitored and collected with the high speed data acquisition system. This data is processed and presented in real-time display to indicate useful welding process information such as platen crabbing, upset force, peak upset current, and many others. Alarming for each variable is provided and allows detailed maintenance reports and summary information to be generated. All weld quality and process parameter data are stored, traceable to each unique weld, and available for post process evaluation. Installation of the Temate 2000 system in a major flat rolled steel mill has contributed to near elimination of weld breakage and increased productivity at this facility.

  4. PHYSICAL CONDITIONS IN THE X-RAY EMISSION-LINE GAS IN NGC 1068

    SciTech Connect

    Kraemer, S. B.; Sharma, N.; Turner, T. J.; George, Ian M.; Crenshaw, D. Michael

    2015-01-01

    We present a detailed, photoionization modeling analysis of XMM-Newton/Reflection Grating Spectrometer observations of the Seyfert 2 galaxy NGC 1068. The spectrum, previously analyzed by Kinkhabwala et al., reveals a myriad of soft X-ray emission lines, including those from H- and He-like carbon, nitrogen, oxygen, and neon, and M- and L-shell iron. As noted in the earlier analysis, based on the narrowness of the radiative recombination continua, the electron temperatures in the emission-line gas are consistent with photoionization, rather than collisional ionization. The strengths of the carbon and nitrogen emission lines, relative to those of oxygen, suggest unusual elemental abundances, which we attribute to the star formation history of the host galaxy. Overall, the emission lines are blueshifted with respect to systemic, with radial velocities ∼160 km s{sup –1}, similar to that of [O III] λ5007, and thus consistent with the kinematics and orientation of the optical emission-line gas and, hence, likely part of an active galactic nucleus driven outflow. We were able to achieve an acceptable fit to most of the strong emission lines with a two-component photoionization model, generated with CLOUDY. The two components have ionization parameters and column densities of logU = –0.05 and 1.22 and logN {sub H} = 20.85 and 21.2 and covering factors of 0.35 and 0.84, respectively. The total mass of the X-ray gas is roughly an order of magnitude greater than the mass of ionized gas determined from optical and near-IR spectroscopy, which indicates that it may be the dominant component of the narrow-line region. Furthermore, we suggest that the medium that produces the scattered/polarized optical emission in NGC 1068 possesses similar physical characteristics to those of the more highly ionized of the X-ray model components.

  5. Abell 262 and RXJ0341: Two Brightest Cluster Galaxies with Line Emission Blanketing a Cool Core

    NASA Astrophysics Data System (ADS)

    Edwards, Louise O. V.; Heng, Renita

    2014-08-01

    Over the last decade, integral field (IFU) analysis of the brightest cluster galaxies (BCGs) in several cool core clusters has revealed the central regions of these massive old red galaxies to be far from dead. Bright line emission alongside extended X-ray emission links nearby galaxies, is superposed upon vast dust lanes and extends out in long thin filaments from the galaxy core. Yet, to date no unifying picture has come into focus, and the activity across systems is currently seen as a grab-bag of possibile emission line mechanisms. Our primary goal is to work toward a consistent picture for why the BCGs seem are undergoing a renewed level of activity. One problem is most of the current data remains focused on mapping the very core of the BCG, but neglects surrounding galaxies. We propose to discover the full extent of line emission in a complementary pair of BCGs. In Abell 262, an extensive dust patch screens large portions of an otherwise smooth central galaxy, whereas RXJ0341 appears to be a double-core dust free BCG. We will map the full extent of the line emission in order to deduce whether the line emission is a product of local interactions, or the large-scale cluster X-ray gas. The narrow band filter set and large FOV afforded by the the Mayall MOSAIC-1 (MOSA) imager allows us to concurrently conduct an emission line survey of both clusters, locating all line emitting members and beginning a search for the effect of the environment of the different regions (outskirts vs. cluster core) out to the virial radius. We will combine our results with publically available data from 2MASS to determine the upper limits on specific star formation in the BCG and other cluster galaxies within the cluster virial radius.

  6. Extended H2 emission line sources from UWISH2

    NASA Astrophysics Data System (ADS)

    Froebrich, D.; Makin, S. V.; Davis, C. J.; Gledhill, T. M.; Kim, Y.; Koo, B.-C.; Rowles, J.; Eislöffel, J.; Nicholas, J.; Lee, J. J.; Williamson, J.; Buckner, A. S. M.

    2015-12-01

    We present the extended source catalogue for the UKIRT Wide Field Infrared Survey for H2 (UWISH2). The survey is unbiased along the inner Galactic Plane from l ≈ 357° to l ≈ 65° and |b| ≤ 1.5° and covers 209 deg2. A further 42.0 and 35.5 deg2 of high dust column density regions have been targeted in Cygnus and Auriga. We have identified 33 200 individual extended H2 features. They have been classified to be associated with about 700 groups of jets and outflows, 284 individual (candidate) planetary nebulae, 30 supernova remnants and about 1300 photodissociation regions. We find a clear decline of star formation activity (traced by H2 emission from jets and photodissociation regions) with increasing distance from the Galactic Centre. About 60 per cent of the detected candidate planetary nebulae have no known counterpart and 25 per cent of all supernova remnants have detectable H2 emission associated with them.

  7. Anisotropic. cap alpha. -emission of on-line separated isotopes

    SciTech Connect

    Wouters, J.; Vandeplassche, D.; van Walle, E.; Severijns, N.; Van Haverbeke, J.; Vanneste, L.

    1987-12-10

    The technical realization of particle detection at very low temperatures (4K) has made it possible to study for the first time the anisotropic ..cap alpha..-decay of oriented nuclei which have been produced, separated and implanted on line. The measured ..cap alpha..-angular distributions reveal surprising new results on nuclear aspects as well as in solid state physics. The nuclear structure information from these data questions the older ..cap alpha..-decay theoretical interpretation and urges for a reaxamination of the earliest work on anisotropic ..cap alpha..-decay.

  8. A High Fraction of Double-peaked Narrow Emission Lines in Powerful Active Galactic Nuclei

    NASA Astrophysics Data System (ADS)

    Lyu, Yang; Liu, Xin

    2016-08-01

    One percent of redshift z ˜ 0.1 Active Galactic Nuclei (AGNs) show velocity splitting of a few hundred km s-1 in the narrow emission lines in spatially integrated spectra. Such line profiles have been found to arise from the bulk motion of ionized gas clouds associated with galactic-scale outflows, merging pairs of galaxies each harboring a supermassive black hole (SMBH), and/or galactic-scale disk rotation. It remains unclear, however, how the frequency of narrow-line velocity splitting may depend on AGN luminosity. Here we study the correlation between the fraction of Type 2 AGNs with double-peaked narrow emission lines and AGN luminosity as indicated by [O III]λ5007 emission-line luminosity L[O III]. We combine the sample of Liu et al. (2010a) at z ˜ 0.1 with a new sample of 178 Type 2 AGNs with double-peaked [O III] emission lines at z ˜ 0.5. We select the new sample from a parent sample of 2089 Type 2 AGNs from the SDSS-III/Baryon Oscillation Spectroscopic Survey. We find a statistically significant (˜4.2σ) correlation between L[O III] and the fraction of objects that exhibit double-peaked narrow emission lines among all Type 2 AGNs, corrected for selection bias and incompleteness due to [O III] line width, equivalent width, splitting velocity, and/or equivalent width ratio between the two velocity components. Our result suggests that galactic-scale outflows and/or merging pairs of SMBHs are more prevalent in more powerful AGNs, although spatially resolved follow up observations are needed to resolve the origin(s) for the narrow-line velocity splitting for individual AGNs.

  9. Gearbox Tooth Cut Fault Diagnostics Using Acoustic Emission and Vibration Sensors — A Comparative Study

    PubMed Central

    Qu, Yongzhi; He, David; Yoon, Jae; Van Hecke, Brandon; Bechhoefer, Eric; Zhu, Junda

    2014-01-01

    In recent years, acoustic emission (AE) sensors and AE-based techniques have been developed and tested for gearbox fault diagnosis. In general, AE-based techniques require much higher sampling rates than vibration analysis-based techniques for gearbox fault diagnosis. Therefore, it is questionable whether an AE-based technique would give a better or at least the same performance as the vibration analysis-based techniques using the same sampling rate. To answer the question, this paper presents a comparative study for gearbox tooth damage level diagnostics using AE and vibration measurements, the first known attempt to compare the gearbox fault diagnostic performance of AE- and vibration analysis-based approaches using the same sampling rate. Partial tooth cut faults are seeded in a gearbox test rig and experimentally tested in a laboratory. Results have shown that the AE-based approach has the potential to differentiate gear tooth damage levels in comparison with the vibration-based approach. While vibration signals are easily affected by mechanical resonance, the AE signals show more stable performance. PMID:24424467

  10. Gearbox tooth cut fault diagnostics using acoustic emission and vibration sensors--a comparative study.

    PubMed

    Qu, Yongzhi; He, David; Yoon, Jae; Van Hecke, Brandon; Bechhoefer, Eric; Zhu, Junda

    2014-01-01

    In recent years, acoustic emission (AE) sensors and AE-based techniques have been developed and tested for gearbox fault diagnosis. In general, AE-based techniques require much higher sampling rates than vibration analysis-based techniques for gearbox fault diagnosis. Therefore, it is questionable whether an AE-based technique would give a better or at least the same performance as the vibration analysis-based techniques using the same sampling rate. To answer the question, this paper presents a comparative study for gearbox tooth damage level diagnostics using AE and vibration measurements, the first known attempt to compare the gearbox fault diagnostic performance of AE- and vibration analysis-based approaches using the same sampling rate. Partial tooth cut faults are seeded in a gearbox test rig and experimentally tested in a laboratory. Results have shown that the AE-based approach has the potential to differentiate gear tooth damage levels in comparison with the vibration-based approach. While vibration signals are easily affected by mechanical resonance, the AE signals show more stable performance. PMID:24424467

  11. Submillimeter Narrow Emission Lines from the Inner Envelope of IRC+10216

    NASA Astrophysics Data System (ADS)

    Patel, Nimesh A.; Young, Ken H.; Brünken, Sandra; Wilson, Robert W.; Thaddeus, Patrick; Menten, Karl M.; Reid, Mark; McCarthy, Michael C.; Dinh-V-Trung; Gottlieb, Carl A.; Hedden, Abigail

    2009-02-01

    A spectral-line survey of IRC+10216 in the 345 GHz band has been undertaken with the Submillimeter Array. Although not yet completed, it has already yielded a fairly large sample of narrow molecular emission lines with line widths indicating expansion velocities of ~ 4 km s-1, less than three times the well known value of the terminal expansion velocity (14.5 km s-1) of the outer envelope. Five of these narrow lines have now been identified as rotational transitions in vibrationally excited states of previously detected molecules: the v = 1, J = 17-16, and J = 19-18 lines of Si34S and 29SiS and the v = 2, J = 7-6 line of CS. Maps of these lines show that the emission is confined to a region within ~ 60 AU of the star, indicating that the narrow-line emission is probing the region of dust formation where the stellar wind is still being accelerated.

  12. Ionization energy shift of characteristic K x-ray lines from high-Z materials for plasma diagnostics

    SciTech Connect

    Słabkowska, K.; Szymańska, E.; Polasik, M.; Pereira, N. R.; Rzadkiewicz, J.; Seely, J. F.; Weber, B. V.; Schumer, J. W.

    2014-03-15

    The energy of the characteristic x-rays emitted by high atomic number atoms in a plasma that contains energetic electrons depends on the atom's ionization. For tungsten, the ionization energy shift of the L-lines has recently been used to diagnose the plasma's ionization; the change in energy of a K-line has been measured for iridium and observed for ytterbium. Here, we present detailed computations of the ionization energy shift to K-lines of these and an additional element, dysprosium; for these atoms, some K-lines nearly coincide in energy with K-edges of slightly lower Z atoms so that a change in transmission behind a K-edge filter betrays a change in energy. The ionization energy shift of such high-energy K-lines may enable a unique diagnostic when the plasma is inside an otherwise opaque enclosure such as hohlraums used on the National Ignition Facility.

  13. Dayglow Emission Line Profiles from the Outer Planets Cycle 4-MED Part 2 OF 5414

    NASA Astrophysics Data System (ADS)

    Clarke, John

    1994-01-01

    Recent IUE observations of the H Ly alpha emission line profilefrom Jupiter's dayglow and aurora reveal a substantial line broadening,implying that the observed high brightness is due to resonantscattering of solar emission with a broad line rather than chargedparticle excitation. This may reflect highly energetic processesproducing a 5-10 km/sec suprathermal population of H atoms in Jupiter'supper atmosphere, which in turn may be related to the unresolved questionof the high exospheric temperatures of 400-1200 K detected on all 4 giantplanets during the Voyager encounters. It is clear that if the bright HLy alpha emissions from the outer planets are due mainly to resonantscattering of solar and interplanetary emissions, as observedon Jupiter and Saturn from long term correlations with the solarLy alpha flux, then the lines from all 4 planets must be broad toexplain the observed high albedos. The H Ly alpha lineshapes providea discriminant between the processes of resonant scattering andcharged particle excitation. We propose to obtain high signal to noiseH Ly alpha line profile measurements from Saturn, Uranus, and Neptuneto resolve the questions about the excitation processes for the brightairglow emissions.SATURN PART ONLY - NEPTUNE AND URANUS IN ORIGIAL PROP (5414).

  14. Emission Line Science in the Faint Infrared Grism Survey (FIGS) Sample

    NASA Astrophysics Data System (ADS)

    Smith, Mark David; Malhotra, Sangeeta; Pharo, John; Rhoads, James E.; FIGS Team

    2016-01-01

    Emission lines can reveal a bounty of information about the processes occurring within a galaxy. Physical properties such as star formation rate and metallicity can be determined from ratios of emission line fluxes. The study of emission line galaxies (ELGs) through cosmic time gives insight into the processes by which galaxies evolve. Extreme emission line galaxies (EELGs), typified by strong nebular emission lines which dominate their spectra, are of interest because they are well known to be galaxies undergoing periods of intense star formation. Slitless grism spectroscopy offers a significant advantage to the study of ELGs and EELGs, allowing for measurement of the spectra of a large number of galaxies within a field. This allows for detection of ELGs and EELGs with few selection biases. Optical follow-up of FIGS-selected sources allows for analysis of star formation rate (SFR) through H-alpha measurements over the redshift range 0.3

  15. X-RAY EMISSION LINE PROFILES FROM WIND CLUMP BOW SHOCKS IN MASSIVE STARS

    SciTech Connect

    Ignace, R.; Waldron, W. L.; Cassinelli, J. P.; Burke, A. E. E-mail: wwaldron@satx.rr.com E-mail: burke.alexander@gmail.com

    2012-05-01

    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 emission lines that arise from such bow shock morphologies. To compute emission line 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 emission line profiles, a group of bow shocks can lead to line profiles with a range of shapes with blueshifted peak emission 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 emission measure and temperature distribution throughout the wind can be derived. The emission 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 emission measure distributions in stellar winds and their impact on X-ray line 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 line profile shapes for massive stars.

  16. The Binary Black Hole Model for Mrk 231 Can Not Explain the Observed Emission Lines

    NASA Astrophysics Data System (ADS)

    Leighly, Karen; Terndrup, Donald M.; Gallagher, Sarah; Lucy, Adrian B.

    2016-01-01

    Quasars are known for their strong, broad emission lines and their broad-band continua peaking in the extreme UV. While there are observable and interesting differences from object to object, the emission-line equivalent widths and ratios are, overall, quite uniform over a broad range of luminosity. This result is consistent with photoionization of the broad-line region by continuum emission from an accretion disk, where the luminosity and number of photoionizing photons generally scale with the black hole mass and accretion rate.Mrk 231 is a nearby quasar with an unusually red continuum, generally explained by heavy reddening from dust (e.g., Veilleux et al. 2013, Leighly et al. 2014). Yan et al. 2015 recently proposed that Mrk 231 is a black-hole binary system with very little intrinsic reddening, in which the large black hole experiences advection dominated accretion, emitting little continuum, while the accretion disk of the small black hole emits as an ordinary quasar, dominating the observed weak UV continuum and the photoionizing flux.Using Cloudy photo-ionization modeling, recombination broad lines in the relatively unreddened near-IR, and CIV and CIII] lines in the reddened UV, we show that the observed line emission is not consistent with the binary black hole hypothesis. The observed near-IR recombination line flux is too strong to be produced by the weak continuum of the putative small black hole. Moreover, the lack of intrinsic reddening in the binary model implies a small intrinsic CIV/IR line ratio from the observed lines, which would in turn require a very low ionization parameter that would under-predict the observed near-IR recombination line flux.

  17. X-Ray Line-Shape Diagnostics and Novel Stigmatic Imaging Schemes For the National Ignition Facility

    SciTech Connect

    M. Bitter,, K.W. Hill, N.A. Pablant, L.F. Delgado-Aparicio, P. Beiersdorfer, E. Wang, and M. Sanchez del Rio

    2011-08-15

    In response to a recent solicitation from the US Department of Energy we proposed the development of a new x-ray line-shape diagnostic and novel stigmatic imaging schemes for the National Ignition Facility (NIF). These diagnostics are based on the imaging properties of spherically bent crystals, explained in Fig. 1, which have already been successfully applied to the diagnosis of extended tokamak plasmas for measurements of the ion-temperature and toroidal flow-velocity profiles [United States Patent: US 6, 259, 763 B1] and refs. [1, 2].

  18. ON THE ACCURACY OF THE DIFFERENTIAL EMISSION MEASURE DIAGNOSTICS OF SOLAR PLASMAS. APPLICATION TO SDO/AIA. II. MULTITHERMAL PLASMAS

    SciTech Connect

    Guennou, C.; Auchere, F.; Soubrie, E.; Bocchialini, K.; Barbey, N.

    2012-12-15

    Differential emission measure (DEM) analysis is one of the most used diagnostic tools for solar and stellar coronae. Being an inverse problem, it has limitations due to the presence of random and systematic errors. We present in this series of papers an analysis of the robustness of the inversion in the case of SDO/AIA observations. We completely characterize the DEM inversion and its statistical properties, providing all the solutions consistent with the data along with their associated probabilities, and a test of the suitability of the assumed DEM model. While Paper I focused on isothermal conditions, we now consider multithermal plasmas and investigate both isothermal and multithermal solutions. We demonstrate how the ambiguity between noises and multithermality fundamentally limits the temperature resolution of the inversion. We show that if the observed plasma is multithermal, isothermal solutions tend to cluster on a constant temperature whatever the number of passbands or spectral lines. The multithermal solutions are also found to be biased toward near-isothermal solutions around 1 MK. This is true even if the residuals support the chosen DEM model, possibly leading to erroneous conclusions on the observed plasma. We propose tools for identifying and quantifying the possible degeneracy of solutions, thus helping the interpretation of DEM inversion.

  19. Line integration effects on ion temperatures in tokamak plasmas measured with neutron emission spectroscopy

    SciTech Connect

    Ognissanto, F.; Gorini, G.; Tardocchi, M.; Albergante, M.; Ballabio, L.; Conroy, S.; Kaellne, J.

    2008-10-15

    The line integrated line emission measured by neutron spectrometers at JET along sight lines in the vertical and horizontal planes has been simulated in Monte Carlo calculations to determine the relationship between the measured (effective) ion temperature (T{sub eff}) relative to the peak value of the profile (T{sub 0}). The general sight line dependence of (T{sub eff}) was expressed analytically for circular plasmas which was used to explain the simulated results for the actual JET sight lines. The analytical model with parametrization of sight lines and plasma profiles is described and the results are used to discuss dual sight line measurements that can be tested at JET and its forward implications for study burning (nearly thermal) plasmas of ITER.

  20. C IV emission-line properties and systematic trends in quasar black hole mass estimates

    NASA Astrophysics Data System (ADS)

    Coatman, Liam; Hewett, Paul C.; Banerji, Manda; Richards, Gordon T.

