Science.gov

Sample records for absorption line bal

  1. Balmer Absorption Lines in FeLoBALs

    NASA Astrophysics Data System (ADS)

    Aoki, K.; Iwata, I.; Ohta, K.; Tamura, N.; Ando, M.; Akiyama, M.; Kiuchi, G.; Nakanishi, K.

    2007-10-01

    We discovered non-stellar Balmer absorption lines in two many-narrow-trough FeLoBALs (mntBALs) by the near-infrared spectroscopy with Subaru/CISCO. Presence of the non-stellar Balmer absorption lines is known to date only in the Seyfert galaxy NGC 4151; thus our discovery is the first cases for quasars. Since all known active galactic nuclei with Balmer absorption lines share similar characteristics, it is suggested that there is a population of BAL quasars which have unique structures at their nuclei or unique evolutionary phase.

  2. SimBAL: A Spectral Synthesis Approach to Analyzing Broad Absorption Line Quasar Spectra

    NASA Astrophysics Data System (ADS)

    Terndrup, Donald M.; Leighly, Karen; Gallagher, Sarah; Richards, Gordon T.

    2017-01-01

    Broad Absorption Line quasars (BALQSOs) show blueshifted absorption lines in their rest-UV spectra, indicating powerful winds emerging from the central engine. These winds are essential part of quasars: they can carry away angular momentum and thus facilitate accretion through a disk, they can distribute chemically-enriched gas through the intergalactic medium, and they may inject kinetic energy to the host galaxy, influencing its evolution. The traditional method of analyzing BALQSO spectra involves measuring myriad absorption lines, computing the inferred ionic column densities in each feature, and comparing with the output of photonionization models. This method is inefficient and does not handle line blending well. We introduce SimBAL, a spectral synthesis fitting method for BALQSOs, which compares synthetic spectra created from photoionization model results with continuum-normalized observed spectra using Bayesian model calibration. We find that we can obtain an excellent fit to the UV to near-IR spectrum of the low-redshift BALQSO SDSS J0850+4451, including lines from diverse ionization states such as PV, CIII*, SIII, Lyalpha, NV, SiIV, CIV, MgII, and HeI*.

  3. The ultraviolet spectrum of the gravitational lens candidate UM 425 = QSO 1120+019: Evidence for broad absorption line (BAL) structure

    NASA Technical Reports Server (NTRS)

    Michelitsianos, A. G.; Oliversen, R. J.

    1995-01-01

    The UV line profile structure of high-ionization resonance lines found with the International Ultraviolet Explorer (IUE) in the brightest of four multiply imaged sources (images-A) in the candidate gravitational lens UM 425 = QSO 1120+019 indicates broad absorption line (BAL) structure. The deep-broad trough associated with the O IV line extends to velocities approiximately -12,000 km/s, and contains disrete features that suggest multicomponent velocity structure. This structure may include contributions from C IV absorption from the early-type galaxy that is believed to lens UM 425. A strong absorption feature in the blue wing of the Lyman-alpha lambda 1216 emission line may be a Lyman alpha absorption system at a Z(sub Ly alpha) = 1.437 +/- 0.003, or it may be formed by the superposition of the broad N V lambda lambda 1238, 1242 absorption trough on the extended blue emission wing of the QSO Lyman-alpha line. We obtained a redshift of Z(sub QSO) = 1.471 +/- 0.003 from Lyman-alpha lambda 1215, consistent with the redshift found by Meylan and Djorgovski in the optical. The Lyman-alpha line appears unusally weak due to the presence of N V lambda 1240 BAL absorption. A Lyman-limit absorption system at lambda 912 was not observed in the QSO rest frame. The detection of BAL structure in the other weaker ground-state resonance lines of N II (l) and S IV (l) was not found, suggesting these lines are formed in a region that is distinct from the BAL component. Detection of BAL structure in the other fainter images in this system with Hubble Space Telescope (HST) instrumentation, similar to structure observed here in image A, could provide evidence that UM 425 is a gravitational lens.