    2016-09-01

    Black hole masses are crucial to understanding the physics of the connection between quasars and their host galaxies and measuring cosmic black hole-growth. At high redshift, z ≳ 2.1, black hole masses are normally derived using the velocity width of the C IV λ λ1548, 1550 broad emission line, based on the assumption that the observed velocity widths arise from virial-induced motions. In many quasars, the C IV emission line exhibits significant blue asymmetries (`blueshifts') with the line centroid displaced by up to thousands of km s-1 to the blue. These blueshifts almost certainly signal the presence of strong outflows, most likely originating in a disc wind. We have obtained near-infrared spectra, including the Hα λ6565 emission line, for 19 luminous (LBol = 46.5-47.5 erg s-1) Sloan Digital Sky Survey quasars, at redshifts 2 < z < 2.7, with C IV emission lines spanning the full range of blueshifts present in the population. A strong correlation between C IV velocity width and blueshift is found and, at large blueshifts, >2000 km s-1, the velocity widths appear to be dominated by non-virial motions. Black hole masses, based on the full width at half-maximum of the C IV emission line, can be overestimated by a factor of 5 at large blueshifts. A larger sample of quasar spectra with both C IV and H β, or Hα, emission lines will allow quantitative corrections to C IV-based black hole masses as a function of blueshift to be derived. We find that quasars with large C IV blueshifts possess high Eddington luminosity ratios and that the fraction of high-blueshift quasars in a flux-limited sample is enhanced by a factor of approximately 4 relative to a sample limited by black hole mass.

  1. Tracing Slow Winds from T Tauri Stars via Low Velocity Forbidden Line Emission

    NASA Astrophysics Data System (ADS)

    Simon, Molly; Pascucci, Ilaria; Edwards, Suzan; Feng, Wanda; Rigliaco, Elisabetta; Gorti, Uma; Hollenbach, David J.; Tuttle Keane, James

    2016-06-01

    Protoplanetary disks are a natural result of star formation, and they provide the material from which planets form. The evolutional and eventual dispersal of protoplanetary disks play critical roles in determining the final architecture of planetary systems. Models of protoplanetary disk evolution suggest that viscous accretion of disk gas onto the central star and photoevaporation driven by high-energy photons from the central star are the main mechanisms that drive disk dispersal. Understanding when photoevaporation begins to dominate over viscous accretion is critically important for models of planet formation and planetary migration. Using Keck/HIRES (resolution of ~ 7 km/s) we analyze three low excitation forbidden lines ([O I] 6300 Å, [O I] 5577 Å, and [S II] 6731 Å) previously determined to trace winds (including photoevaporative winds). These winds can be separated into two components, a high velocity component (HVC) with blueshifts between ~30 – 150 km/s, and a low velocity component (LVC) with blueshifts on the order of ~5 km/s (Hartigan et al. 1995). We selected a sample of 32 pre-main sequence T Tauri stars in the Taurus-Auriga star-forming region (plus TW Hya) with disks that span a range of evolutionary stages. We focus on the origin of the LVC specifically, which we are able to separate into a broad component (BC) and a narrow component (NC) due to the high resolution of our optical spectra. We focus our analysis on the [O I] 6300 Å emission feature, which is detected in 30/33 of our targets. Interestingly, we find wind diagnostics consistent with photoevaporation for only 21% of our sample. We can, however, conclude that a specific component of the LVC is tracing a magnetohydrodynamic (MHD) wind rather than a photoevaporative wind. We will present the details behind these findings and the implications they have for planet formation more generally.

  2. On the Thermal Line Emission from the Outflows in Ultraluminous X-Ray Sources

    NASA Astrophysics Data System (ADS)

    Xu, Ya-Di; Cao, Xinwu

    2016-08-01

    The atomic features in the X-ray spectra of ultraluminous X-ray sources (ULXs) may be associated with the outflow, which may provide a way to explore the physics of the ULXs. We construct a conical outflow model and calculate the thermal X-ray Fe emission lines from the outflows. Our results show that thermal line luminosity decreases with increasing outflow velocity and/or opening angle of the outflow for a fixed kinetic power of the outflows. Assuming the kinetic power of the outflows to be comparable with the accretion power in the ULXs, we find that the equivalent width can be several eV for the thermal X-ray Fe emission line from the outflows in the ULXs with stellar-mass black holes. The thermal line luminosity is proportional to 1/M bh (M bh is the black hole mass of the ULX). The equivalent width decreases with the black hole mass, which implies that the Fe line emission from the outflows can hardly be detected if the ULXs contain intermediate-mass black holes. Our results suggest that the thermal X-ray Fe line emission should be preferentially be detected in the ULXs with high kinetic power slowly moving outflows from the accretion disks surrounding stellar-mass black holes/neutron stars. The recently observed X-ray atomic features of the outflows in a ULX may imply that it contains a stellar-mass black hole.

  3. Mid Infrared Hydrogen Recombination Line Emission from the Maser Star MWC 349A

    NASA Technical Reports Server (NTRS)

    Smith, Howard A.; Strelnitski, V.; Miles, J. W.; Kelly, D. M.; Lacy, J. H.

    1997-01-01

    We have detected and spectrally resolved the mid-IR hydrogen recombination lines 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 emission (reported in the millimeter and submillimeter hydrogen recombination lines from H36(alpha) to H21(alpha)) and laser emission (reported in the H15(alpha), H12(alpha) and H10(alpha) lines). The lasers/masers are thought to arise predominantly in a Keplerian disk around the star. The mid-IR lines 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 lines. 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 emission from such regions is small compared to the spontaneous background emission from the rest of the source as observed with a large beam. The results reinforce the interpretation of the far-IR lines as true lasers.

  4. Ultrafast laser produced zinc plasma: Stark broadening of emission lines in nitrogen ambient

    NASA Astrophysics Data System (ADS)

    Rao, Kavya H.; Smijesh, N.; Nivas, Jijil JJ; Philip, Reji

    2016-04-01

    The effect of ambient pressure on Stark broadening of emission lines from neutrals and ions in an ultrafast laser (100 fs, 800 nm) produced zinc plasma is investigated. Measured spectra reveal that the full width at half maximum (δλ) of neutral lines remains unchanged in the pressure range of 10-6 to 10-1 Torr, shows an even fluctuation in the pressure range of 0.1 to 100 Torr, and then increases with pressure. On the other hand, δλ of ion lines is nearly a constant from 10-6 to 10-3 Torr, and then increases consistently with ambient pressure. A line narrowing of neutral emissions observed in the region of 1 to 100 Torr can be attributed to larger plasma temperatures, whereas the consistent increase in δλ with pressure seen for ion emission results from the prevalence of additional broadening mechanisms related to Coulomb interactions, ion-ion interaction, and Debye shielding. An accurate knowledge of emission line width is crucial for unambiguously calculating number density values for any given ambient pressure. Moreover, it can be relevant for the design of narrow line width, bright plasma sources for various applications.

  5. VizieR Online Data Catalog: Proxima Cen chromospheric emission lines (Fuhrmeister+, 2011)

    NASA Astrophysics Data System (ADS)

    Fuhrmeister, B.; Lalitha, S.; Poppenhaeger, K.; Rudolf, N.; Liefke, C.; Reiners, A.; Schmitt, J. H. M. M.; Ness, J.-U.

    2011-08-01

    We present an extensive identification catalog of chromospheric emission lines in the optical range for a flare on Proxima Centauri. The data were obtained with ESO's Kueyen telescope equipped with the UVES spectrograph on March 9/10, 11/12, 13/14 in 2009. The instrument was operated in dichroic mode (spectral coverage from 3290 to 4500 and from 6400 to 10080Å). We tabulate measured wavelength, line flux and FWHM for every line and also provide the rest wavelength from the Moore catalog which was used for identification (Moore, 1972, Nat. Stand. Ref. Data. Ser., 40). Few lines were identified with the NIST database. (1 data file).

  6. A Relativistic Fe Kα Emission Line in the Intermediate-Luminosity BeppoSAX Spectrum of the Galactic Microquasar V4641 Sgr

    NASA Astrophysics Data System (ADS)

    Miller, J. M.; Fabian, A. C.; in't Zand, J. J. M.; Reynolds, C. S.; Wijnands, R.; Nowak, M. A.; Lewin, W. H. G.

    2002-09-01

    Broad Fe Kα emission lines have recently been reported in a number of Galactic black holes. Such lines are useful accretion flow diagnostics because they may be produced at the inner accretion disk and shaped by relativistic effects, but in general they have been observed only at luminosities of LX~1037-1038 ergs s-1 in soft X-rays. The Galactic microquasar V4641 Sgr-widely known for its 12.2 Crab (1.5-12 keV) outburst in 1999 September-displayed low-level activity in 1999 March. BeppoSAX observed the source in this state, and Fe Kα line emission was found by in 't Zand et al. In reanalyzing these data, we find strong evidence that the Fe Kα line profile is broadened. For the most likely values of the source distance and black hole mass measured by Orosz et al., our fits to the total spectrum indicate that the source was observed at a luminosity of LX=1.9+1.0-0.8×1036 ergs s-1 (2-10 keV), or LX/LEdd=1.8+0.9- 0.8×10-3. Advection-dominated accretion flow models predict a radially recessed disk in this regime. In contrast, fits to the observed Fe Kα emission-line profile with a relativistic line model constrain the inner disk to be consistent with the marginally stable circular orbit of a Schwarzschild black hole.

  7. Measurement of spatial and temporal behavior of Hα emission from Aditya tokamak using a diagnostic based on a photomultiplier tube array

    NASA Astrophysics Data System (ADS)

    Chowdhuri, M. B.; Ghosh, J.; Manchanda, R.; Kumar, Ajay; Banerjee, S.; Ramaiya, N.; Virani, Niral; Mali, Aniruddh; Amardas, A.; Kumar, Pintu; Tanna, R. L.; Gupta, C. N.; Bhatt, S. B.; Chattopadhyay, P. K.

    2014-11-01

    A photo multiplier tube (PMT) array based spectroscopic diagnostic with fast time response of 10 μs and spatial resolution ˜3 cm has been developed and installed on Aditya tokamak to study the spatial and temporal behavior of Hα emissions from typical discharges. Collimated light has been collected from the plasma along 16 lines of sight passing through entire plasma poloidal cross section of Aditya and detected by two 8 channels PMT arrays after selecting Hα emission using interference filter. The studies are carried out during plasma formation phase of Aditya by changing vertical field and its delay with respect to loop voltage. It is observed that plasma initiated in the high field side in typical discharges of Aditya. The plasma formation position is matched with null field location estimated through simulation.

  8. Measurement of spatial and temporal behavior of H(α) emission from Aditya tokamak using a diagnostic based on a photomultiplier tube array.

    PubMed

    Chowdhuri, M B; Ghosh, J; Manchanda, R; Kumar, Ajay; Banerjee, S; Ramaiya, N; Virani, Niral; Mali, Aniruddh; Amardas, A; Kumar, Pintu; Tanna, R L; Gupta, C N; Bhatt, S B; Chattopadhyay, P K

    2014-11-01

    A photo multiplier tube (PMT) array based spectroscopic diagnostic with fast time response of 10 μs and spatial resolution ∼3 cm has been developed and installed on Aditya tokamak to study the spatial and temporal behavior of Hα emissions from typical discharges. Collimated light has been collected from the plasma along 16 lines of sight passing through entire plasma poloidal cross section of Aditya and detected by two 8 channels PMT arrays after selecting Hα emission using interference filter. The studies are carried out during plasma formation phase of Aditya by changing vertical field and its delay with respect to loop voltage. It is observed that plasma initiated in the high field side in typical discharges of Aditya. The plasma formation position is matched with null field location estimated through simulation. PMID:25430318

  9. Measurement of spatial and temporal behavior of H{sub α} emission from Aditya tokamak using a diagnostic based on a photomultiplier tube array

    SciTech Connect

    Chowdhuri, M. B. Ghosh, J.; Manchanda, R.; Banerjee, S.; Ramaiya, N.; Virani, Niral; Mali, Aniruddh; Amardas, A.; Kumar, Pintu; Tanna, R. L.; Gupta, C. N.; Bhatt, S. B.; Chattopadhyay, P. K.; Kumar, Ajay

    2014-11-15

    A photo multiplier tube (PMT) array based spectroscopic diagnostic with fast time response of 10 μs and spatial resolution ∼3 cm has been developed and installed on Aditya tokamak to study the spatial and temporal behavior of H{sub α} emissions from typical discharges. Collimated light has been collected from the plasma along 16 lines of sight passing through entire plasma poloidal cross section of Aditya and detected by two 8 channels PMT arrays after selecting H{sub α} emission using interference filter. The studies are carried out during plasma formation phase of Aditya by changing vertical field and its delay with respect to loop voltage. It is observed that plasma initiated in the high field side in typical discharges of Aditya. The plasma formation position is matched with null field location estimated through simulation.

  10. Removing Spectral Diagnostics of Galactic and Stellar X-Ray Emission from Charged Exchange Recombination

    NASA Technical Reports Server (NTRS)

    Wargelin, Brad

    2004-01-01

    feasibility of our longer-range plan. For example, we successfully injected He into EBIT (not a small feat because of the difficulty of maintaining a good vacuum with He and avoiding electrical breakdown) to collect a H-like oxygen CX spectrum. The highest energy CX spectrum recorded with the XRS to date is that of the Ar K-shell emission. These measurements provided the first observation of the relative intensity ratios of resolved He-like singlet and triplet n=2->1 lines. We also carried out measurements of He-like Ne as a function of collision energy (i.e., ion temperature). Significant differences in the resulting x-ray spectra were noted. In all cases, the intensity of high-n H-like Lyman lines is significantly higher than current theoretical CX models predict.

  11. Strong optical and UV intermediate-width emission lines in the quasar SDSS J232444.80–094600.3: dust-free and intermediate-density gas at the skin of dusty torus?

    NASA Astrophysics Data System (ADS)

    Li, Zhen-Zhen; Zhou, Hong-Yan; Hao, Lei; Wang, Shu-Fen; Ji, Tuo; Liu, Bo

    2016-09-01

    Emission lines from the broad emission line region (BELR) and the narrow emission line region (NELR) of active galactic nuclei (AGNs) have been extensively studied. However, emission lines are rarely detected between these two regions. We present a detailed analysis of quasar SDSS J232444.80–094600.3 (SDSS J2324–0946), which is remarkable for its strong intermediate-width emission lines (IELs) with FWHM ≈ 1800 km s‑1. The IEL component is present in different emission lines, including the permitted lines Lyα λ1216, CIV λ1549, semiforbidden line [CIII] λ1909, and forbidden lines [OIII] λλ4959, 5007. With the aid of photo-ionization models, we found that the IELs are produced by gas with a hydrogen density of nH ∼ 106.2 ∼ 106.3 cm‑3, a distance from the central ionizing source of R ∼ 35 – 50 pc, a covering factor of ∼ 6%, and a dust-to-gas ratio of ≤ 4% that of the SMC. We suggest that the strong IELs of this quasar are produced by nearly dust-free and intermediate-density gas located at the skin of the dusty torus. Such strong IELs, which serve as a useful diagnostic, can provide an avenue to study the properties of gas between the BELR and the NELR.

  12. Excitation of emission lines by fluorescence and recombination in IC 418

    NASA Astrophysics Data System (ADS)

    Escalante, V.; Morisset, C.; Georgiev, L.

    2012-11-01

    We compare calculated intensities of lines of C II, N I, N II, O I and O II with a published deep spectroscopic survey of IC 418. Our calculations use a self-consistent nebular model and a synthetic spectrum of the central star atmosphere to take into account line excitation by continuum fluorescence and electron recombination. We found that the N II spectrum of the s, p and most d states is excited by fluorescence due to the low-excitation conditions of the nebula. Many C II and O II lines have significant amount of excitation by fluorescence. Recombination excites all the lines from the f and g states and most O II lines. In the neutral-ionized boundary, the N I quartet and O I triplet dipole-allowed lines are excited by fluorescence, while the quintet O I lines are excited by recombination. Electron excitation produces the forbidden optical lines of O I, and continuum fluorescence enhances the N I forbidden line intensities. Lines excited by fluorescence of light below the Lyman limit thus suggest a new diagnostic to explore the inner boundary of the photodissociation region of the nebula.

  13. Spectral diagnostics based on Doppler-broadened H{sub α} line shape in a single element of a matrix source

    SciTech Connect

    Iordanova, S.; Pashov, A.

    2015-04-08

    The study is on optical emission spectroscopy diagnostics of a single element of a matrix source of negative hydrogen ions. The method developed for description of the hydrogen atoms behaviour is based on analysis of the Balmer H{sub α} line profile, and it can be readily applied to various low pressure hydrogen discharges. The present observations reveal the existence of thermal as well as of non-thermal fast hydrogen atoms in the discharge. For processing of the experimental data a line shape model, which accounts for details of the plasma kinetics and the fine structure of the Balmer lines is developed. The fit of this model to the recorded at different experimental conditions line shapes results in the temperature of the thermal atoms, the mean energy of the fast atoms, the ratio between the densities of these two group of atoms and the relative populations of the fine structure components of the n = 3 hydrogen state. The present study indicates that the reactions leading to production of fast atoms and the process of energy exchange between thermal and fast atoms may be important for the correct modeling of the plasma kinetics.

  14. Characterizing ICF Neutron Scintillation Diagnostics on the nTOF line at SUNY Geneseo

    NASA Astrophysics Data System (ADS)

    Lawson-Keister, Pat; Padawar-Curry, Jonah; Visca, Hannah; Fletcher, Kurt; Padalino, Stephen; Sangster, T. Craig; Regan, Sean

    2015-11-01

    Neutron scintillator diagnostics for ICF and HEDP can be characterized using the neutron time-of-flight (nTOF) line on Geneseo's 1.7 MV tandem Pelletron accelerator. Neutron signals can be differentiated from gamma signals by employing coincidence methods. A 1.8-MeV beam of deuterons incident on a deuterated polyethylene target produces neutrons via the 2H(d,n)3He reaction. Neutrons emerging at a lab angle of 88° have an energy of 2.96 MeV; the 3He ions associated with these neutrons are detected at a scattering angle of 43° using a surface barrier detector. The time of flight of the neutron can be measured by using the 3He detection as a ``start'' signal and the scintillation detection as a ``stop'' signal. This time of flight requirement is used to identify the 2.96-MeV neutron signals in the scintillator. To measure the light curve produced by these monoenergetic neutrons, two photomultiplier (PMT) tubes are attached to the scintillator. The full aperture PMT establishes the nTOF coincidence. The other PMT is fitted with a pinhole to collect single events. The time between the full aperture PMT signal and the arrival of the signal in the pinhole PMT is used to determine the light curve for the scintillator. This system will enable the neutron response of various scintillators to be compared. Supported in part by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944.

  15. New electron cyclotron emission diagnostic for measurement of temperature based upon the electron Bernstein wave

    SciTech Connect

    Efthimion, P.C.; Hosea, J.C.; Kaita, R.; Majeski, R.; Taylor, G.

    1999-01-01

    Most magnetically confined plasma devices cannot take advantage of standard electron cyclotron emission (ECE) diagnostics to measure temperature. They either operate at high density relative to their magnetic field (e.g., {omega}{sub p}{gt}{Omega}{sub c} in spherical tokamaks) or they do not have sufficient density and temperature to reach the blackbody condition ({tau}{gt}2). The standard ECE technique measures the electromagnetic waves emanating from the plasma. Here we propose to measure electron Bernstein waves (EBW) to ascertain the local electron temperature in these plasmas. The optical thickness of EBW is extremely high because it is an electrostatic wave with a large k{sub i}. For example, the National Spherical Torus Experiment (NSTX) will have an optical thickness {tau}{approx}3000 and CDX-U will have {tau}{approx}300. One can reach the blackbody condition with a plasma density {approx}10{sup 11}thinspcm{sup {minus}3} and T{sub e}{approx}1thinspeV. This makes it attractive to most plasma devices. The serious issue with using EBW is the wave accessibility for the emission measurement. Simple accessibility arguments indicate the wave may be accessible by either direct coupling or mode conversion through an extremely narrow layer ({approx}1{endash}2 mm). EBW experiments on the Current Drive Experiment-Upgrade (CDX-U) will test the accessibility properties of the spherical tokamak configuration. {copyright} {ital 1999 American Institute of Physics.}

  16. Spectrometer for single-shot x-ray emission and photon diagnostics

    NASA Astrophysics Data System (ADS)

    Frassetto, F.; Miotti, P.; Callegari, C.; de Simone, M.; Finetti, P.; Giangrisostomi, E.; Grazioli, C.; Iesari, F.; Kivimäki, A.; Mincigrucci, R.; Principi, E.; Stagira, S.; Di Cicco, A.; Coreno, M.; Poletto, L.

    2014-09-01

    We present the design and characterization of a compact and portable spectrometer realized for photon in-photon out experiments (in particular X-Ray Emission Spectroscopy, XES), in particular tailored to be used at the FERMI freeelectron- laser (FEL) at ELETTRA (Italy). The spectrometer can be installed on different end stations at variable distances from the target area both at synchrotron and FEL beamlines. Different input sections can be accommodated in order to fit the experimental requests, with/without an entrance slit and with/without an additional relay mirror. The design is compact in order to realize a portable instrument within a total footprint of less than one square meter. The instrument is based on the use of two flat-field grazing-incidence gratings and an EUV-enhanced CCD detector to cover the 25-800 eV spectral range, with spectral resolution better than 0.2%. The absolute response of the spectrometer, has been measured in the whole spectral region of operation, allowing calibrated measurements of the photon flux. The characterization on the Gas Phase beamline at ELETTRA Synchrotron as instrument for XES and some experimental data of the FEL emission taken at EIS-TIMEX beamline at FERMI, where the instrument has been used for photon beam diagnostics, are presented.

  17. The Far-Infrared Emission Line and Continuum Spectrum of the Seyfert Galaxy NGC 1068

    NASA Technical Reports Server (NTRS)

    Spinoglio, Luigi; Smith, Howard A.; Gonzalez-Alfonso, Eduardo; Fisher, Jacqueline

    2005-01-01

    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 emission lines, the OH rotational lines at 79, 119 and 163 microns were all detected in emission, which is unique among galaxies with full LWS spectra, where the 119 micron line, where detected, is always in absorption. The observed line intensities were modelled together with IS0 Short Wavelength Spectrometer (SWS) and optical and ultraviolet line intensities from the literature, considering two independent emission components: the AGN component and the starburst component in the circumnuclear ring of approximately 3kpc in size. Using the UV to mid-IR emission line 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 line emission, 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 line fluxes to within a factor 2.0 on average with a standard deviation of 1.4. The OH 119 micron emission indicates that the line is collisionally excited, and arises in a warm and dense region. The OH emission has been modeled using spherically symmetric, non-local, non-LTE radiative transfer models. The models indicate that the bulk of the emission arises from the nuclear region, although some extended contribution from the starburst is not ruled out. The OH abundance

  18. The Connections Between the UV and Optical Fe ii Emission Lines in Type 1 AGNs

    NASA Astrophysics Data System (ADS)

    Kovačević-Dojčinović, Jelena; Popović, Luka Č.

    2015-12-01

    We investigate the spectral properties of the UV (λλ2650-3050 Å) and optical (λλ4000-5500 Å) Fe ii emission 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 emission line properties, as well as the correlations with other emission lines 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 lines, indicating that the UV and optical Fe ii lines originate from the outer part of the broad line region, the so-called intermediate line region. (ii) The unexplained anticorrelations of the optical Fe ii equivalent width (EW Fe iiopt) versus EW [O iii] 5007 Å and EW Fe iiopt versus FWHM Hβ have not been detected for the UV Fe ii lines. (iii) The significant averaged redshift in the UV Fe ii lines, 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 lines 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 line ratios of the UV and optical Fe ii lines.

  19. THE BALDWIN EFFECT IN THE NARROW EMISSION LINES OF ACTIVE GALACTIC NUCLEI

    SciTech Connect

    Zhang, Kai; Wang, Ting-Gui; Dong, Xiao-Bo; Gaskell, C. Martin E-mail: twang@ustc.edu.cn E-mail: martin.gaskell@uv.cl

    2013-01-01

    The anti-correlations between the equivalent widths of emission lines and the continuum luminosity in active galactic nuclei (AGNs), known as the Baldwin effect, are well established for broad lines, but are less well studied for narrow lines. In this paper we explore the Baldwin effect of narrow emission lines over a wide range of ionization levels and critical densities using a large sample of broad-line, radio-quiet AGNs taken from Sloan Digital Sky Survey Data Release 4. These type 1 AGNs span three orders of magnitude in continuum luminosity. We show that most narrow lines show a similar Baldwin effect slope of about -0.2, while the significant deviations of the slopes for [N II] {lambda}6583, [O II] {lambda}3727, [Ne V] {lambda}3425, and the narrow component of H{alpha} can be explained by the influence of metallicity, star formation contamination, and possibly by the difference in the shape of the UV-optical continuum. The slopes do not show any correlation with either the ionization potential or the critical density. We show that a combination of 50% variations in continuum near 5100 A and a lognormal distribution of observed luminosity can naturally reproduce a constant Baldwin effect slope of -0.2 for all narrow lines. The variations of the continuum could be due to variability, intrinsic anisotropic emission, or an inclination effect.

  20. The asymmetric profile of the H76 alpha line emission from MWC349

    NASA Technical Reports Server (NTRS)

    Rodriquez, L. F.; Canto, J.; Escalante, V.; Moran, J. M.

    1986-01-01

    MWC349 is an emission-line star found by Merrill, Humason and Burwell (1932). Braes, Habing and Schoenmaker (1972) discovered that it is a strong radio source. The radio emission originates in a massive ionized wind that is expanding with a velocity of about 50 km s(-1). Its continuum spectrum fits well a nu(0.6) power law from the cm wavelengths to the far-IR. Radio recombination line emission from the envelope of MWC349 was first detected by Altenhoff, Strittmatter and Wendker (1981). We have obtained good signal-to-noise ratio, Very Large Array observations of the H76 alpha radio recombination line from the ionized wind of MWC349. Our data reveal that the profile is markedly asymmetric, with a steep rise on the blue side. This asymmetry could be due to non-LTE effects in the formation and transfer of the line or to intrinsic asymmetries in the envelope. Our analysis suggests that most probably the peculiar profile is caused by a non-LTE enhancement of the line emission from the side of the envelope nearer to the observer. This asymmetry has the opposite sense than that observed in optical and IR recombination lines, where a different effect (absorption of the stellar continuum by the gas in the wind between the star and the observer) is known to be dominant, leading to the classic P Cygni profile. We propose that the profiles of the radio recombination lines from ionized stellar winds will have this characteristic shape, while optical and IR recombination lines are characterized by P Cygni-like profiles. Unfortunately, at present the detection of radio recombination lines from ionized stellar winds is only feasible for MWC349 and a few other objects.

  1. HST WFC3 Early Release Science: Emission-line Galaxies from IR Grism Observations

    NASA Astrophysics Data System (ADS)

    Straughn, Amber; Kuntschner, H.; Kuemmel, M.; Walsh, J.; Cohen, S.; Gardner, J. P.; Windhorst, R. A.; O'Connell, R. W.; Pirzkal, N.; Meurer, G.; McCarthy, P. J.; Hathi, N. P.; Malhotra, S.; Rhoads, J.; SOC, WFC3

    2011-01-01

    The Early Release Science II program for HST WFC3 includes one pointing observed with the G102 (0.8-1.1 microns; R 210) and G141 (1.1-1.6 microns; R 130) infrared grisms at a depth of 2 orbits/grism. From this data we detect 48 actively star-forming emission-line galaxies and measure the galaxies' redshifts, line fluxes, star-formation rates, and masses. In particular, the prominent emission lines Ha, [OII], and [OIII] fall into the two infrared grism bandpasses over a redshift range z=0.2-3.6, and the majority of galaxies have at least two lines in the observable wavelength range resulting in secure line identification and redshift determination. We detect galaxies with line fluxes to 3 x 10-17 erg/s/cm2 as well as several sources with very high EW lines. The higher spectral resolution and sensitivity of the WFC3 grisms over previous instrumentation also allows detection of other emission lines in some galaxies. The average magnitude of the emission-line galaxy sample is mAB(F098M)=23.6 mag with more than 20% of the sample fainter than mAB(F098M)=25 mag, demonstrating the remarkable efficiency and capability of the WFC3 NIR grisms for measuring galaxy properties to faint magnitudes and intermediate redshifts. Our results point to the promising potential for future science with WFC3 grism spectroscopy, as well as upcoming missions such as JWST and WFIRST. This paper is based on Early Release Science observations made by the WFC3 Scientific Oversight Committee. We are grateful to the Director of the Space Telescope Science Institute for awarding Director's Discretionary time for this program. This research was supported in part by an appointment to the NASA Postdoctoral Program at Goddard Space Flight Center, administered by Oak Ridge Associated Universities through a contract with NASA (ANS).

  2. Comparison of Fe XVIII and Fe XIX Line Emissions with Spectral Models

    NASA Astrophysics Data System (ADS)

    Desai, P.; Brickhouse, N. S.; Drake, J. J.; Edgar, R. J.; Hoogerwerf, R.; Kashyap, V.; Wargelin, B. J.; Smith, R. K.; Huenemoerder, D. P.; Liedahl, D. A.

    2005-06-01

    We discuss here the observations of Fe XVIII and XIX emission lines and compare the X-ray, EUV and FUV lines with the spectral codes widely used today (e.g. FAC and APEC). We assess the relative accuracy of these spectral models and try to identify the critical atomic data and processes. Capella with a narrow enhancement in its emission measure distribution at 6 MK provides a unique opportunity to test the Fe XVIII and Fe XIX model emissivities which peak from 6 to 8 MK. We use the summed spectra from Chandra HETG/ACIS-S and LETG/HRC-S, as well as contemporaneous EUVE and FUSE observations, to measure line ratios for comparison with predictions.

  3. A Calibrated H-alpha Index to Monitor Emission Line Objects

    NASA Astrophysics Data System (ADS)

    Hintz, Eric G.; Joner, M. D.

    2013-06-01

    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 emission line 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 emission line objects are easily detected. We will present the overall location of these emission line objects. We will also present the changes experiences by these objects over the course of the years of the project.

  4. An optical emission-line phase of the extreme carbon star IRC +30219

    NASA Technical Reports Server (NTRS)

    Cohen, M.

    1980-01-01

    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 emission line 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 lines arose in a shocked region where recent stellar mass loss encountered the extensive circumstellar envelope. By late 1979, this emission-line 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 emission, both due to recently condensed hot dust grains.

  5. RELATIVISTIC BROADENING OF IRON EMISSION LINES IN A SAMPLE OF ACTIVE GALACTIC NUCLEI

    SciTech Connect

    Brenneman, Laura W.; Reynolds, Christopher S.

    2009-09-10

    We present a uniform X-ray spectral analysis of eight type-1 active galactic nuclei that have been previously observed with relativistically broadened iron emission lines. Utilizing data from the XMM-Newton European Photon Imaging Camera (EPIC-pn) we carefully model the spectral continuum, taking complex intrinsic absorption and emission into account. We then proceed to model the broad Fe K{alpha} feature in each source with two different accretion disk emission line codes, as well as a self-consistent, ionized accretion disk spectrum convolved with relativistic smearing from the inner disk. Comparing the results, we show that relativistic blurring of the disk emission is required to explain the spectrum in most sources, even when one models the full reflection spectrum from the photoionized disk.

  6. Diagnostics of a see-through hollow cathode discharge by emission, absorption, and fluorescence spectroscopy

    NASA Astrophysics Data System (ADS)

    Taylor, Nicholas

    Atomic line filters have been suggested to be attractive in areas of Doppler velocimetry, resonance fluorescence detection, and resonance ionization detection. They are based on the resonant absorption of photons by an atomic vapor, and allow all other radiation to pass. This allows the detection of very low levels of light superimposed on a large optical background. Several elements have been studied for use as atomic line filters, such as the alkali metals, alkaline earths, and thallium. As previously recognized, thallium is especially attractive since the 535.046 nm metastable transition overlaps with the second harmonic output of an Nd:La2Be2O 5 (BEL) laser (1070 nm). This makes thallium ideal for certain applications as an atomic line filter. Recently a see-through hollow cathode lamp, or galvatron (Hamamatsu), was made commercially available. The galvatron geometry is unique compared to traditional hollow cathode lamps since the cathode and cell are oriented in a T-shape, with the cathode bored completely through to allow the propagation of a light source through the cathode. This allows multi-step excitation of the atomic vapor, not easily accomplished with a traditional hollow cathode lamp. The advantages that a galvatron offers over conventional atomic reservoirs make it an attractive candidate for the application as an atomic line filter; however, little spectroscopic data have been found in the literature. For this reason, Doppler temperatures, number densities, quantum efficiencies, and lifetimes have been determined in order to characterize this atomic reservoir as a potential atomic line filter. These parameters are determined by use of various spectroscopic techniques which include emission, absorption, time-resolved fluorescence, and time-resolved laser-induced saturated fluorescence spectroscopy. From these measurements, it has been demonstrated that a galvatron is an attractive atomic reservoir for applications as an atomic line filter. The

  7. (12)CO (3-2) & (1-0) emission line observations of nearby starburst galaxy nuclei

    NASA Technical Reports Server (NTRS)

    Devereux, Nicholas; Taniguchi, Yoshiaki; Sanders, D. B.; Nakai, N.; Young, J. S.

    1994-01-01

    New measurements of the (12)CO (1-0) and (12)CO (3-2) line emission 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) emission line 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) emission line 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) emission line ratio measured for the seven starburst galaxy nuclei is -0.64 +/- 0.06. The (12)CO (3-2)/(1-0) emission line 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) emission line 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.

  8. Composition of an emission line system in black hole host globular cluster RZ2109

    SciTech Connect

    Steele, Matthew M.; Zepf, Stephen E.; Maccarone, Thomas J.; Kundu, Arunav; Rhode, Katherine L.; Salzer, John J.

    2014-04-20

    We present an analysis of optical spectra from the globular cluster RZ2109 in NGC 4472, which hosts the first unambiguous globular cluster black hole. We use these spectra to determine the elemental composition of the emission line system associated with this source, and to constrain the age and metallicity of the host globular cluster. For the emission line system of RZ2109, our analysis indicates the [O III] λ5007 equivalent width is 33.82 ± 0.39 Å and the Hβ equivalent width is 0.32 ± 0.32 Å, producing a formal [O III] λ5007/Hβ emission line ratio of 106 for a 3200 km s{sup –1} measurement aperture covering the full velocity width of the [O III] λ5007 line. Within a narrower 600 km s{sup –1} aperture covering the highest luminosity velocity structure in the line complex, we find [O III] λ5007/Hβ = 62. The measured [O III] λ5007/Hβ ratios are significantly higher than can be produced in radiative models of the emission line region with solar composition, and the confidence interval limits exclude all but models which have gas masses much larger than those for a single star. Therefore, we conclude that the region from which the [O III] λ5007 emission originates is hydrogen-depleted relative to solar composition gas. This finding is consistent with emission from an accretion-powered outflow driven by a hydrogen-depleted donor star, such as a white dwarf, being accreted onto a black hole.

  9. Diagnostics of H^- and D^- in High-Density H2 and D2 Plasmas by Laser Photodetachment and Optical Emission Spectroscopy

    NASA Astrophysics Data System (ADS)

    Yamaguchi, H.; Sasaki, K.; Kadota, K.; Goto, M.; Morita, S.; Kawahata, K.

    2000-10-01

    In the present work, we propose a simple method for diagnostics of negative ions in hydrogen plasmas. Since the present method employs optical emission spectroscopy, it has good accessibility to fusion and processing plasmas which have a limited number of observation ports. The principle of the method is based on mutual neutralization reaction between positive and negative ions (H^+ + H^- arrow H + H). Excited hydrogen atoms are produced by this reaction, and the excited state decays with optical emissions. If we detect the optical emission from H^* produced by this reaction, we can monitor negative ions in plasmas. This method has been demonstrated in an oxygen plasma successfully (T. Ishikawa, D. Hayashi, K. Sasaki, and K. Kadota, Appl. Phys. Lett. 72, 2391 (1998)). Experiments were carried out in pulse-modulated high-density H2 and D2 plasmas. Optical emission at the H_α line was observed in the afterglow. The H^- density was measured by probe-assisted laser photodetachment. Temporal variation of the emission intensity due to H^+ + H^- arrow H + H^* was compared with that of the product between H^+ and H^- densities.

  10. B Stars with and without emission lines, parts 1 and 2

    NASA Technical Reports Server (NTRS)

    Underhill, A. (Editor); Doazan, V. (Editor)

    1982-01-01

    The spectra for B stars for which emission lines occur not on the main sequence, but only among the supergiants, and those B stars for which the presence of emission 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.

  11. Emission line shape of B850 band of light-harvesting complex II

    NASA Astrophysics Data System (ADS)

    Kumar, Praveen; Jang, Seogjoo

    2011-03-01

    A theoretical framework is developed for the emission line shape of the single complex spectroscopy (SCS). The quantum mechanical characteristics of the single complex emission line shapes for the model B850 band of the light harvesting complex 2 of purple bacteria are studied including both static and quasi-static disorders within the exciton Hamiltonian. The bath is modeled as an infinite sum of harmonic oscillators. For the Gaussian type of disorder, we examined the dependencies of the spectral line shapes on the temperature, polarization of the radiation, and on the type of exciton-bath coupling. Theoretically obtained emission profile is also compared with the absorption profile in the frequency domain. It is observed that emission profile contains an extra inhomogeneous term coming from the entanglement of the system and bath degrees of freedom in the initial equilibrium density operator. Contribution of this term to the overall emission line shape is studied in detail. This research was supported by the Department of Energy, Office of Basic Energy Sciences.

  12. Emission Line Galaxies in the STIS Parallel Survey. 1; Observations and Data Analysis

    NASA Technical Reports Server (NTRS)

    Teplitz, Harry I.; Collins, Nicholas R.; Gardner, Jonathan P.; Hill, Robert S.; Heap, Sara R.; Lindler, Don J.; Rhodes, Jason; Woodgate, Bruce E.

    2002-01-01

    In the first three years of operation STIS obtained slitless spectra of approximately 2500 fields in parallel to prime HST observations as part of the STIS Parallel Survey (SPS). The archive contains approximately 300 fields at high galactic latitude (|b| greater than 30) with spectroscopic exposure times greater than 3000 seconds. This sample contains 220 fields (excluding special regions and requiring a consistent grating angle) observed between 6 June 1997 and 21 September 2000, with a total survey area of approximately 160 square arcminutes. At this depth, the SPS detects an average of one emission line galaxy per three fields. We present the analysis of these data, and the identification of 131 low to intermediate redshift galaxies detected by optical emission lines. The sample contains 78 objects with emission lines that we infer to be redshifted [OII]3727 emission at 0.43 < z < 1.7. The comoving number density of these objects is comparable to that of Halpha-emitting galaxies in the NICMOS parallel observations. One quasar and three probable Seyfert galaxies are detected. Many of the emission-line objects show morphologies suggestive of mergers or interactions. The reduced data are available upon request from the authors.

  13. Understanding the Physical Conditions that Drive Line Emission in Nebular Regions of High-Redshift Galaxies

    NASA Astrophysics Data System (ADS)

    Zeimann, Gregory; Gebhardt, H.; Ciardullo, R.; Gronwall, C.; Hagen, A.