  4. Narrow UV Absorption Line Outflows from Quasars

    NASA Astrophysics Data System (ADS)

    Hamann, F.; Simon, L.; Rodriguez Hidalgo, P.; Capellupo, D.

    2012-08-01

    Narrow absorption line (NAL) outflows are an important yet poorly understood part of the quasar outflow phenomenon. We discuss one particular NAL outflow that has high speeds, time variability, and moderate ionizations like typical BAL flows, at an estimated location just ˜5 pc from the quasar. It also has a total column density and line widths (internal velocity dispersions) ˜100 times smaller than BALs, with no substantial X-ray absorption. We argue that radiative shielding (in the form of an X-ray/warm absorber) is not critical for the outflow acceleration and that the moderate ionizations occur in dense substructures that have an overall small volume filling factor in the flow. We also present new estimates of the overall incidence of quasar outflow lines; e.g., ˜43% of bright quasars have a C IV NAL outflow while ˜68% have a C IV outflow line of any variety (NAL, BAL, or mini-BAL).

  5. The VLBI structure of radio-loud Broad Absorption Line quasars

    NASA Astrophysics Data System (ADS)

    Liu, Y.; Jiang, D. R.; Gu, M.

    2016-02-01

    The nature and origin of Broad Absorption Line (BAL) quasars and their relationship to non-BAL quasars are an open question. The BAL quasars are probably normal quasars seen along a particular line of sight. Alternatively, they are young or recently refueled. The high resolution radio morphology of BAL quasars is very important to understand the radio properties of BAL quasars. We present VLBA observations at L and C bands for a sample of BAL quasars. The observations will help us to explore the VLBI radio properties, and distinguish the present models of explaining BAL phenomena.

  6. Spectrophotometry of six broad absorption line QSOs

    NASA Technical Reports Server (NTRS)

    Junkkarinen, Vesa T.; Burbidge, E. Margaret; Smith, Harding E.

    1987-01-01

    Spectrophotometric observations of six broad absorption-line QSOs (BALQSOs) are presented. The continua and emission lines are compared with those in the spectra of QSOs without BALs. A statistically significant difference is found in the emission-line intensity ratio for (N V 1240-A)/(C IV 1549-A). The median value of (N V)/(C IV) for the BALQSOs is two to three times the median for QSOs without BALs. The absorption features of the BALQSOs are described, and the column densities and limits on the ionization structure of the BAL region are discussed. If the dominant ionization mechanism is photoionization, then it is likely that either the ionizing spectrum is steep or the abundances are considerably different from solar. Collisional ionization may be a significant factor, but it cannot totally dominate the ionization rate.

  7. Polarization and Broad Absorption Lines in Quasars

    NASA Astrophysics Data System (ADS)

    Antonucci, Robert

    1990-12-01

    OI 287 is a unique extragalactic source. It appears to take one property from each class of object. It is either some kind of missing link, or a new type of activity. Because of the high optical polarization, OI 287 has been classified with the blazars. However, every other blazar is variable in optical flux, polarization, and polarization angle., while OI 287 is constant at V=17, P=8%, and theta=145 degrees. Also, every other blazar has a radio source dominated by an intense flat-spectrum core, while OI 287 has an upper limit of 2% of the total 20cm flux in the core. The only group of quasars which ever shows even moderate (2-5%) constant optical polarization is the broad absorption line (BAL) objects, e.g. PHL 5200 and H1413+113. Among the BAL quasars, PHL 5200 and H1413+113 have exceptionally smooth deep, attached absorption lines, and also the highest polarization. We want to know whether OI 287 is a BAL quasar. It would be the first definite radio loud example. If it is a BAL quasar then the high polarization is really related to (and perhaps the key to) the BAL phenomenon, and we can use the techniques of spectropolarimetry to help unlock the BAL geometry. The UV spectral shape would also provide help determining the cause of polarization.