    2014-01-01

    We use the 3D-HST near-IR grism survey to study the physical conditions of the nebular regions within a statistically complete sample of ~ 300 emission-line selected star forming galaxies in the redshift range of 2.0 < z < 2.3. These spectra include the emission lines of oxygen ([O II] 3727, [O III] 5007), neon ([Ne III] 3869), and hydrogen (H-beta, H-gamma); when coupled with constraints on reddening and stellar mass derived from the objects' spectral energy distributions, these data allow us to explore parameters such as the systems' alpha-element abundances and ionization parameters. We try to reproduce these line ratios using theoretical models, such as CLOUDY, and compare line ratios with that of possible local analogs like Green Pea galaxies and Blue Compact Dwarfs. With our sample we can study any possible evolution in the physical conditions of star formation regions.

  14. Theoretical quasar emission-line profiles. I - Curve-of-growth effects on observed profiles

    NASA Technical Reports Server (NTRS)

    Hubbard, E. N.; Puetter, R. C.

    1983-01-01

    Radiative transfer effects are examined in an investigation of the kinematics of quasar and Seyfert emission-line regions with pancake cloud geometries. Consideration is given only to the effects of limb brightening with the aspect angle of pancake clouds, assuming that all lines lie on a single portion of the curve of growth. This effect is coupled with several simple but plausible ensemble geometries and dynamics, and a number of theoretical emission-line profiles have been generated. It is shown that these profiles differ substantially depending on both the ensemble geometry and the portion of the curve of growth considered; for a given ensemble geometry, optically thick line profiles are different from optically thick profiles. It is shown that, for radiatively driven clouds, ensembles of clouds which have maximum velocities approaching the terminal velocity of the acceleration mechanism never produce acceptable profiles unless the cloud luminosity is a strongly decreasing function of radius.

  15. VizieR Online Data Catalog: Classification of emission-line gal. (Dessauges-Zavadsky 2000)

    NASA Astrophysics Data System (ADS)

    Dessauges-Zavadsky, M.; Pindao, M.; Maeder, A.; Kunth, D.

    2000-01-01

    The main goal of this work was to further investigate the classification of emission-line galaxies from the "Spectrophotometric Catalogue of HII galaxies" by Terlevich et al. (1991, Cat. J/A+AS/91/285) in a homogeneous and objective way, using the three line-ratio diagrams of Veilleux & Osterbrock (1987ApJS...63..295V). The re-measurements of the most important nebular lines and a revised classification are presented for 314 narrow-emission-line galaxies (represented by 405 spectra) from Terlevich's et al. (1991, Cat. J/A+AS/91/285) catalogue. The revised catalogue contains 267 HII galaxies, 25 Seyfert2 galaxies, 3 LINERs, 4 "revised" galaxies, 13 "transition" galaxies and 2 "ambiguous" galaxies. (1 data file).

  16. [A new automated method to identify emission line star from massive spectra].

    PubMed

    Pan, Jing-Chang; Zhang, Cai-Ming; Wei, Peng; Luo, A-Li; Zhao, Yong-Heng

    2012-06-01

    Stellar spectra are characterized by obvious absorption lines or absorption bands, while those with emission lines are usually special stars such as cataclysmic variable stars (CVs), HerbigAe/Be etc. The further study of this kind of spectra is meaningful. The present paper proposed a new method to identify emission line stars (ELS) spectra automatically. After the continuum normalization is done for the original spectral flux, line detection is made by comparing the normalized flux with the mean and standard deviation of the flux in its neighbor region The results of the experiment on massive spectra from SDSS DR8 indicate that the method can identify ELS spectra completely and accurately. Since no complex transformation and computation are involved in this method, the identifying process is fast and it is ideal for the ELS detection in large sky survey projects like LAMOST and SDSS. PMID:22870668

  17. 40 CFR 86.1717-99 - Emission control diagnostic system for 1999 and later light-duty vehicles and light-duty trucks.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 19 2010-07-01 2010-07-01 false Emission control diagnostic system for... Emission Vehicle Program for Light-Duty Vehicles and Light-Duty Trucks § 86.1717-99 Emission control... Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM...

  18. 40 CFR 86.1717-01 - Emission control diagnostic system for 1999 and later light-duty vehicles and light-duty trucks.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 19 2010-07-01 2010-07-01 false Emission control diagnostic system for... Emission Vehicle Program for Light-Duty Vehicles and Light-Duty Trucks § 86.1717-01 Emission control... Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM...

  19. The size of the narrow-line-emitting region in the Seyfert 1 galaxy NGC 5548 from emission-line variability

    SciTech Connect

    Peterson, B. M.; Denney, K. D.; De Rosa, G.; Grier, C. J.; Pogge, R. W.; Kochanek, C. S.; Bentz, M. C.; Vestergaard, M.; Kilerci-Eser, E.; Dalla Bontà, E.; Ciroi, S.

    2013-12-20

    The narrow [O III] λλ4959, 5007 emission-line fluxes in the spectrum of the well-studied Seyfert 1 galaxy NGC 5548 are shown to vary with time. From this we show that the narrow-line-emitting region has a radius of only 1-3 pc and is denser (n {sub e} ∼ 10{sup 5} cm{sup –3}) than previously supposed. The [O III] line width is consistent with virial motions at this radius given previous determinations of the black hole mass. Since the [O III] emission-line flux is usually assumed to be constant and is therefore used to calibrate spectroscopic monitoring data, the variability has ramifications for the long-term secular variations of continuum and emission-line fluxes, though it has no effect on shorter-term reverberation studies. We present corrected optical continuum and broad Hβ emission-line light curves for the period 1988-2008.

  20. VizieR Online Data Catalog: Nebular emission lines towards NGC3372 center (Damiani+, 2016)

    NASA Astrophysics Data System (ADS)

    Damiani, F.; Bonito, R.; Magrini, L.; Prisinzano, L.; Mapelli, M.; Micela, G.; Kalari, V.; Maiz Apellaniz, J.; Gilmore, G.; Randich, S.; Alfaro, E.; Flaccomio, E.; Koposov, S.; Klutsch, A.; Lanzafame, A. C.; Pancino, E.; Sacco, G. G.; Bayo, A.; Carraro, G.; Casey, A. R.; Costado, M. T.; Franciosini, E.; Hourihane, A.; Lardo, C.; Lewis, J.; Monaco, L.; Morbidelli, L.; Worley, C.; Zaggia, S.; Zwitter, T.; Dorda, R.

    2016-04-01

    Nebular emission lines of H-alpha, [NII] 6584Å, HeI 6678Å, [SII] 6717Å, [SII] 6731Å, towards the center of Carina nebula, are modeled with two gaussians each ('blue' and 'red' components). Best-fit parameters are given in the table. Line widths include the instrumental width of the Giraffe spectrograph (7km/s). Radial velocities are heliocentric. (1 data file).

  1. Time-dependent modelling of the molecular line emission from shock waves in outflow sources

    NASA Astrophysics Data System (ADS)

    Flower, D. R.; Pineau des Forêts, G.

    2012-04-01

    We have developed further the technique of time-dependent modelling of magnetohydrodynamic shock waves, with a view to interpreting the molecular line emission from outflow sources. The extensively observed source L1157 B1 was chosen as an exemplar of the application of this technique. The dynamical age of the shock wave model was varied in the range 500 ≤t≤ 5000 yr, with the best fit to the observed line intensities being obtained for t= 1000 yr; this is of the same order as the dynamical age derived by Gueth, Guilloteau & Bachiller from their observations of L1157 B1. The emission line spectra of H2, CO, SiO, ortho- and para-H2O, ortho- and para-NH3, and A- and E-type CH3OH were calculated in parallel with the dynamical and chemical parameters of the model, using the 'large velocity gradient' (LVG) approximation to the line transfer problem. We compared the predictions of the models with the observed intensities of emission lines of H2, CO, SiO, ortho-H2O, ortho-NH3 and CH3OH, which include recent Herschel satellite measurements. In the case of SiO, we show (in Appendix A) that extrapolations of the collisional rate coefficients beyond the range of kinetic temperature for which they were originally calculated lead to spurious rotational line intensities and profiles. The computed emission-line spectra of SiO, NH3 and CH3OH are shown to depend on the assumed initial composition of the grain mantles, from whence they are released, by sputtering in the shock wave, into the gas phase. The dependence of the model predictions on the adopted form of the grain-size distribution is investigated in Appendix B; the corresponding integral line intensities are given in tabular form, for a range of C-type shock speeds, in the online Supporting Information.

  2. Identification of Emission Lines in a Meteor Spectrum Obtained on August 2, 2011

    NASA Astrophysics Data System (ADS)

    Mozgova, A. M.; Borovicka, J.; Spurny, P.; Churyumov, K. I.

    125 emission lines were found in a meteor spectrum obtained on August 2, 2011. The identification of most of the lines is given. The following species were found in the spectrum: CrI, FeI, MgI, SiI, AlI, MnI, CaI, TiI, NaI, FeII, CaII, MgII, SiII, SrII.

  3. Polycyclic Aromatic Hydrocarbon Emission in Spitzer/IRS Maps. I. Catalog and Simple Diagnostics

    NASA Astrophysics Data System (ADS)

    Stock, D. J.; Choi, W. D.-Y.; Moya, L. G. V.; Otaguro, J. N.; Sorkhou, S.; Allamandola, L. J.; Tielens, A. G. G. M.; Peeters, E.

    2016-03-01

    We present a sample of resolved galactic H ii regions and photodissociation regions (PDRs) observed with the Spitzer infrared spectrograph in spectral mapping mode between the wavelengths of 5-15 μm. For each object we have spectral maps at a spatial resolution of ˜4″ in which we have measured all of the mid-infrared emission and absorption features. These include the polycyclic aromatic hydrocarbon (PAH) emission bands, primarily at 6.2, 7.7, 8.6, 11.2, and 12.7 μm, as well as the spectral emission lines of neon and sulfur and the absorption band caused by silicate dust at around 9.8 μm. In this work we describe the data in detail, including the data reduction and measurement strategies, and subsequently present the PAH emission band intensity correlations for each of the objects and the sample as a whole. We find that there are distinct differences between the sources in the sample, with two main groups: the first comprising the H ii regions and the second the reflection nebulae (RNe). Three sources—the reflection nebula NGC 7023, the Horsehead nebula PDR (an interface between the H ii region IC 434 and the Orion B molecular cloud), and M17—resist this categorization, with the Horsehead PDR points mimicking the RNe and the NGC 7023 fluxes displaying a unique bifurcated appearance in our correlation plots. These discrepancies seem to be due to the very low radiation field experienced by the Horsehead PDR and the very clean separation between the PDR environment and a diffuse environment in the NGC 7023 observations.

  4. Warm ionized gas in CALIFA early-type galaxies. 2D emission-line patterns and kinematics for 32 galaxies

    NASA Astrophysics Data System (ADS)

    Gomes, J. M.; Papaderos, P.; Kehrig, C.; Vílchez, J. M.; Lehnert, M. D.; Sánchez, S. F.; Ziegler, B.; Breda, I.; Dos Reis, S. N.; Iglesias-Páramo, J.; Bland-Hawthorn, J.; Galbany, L.; Bomans, D. J.; Rosales-Ortega, F. F.; Cid Fernandes, R.; Walcher, C. J.; Falcón-Barroso, J.; García-Benito, R.; Márquez, I.; Del Olmo, A.; Masegosa, J.; Mollá, M.; Marino, R. A.; González Delgado, R. M.; López-Sánchez, Á. R.; Califa Collaboration

    2016-04-01

    Context. The morphological, spectroscopic, and kinematical properties of the warm interstellar medium (wim) in early-type galaxies (ETGs) hold key observational constraints to nuclear activity and the buildup history of these massive, quiescent systems. High-quality integral field spectroscopy (IFS) data with a wide spectral and spatial coverage, such as those from the CALIFA survey, offer an unprecedented opportunity for advancing our understanding of the wim in ETGs. Aims: This article centers on a 2D investigation of the wim component in 32 nearby (≲150 Mpc) ETGs from CALIFA, complementing a previous 1D analysis of the same sample. Methods: The analysis presented here includes Hα intensity and equivalent width (EW) maps and radial profiles, diagnostic emission-line ratios, and ionized-gas and stellar kinematics. It is supplemented by τ-ratio maps, which are a more efficient means to quantify the role of photoionization by the post-AGB stellar component than alternative mechanisms (e.g., AGN, low-level star formation). Results: Confirming and strengthening our previous conclusions, we find that ETGs span a broad continuous sequence in the properties of their wim, exemplified by two characteristic classes. The first (type i) comprises systems with a nearly constant EW(Hα) in their extranuclear component, which quantitatively agrees with (but is no proof of) the hypothesis that photoionization by the post-AGB stellar component is the main driver of extended wim emission. The second class (type ii) stands for virtually wim-evacuated ETGs with a very low (≤0.5 Å), outwardly increasing EW(Hα). These two classes appear indistinguishable from one another by their LINER-specific emission-line ratios in their extranuclear component. Here we extend the tentative classification we proposed previously by the type i+, which is assigned to a subset of type i ETGs exhibiting ongoing low-level star-forming activity in their periphery. This finding along with faint

  5. Achieving EMC Emissions Compliance for an Aeronautics Power Line Communications System

    NASA Astrophysics Data System (ADS)

    Dominiak, S.; Vos, G.; ter Meer, T.; Widmer, H.

    2012-05-01

    Transmitting data over the power distribution network - Power Line 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 emissions compliance. In this article an overview of the EMC conducted and radiated emissions testing for PLC- enabled aeronautics equipment is presented. Anomalies resulting from chamber resonances leading to discrepancies between the conducted emissions tests and the measured radiated emissions 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 emissions compliance.

  6. Method for measuring radial impurity emission profiles using correlations of line integrated signals

    SciTech Connect

    Kuldkepp, M.; Brunsell, P.R.; Drake, J.; Menmuir, S.; Rachlew, E.

    2006-04-15

    A method of determining radial impurity emission profiles is outlined. The method uses correlations between line integrated signals and is based on the assumption of cylindrically symmetric fluctuations. Measurements at the reversed field pinch EXTRAP T2R show that emission 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 emission profiles that are remarkably close to emission 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 10 kHz 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 emission reconstruction procedure.

  7. ON THE DOPPLER VELOCITY OF EMISSION LINE PROFILES FORMED IN THE 'CORONAL CONTRAFLOW' THAT IS THE CHROMOSPHERE-CORONA MASS CYCLE

    SciTech Connect

    McIntosh, Scott W.; Tian Hui; Sechler, Marybeth; De Pontieu, Bart

    2012-04-10

    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 emission line profiles (formed above 1 MK) at the base of coronal loop structures indicate material blueshifts of 5-10 km s{sup -1}, while cool emission line 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 emission with apparent speeds of 50-150 km s{sup -1}. Spectroscopic observations indicate that these propagating disturbances produce a weak emission component in the blue wing at commensurate speed, but that they contribute only a few percent to the (ensemble) emission line profile in a single spatio-temporal resolution element. Subsequent analysis of imaging data shows material 'draining' slowly ({approx}10 km s{sup -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 emission lines 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 line profiles, their interpretation, and asymmetry diagnoses, but allows a different physical picture of the lower corona to develop.

  8. Cr-K EMISSION LINE AS A CONSTRAINT ON THE PROGENITOR PROPERTIES OF SUPERNOVA REMNANTS

    SciTech Connect

    Yang, X. J.; Xiang, F. Y.; Xiao, H. P.; Zhong, J. X.; Tsunemi, H.; Lu, F. J.; Li, Aigen

    2013-03-20

    We perform a survey of the Cr, Mn, and Fe-K emission lines in young supernova remnants (SNRs) with the Japanese X-ray astronomy satellite Suzaku. The Cr and/or Mn emission lines are detected in 3C 397 and 0519-69.0 for the first time. We also confirm the detection of these lines in Kepler, W49B, N103B, and Cas A. We derive the line parameters (i.e., the line centroid energy, flux, and equivalent width (EW)) for these six sources and perform a correlation analysis for the line center energies of Cr, Mn, and Fe. Also included in the correlation analysis are Tycho and G344.7-0.1 for which the Cr, Mn, and Fe-K line parameters were available in the literature through Suzaku observations. We find that the line center energies of Cr correlate very well with that of Fe and that of Mn. This confirms our previous findings that Cr, Mn, and Fe are spatially co-located, share a similar ionization state, and have a common origin in the supernova nucleosynthesis. We find that the ratio of the EW of the Cr emission line to that of Fe ({gamma}{sub Cr/Fe}{identical_to}EW(Cr)/EW(Fe)) provides useful constraints on the SNR progenitors and on the SN explosion mechanisms: for SNRs with {gamma}{sub Cr/Fe} > 2%, a Type Ia origin is favored (e.g., N103B, G344.7-0.1, 3C 397, and 0519-69.0); for SNRs with {gamma}{sub Cr/Fe} < 2%, they could be of either core-collapse origin or carbon-deflagration Ia origin.

  9. Cr-K Emission Line as a Constraint on the Progenitor Properties of Supernova Remnants

    NASA Astrophysics Data System (ADS)

    Yang, X. J.; Tsunemi, H.; Lu, F. J.; Li, Aigen; Xiang, F. Y.; Xiao, H. P.; Zhong, J. X.

    2013-03-01

    We perform a survey of the Cr, Mn, and Fe-K emission lines in young supernova remnants (SNRs) with the Japanese X-ray astronomy satellite Suzaku. The Cr and/or Mn emission lines are detected in 3C 397 and 0519-69.0 for the first time. We also confirm the detection of these lines in Kepler, W49B, N103B, and Cas A. We derive the line parameters (i.e., the line centroid energy, flux, and equivalent width (EW)) for these six sources and perform a correlation analysis for the line center energies of Cr, Mn, and Fe. Also included in the correlation analysis are Tycho and G344.7-0.1 for which the Cr, Mn, and Fe-K line parameters were available in the literature through Suzaku observations. We find that the line center energies of Cr correlate very well with that of Fe and that of Mn. This confirms our previous findings that Cr, Mn, and Fe are spatially co-located, share a similar ionization state, and have a common origin in the supernova nucleosynthesis. We find that the ratio of the EW of the Cr emission line to that of Fe (\\gamma _Cr/Fe\\equiv EW(Cr)/EW(Fe)) provides useful constraints on the SNR progenitors and on the SN explosion mechanisms: for SNRs with γCr/Fe > 2%, a Type Ia origin is favored (e.g., N103B, G344.7-0.1, 3C 397, and 0519-69.0) for SNRs with γCr/Fe < 2%, they could be of either core-collapse origin or carbon-deflagration Ia origin.

  10. THE PREVALENCE OF NARROW OPTICAL Fe II EMISSION LINES IN TYPE 1 ACTIVE GALACTIC NUCLEI

    SciTech Connect

    Dong Xiaobo; Wang Jianguo; Wang Tinggui; Wang Huiyuan; Zhou Hongyan; Ho, Luis C.; Fan Xiaohui

    2010-10-01

    From detailed spectral analysis of a large sample of low-redshift active galactic nuclei (AGNs) selected from the Sloan Digital Sky Survey, we demonstrate-statistically for the first time-that narrow optical Fe II emission lines, both permitted and forbidden, are prevalent in type 1 AGNs. Remarkably, these optical lines are completely absent in type 2 AGNs, across a wide luminosity range, from Seyfert 2 galaxies to type 2 quasars. We suggest that the narrow Fe II-emitting gas is confined to a disk-like geometry in the innermost regions of the narrow-line region on physical scales smaller than the obscuring torus.

  11. THE SURVEY OF LINES IN M31 (SLIM): INVESTIGATING THE ORIGINS OF [C II] EMISSION

    SciTech Connect

    Kapala, M. J.; Sandstrom, K.; Groves, B.; Kreckel, K.; Schinnerer, E.; Walter, F.; Fouesneau, M.; Croxall, K.; Dalcanton, J.; Leroy, A.