  8. BROAD ABSORPTION LINE VARIABILITY ON MULTI-YEAR TIMESCALES IN A LARGE QUASAR SAMPLE

    SciTech Connect

    Filiz Ak, N.; Brandt, W. N.; Schneider, D. P.; Hall, P. B.; Anderson, S. F.; Hamann, F.; Lundgren, B. F.; Myers, Adam D.; Pâris, I.; Petitjean, P.; Ross, Nicholas P.; Shen, Yue; York, Don

    2013-11-10

    We present a detailed investigation of the variability of 428 C IV and 235 Si IV broad absorption line (BAL) troughs identified in multi-epoch observations of 291 quasars by the Sloan Digital Sky Survey-I/II/III. These observations primarily sample rest-frame timescales of 1-3.7 yr over which significant rearrangement of the BAL wind is expected. We derive a number of observational results on, e.g., the frequency of BAL variability, the velocity range over which BAL variability occurs, the primary observed form of BAL-trough variability, the dependence of BAL variability upon timescale, the frequency of BAL strengthening versus weakening, correlations between BAL variability and BAL-trough profiles, relations between C IV and Si IV BAL variability, coordinated multi-trough variability, and BAL variations as a function of quasar properties. We assess implications of these observational results for quasar winds. Our results support models where most BAL absorption is formed within an order-of-magnitude of the wind-launching radius, although a significant minority of BAL troughs may arise on larger scales. We estimate an average lifetime for a BAL trough along our line-of-sight of a few thousand years. BAL disappearance and emergence events appear to be extremes of general BAL variability, rather than being qualitatively distinct phenomena. We derive the parameters of a random-walk model for BAL EW variability, finding that this model can acceptably describe some key aspects of EW variability. The coordinated trough variability of BAL quasars with multiple troughs suggests that changes in 'shielding gas' may play a significant role in driving general BAL variability.

  9. The Redshifted Hydrogen Balmer and Metastable He 1 Absorption Line System in Mini-FeLoBAL Quasar SDSS J112526.12+002901.3: A Parsec-scale Accretion Inflow?

    NASA Astrophysics Data System (ADS)

    Shi, Xi-Heng; Jiang, Peng; Wang, Hui-Yuan; Zhang, Shao-Hua; Ji, Tuo; Liu, Wen-Juan; Zhou, Hong-Yan

    2016-10-01

    The accretion of the interstellar medium onto central super-massive black holes is widely accepted as the source of the gigantic energy released by the active galactic nuclei. However, few pieces of observational evidence have been confirmed directly demonstrating the existence of the inflows. The absorption line system in the spectra of quasar SDSS J112526.12+002901.3 presents an interesting example in which the rarely detected hydrogen Balmer and metastable He i absorption lines are found redshifted to the quasar's rest frame along with the low-ionization metal absorption lines Mg ii, Fe ii, etc. The repeated SDSS spectroscopic observations suggest a transverse velocity smaller than the radial velocity. The motion of the absorbing medium is thus dominated by infall. The He i* lines present a powerful probe to the strength of ionizing flux, while the Balmer lines imply a dense environment. With the help of photoionization simulations, we find that the absorbing medium is exposed to the radiation with ionization parameter U ≈ 10-1.8, and the density is n({{H}})≈ {10}9 {{cm}}-3. Thus the absorbing medium is located ˜4 pc away from the central engine. According to the similarity in the distance and physical conditions between the absorbing medium and the torus, we strongly propose the absorption line system as a candidate for the accretion inflow, which originates in the inner surface of the torus.

  10. Is there a connection between broad absorption line quasars and narrow-line Seyfert 1 galaxies?

    SciTech Connect

    Grupe, Dirk; Nousek, John A.