    2015-01-01

    The [C II] 158 μm line is one of the strongest emission lines observed in star-forming galaxies and has been empirically measured to correlate with the star-formation rate (SFR) globally and on kiloparsec scales. However, because of the multiphase origins of [C II], one might expect this relation to break down at small scales. We investigate the origins of [C II] emission by examining high spatial resolution observations of [C II] in M31 with the Survey of Lines in M31. We present five ∼700 × 700 pc (3' × 3') fields mapping the [C II] emission, Hα emission, and the ancillary infrared (IR) data. We spatially separate star-forming regions from diffuse gas and dust emission on ∼50 pc scales. We find that the [C II]-SFR correlation holds even at these scales, although the relation typically has a flatter slope than found at larger (kiloparsec) scales. While the Hα emission in M31 is concentrated in the SFR regions, we find that a significant amount (∼20%-90%) of the [C II] emission comes from outside star-forming regions and that the total IR emission (TIR) has the highest diffuse fraction of all SFR tracers. We find a weak correlation of the [C II]/TIR to dust color in each field and find a large-scale trend of increasing [C II]/TIR with galactocentric radius. The differences in the relative diffuse fractions of [C II], Hα, and IR tracers are likely caused by a combination of energetic photon leakage from H II regions and heating by the diffuse radiation field arising from older (B-star) stellar populations. However, we find that by averaging our measurements over kiloparsec scales, these effects are minimized, and the relation between [C II] and SFR found in other nearby galaxy studies is retrieved.

  12. Locally Optimally Emitting Clouds and the Variable Broad Emission Line Spectrum of NGC 5548

    NASA Astrophysics Data System (ADS)

    Korista, Kirk T.; Goad, Michael R.

    2000-06-01

    In recent work Baldwin et al. proposed that in the geometrically extended broad-line regions (BLRs) of quasars and active galactic nuclei, a range in line-emitting gas properties (e.g., density, column density) might exist at each radius and showed that under these conditions the broad emission line spectra of these objects may be dominated by selection effects introduced by the atomic physics and general radiative transfer within the large pool of line-emitting entities. In this picture, the light we see originates in a vast amalgam of emitters but is dominated by those emitters best able to reprocess the incident continuum into a particular emission line. We test this ``locally optimally emitting clouds'' (LOC) model against the extensive spectroscopic database of the Seyfert 1 galaxy NGC 5548. The time-averaged, integrated-light UV broad emission line spectrum from the 1993 Hubble Space Telescope (HST) monitoring campaign is reproduced via the optimization of three global geometric parameters: the outer radius, the index controlling the radial cloud covering fraction of the continuum source, and the integrated cloud covering fraction. We make an ad hoc selection from the range of successful models, and for a simple spherical BLR geometry we simulate the emission-line light curves for the 1989 IUE and 1993 HST campaigns, using the respective observed UV continuum light curves as drivers. We find good agreement between the predicted and observed light curves and lags-a demonstration of the LOC picture's viability as a means to understanding the BLR environment. Finally, we discuss the next step in developing the LOC picture, which involves the marriage of echo-mapping techniques with spectral simulation grids such as those presented here, using the constraints provided by a high-quality, temporally well-sampled spectroscopic data set.

  13. Physical and morphological properties of z ~ 3 Lyman break galaxies: dependence on Lyα line emission

    NASA Astrophysics Data System (ADS)

    Pentericci, L.; Grazian, A.; Scarlata, C.; Fontana, A.; Castellano, M.; Giallongo, E.; Vanzella, E.

    2010-05-01

    Aims: We investigate the physical and morphological properties of Lyman break galaxies (LBGs) at redshift ~2.5 to ~3.5, to determine if and how they depend on the nature and strength of the Lyα emission. Methods: We selected U-dropout galaxies from the z-detected GOODS-MUSIC catalog by adapting the classical Lyman break criteria on the GOODS filter set. We kept only those galaxies with spectroscopic confirmation, mainly from VIMOS and FORS public observations. Using the full multi-wavelength 14-bands information (U to IRAC), we determined the physical properties of the galaxies through a standard spectral energy distribution fitting procedure with the updated Charlot & Bruzual (2009) templates. We also added other relevant observations of the GOODS field, i.e. the 24 μm observations from Spitzer/MIPS and the 2 MSec Chandra X-ray observations. Finally, using non parametric diagnostics (Gini, Concentration, Asymmetry, M20 and ellipticity), we characterized the rest-frame UV morphologies of the galaxies. We then analyzed how these physical and morphological properties correlate with the presence of the Lyα emission line in the optical spectra. Results: We find that unlike at higher redshift, the dependence of physical properties on the Lyα line is milder: galaxies without Lyα in emission tend to be more massive and dustier than the rest of the sample, but all other parameters, ages, star formation rates (SFR), X-ray emission and UV morphology do not depend strongly on the presence of the Lyα emission. A simple scenario where all LBGs have intrinsically high Lyα emission, but where the dust and neutral hydrogen content (which shapes the final appearance of the Lyα) depend on the mass of the galaxies, is able to reproduce the majority of the observed properties at z˜3. Some modification might be needed to account for the observed evolution of these properties with cosmic epoch, which is also discussed.

  14. Laboratory Measurements of Fe XXIV Line Emission: 3-->2 Transitions near Excitation Threshold

    NASA Astrophysics Data System (ADS)

    Gu, M. F.; Kahn, S. M.; Savin, D. W.; Beiersdorfer, P.; Brown, G. V.; Liedahl, D. A.; Reed, K. J.; Bhalla, C. P.; Grabbe, S. R.

    1999-06-01

    Using the Electron Beam Ion Trap facility at Lawrence Livermore National Laboratory, we have measured relative cross sections for Fe XXIV line emission at electron energies between 0.7 and 3.0 keV. The measurements include line formation by direct electron impact excitation (DE), radiative cascades, resonant excitation (RE), and dielectronic recombination (DR) satellites with captured electrons in n>=5 levels. Good agreement with R-matrix and distorted wave calculations is found. In collisionally ionized plasmas, at temperatures near where the ion abundance peaks (kTe~1.7 keV), the RE contributions arefound to be <~5% of the line emission, while the DR satellites contribute <~10%. While good agreement with state-of-the-art atomic physics calculations is found, there is less good agreement with existingspectral synthesis codes in common astrophysical use. For the Fe XXIV 3p3/2-->2s1/2, 3p1/2-->2s1/2, and 3d5/2-->2p3/2 transitions, the synthesis code MEKAL underestimates the emissivity in coronal equilibrium by ~20% at temperatures near where the ion abundance peaks. In situations where the ionization balance is not solely determined by the electron temperature, RE and DR satellites may contribute a considerable fraction of the line emission.

  15. Emission-line mapping of the dwarf nova IP Pegasi in outburst and quiescence

    SciTech Connect

    Marsh, T.R.; Horne, K. )

    1990-02-01

    Time-resolved spectroscopy covering half an orbit and one eclipse during an outburst of the dwarf nova IP Peg are presented and compared with quiescent data. The outburst spectra show strong Balmer and He II 4686 A emission lines that are atypical of outbursting dwarf novae. Double-peaked velocity profiles and rotational distortions during eclipse show that the lines arise primarily in a Keplerian accretional disk. The He II line profile is filled in between the two disk peaks by non-Keplerian emission from close to the white dwarf, possibly indicative of a compact outflowing wind or inflowing magnetic accretion column. During outburst, an accretion rate of roughly 10 to the 17th g/s is needed to acccount for the continuum emission of the disk. The associated boundary layer generates soft X-ray and Lyman continuum fluxes sufficient to photoionize the disk's He II and Balmer emission-line regions. The disk appears to shield the red star totally from the soft X-rays, and in the equatorial region, from the Lyman continuum. 46 refs.

  16. A commercial tunable diode laser (TDL) system for on-line remote measurements of automobile emissions

    NASA Astrophysics Data System (ADS)

    Weber, Konradin; Ropertz, Alexander; Schwabe, Thomas; Fischer, Christian; van Haren, Gunther

    2004-11-01

    An innovative tunable diode laser (TDL) measurement system has been used for the on-line estimation of emissions of cars, driving through the measurement beam of the system. This paper describes the measurement principle and gives first measurement results, taken for different types of cars.

  17. Determination of sulfur in biodiesel microemulsions using the summation of the intensities of multiple emission lines.

    PubMed

    Young, Carl G; Amais, Renata S; Schiavo, Daniela; Garcia, Edivaldo E; Nóbrega, Joaquim A; Jones, Bradley T

    2011-05-15

    A method for the determination of sulfur in biodiesel samples by inductively coupled plasma optical emission spectrometry which uses microemulsion for sample preparation and the summation of the intensities of multiple emission lines has been developed. Microemulsions were prepared using 0.5 mL of 20% v/v HNO(3), 0.5 mL of Triton X-100, 2-3 mL of biodiesel sample, and diluted with n-propanol to a final volume of 10 mL. Summation of the emission intensities of multiple sulfur lines allowed for increased accuracy and sensitivity. The amounts of sulfur determined experimentally were between 2 and 7 mg L(-1), well below legislative standards for many countries. Recoveries obtained ranged from 72 to 119%, and recoveries obtained for the 182.562 nm line were slightly lower. This is most likely due to its lower sensitivity. Using microemulsion for sample preparation and the summation of the intensities of multiple emission lines for the successful determination of sulfur in biodiesel has been demonstrated. PMID:21482315

  18. An atlas of emission line fluxes of planetary nebulae in the 1150-3200 A region

    NASA Technical Reports Server (NTRS)

    Feibelman, W. A.; Mccracken, C. W.

    1981-01-01

    Emission line fluxes for 28 planetary nebulae are presented. The nebulae were chosen to cover a wide range of excitation classes, apparent diameters, location in the sky, and types of central stars. All objects were observed in the low dispersion mode of the IUE spectrographs, using the large entrance aperture.

  19. The stability of the He II 4686 line emission across periastron passages in eta Carinae

    NASA Astrophysics Data System (ADS)

    Teodoro, Mairan; Heathcote, Bernard; Richardson, Noel; Prates, Rodrigo; Damineli, Augusto; Hickel, Gabriel; Bohlsen, Terry; Luckas, Paul; Locke, Malcolm; Navarete, Felipe; West, Julian; Andrade, Thiago A.; Coimbra, Adriano M.; Fernandez-Lajus, Eduardo; Gull, Theodore; Jablonski, Francisco; Corcoran, Michael F.; Groh, Jose H.; Hamaguchi, Kenji; Madura, Thomas; St-Jean, Lucas; Weigelt, Gerd

    2014-08-01

    Preliminary analysis of data from the international campaign to monitor eta Carinae through the 2014 event shows that, as expected, the equivalent width of the He II 4686 emission line has reached its minimum strength on JD=2456870.8 (August 01 2014).

  20. VizieR Online Data Catalog: Hα emission-line stars in M42 (Pettersson+, 2014)

    NASA Astrophysics Data System (ADS)

    Pettersson, B.; Armond, T. Reipurth B.

    2014-09-01

    We present H-α strength estimates for 1699 emission-line stars in the M42 region. Positions and JHKs-photometry were extracted from 2MASS and mJmFm_N-photometry from the USNO-B or GSC 2.2 catalogue. (2 data files).

  1. Atomic emission line wavelength calculations below 2000 angstroms for Lithium II through Cobalt XXVI

    NASA Technical Reports Server (NTRS)

    Williams, M. D.

    1971-01-01

    Atomic-emission-line wavelengths are presented which were calculated from wavelengths of previously identified transition sequences using second-degree polynomials fitted to known wave numbers by the least squares method. Wavelengths less than 2000 angstroms are included for ions from Li II to Co XXVI. The computer program written in FORTRAN 4 is also included.

  2. Errors associated with fitting Gaussian profiles to noisy emission-line spectra

    NASA Technical Reports Server (NTRS)

    Lenz, Dawn D.; Ayres, Thomas R.

    1992-01-01

    Landman et al. (1982) developed prescriptions to predict profile fitting errors for Gaussian emission lines 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.

  3. Cross section calculations of astrophysical interest. [for theories of absorption and emission lines

    NASA Technical Reports Server (NTRS)

    Gerjuoy, E.

    1974-01-01

    Cross sections are discussed for rotational excitation associated with theories of absorption and emission lines from molecules in space with emphasis on H2CO, CO, and OH by collisions with neutral particles such H, H2, and He. The sensitivity of the Thaddeus equation for the H2CO calculation is examined.

  4. THE ULTRAVIOLET-TO-MID-INFRARED SPECTRAL ENERGY DISTRIBUTION OF WEAK EMISSION LINE QUASARS

    SciTech Connect

    Lane, Ryan A.; Shemmer, Ohad; Diamond-Stanic, Aleksandar M.; Fan Xiaohui; Anderson, Scott F.; Brandt, W. N.; Schneider, Donald P.; Plotkin, Richard M.; Richards, Gordon T.; Strauss, Michael A. E-mail: ohad@unt.edu

    2011-12-20

    We present Spitzer Space Telescope photometry of 18 Sloan Digital Sky Survey (SDSS) quasars at 2.7 {<=} z {<=} 5.9 which have weak or undetectable high-ionization emission lines in their rest-frame ultraviolet (UV) spectra (hereafter weak-lined quasars, or WLQs). The Spitzer data are combined with SDSS spectra and ground-based, near-infrared (IR) photometry of these sources to produce a large inventory of spectral energy distributions (SEDs) of WLQs across the rest-frame {approx}0.1-5 {mu}m spectral band. The SEDs of our sources are inconsistent with those of BL Lacertae objects which are dominated by synchrotron emission due to a jet aligned close to our line of sight, but are consistent with the SED of ordinary quasars with similar luminosities and redshifts that exhibit a near-to-mid-IR 'bump', characteristic of hot dust emission. This indicates that broad emission lines in WLQs are intrinsically weak, rather than suffering continuum dilution from a jet, and that such sources cannot be selected efficiently from traditional photometric surveys.

  5. ALMA WILL DETERMINE THE SPECTROSCOPIC REDSHIFT z > 8 WITH FIR [O III] EMISSION LINES

    SciTech Connect

    Inoue, A. K.; Shimizu, I.; Tamura, Y.; Matsuo, H.; Okamoto, T.; Yoshida, N.

    2014-01-10

    We investigate the potential use of nebular emission lines 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 line emissivity model as a function of metallicity, especially for the [O III] 88 μm line which is likely to be the strongest FIR line from H II regions, we predict the line 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 expect the [O III] 88 μm line 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 line would be the best tool to confirm the spectroscopic redshifts beyond z = 8.

  6. Probing the Flare Atmospheres of M Dwarfs Using Infrared Emission Lines

    NASA Astrophysics Data System (ADS)

    Schmidt, Sarah J.; Kowalski, Adam F.; Hawley, Suzanne L.; Hilton, Eric J.; Wisniewski, John P.; Tofflemire, Benjamin M.

    2012-01-01

    We present the results of a campaign to monitor active M dwarfs using infrared spectroscopy, supplemented with optical photometry and spectroscopy. We detected 16 flares during nearly 50 hr of observations on EV Lac, AD Leo, YZ CMi, and VB 8. The three most energetic flares also showed infrared emission, including the first reported detections of Pβ, Pγ, He I λ10830, and Brγ during an M dwarf flare. The strongest flare (Δu = 4.02 on EV Lac) showed emission from Hγ, Hδ, He I λ4471, and Ca II K in the UV/blue and Pβ, Pγ, Pδ, Brγ, and He I λ10830 in the infrared. The weaker flares (Δu = 1.68 on EV Lac and ΔU = 1.38 on YZ CMi) were only observed with photometry and infrared spectroscopy; both showed emission from Pβ, Pγ, and He I λ10830. The strongest infrared emission line, Pβ, occurred in the active mid-M dwarfs with a duty cycle of ~3%-4%. To examine the most energetic flare, we used the static NLTE radiative transfer code RH to produce model spectra based on a suite of one-dimensional model atmospheres. Using a hotter chromosphere than previous one-dimensional atmospheric models, we obtain line ratios that match most of the observed emission lines. Based on observations obtained with the Apache Point Observatory 3.5 m telescope, which is owned and operated by the Astrophysical Research Consortium.

  7. PROBING THE FLARE ATMOSPHERES OF M DWARFS USING INFRARED EMISSION LINES

    SciTech Connect

    Schmidt, Sarah J.; Kowalski, Adam F.; Hawley, Suzanne L.; Hilton, Eric J.; Wisniewski, John P.; Tofflemire, Benjamin M.

    2012-01-20

    We present the results of a campaign to monitor active M dwarfs using infrared spectroscopy, supplemented with optical photometry and spectroscopy. We detected 16 flares during nearly 50 hr of observations on EV Lac, AD Leo, YZ CMi, and VB 8. The three most energetic flares also showed infrared emission, including the first reported detections of P{beta}, P{gamma}, He I {lambda}10830, and Br{gamma} during an M dwarf flare. The strongest flare ({Delta}u = 4.02 on EV Lac) showed emission from H{gamma}, H{delta}, He I {lambda}4471, and Ca II K in the UV/blue and P{beta}, P{gamma}, P{delta}, Br{gamma}, and He I {lambda}10830 in the infrared. The weaker flares ({Delta}u = 1.68 on EV Lac and {Delta}U = 1.38 on YZ CMi) were only observed with photometry and infrared spectroscopy; both showed emission from P{beta}, P{gamma}, and He I {lambda}10830. The strongest infrared emission line, P{beta}, occurred in the active mid-M dwarfs with a duty cycle of {approx}3%-4%. To examine the most energetic flare, we used the static NLTE radiative transfer code RH to produce model spectra based on a suite of one-dimensional model atmospheres. Using a hotter chromosphere than previous one-dimensional atmospheric models, we obtain line ratios that match most of the observed emission lines.

  8. Analysis of the variability of the luminous emission line star MWC 314

    NASA Astrophysics Data System (ADS)

    Muratorio, G.; Rossi, C.; Friedjung, M.

    2008-08-01

    Context: We investigated the surroundings of MWC 314 in the framework of the study of hot emission line star environments using the SAC method. This star is either a B[e] supergiant or a luminous blue variable and appears to be extremely luminous and massive. Aims: We determine the structure and physical conditions of the emitting region and study the possible variations. Methods: We measured the absorption and emission line radial velocities and the emission line fluxes on high-resolution spectra obtained with Aurelie at the 1.52 m OHP telescope in July 1998, with Elodie at the 1.93 m OHP telescope at various epochs, and with echelle spectrographs of the Asiago and Loiano observatories (Italy) in 2006. We used the statistical approach of the self-absorption curve method (SAC) to derive physical parameters of the line-emitting region. Results: We detected drastic variations of the photospheric absorption line radial velocities with time, while the emission line velocities appear to be stable. The Cr II, Ti II, and Fe II emission lines have a complex structure. They are double-peaked, and each of these two 60 km s-1 separated components, is composed of a narrow and a broad component, while the [Fe II] line components are narrower. The fit of the various components of the Fe II lines to a SAC curve indicates that their intensities are affected by some self absorption. We obtained a Boltzmann-type population law whose mean excitation temperature is 6500-1000+1500 K for the narrow component lower and upper levels. We obtained a higher Boltzmann-type population law of 10 500-2000+3000 K for the forbidden transition upper levels. Conclusions: From the absorption lines we confirm the binarity for MWC 314. The periodicity has nevertheless to be improved with a higher sampling frequency. Our results from the emission lines are consistent with line formation in a rotating disk around a star. The typical minimum radius of the line emitting region obtained from the SAC study

  9. The structure and ionization of the extended emission-line filaments surrounding the QSO MR 2251-178

    SciTech Connect

    Macchetto, F.; Colina, L.; Golombek, D.; Perryman, M.A.C.; Di Serego Alighieri, S. ESA, Astrophysics Div., Noordwijk ESA, Space Telescope European Coordinating Facility, Garching )

    1990-06-01

    This paper presents new VLA radio maps, at 6 cm and 20 cm, of the QSO MR 2251-178, together with deep high-spatial-resolution images in the O II forbidden 3727-A line in the O III forbidden 5007-A line, and H-alpha emission lines, showing the presence of extended emission-line filaments surrounding the MR 2251-178. The morphology of the circumnuclear emission-line regions and an extended system of filaments in different ionization states are shown. The physical characteristics, such as luminosities, densities, mass, and ionization parameters of different filaments are derived. 48 refs.

  10. The Importance of Nebular Continuum and Line Emission in Observations of Young Massive Star Clusters

    NASA Astrophysics Data System (ADS)

    Reines, Amy E.; Nidever, David L.; Whelan, David G.; Johnson, Kelsey E.

    2010-01-01

    In this spectroscopic study of infant massive star clusters, we find that continuum emission from ionized gas rivals the stellar luminosity at optical wavelengths. In addition, we find that nebular line emission is significant in many commonly used broadband Hubble Space Telescope (HST) filters including the F814W I-band, the F555W V-band, and the F435W B-band. Two young massive clusters (YMCs) in the nearby starburst galaxy NGC 4449 were targeted for follow-up spectroscopic observations after Reines et al. discovered an F814W I-band excess in their photometric study of radio-detected clusters in the galaxy. The spectra were obtained with the Dual Imaging Spectrograph (DIS) on the 3.5 m Apache Point Observatory (APO) telescope and have a spectral range of ~3800-9800 Å. We supplement these data with HST and Sloan Digital Sky Survey photometry of the clusters. By comparing our data to the Starburst99 and GALEV evolutionary synthesis models, we find that nebular continuum emission competes with the stellar light in our observations and that the relative contribution from the nebular continuum is largest in the U- and I-bands, where the Balmer (3646 Å) and Paschen jumps (8207 Å) are located. The spectra also exhibit strong line emission including the [S III] λλ9069, 9532 lines in the HST F814W I-band. We find that the combination of nebular continuum and line emission can account for the F814W I-band excess previously found by Reines et al. In an effort to provide a benchmark for estimating the impact of ionized gas emission on photometric observations of young massive stellar populations, we compute the relative contributions of the stellar continuum, nebular continuum, and emission lines to the total observed flux of a 3 Myr old cluster through various HST filter/instrument combinations, including filters in the Wide Field Camera 3. We urge caution when comparing observations of YMCs to evolutionary synthesis models since nebular continuum and line emission can

  11. Silicon X-ray line emission from solar flares and active regions

    NASA Technical Reports Server (NTRS)

    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.

    1978-01-01

    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 line 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 lines between 1.5 and 7.0 A have been resolved and identified, including several dielectronic recombination satellite lines to Si XIV and Si XIII lines which have been observed for the first time. It has been found that thermal continuum models specified by single values of temperature and emission measure have fitted the data adequately, there being good agreement with the values of these parameters derived from line intensity ratios.

  12. Detection of emission lines from z ˜ 3 DLAs towards the QSO J2358+0149

    NASA Astrophysics Data System (ADS)

    Srianand, Raghunathan; Hussain, Tanvir; Noterdaeme, Pasquier; Petitjean, Patrick; Krühler, Thomas; Japelj, Jure; Pâris, Isabelle; Kashikawa, Nobunari

    2016-04-01

    Using VLT/X-shooter we searched for emission line galaxies associated to four damped Lyman-α systems (DLAs) and one sub-DLA at 2.73≤z ≤3.25 towards QSO J2358+0149. We detect [O III] emission 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 disk and the gas is part of either a large scale wind or cold accretion. We detect Lyα emission from the zabs= 3.2477 DLA (having log N(H I)=21.12±0.10 and [Zn/H]=-0.97 ± 0.13). The Lyα emission is redshifted with respect to the metal absorption lines 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 emission line is detected from this system. Because the DLA has a small velocity separation from the quasar (˜500 km s-1) and the DLA emission is located within a small projected distance (ρ < 5 kpc), we also explore the possibility that the Lyα emission 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 emission lines would disfavor this possibility. We do not detect any emission line from the remaining three systems.

  13. Detection of emission lines from z ˜ 3 DLAs towards the QSO J2358+0149

    NASA Astrophysics Data System (ADS)

    Srianand, Raghunathan; Hussain, Tanvir; Noterdaeme, Pasquier; Petitjean, Patrick; Krühler, Thomas; Japelj, Jure; Pâris, Isabelle; Kashikawa, Nobunari

    2016-07-01

    Using VLT/X-shooter, we searched for emission line 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] emission 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 emission from the zabs = 3.2477 DLA [having log N(H I) = 21.12 ± 0.10 and [Zn/H] = -0.97 ± 0.13]. The Lyα emission is redshifted with respect to the metal absorption lines 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 emission line is detected from this system. Because the DLA has a small velocity separation from the quasar (˜500 km s-1) and the DLA emission is located within a small projected distance (ρ < 5 kpc), we also explore the possibility that the Lyα emission 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 emission lines would disfavour this possibility. We do not detect any emission line from the remaining three systems.

  14. Detection of an oxygen emission line from a high-redshift galaxy in the reionization epoch

    NASA Astrophysics Data System (ADS)

    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

    2016-06-01

    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 emission line 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 emission indicates a deficiency of interstellar dust in the galaxy. A carbon emission line 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.

  15. Emission line flaring in the SW Sex old nova V533 Herculis

    NASA Astrophysics Data System (ADS)

    Rodríguez-Gil, Pablo; Martínez-Pais, Ignacio G.

    2002-11-01

    We present high time resolution spectroscopy of the non-eclipsing old nova V533 Herculis (N Her 1963). It is the second nova remnant affected by the `SW Sex syndrome'. A modulation of the equivalent width of the emission lines with a period of 23.33 min has been detected. This, together with the strong He II λ4686 emission characteristic of magnetic systems, leads us to link this period to the spin of a magnetic white dwarf. Similar flaring activity has been recorded in other SW Sex stars, namely, the old nova BT Mon, LS Peg and DW UMa, supporting the idea of these systems being magnetic accretors. Stationary emission features are also observed in the Balmer lines, which we attribute to the ejected nova shell.

  16. V533 Herculis: the second SW Sex old nova displaying emission-line flaring

    NASA Astrophysics Data System (ADS)

    Rodríguez-Gil, P.; Martínez-Pais, I. G.

    2002-11-01

    We present high-time-resolution spectroscopy of the non-eclipsing old nova V533 Herculis (N Her 1963). It is the second nova remnant affected by the `SW Sex syndrome'. A modulation of the equivalent width of the emission lines with a period of 23.33 min has been detected. This, together with the strong He IIλ4686 emission characteristic of magnetic systems, leads us to link this period to the spin of a magnetic white dwarf. Similar flaring activity has been recorded in other SW Sex stars, namely, the old nova BT Mon, LS Peg and DW UMa, supporting the idea of these systems being magnetic accretors. Stationary emission features are also observed in the Balmer lines, which we attribute to the ejected nova shell.

  17. Detection of an oxygen emission line from a high-redshift galaxy in the reionization epoch.

    PubMed

    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

    2016-06-24

    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 emission line 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 emission indicates a deficiency of interstellar dust in the galaxy. A carbon emission line 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. PMID:27312046

  18. Exceptional X-ray Weak Quasars: Implications for Accretion Flows and Emission-Line Formation

    NASA Astrophysics Data System (ADS)

    Brandt, W. Niel; Luo, Bin; Hall, Patrick B.; Wu, Jianfeng; Anderson, Scott F.; Garmire, Gordon; Gibson, Robert; Plotkin, Richard; Richards, Gordon T.; Schneider, Donald P.; Shemmer, Ohad; Shen, Yue

    2016-01-01

    Actively accreting supermassive black holes are found, nearly universally, to create luminous X-ray emission, and this point underlies the utility of X-ray surveys for finding active galactic nuclei throughout the Universe. However, there are apparent X-ray weak exceptions to this rule that are now providing novel insights, including weak-line quasars (WLQs) and especially analogs of the extreme WLQ, PHL 1811. We have been systematically studying such X-ray weak quasars with Chandra and near-infrared spectroscopy, and I will report results on their remarkable properties and describe implications for models of the accretion disk/corona and emission-line formation. We have found evidence that many of these quasars may have geometrically thick inner accretion disks, likely due to high accretion rates, that shield the high-ionization broad line region from the relevant ionizing continuum. This model can explain, in a simple and unified manner, their weak lines and diverse X-ray properties. Such shielding may, more generally, play a role in shaping the broad distributions of quasar emission-line equivalent widths and blueshifts.

  19. Dense gas in nearby galaxies. XIII. CO submillimeter line emission from the starburst galaxy M 82

    NASA Astrophysics Data System (ADS)

    Mao, R. Q.; Henkel, C.; Schulz, A.; Zielinsky, M.; Mauersberger, R.; Störzer, H.; Wilson, T. L.; Gensheimer, P.

    2000-06-01

    12CO J = 1-0, 2-1, 4-3, 7-6, and 13CO 1-0, 2-1, and 3-2 line emission was mapped with angular resolutions of 13'' - 22'' toward the nuclear region of the archetypical starburst galaxy M 82. There are two hotspots on either side of the dynamical center, with the south-western lobe being slightly more prominent. Lobe spacings are not identical for all transitions: For the submillimeter CO lines, the spacing is ~ 15''; for the millimeter lines (CO J = 2-1 and 1-0) the spacing is ~ 26'', indicating the presence of a `low' and a `high' CO excitation component. A Large Velocity Gradient (LVG) excitation analysis of the submillimeter lines leads to inconsistencies, since area and volume filling factors are almost the same, resulting in cloud sizes along the lines-of-sight that match the entire size of the M 82 starburst region. Nevertheless, LVG column densities agree with estimates derived from the dust emission in the far infrared and at submillimeter wavelengths. 22'' beam averaged total column densities are N(CO) ~ 5 1018 and N(H_2) ~ 1023 \\cmsq; the total molecular mass is a few 108 \\solmass. Accounting for high UV fluxes and variations in kinetic temperature and assuming that the observed emission arises from photon dominated regions (PDRs) resolves the problems related to an LVG treatment of the radiative transfer. Spatial densities are as in the LVG case (\

  20. An analysis of emission lines in the spectrum of P Cygni.

    NASA Astrophysics Data System (ADS)

    Markova, N.; de Groot, M.

    1997-10-01

    Using the coude spectrograph of the NAO 2m telescope at the Rhodope Mountains, Bulgaria, 9 spectra in the blue and 8 spectra in the red photographic region of P Cygni were obtained during 1990. By averaging the spectra in each set a S/N-ratio of about 45 was achieved. Comparing the lists of identifications published by Beals (1950PDAO....9....1B), de Groot (1969BAN....20..225D), Ozemre (1978PIstO.101....1O), Stahl et al. (1993A&AS...99..167S), Markova (1994A&AS..108..561M) and Markova & Zamanov (1995A&AS..114..499M), we conclude that the emission spectrum of P Cygni in our days is probably much richer and intensive than 60 years ago. A number of line parameters of the pure emission lines are measured. An estimate of the electron density and temperature in the region of [NII]-lines formation is obtained. Different velocity laws yielding similar density structures are discussed aiming to account for the results obtained on the basis of the [NII] lines. Possible mechanisms for the formation of the permitted pure emission-line spectrum are proposed.

  1. A z ∼ 5.7 Lyα emission line with an ultrabroad red wing

    SciTech Connect

    Yang, Huan; Wang, JunXian; Zheng, Zhen-Ya; Malhotra, Sangeeta; Rhoads, James E.; Infante, Leopoldo E-mail: jxw@mail.ustc.edu.cn E-mail: smalhotr@asu.edu E-mail: linfante@astro.puc.cl

    2014-03-20

    Using the Lyα emission line as a tracer of high-redshift, star-forming galaxies, hundreds of Lyα emission line galaxies (LAEs) at z > 5 have been detected. These LAEs are considered to be low-mass young galaxies, critical to the re-ionization of the universe and the metal enrichment of the circumgalactic medium (CGM) and the intergalactic medium (IGM). It is assumed that outflows in LAEs can help both ionizing photons and Lyα photons escape from galaxies. However, we still know little about the outflows in high-redshift LAEs due to observational difficulties, especially at redshift >5. Models of Lyα radiative transfer predict asymmetric Lyα line profiles with broad red wings in LAEs with outflows. Here, we report a z ∼ 5.7 Lyα emission line with a broad red wing extending to >1000 km s{sup –1} relative to the peak of Lyα line, which has been detected in only a couple of z > 5 LAEs until now. If the broad red wing is ascribed to gas outflow instead of active galactic nucleus activity, the outflow velocity could be larger than the escape velocity (∼500 km s{sup –1}) of a typical halo mass of z ∼ 5.7 LAEs, which is consistent with the idea that outflows in LAEs disperse metals to CGM and IGM.

  2. Calibration of H-alpha/H-beta Indexes for Emission Line Objects

    NASA Astrophysics Data System (ADS)

    Hintz, Eric G.; Joner, Michael D.

    2016-01-01

    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 emission line objects were also observed. We will report on the preliminary results for the emission line data set. This will include a comparison of equivalent width measurements of each line with the matching index. We will also examine the relation between the absorption line objects previously published and the emission line 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.

  3. Weak Emission-line Quasars in the Context of a Modified Baldwin Effect

    NASA Astrophysics Data System (ADS)

    Shemmer, Ohad

    2016-01-01

    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-emission line 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 emission line 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 line, 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 lines 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-emission lines in quasars.

  4. A correlation electron cyclotron emission diagnostic and the importance of multifield fluctuation measurements for testing nonlinear gyrokinetic turbulence simulations

    SciTech Connect

    White, A. E.; Schmitz, L.; Peebles, W. A.; Carter, T. A.; Rhodes, T. L.; Doyle, E. J.; Gourdain, P. A.; Hillesheim, J. C.; Wang, G.; Holland, C.; Tynan, G. R.; Austin, M. E.; McKee, G. R.; Shafer, M. W.; Burrell, K. H.; Candy, J.; DeBoo, J. C.; Prater, R.; Staebler, G. M.; Waltz, R. E.

    2008-10-15

    A correlation electron cyclotron emission (CECE) diagnostic has been used to measure local, turbulent fluctuations of the electron temperature in the core of DIII-D plasmas. This paper describes the hardware and testing of the CECE diagnostic and highlights the importance of measurements of multifield fluctuation profiles for the testing and validation of nonlinear gyrokinetic codes. The process of testing and validating such codes is critical for extrapolation to next-step fusion devices. For the first time, the radial profiles of electron temperature and density fluctuations are compared to nonlinear gyrokinetic simulations. The CECE diagnostic at DIII-D uses correlation radiometry to measure the rms amplitude and spectrum of the electron temperature fluctuations. Gaussian optics are used to produce a poloidal spot size with w{sub o}{approx}1.75 cm in the plasma. The intermediate frequency filters and the natural linewidth of the EC emission determine the radial resolution of the CECE diagnostic, which can be less than 1 cm. Wavenumbers resolved by the CECE diagnostic are k{sub {theta}}{<=}1.8 cm{sup -1} and k{sub r}{<=}4 cm{sup -1}, relevant for studies of long-wavelength turbulence associated with the trapped electron mode and the ion temperature gradient mode. In neutral beam heated L-mode plasmas, core electron temperature fluctuations in the region 0.5emission spectroscopy. After incorporating 'synthetic diagnostics' to effectively filter the code output, the simulations reproduce the characteristics of the turbulence and transport at one radial location r/a=0.5, but not at a second location, r/a=0.75. These results illustrate that measurements of the profiles of multiple fluctuating fields can provide a significant constraint on the turbulence models employed by the code.

  5. A correlation electron cyclotron emission diagnostic and the importance of multifield fluctuation measurements for testing nonlinear gyrokinetic turbulence simulationsa)

    NASA Astrophysics Data System (ADS)

    White, A. E.; Schmitz, L.; Peebles, W. A.; Carter, T. A.; Rhodes, T. L.; Doyle, E. J.; Gourdain, P. A.; Hillesheim, J. C.; Wang, G.; Holland, C.; Tynan, G. R.; Austin, M. E.; McKee, G. R.; Shafer, M. W.; Burrell, K. H.; Candy, J.; DeBoo, J. C.; Prater, R.; Staebler, G. M.; Waltz, R. E.; Makowski, M. A.

    2008-10-01

    A correlation electron cyclotron emission (CECE) diagnostic has been used to measure local, turbulent fluctuations of the electron temperature in the core of DIII-D plasmas. This paper describes the hardware and testing of the CECE diagnostic and highlights the importance of measurements of multifield fluctuation profiles for the testing and validation of nonlinear gyrokinetic codes. The process of testing and validating such codes is critical for extrapolation to next-step fusion devices. For the first time, the radial profiles of electron temperature and density fluctuations are compared to nonlinear gyrokinetic simulations. The CECE diagnostic at DIII-D uses correlation radiometry to measure the rms amplitude and spectrum of the electron temperature fluctuations. Gaussian optics are used to produce a poloidal spot size with wo˜1.75 cm in the plasma. The intermediate frequency filters and the natural linewidth of the EC emission determine the radial resolution of the CECE diagnostic, which can be less than 1 cm. Wavenumbers resolved by the CECE diagnostic are kθ≤1.8 cm-1 and kr≤4 cm-1, relevant for studies of long-wavelength turbulence associated with the trapped electron mode and the ion temperature gradient mode. In neutral beam heated L-mode plasmas, core electron temperature fluctuations in the region 0.5emission spectroscopy. After incorporating "synthetic diagnostics" to effectively filter the code output, the simulations reproduce the characteristics of the turbulence and transport at one radial location r /a=0.5, but not at a second location, r /a=0.75. These results illustrate that measurements of the profiles of multiple fluctuating fields can provide a significant constraint on the turbulence models employed by the code.

  6. A correlation electron cyclotron emission diagnostic and the importance of multifield fluctuation measurements for testing nonlinear gyrokinetic turbulence simulations.

    PubMed

    White, A E; Schmitz, L; Peebles, W A; Carter, T A; Rhodes, T L; Doyle, E J; Gourdain, P A; Hillesheim, J C; Wang, G; Holland, C; Tynan, G R; Austin, M E; McKee, G R; Shafer, M W; Burrell, K H; Candy, J; DeBoo, J C; Prater, R; Staebler, G M; Waltz, R E; Makowski, M A

    2008-10-01

    A correlation electron cyclotron emission (CECE) diagnostic has been used to measure local, turbulent fluctuations of the electron temperature in the core of DIII-D plasmas. This paper describes the hardware and testing of the CECE diagnostic and highlights the importance of measurements of multifield fluctuation profiles for the testing and validation of nonlinear gyrokinetic codes. The process of testing and validating such codes is critical for extrapolation to next-step fusion devices. For the first time, the radial profiles of electron temperature and density fluctuations are compared to nonlinear gyrokinetic simulations. The CECE diagnostic at DIII-D uses correlation radiometry to measure the rms amplitude and spectrum of the electron temperature fluctuations. Gaussian optics are used to produce a poloidal spot size with w(o) approximately 1.75 cm in the plasma. The intermediate frequency filters and the natural linewidth of the EC emission determine the radial resolution of the CECE diagnostic, which can be less than 1 cm. Wavenumbers resolved by the CECE diagnostic are k(theta) < or = 1.8 cm(-1) and k(r) < or = 4 cm(-1), relevant for studies of long-wavelength turbulence associated with the trapped electron mode and the ion temperature gradient mode. In neutral beam heated L-mode plasmas, core electron temperature fluctuations in the region 0.5 < r/a < 0.9, increase with radius from approximately 0.5% to approximately 2%, similar to density fluctuations that are measured simultaneously with beam emission spectroscopy. After incorporating "synthetic diagnostics" to effectively filter the code output, the simulations reproduce the characteristics of the turbulence and transport at one radial location r/a = 0.5, but not at a second location, r/a = 0.75. These results illustrate that measurements of the profiles of multiple fluctuating fields can provide a significant constraint on the turbulence models employed by the code. PMID:19044712

  7. New Electron Cyclotron Emission Diagnostic Based Upon the Electron Bernstein Wave

    SciTech Connect

    P.C. Efthimion; J.C. Hosea; R. Kaita; R. Majeski; G. Taylor

    1999-05-01

    Most magnetically confined plasma devices cannot take advantage of standard Electron Cyclotron Emission (ECE) diagnostics to measure temperature. They either operate at high density relative to their magnetic field or they do not have sufficient density and temperature to reach the blackbody condition. The standard ECE technique measures the electromagnetic waves emanating from the plasma. Here we propose to measure electron Bernstein waves (EBW) to ascertain the local electron temperature in these plasmas. The optical thickness of EBW is extremely high because it is an electrostatic wave with a large k(subscript i). One can reach the blackbody condition with a plasma density approximately equal to 10(superscript 11) cm(superscript -3) and electron temperature approximately equal to 1 eV. This makes it attractive to most plasma devices. One serious issue with using EBW is the wave accessibility. EBW may be accessible by either direct coupling or mode conversion through an extremely narrow layer (approximately 1-2 mm) in low field devices.