    2015-02-01

    We consider whether broad absorption line quasars (BAL QSOs) and narrow-line Seyfert 1 galaxies (NLS1s) are similar, as suggested by Brandt and Gallagher and Boroson. For this purpose, we constructed a sample of 11 BAL QSOs from existing Chandra and Swift observations. We found that BAL QSOs and NLS1s both operate at high Eddington ratios L/L{sub Edd}, although BAL QSOs have slightly lower L/L{sub Edd}. BAL QSOs and NLS1s in general have high Fe ii/Hβ and low [O iii]/Hβ ratios following the classic “Boroson and Green” eigenvector 1 relation. We also found that the mass accretion rates M-dot of BAL QSOs and NLS1s are more similar than previously thought, although some BAL QSOs exhibit extreme mass accretion rates of more than 10 M{sub ⊙} yr{sup −1}. These extreme mass accretion rates may suggest that the black holes in BAL QSOs are relativistically spinning. Black hole masses in BAL QSOs are a factor of 100 larger than NLS1s. From their location on a M−σ plot, we find that BAL QSOs contain fully developed black holes. Applying a principal component analysis to our sample, we find eigenvector 1 to correspond to the Eddington ratio L/L{sub Edd}, and eigenvector 2 to black hole mass.

  11. A Comprehensive Study of Broad Absorption Line Quasars. I. Prevalence of HeI* Absorption Line Multiplets in Low-ionization Objects

    NASA Astrophysics Data System (ADS)

    Liu, Wen-Juan; Zhou, Hongyan; Ji, Tuo; Yuan, Weimin; Wang, Ting-Gui; Jian, Ge; Shi, Xiheng; Zhang, Shaohua; Jiang, Peng; Shu, Xinwen; Wang, Huiyuan; Wang, Shu-Fen; Sun, Luming; Yang, Chenwei; Liu, Bo; Zhao, Wen

    2015-03-01

    Neutral helium multiplets, He i* λ λ 3189,3889,10830, are very useful diagnostics for the geometry and physical conditions of the absorbing gas in quasars. So far only a handful of He i* detections have been reported. Using a newly developed method, we detected the He i*λ 3889 absorption line in 101 sources of a well-defined sample of 285 Mg ii broad absorption line (BAL) quasars selected from SDSS DR5. This has increased the number of He i* BAL quasars by more than one order of magnitude. We further detected He i*λ 3189 in 50% (52/101) of the quasars in the sample. The detection fraction of He i* BALs in Mg ii BAL quasars is ∼35% as a whole, and it increases dramatically with increasing spectral signal-to-noise ratio (S/N), from ∼18% at S/N ≤slant 10 to ∼93% at S/N ≥slant 35. This suggests that He i* BALs could be detected in most Mg ii LoBAL quasars, provided the spectra S/N is high enough. Such a surprisingly high He i* BAL fraction is actually predicted from photoionization calculations based on a simple BAL model. The result indicates that He i* absorption lines can be used to search for BAL quasars at low z, which cannot be identified by ground-based optical spectroscopic surveys with commonly seen UV absorption lines. Using He i* λ3889, we discovered 19 BAL quasars at z\\lt 0.3 from the available SDSS spectral database. The fraction of He i* BAL quasars is similar to that of LoBAL objects.

  12. Monitoring the variability of intrinsic absorption lines in quasar spectra , ,

    SciTech Connect

    Misawa, Toru; Charlton, Jane C.; Eracleous, Michael

    2014-09-01

    We have monitored 12 intrinsic narrow absorption lines (NALs) in five quasars and seven mini-broad absorption lines (mini-BALs) in six quasars for a period of 4-12 yr (1-3.5 yr in the quasar rest-frame). We present the observational data and the conclusions that follow immediately from them, as a prelude to a more detailed analysis. We found clear variability in the equivalent widths (EWs) of the mini-BAL systems but no easily discernible changes in their profiles. We did not detect any variability in the NAL systems or in narrow components that are often located at the center of mini-BAL profiles. Variations in mini-BAL EWs are larger at longer time intervals, reminiscent of the trend seen in variable BALs. If we assume that the observed variations result from changes in the ionization state of the mini-BAL gas, we infer lower limits to the gas density ∼10{sup 3}-10{sup 5} cm{sup –3} and upper limits on the distance of the absorbers from the central engine of the order of a few kiloparsecs. Motivated by the observed variability properties, we suggest that mini-BALs can vary because of fluctuations of the ionizing continuum or changes in partial coverage while NALs can vary primarily because of changes in partial coverage.