  8. New electron cyclotron emission diagnostic based upon the electron Bernstein wave

    SciTech Connect

    Efthimion, P. C.; Hosea, J. C.; Kaita, R.; Majeski, R.; Taylor, G.

    1999-09-20

    Most magnetically confined plasma devices cannot take advantage of standard Electron Cyclotron Emission (ECE) diagnostics to measure temperature. They either operate at high density relative to their magnetic field or they do not have sufficient density and temperature to reach the blackbody condition. The standard ECE technique measures the electromagnetic waves emanating from the plasma. Here we propose to measure electron Bernstein waves (EBW) to ascertain the local electron temperature in these plasmas. The optical thickness of EBW is extremely high because it is an electrostatic wave with a large k{sub i}. One can reach the blackbody condition with a plasma density{approx_equal}10{sup 11} cm{sup -3} and T{sub e}{approx_equal}1 eV. This makes it attractive to most plasma devices. One serious issue with using EBW is the wave accessibility. EBW may be accessible by either direct coupling or mode conversion through an extremely narrow layer ((approx =)1-2 mm) in low field devices. (c) 1999 American Institute of Physics.

  9. VUV emission spectroscopy diagnostics of a 14 GHz ECR negative hydrogen ion source

    SciTech Connect

    Tamura, R. Ichikawa, T.; Kasuya, T.; Wada, M.; Nishiura, M.; Shimozuma, T.

    2015-04-08

    Vacuum Ultra Violet(VUV) emission from a 4 cm diameter 2 cm long compact ion source excited by 14 GHz microwave has been investigated. Intensity ratio of band spectrum emission near Ly-α to Ly-α line spectrum is determined from the measured spectrum. which shows preferential excitation of molecules near the entrance of microwave input power. The ratio does not depend strongly upon pressure nor the input microwave power when the intensity is integrated over the volume of the plasma. The spatial distribution of the spectrum intensity ratio exhibits concentrations near microwave inlet and the opposite side where the microwave matching structure is located. The ratio at these peripheral regions is about two times as high as that of the central region. The ratio increased in proportion to the ion source pressure up to about 3.0 Pa, indicating efficient production of high energy electrons by ECR up to this pressure.

  10. Physical properties of Be star envelopes from Balmer and Fe II emission lines

    NASA Astrophysics Data System (ADS)

    Slettebak, Arne; Collins, George W., II; Truax, Ryland

    1992-07-01

    The study obtains H-alpha, B-beta, H-gamma, and Fe II 6516 line profiles with resolution 0.45 A for 41 bright Be stars with a CCD detonator during two observing periods in 1989. Analysis of the structure of the emission profiles indicates that the Be star emitting envelope is most likely axially symmetric, consistent with a rotating, equatorial disk. A number of Be stars show either a 'wine bottle' structure or inflection points on one side of their H-alpha emission profiles, suggesting a two-component structure for the emitting envelope: an inner disk, possibly turbulent, and an outer extended disk. Differentially rotating disks producing weak H-alpha emission are closer to the central star where rotation broadens the line more strongly, relative to stars with extended envelopes which emit strongly but rotate more slowly. From the Balmer emission decrements it is found that Be star envelopes with Te near 10,000 K have electron densities in the range 10 exp 11 to 10 exp 13/cu cm. Be stars with weak Balmer emission have, on average, somewhat flatter Balmer decrements than stars with strong emission, suggesting envelopes with higher electron densities.

  11. On-line field measurements of VOC emissions from a spruce tree at SMEAR Estonia

    NASA Astrophysics Data System (ADS)

    Bourtsoukidis, Efstratios; Bonn, Boris; Noe, Steffen

    2013-04-01

    We have investigated VOC emissions from a Norway spruce tree (Picea abies) in a hemi-boreal mixed forest in September and October 2012, using Proton Transfer Reaction Mass Spectrometry and Gas Chromatography - Mass Spectrometry techniques, applied in a dynamic branch enclosure system that was automatically operated with an electrical compressor. Parallel to BVOC measurements a vast amount of atmospheric (CO2, CH4, H2O, CO, particles) and meteorological (temperature, relative humidity, photosynthetic active radiation, wind speed and direction, precipitation) parameters were measured in the ambient atmosphere and inside the cuvette enclosure (temperature, relative humidity, O3). Prior to the measuring period, an innovatory experimental setup was built at Järvselja forest station, in order to accomplish the detection of BVOC and minimize sampling losses. Therefore, a new inlet line, consisting of 19.4m of heated and isolated glass tube was constructed. The new inlet system applied, allowed the on-line detection and calculation of sesquiterpene (SQT) emission rates for the first time in a hemi-boreal forest site. It total, 12 atmospheric relevant BVOCs were continuously monitored for a three week period and the emission rates were derived. Along with diurnal profiles and continuous timeless, some interesting observations showed the possibility of ozone effect on SQT emissions, the possibility of radiation effect on MT emissions, the higher induced emissions due to mechanical stress and the possibility for a valid intercomparison between different spruce trees located in mountain Kleiner Feldberg (Germany) and in Järvseja forest station (Estonia).

  12. Spectral classification indicators of emission-line galaxies from the Sloan Digital Sky Survey

    NASA Astrophysics Data System (ADS)

    Shi, Fei; Liu, Yu-Yan; Li, Pei-Yu; Yu, Ming; Lei, Yu-Ming; Wang, Jian

    2015-07-01

    To find efficient spectral classification diagrams to classify emission-line galaxies, especially in large surveys and huge data bases, an artificial neural network (ANN) supervised learning algorithms is applied to a sample of emission-line galaxies from the Sloan Digital Sky Survey data release 9 provided by the Max Planck Institute and the Johns Hopkins University (MPA/JHU) (http://www.sdss3.org/dr9/spectro/spectroaccess.php). A two-step approach is adopted. (i) The ANN network must be trained with a subset of objects that are known to be active galactic nuclei (AGNs) hosts, composites or star-forming galaxies, treating the strong emission-line flux measurements as input feature vectors in n-dimensional space, where n is the number of strong emission-line flux ratios. (ii) After the network is trained on a sample of galaxies, the remaining galaxies are classified in the automatic test analysis as AGN hosts, composites or star-forming galaxies. We show that the classification diagrams based on the [N II]/Hα versus other emission-line 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 98 per cent for classification of AGN hosts, composites or star-forming galaxies. The other diagrams above except the diagram of [N II]/Hα versus [O III]/Hβ give an accuracy of ˜90 per cent. The code in the paper is available on the web (http://fshi5388.blog.163.com).

  13. The optical emission lines of type 1 X-ray bright Active Galactic Nuclei

    NASA Astrophysics Data System (ADS)

    La Mura, G.; Berton, M.; Ciroi, S.; Cracco, V.; Di Mille, F.; Rafanelli, P.

    2014-10-01

    A strong X-ray emission is one of the defining signatures of nuclear activity in galaxies. According to the Unified Model for Active Galactic Nuclei (AGN), both the X-ray radiation and the prominent broad emission lines, characterizing the optical and UV spectra of Type 1 AGNs, are originated in the innermost regions of the sources, close to the Super Massive Black Holes (SMBH), which power the central engine. Since the emission is concentrated in a very compact region (with typical size r⩽0.1 pc) and it is not possible to obtain resolved images of the source, spectroscopic studies of this radiation represent the only valuable key to constrain the physical properties of matter and its structure in the center of active galaxies. Based on previous studies on the physics of the Broad Line Region (BLR) and on the X-ray spectra of broad (FWHMHβ ⩾ 2000 km s-1) and narrow line (1000 km s-1 ⩽FWHMHβ ⩽ 2000 km s-1) emitting objects, it has been observed that the kinematic and ionization properties of matter close to the SMBHs are related together, and, in particular, that ionization is higher in narrow line sources. Here we report on the study of the optical and X-ray spectra of a sample of Type 1 AGNs, selected from the Sloan Digital Sky Survey (SDSS) database, within an upper redshift limit of z=0.35, and detected at X-ray energies. We present analysis of the broad emission line fluxes and profiles, as well as the properties of the X-ray continuum and Fe Kα emission and we use these parameters to assess the consistency of our current AGN understanding.

  14. Identification of emission lines in the low-ionization strontium filament near Eta Carinae

    NASA Astrophysics Data System (ADS)

    Hartman, H.; Gull, T.; Johansson, S.; Smith, N.; HST Eta Carinae Treasury Project Team

    2004-05-01

    We have obtained deep spectra from 1640 to 10 100 Å with the Space Telescope Imaging Spectrograph (STIS) of the strontium filament, a largely neutral emission nebulosity lying close to the very luminous star Eta Carinae and showing an uncommon spectrum. Over 600 emission lines, both permitted and forbidden, have been identified. The majority originates from neutral or singly-ionized iron group elements (Sc, Ti, V, Cr, Mn, Fe, Co, Ni). Sr is the only neutron capture element detected. The presence of Sr II, numerous strong Ti II and V II lines and the dominance of Fe I over Fe II are notable discoveries. While emission lines of hydrogen, helium, and nitrogen are associable with other spatial structures at other velocities within the Homunculus, no emission lines from these elements correspond to the spatial structure or velocity of the \\ion{Sr} filament. Moreover, no identified \\ion{Sr} filament emission line requires an ionization or excitation energy above approximately 8 eV. Ionized gas extends spatially along the aperture, oriented along the polar axis of the Homunculus, and in velocity around the strontium filament. We suggest that the strontium filament is shielded from ultraviolet radiation at energies above 8 eV, but is intensely irradiated by the central star at wavelengths longward of 1500 Å. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555. Tables 2 and 3 are only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/419/215

  15. Ultraviolet Fe VII absorption and Fe II emission lines of central stars of planetary nebulae

    NASA Technical Reports Server (NTRS)

    Cheng, Kwang-Ping; Feibelman, Walter A.; Bruhweiler, Frederick C.

    1991-01-01

    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 emission lines in five additional very hot central stars of planetary nebulae. Some of the Fe VII lines 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 emission lines 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.

  16. Scattering of emission lines in galaxy cluster cores: measuring electron temperature

    NASA Astrophysics Data System (ADS)

    Khedekar, S.; Churazov, E.; Sazonov, S.; Sunyaev, R.; Emsellem, E.

    2014-06-01

    The central galaxies of some clusters can be strong emitters in the Lyα and Hα lines. This emission may arise either from the cool/warm gas located in the cool core of the cluster or from the bright AGN within the central galaxy. The luminosities of such lines can be as high as 1042-1044 erg s-1. This emission originating from the core of the cluster will get Thomson scattered by hot electrons of the intra-cluster medium with an optical depth ˜0.01 giving rise to very broad (Δλ/λ ˜ 15 per cent) features in the scattered spectrum. We discuss the possibility of measuring the electron density and temperature using information on the flux and width of the highly broadened line features.

  17. Solar flare line emission between 6 A and 25 A. [using crystal spectrometer onboard OSO-5

    NASA Technical Reports Server (NTRS)

    Neupert, W. M.; Swartz, M.; Kastner, S. O.

    1973-01-01

    A list of emission lines in the spectra of solar flares between 6 and 25 A has been compiled using data obtained with a KAP crystal spectrometer on the OSO-5 satellite. The emission lines have been classified according to their sensitivity to flare activity. This classification provides a method for discriminating between iron in high stages of ionization (Fe XX-Fe XXV) and lower stages (Fe XVII-Fe XIX), the lines of which are both present in the same spectral region during flares. Identifications consistent with these classifications are proposed. Anomalous intensities in the spectra of Fe XVII and Fe XX are pointed out, and implications of the observations for models of the X-ray emitting regions are discussed.

  18. HST WFC3 Early Release Science: Emission-Line Galaxies from IR Grism Observations

    NASA Technical Reports Server (NTRS)

    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.; McCarthy, P. J.; Hathi, N. P.; Malhotra, S.; Rhoads, J.; Balick, B.; Bond, H. E.; Calzetti, D.; Disney, M. J.; Dopita, M. A.; Frogel, J. A.; Hall, D. N. B.; Holtzman, J. A.; Kimlbe, R. A.; Trauger, J. T.; Young, E. T.

    2010-01-01

    We present grism spectra of emission line 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] emission lines 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 emission lines not detectable with the G800L grism (e.g., [S II] and [S III] lines). From these relatively shallow observations, line 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 emission line--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.

  19. Hot surface ionic line emission and cold K-inner shell emission from petawatt-laser irradiated Cu foil targets

    SciTech Connect

    Theobald, W; Akli, K; Clarke, R; Delettrez, J A; Freeman, R R; Glenzer, S; Green, J; Gregori, G; Heathcote, R; Izumi, N; King, J A; Koch, J A; Kuba, J; Lancaster, K; MacKinnon, A J; Key, M; Mileham, C; Myatt, J; Neely, D; Norreys, P A; Park, H; Pasely, J; Patel, P; Regan, S P; Sawada, H; Shepherd, R; Snavely, R; Stephens, R B; Stoeckl, C; Storm, M; Zhang, B; Sangster, T C

    2005-12-13

    A hot, T{sub e} {approx} 2- to 3-keV surface plasma was observed in the interaction of a 0.7-ps petawatt laser beam with solid copper-foil targets at intensities >10{sup 20} W/cm{sup 2}. Copper K-shell spectra were measured in the range of 8 to 9 keV using a single-photon-counting x-ray CCD camera. In addition to K{sub {alpha}} and K{sub {beta}} inner-shell lines, the emission contained the Cu He{sub {alpha}} and Ly{sub {alpha}} lines, allowing the temperature to be inferred. These lines have not been observed previously with ultrafast laser pulses. For intensities less than 3 x 10{sup 18} W/cm{sup 2}, only the K{sub {alpha}} and K{sub {beta}} inner-shell emissions are detected. Measurements of the absolute K{sub {alpha}} yield as a function of the laser intensity are in agreement with a model that includes refluxing and confinement of the suprathermal electrons in the target volume.

  20. High-Frequency Evolving Emission Lines for the 25 August 1999 Solar Flare

    NASA Astrophysics Data System (ADS)

    Ning, Zongjun; Wu, H.; Xu, F.; Meng, X.

    2008-07-01

    We analyze a special kind of temporal fine structure in microwave radio emission for the 25 August 1999 solar flare observed by the PMO spectrometer over the range of 4.5 - 7.5 GHz. This flare displays continuum emission after a group of reverse-slope type III bursts around 6 GHz. High-resolution dynamic spectra reveal three evolving emission lines (EELs) following the type III group. They are characterized by isolated, narrow, and continuous emission strips, which display frequency fluctuations with time. Their frequency-drift rates are between -2 and 3 GHz s-1. Distinct from the EELs at lower frequencies, three EELs have a very short duration of a few seconds. They show an average bandwidth of Δ f≈330 MHz and a relative bandwidth of Δ f/ f≈0.057. This is the first time that this kind of fine structure has been observed around 6 GHz.

  1. Iron Line and Diffuse Hard X-Ray Emission from the Starburst Galaxy M82

    NASA Astrophysics Data System (ADS)

    Strickland, David K.; Heckman, Timothy M.

    2007-03-01

    We examine the properties of the diffuse hard X-ray emission in the classic starburst galaxy M82. We use new Chandra ACIS-S observations in combination with reprocessed archival Chandra ACIS-I and XMM-Newton observations. We find that E~6.7 keV Fe Heα emission is present in the central |r|<200 pc, |z|<100 pc of M82 in all data sets, in addition to a possibly nonthermal X-ray continuum and marginally significant E=6.4 keV Fe Kα line emission. No statistically significant Fe emission is found in the summed X-ray spectra of the pointlike X-ray sources or the ULXs in the two epochs of Chandra observation. The total nuclear region iron line fluxes in the 2004 April 21 XMM-Newton observation are consistent with those of the Chandra-derived diffuse component, but in the 2001 May 6 XMM-Newton observation they are significantly higher and also both E=6.4 and 6.9 keV iron lines are detected. We attribute the excess iron line emission to the ULX in its high state. In general, the iron K-shell luminosity of M82 is dominated by the diffuse component. The total X-ray luminosity of the diffuse hard X-ray emission is LX,2-8keV~4.4×1039 ergs s-1 in the E=2-8 keV energy band, and the 6.7 keV iron line luminosity is LX,6.7keV~(1.1-1.7)×1038 ergs s-1. The 6.7 keV iron line luminosity is consistent with that expected from the previously unobserved metal-enriched merged SN ejecta that is thought to drive the larger scale galactic superwind. The iron line luminosity implies a thermal pressure within the starburst region of P/k~2×107 K cm-3, consistent with independent observational estimates of the starburst region pressure.

  2. Strong Field Effects on Emission Line Profiles: Kerr Black Holes and Warped Accretion Disks

    NASA Astrophysics Data System (ADS)

    Wang, Yan; Li, Xiang-Dong

    2012-01-01

    If an accretion disk around a black hole is illuminated by hard X-rays from non-thermal coronae, fluorescent iron lines will be emitted from the inner region of the accretion disk. The emission line profiles will show a variety of strong field effects, which may be used as a probe of the spin parameter of the black hole and the structure of the accretion disk. In this paper, we generalize the previous relativistic line profile models by including both the black hole spinning effects and the non-axisymmetries of warped accretion disks. Our results show different features from the conventional calculations for either a flat disk around a Kerr black hole or a warped disk around a Schwarzschild black hole by presenting, at the same time, multiple peaks, rather long red tails, and time variations of line profiles with the precession of the disk. We show disk images as seen by a distant observer, which are distorted by the strong gravity. Although we are primarily concerned with the iron K-shell lines in this paper, the calculation is general and is valid for any emission lines produced from a warped accretion disk around a black hole.

  3. Strong Field Effects On Emission Line Profiles: Kerr Black Holes And Warped Accretion Disks

    NASA Astrophysics Data System (ADS)

    Wang, Yan; Li, X.

    2012-01-01

    If an accretion disk around a black hole is illuminated by hard X-rays from non-thermal coronae, fluorescent iron lines will be emitted from the inner region of the accretion disk. The emission line profiles will show a variety of strong field effects, which may be used as a probe of the spin parameter of the black hole and the structure of the accretion disk. In this paper we generalize the previous relativistic line profile models by including both the black hole spinning effects and the non-axisymmetry of warped accretion disks. Our results show different features from the conventional calculations for either a flat disk around a Kerr black hole or a warped disk around a Schwarzschild black hole by presenting, at the same time, multiple peaks, rather long red tails and time variations of line profiles with the precession of the disk. We show disk images as seen by a distant observer, which are distorted by the strong gravity. Although we are primarily concerned with the iron K-shell lines in this paper, the calculation is general and is valid for any emission lines produced from a warped accretion disk around a black hole. This work was supported by the Natural Science Foundation of China (under grant number 10873008), and the National Basic Research Program of China (973 Program 2009CB824800).

  4. STRONG FIELD EFFECTS ON EMISSION LINE PROFILES: KERR BLACK HOLES AND WARPED ACCRETION DISKS

    SciTech Connect

    Wang Yan; Li Xiangdong

    2012-01-10

    If an accretion disk around a black hole is illuminated by hard X-rays from non-thermal coronae, fluorescent iron lines will be emitted from the inner region of the accretion disk. The emission line profiles will show a variety of strong field effects, which may be used as a probe of the spin parameter of the black hole and the structure of the accretion disk. In this paper, we generalize the previous relativistic line profile models by including both the black hole spinning effects and the non-axisymmetries of warped accretion disks. Our results show different features from the conventional calculations for either a flat disk around a Kerr black hole or a warped disk around a Schwarzschild black hole by presenting, at the same time, multiple peaks, rather long red tails, and time variations of line profiles with the precession of the disk. We show disk images as seen by a distant observer, which are distorted by the strong gravity. Although we are primarily concerned with the iron K-shell lines in this paper, the calculation is general and is valid for any emission lines produced from a warped accretion disk around a black hole.

  5. The Herschel Comprehensive (U)LIRG Emission Survey (HERCULES): CO Ladders, Fine Structure Lines, and Neutral Gas Cooling

    NASA Astrophysics Data System (ADS)

    Rosenberg, M. J. F.; van der Werf, P. P.; Aalto, S.; Armus, L.; Charmandaris, V.; Díaz-Santos, T.; Evans, A. S.; Fischer, J.; Gao, Y.; González-Alfonso, E.; Greve, T. R.; Harris, A. I.; Henkel, C.; Israel, F. P.; Isaak, K. G.; Kramer, C.; Meijerink, R.; Naylor, D. A.; Sanders, D. B.; Smith, H. A.; Spaans, M.; Spinoglio, L.; Stacey, G. J.; Veenendaal, I.; Veilleux, S.; Walter, F.; Weiß, A.; Wiedner, M. C.; van der Wiel, M. H. D.; Xilouris, E. M.

    2015-03-01

    (Ultra) luminous infrared galaxies ((U)LIRGs) are objects characterized by their extreme infrared (8-1000 μm) luminosities (L LIRG > 1011 L ⊙ and L ULIRG > 1012 L ⊙). The Herschel Comprehensive ULIRG Emission Survey (PI: van der Werf) presents a representative flux-limited sample of 29 (U)LIRGs that spans the full luminosity range of these objects (1011 L ⊙ <= L IR <= 1013 L ⊙). With the Herschel Space Observatory, we observe [C II] 157 μm, [O I] 63 μm, and [O I] 145 μm line emission with Photodetector Array Camera and Spectrometer, CO J = 4-3 through J = 13-12, [C I] 370 μm, and [C I] 609 μm with SPIRE, and low-J CO transitions with ground-based telescopes. The CO ladders of the sample are separated into three classes based on their excitation level. In 13 of the galaxies, the [O I] 63 μm emission line is self absorbed. Comparing the CO excitation to the InfraRed Astronomical Satellite 60/100 μm ratio and to far infrared luminosity, we find that the CO excitation is more correlated to the far infrared colors. We present cooling budgets for the galaxies and find fine-structure line flux deficits in the [C II], [Si II], [O I], and [C I] lines in the objects with the highest far IR fluxes, but do not observe this for CO 4 <= J upp <= 13. In order to study the heating of the molecular gas, we present a combination of three diagnostic quantities to help determine the dominant heating source. Using the CO excitation, the CO J = 1-0 linewidth, and the active galactic nucleus (AGN) contribution, we conclude that galaxies with large CO linewidths always have high-excitation CO ladders, and often low AGN contributions, suggesting that mechanical heating is important. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

  6. Small-scale on-line diagnostics for an HVAC system

    SciTech Connect

    Dodier, R.H.; Kreider, J.F.; Curtiss, P.S.

    1998-10-01

    This paper describes an automated fault detection and diagnosis scheme for HVAC equipment, the Real-Time Diagnostic System (RTDS). The principles of operation of the RTDS are outlined, a computer implementation of the RTDS is described, and results of applying the RTDS to HVAC laboratory data are presented. The tests indicated that application of this inference system to the diagnosis of mixing box failures yields encouraging results. Although misdiagnosis of failure conditions is more frequent than the authors might like, false alarms are uncommon. The tests also show that training a diagnostic model on one mixing box and using the model on the other mixing boxes yields good results.

  7. Detection of an unidentified emission line in the stacked X-ray spectrum of galaxy clusters

    SciTech Connect

    Bulbul, Esra; Foster, Adam; Smith, Randall K.; Randall, Scott W.; Markevitch, Maxim; Loewenstein, Michael

    2014-07-01

    We detect a weak unidentified emission line 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 line 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 lines. The detection is at the limit of the current instrument capabilities. We 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 line in Perseus is much brighter than expected in this model, significantly deviating from other subsamples. This appears to be because of an anomalously bright line at E = 3.62 keV in Perseus, which could be an Ar XVII dielectronic recombination line, although its emissivity would have to be 30 times the expected value and physically difficult to understand. Another alternative is the above anomaly in the Ar line combined with the nearby 3.51 keV K line also exceeding expectation by a factor of 10-20. Confirmation with Astro-H will be critical to determine the nature of this new line.

  8. Far-infrared emission lines of CO and OH in the Orion-KL molecular shock

    NASA Technical Reports Server (NTRS)

    Watson, D. M.; Genzel, R.; Townes, C. H.; Storey, J. M. V.

    1985-01-01

    Observations of far infrared rotational emission lines which arise in the shocked gas associated with Orion-Kl are presented, including detections of the CO J = 34 yields 33, J = 31 yields 30, J = 26 yields 25, and OH sup 2 PI sub (3/2) J sup P = 7/2(-) yields 5/2(+) emission lines, as well as improved measurements of the CO J = 22 yields 21 and OH sup 2 PI sub (3/2) J = 5/2 yields 3/2 lines. These lines are observed to have velocity widths of Del V approx. 20 to 30 km/sec, somewhat less than either the 2 micro H sub 2 lines or the high velocity plateau component of the millimeter wave CO lines seen in this object. An H sub 2 column density of approx. 3 x 10 to the 21st power, a total mass of approx. 1 solar mass and characteristic temperature and density T approx. 750 K and approx. 2 x 10 to the 6th power per cu cm can be derived from the CO intensities. The density is too low by at least an order of magnitude for the observed infrared H sub 2 and far infrared CO emission to be accounted for by a purely hydrodynamic shock, and support is lent to hydromagnetic shock models. From the present measurements, the relative abundance of CO is estimated to be CO H sub 2 = 1.2 x .0001, corresponding to 20% of the cosmic abundance of C existing in the form of CO. The average relative abundance of OH in the shocked gas is O/H sub 2 or = 5 x 10 to the -7th power. An upper limit to the intensity of the HD J = 1 yields 0 line is used to derive an upper limit of tau or = 3 for the D/H relative abundance in the Orion cloud core.

  9. Star formation history in early-type galaxies - I. The line absorption indices diagnostics

    NASA Astrophysics Data System (ADS)

    Tantalo, Rosaria; Chiosi, Cesare

    2004-09-01

    To unravel the formation mechanism and the evolutionary history of elliptical galaxies (EGs) is one of the goals of modern astrophysics. In a simplified picture of the issue, the question to be answered is whether they have formed by hierarchical merging of pre-existing substructures (maybe disc galaxies) made of stars and gas, with each merging event probably accompanied by strong star formation, or conversely, whether they originated from the early aggregation of lumps of gas turned into stars in the remote past via a burst-like episode ever since followed by quiescence so as to mimic a sort of monolithic process. Even if the two alternatives seem to oppose each other, actually they may both contribute to shaping the final properties of EGs as seen today. Are there distinct signatures of the underlying dominant process in the observational data? To this aim we have examined the line absorption indices on the Lick system of the normal, field EGs of Trager and the interacting EGs (pair- and shell-objects) of Longhetti et al. The data show that both normal, field and interacting galaxies have the same scattered but smooth distribution in the Hβ versus [MgFe] plane even if the interacting ones show a more pronounced tail toward high Hβ values. This may suggest that a common physical cause is at the origin of their distribution. There are two straightforward interpretations of increasing complexity. (i) EGs span true large ranges of ages and metallicities. A young age is the signature of the aggregation mechanism, each event accompanied by metal enrichment. This simple scheme cannot, however, explain other spectro-photometric properties of EGs and has to be discarded. (ii) The bulk population of stars is old but subsequent episodes of star formation scatter the EGs in the diagnostic planes. However, this scheme would predict an outstanding clump at low Hβ values, contrary to what is observed. The model can be cured by supposing that the primary star formation

  10. FE Line Diagnostics of Multiply Shocked Stellar Atmospheres: The Mira S. Carinae

    NASA Technical Reports Server (NTRS)

    Bookbinder, Jay

    1997-01-01

    Extensive LWP-HI spectra were obtained of the Mira S Car at a rapid time cadence as compared with the shock cycle time of S Car. These spectra were obtained in an attempt to understand the velocity structures in the shocked wind using the fluoresced iron lines. Data analysis of the IUE observations, which included the primary calibration of all of the IUE spectra obtained of S Car, was carried out. In addition, line identifications, flux calculations, background subtractions, and line profile analysis as a function of S Car's pulsational phase were performed. The database incorporated all line identifications as a function of pulsation phase for all IUE LWP-HI observations to date of S Car. At least 45 separate iron line features are identified in the S Car spectrum at one or more phases of the shock cycle, including those due to Fe II (UV 161) which is pumped by three different iron lines; Fe I(UV 44) which is pumped by the Mg II k line. Other strong multiplets that have been identified include UV(1), UV(2), UV(5), UV(32), UV(60), UV(63), UV(161), UV(207), and UV(399). Over 300 weaker lines have also been tentatively identified with Fe line transitions.

  11. Gamma-Ray Line Flux Ratios as Diagnostics of SN Ia Models

    NASA Astrophysics Data System (ADS)

    Lara, Juan; The, Lih-Sin; Leising, Mark

    2004-05-01

    The ^56Ni decay chain that powers the optical output of Type Ia supernovae produces gamma-ray lines at 158, 812 ( ^56Ni decay ) and 847, 1238 keV ( ^56Co decay ). The detection of the line fluxes have been used to show indeed that ^56Ni is produced by explosive nucleosynthesis. We investigate the measurement precision required to use the flux ratios of these lines to each other and to the compton X-ray continuum to distinguish among a variety of SN Ia models. We compare this to using gamma-ray line profiles to distinguish among models.

  12. emission-line stars in molecular clouds. II. The M 42 region

    NASA Astrophysics Data System (ADS)

    Pettersson, Bertil; Armond, Tina; Reipurth, Bo

    2014-10-01

    We present a deep survey of Hα emission-line stars in the M 42 region using wide-field objective prism films. A total of 1699 Hα emission-line stars were identified, of which 1025 were previously unknown, within an area of 5.̊5 × 5.̊5 centred on the Trapezium Cluster. We present Hα strength estimates, positions, and JHKs photometry extracted from 2MASS, and comparisons to previous surveys. The spatial distribution of the bulk of the stars follows the molecular cloud as seen in CO and these stars are likely to belong to the very young population of stars associated with the Orion Nebula Cluster. Additionally, there is a scattered population of Hα emission-line stars distributed all over the region surveyed, which may consist partly of foreground stars associated with the young NGC 1980 cluster, as well as some foreground and background dMe or Be stars. The present catalogue adds a large number of candidate low-mass young stars belonging to the Orion population, selected independently of their infrared excess or X-ray emission. Full Table 2 is only available in electronic form at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/570/A30

  13. VizieR Online Data Catalog: Vatican Emission-line stars (Coyne+ 1974-1983)

    NASA Astrophysics Data System (ADS)

    Coyne, G. V.; Lee, T. A.; de Graeve, E.; Wisniewski, W.; Corbally, C.; Otten, L. B.; MacConnell, D. J.

    2009-10-01

    The survey represents a search for Hα emission-line stars, and was conducted with a 12{deg} objective prism on the Vatican Schmidt telescope. The Vatican Emission 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 emission-line stars, but instead M giants, where the sharp TiO bandhead at 6544{AA} was mistaken for H-{alpha} emission 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 line, or in longer notes in a separate file, indicated by an asterisk (*) next to the star number. (3 data files).

  14. VizieR Online Data Catalog: Vatican Emission-line stars (Coyne+ 1974-1983)

    NASA Astrophysics Data System (ADS)

    Coyne, G. V.; Lee, T. A.; de Graeve, E.; Wisniewski, W.; Corbally, C.; Otten, L. B.; MacConnell, D. J.

    2008-03-01

    The survey represents a search for Hα emission-line stars, and was conducted with a 12{deg} objective prism on the Vatican Schmidt telescope. The Vatican Emission 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 emission-line stars, but instead M giants, where the sharp TiO bandhead at 6544{AA} was mistaken for H-{alpha} emission 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 line, or in longer notes in a separate file, indicated by an asterisk (*) next to the star number. (2 data files).

  15. IUE observations of the Henize-Carlson sample of peculiar emission line supergiants: The galactic analogs of the Magellanic Zoo

    NASA Technical Reports Server (NTRS)

    Shore, Steven N.; Brown, Douglas N.; Sanduleak, N.

    1986-01-01

    Some 15 stars from the Carlson-Henize survey of southern peculiar emission line stars were studied. From both the optical and UV spectra, they appear to be galactic counterparts of the most extreme early-type emission line supergiants of the Magellanic Clouds.

  16. Emission-Line Variability in the Iron Star XX Orphiuchus Over the Past Decade

    NASA Astrophysics Data System (ADS)

    Pugh, Bryan; Walter, D. K.; Howell, S. B.; Cash, J.

    2013-01-01

    We present the results of an analysis of nine years of spectra taken with the Coudé Feed telescope at KPNO of the Iron Star XX Oph. In addition to numerous iron lines, other metals such as Ti and the hydrogen Balmer series are seen in emission, while still others such as the H and K lines of Ca II are in absorption. Our study covers the years 2003 to 2012 and includes an episode in 2004 where photometry from the AAVSO shows a 1.5 magnitude drop in brightness as discussed in Cool et.al. (2005, PASP, 117, 462). Beginning in 2005 and continuing to the present, our data show Balmer lines with P-Cygni profiles , where the strength of the absorption components generally increase over time while the emission components are diminished. We discuss our results in comparison to the model of Howell et.al. (2009 PASAP, 121, 16) of AS 325, a similar iron emission-line star in a binary system. Support for this work was provided by the NSF PAARE program to South Carolina State University under award AST-0750814. We thank the director of KPNO for his generous allocation of telescope time to this project over the years.

  17. Line emission of sodium and hydroxyl radicals in single-bubble sonoluminescence.

    PubMed

    Schneider, Julia; Pflieger, Rachel; Nikitenko, Sergey I; Shchukin, Dmitry; Möhwald, Helmuth

    2011-01-20

    Spectroscopic studies of single-bubble sonoluminescence (SBSL) in water and aqueous sodium chloride solutions with a defined concentration of argon were performed as a function of the driving acoustic pressure. The broad-band continuum ranging from 200 to 700 nm is characterized by fits using Planck's law of blackbody radiation. The obtained blackbody temperatures are in the range of 10(4) K and are revealed to be independent of the presence of a salt and the acoustic pressure, whereas the SL intensity increases by a factor of more than 10 within the studied acoustic pressure range. The different trends followed by SL intensity and blackbody temperatures question the blackbody model. In solutions with 70 mbar of argon, line emissions of OH(•) radicals and Na* are observed. The shape of the OH(•) radical emission spectrum is very similar to that in MBSL spectra, indicating the strong similarity of intrabubble conditions. An increase of the acoustic pressure causes the continuum to overlap the lines until they become indistinguishable. The emission line of Na* in NaCl is observed only at high NaCl concentrations. When sodium dodecylsulfate is used a pronounced Na* line is already observed in a 1 mM solution thanks to enrichment of sodium ions at the interface. The results presented in this work reveal the strong similarity of SBSL and MBSL under certain experimental conditions. PMID:21166432

  18. The Deepest Spectrum in the Universe? Line Emission from Lyman-alpha Clouds at z 3

    NASA Astrophysics Data System (ADS)

    Bunker, Andrew J.; Rauch, M.; Haehnelt, M.; Becker, G.; Marleau, F.; Graham, J.; Research, European; Inter-Galactic Medium, Training Network on the

    2007-12-01

    We present the results of an extremely deep long-slit optical spectroscopic search for low-luminosity Lyman-alpha emitters. Over several years we have accumulated 150-hours integration on a single field with 8-10m telescopes (VLT/FORS2, Gemini/GMOS and Keck/LRIS) at a spectral resolution of 300km/s. This is the deepest spectrum ever obtained - our 1 sigma sensitivity to line emission in a 1 arcsec2 aperture is 1019erg/cm2/s. We have significant detections of 30 emission line objects, which are most likely Lyman-alpha emitters at 2.7line emission may be powered by star formation in conditions of low metallicity and low dust, or alternatively may arise from cooling radiation or perhaps external photoionzation by the metagalactic Lyman continuum background. Many of the line emitters are significantly spatially extended (with median size 4arcsec, 30kpc) and could plausibly be the host population of the high column density Lyman-alpha absorption clouds seen in QSO spectra (the Damped Lyman-alpha Systems and the Lyman-Limit Systems).

  19. Molecular Line Emission Towards High-Mass Clumps: The MALT90 Catalogue

    NASA Astrophysics Data System (ADS)

    Rathborne, J. M.; Whitaker, J. S.; Jackson, J. M.; Foster, J. B.; Contreras, Y.; Stephens, I. W.; Guzmán, A. E.; Longmore, S. N.; Sanhueza, P.; Schuller, F.; Wyrowski, F.; Urquhart, J. S.

    2016-07-01

    The Millimetre Astronomy Legacy Team 90 GHz survey aims to characterise the physical and chemical evolution of high-mass clumps. Recently completed, it mapped 90 GHz line emission towards 3 246 high-mass clumps identified from the ATLASGAL 870 μm Galactic plane survey. By utilising the broad frequency coverage of the Mopra telescope's spectrometer, maps in 16 different emission lines were simultaneously obtained. Here, we describe the first catalogue of the detected line emission, generated by Gaussian profile fitting to spectra extracted towards each clumps' 870 μm dust continuum peak. Synthetic spectra show that the catalogue has a completeness of > 95%, a probability of a false-positive detection of < 0.3%, and a relative uncertainty in the measured quantities of < 20% over the range of detection criteria. The detection rates are highest for the (1-0) transitions of HCO+, HNC, N2H+, and HCN (~77-89%). Almost all clumps (~95%) are detected in at least one of the molecular transitions, just over half of the clumps (~53%) are detected in four or more of the transitions, while only one clump is detected in 13 transitions. We find several striking trends in the ensemble of properties for the different molecular transitions when plotted as a function of the clumps' evolutionary state as estimated from Spitzer mid-IR images, including (1) HNC is relatively brighter in colder, less evolved clumps than those that show active star formation, (2) N2H+ is relatively brighter in the earlier stages, (3) that the observed optical depth decreases as the clumps evolve, and (4) the optically thickest HCO+ emission shows a `blue-red asymmetry' indicating overall collapse that monotonically decreases as the clumps evolve. This catalogue represents the largest compiled database of line emission towards high-mass clumps and is a valuable data set for detailed studies of these objects.

  20. First Detection of Near-infrared Line Emission from Organics in Young Circumstellar Disks

    NASA Astrophysics Data System (ADS)

    Mandell, Avi M.; Bast, Jeanette; van Dishoeck, Ewine F.; Blake, Geoffrey A.; Salyk, Colette; Mumma, Michael J.; Villanueva, Geronimo

    2012-03-01

    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 emission 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 emission 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. Line 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 emission has both a Keplerian and non-Keplerian component as observed previously for CO emission. 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 line profile to make line 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 line shapes suggests that the molecular emission 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).