  13. VizieR Online Data Catalog: HeI* in broad absorption line QSOs (Liu+, 2015)

    NASA Astrophysics Data System (ADS)

    Liu, W.-J.; Zhou, H.; Ji, T.; Yuan, W.; Wang, T.-G.; Jian, G.; Shi, X.; Zhang, S.; Jiang, P.; Shu, X.; Wang, H.; Wang, S.-F.; Sun, L.; Yang, C.; Liu, B.; Zhao, W.

    2015-04-01

    Neutral helium multiplets, HeI*λλ3189, 3889, 10830, are very useful diagnostics for the geometry and physical conditions of the absorbing gas in quasars. So far only a handful of HeI* detections have been reported. Using a newly developed method, we detected the HeI*λ3889 absorption line in 101 sources of a well-defined sample of 285 MgII broad absorption line (BAL) quasars selected from SDSS DR5. This has increased the number of HeI* BAL quasars by more than one order of magnitude. We further detected HeI*λ3189 in 50% (52/101) of the quasars in the sample. The detection fraction of HeI* BALs in MgII BAL quasars is ~35% as a whole, and it increases dramatically with increasing spectral signal-to-noise ratio (S/N), from ~18% at S/N<=10 to ~93% at S/N>=35. This suggests that HeI* BALs could be detected in most MgII LoBAL quasars, provided the spectra S/N is high enough. Such a surprisingly high HeI* BAL fraction is actually predicted from photoionization calculations based on a simple BAL model. The result indicates that HeI* absorption lines can be used to search for BAL quasars at low z, which cannot be identified by ground-based optical spectroscopic surveys with commonly seen UV absorption lines. Using HeI*λ3889, we discovered 19 BAL quasars at z<0.3 from the available SDSS spectral database. The fraction of HeI* BAL quasars is similar to that of LoBAL objects. (7 data files).

  14. Polarization and Broad Absorption Lines in Quasars-Repeat

    NASA Astrophysics Data System (ADS)

    Antonucci, Robert

    1990-12-01

    OI 287 is a unique extragalactic source. It appears to take one property from each class of object. It is either some kind of missing link, or a new type of activity. Because of the high optical polarization, OI 287 has been classified with the blazars. However, every other blazar is variable in optical flux, polarization, and polarization angle., while OI 287 is constant at V=17, P=8%, and theta=145 degrees. Also, every other blazar has a radio source dominated by an intense flat-spectrum core, while OI 287 has an upper limit of 2% of the total 20cm flux in the core. The only group of quasars which ever shows even moderate (2-5%) constant optical polarization is the broad absorption line (BAL) objects, e.g. PHL 5200 and H1413+113. Among the BAL quasars, PHL 5200 and H1413+113 have exceptionally smooth deep, attached absorption lines, and also the highest polarization. We want to know whether OI 287 is a BAL quasar. It would be the first definite radio loud example. If it is a BAL quasar then the high polarization is really related to (and perhaps the key to) the BAL phenomenon, and we can use the techniques of spectropolarimetry to help unlock the BAL geometry. The UV spectral shape would also provide help determining the cause of polarization.

  15. Absorption-Line Studies of Seyfert Galaxies

    NASA Astrophysics Data System (ADS)

    Shull, J. Michael

    We propose to undertake a "reverberation analysis" of the variable absorption lines ill two Seyfert Galaxies (NGC 4051 and Mrk 279) to help understand the origin of intrinsic absorption lines in AGNs. Stich an analysis is a powerful tool for elucidating the radial distribution of absorbing gas in the broad-line region (BLR) and narrow-line region (NLR). Only two Seyferts have previously been studied with this technique: NGC 4151 (Bromage el al. 1985; Clavel et al. 1987) and NGC 3516 (Voit, Shull, and Begelman 1987). The absorption features have been interpreted as an outflow of ionized clouds from the nuclear region or from an accretion disk affected by UV/X-ray heating. Neither the source of the absorbing gas in these Seyferts nor the "gene" which distingishes them from other Seyferts is known. Until the 1984 onset of absorption in Mrk 279, broad self-absorbed. lines had been observed only in Seyferts of low intrinsic luminosity, such as NGC 4051. Mrk 279 is intrinsically much brighter, and therefore more quasar-like, than the other three absorptionline Seyfert I's in the CfA sample. Thus, it may show how the absorption phenomenon changes at higher luminosity and could bridge the gap between the low luminosity absorption-line Seyferts and the well-studied broad absorption-line (BAL) QSO's. In addition, Mrk 279's significant redshift will allow us to study, for the first time, the Ly-alpha line in an absorption-line Seyfert. With 3 US-1 shifts for each of these two underobserved Seyferts, we can double the number of objects in which absorption-line variability has been studied and investigate why the absorption-line strengths correlate or anti-correlate with the UV continuum.

  16. Variable X-Ray Absorption in the Mini-BAL QSO PG 1126-041

    NASA Technical Reports Server (NTRS)

    Giustini, M.; Cappi, M.; Chartas, G.; Dadina, M.; Eracleous, M.; Ponti, G.; Proga, D.; Tombesi, F.; Vignali, C.; Palumbo, G. G. C.

    2011-01-01

    Context. X-ray studies of AGN with powerful nuclear winds are important to constrain the physics of the inner accretion/ejection flow around SMBH, and to understand the impact of such winds on the AGN environment. Aims. Our main scientific goal is to constrain the properties of a variable outflowing absorber that is thought to be launched near the SMBH of the mini-BAL QSO PG 1126-041 using a multi-epoch observational campaign performed with XMM-Newton. Methods. We performed temporally resolved X-ray spectroscopy and simultaneous UV and X-ray photometry on the most complete set of observations and on the deepest X-ray exposure of a mini-BAL QSO to date. Results. We found complex X-ray spectral variability on time scales of both months and hours, best reproduced by means of variable massive ionized absorbers along the line of sight. As a consequence, the observed optical-to-X-ray spectral index is found to be variable with time. In the highest signal-to-noise observation we detected highly ionized X-ray absorbing material outflowing much faster (u(sub X) approx. 16 500 km/s) than the UV absorbing one (u(sub uv) approx. 5,000 km/s). This highly ionized absorber is found to be variable on very short (a few kiloseconds) time scales. Conclusions. Our findings are qualitatively consistent with line driven accretion disk winds scenarios. Our observations have opened the time-resolved X-ray spectral analysis field for mini-BAL QSOs; only with future deep studies will we be able to map the dynamics of the inner flow and understand the physics of AGN winds and their impact on the environment.

  17. C IV Broad Absorption Line Acceleration in Sloan Digital Sky Survey Quasars

    NASA Astrophysics Data System (ADS)

    Grier, C. J.; Brandt, W. N.; Hall, P. B.; Trump, J. R.; Filiz Ak, N.; Anderson, S. F.; Green, Paul J.; Schneider, D. P.; Sun, M.; Vivek, M.; Beatty, T. G.; Brownstein, Joel R.; Roman-Lopes, Alexandre

    2016-06-01

    We present results from the largest systematic investigation of broad absorption line (BAL) acceleration to date. We use spectra of 140 quasars from three Sloan Digital Sky Survey programs to search for global velocity offsets in BALs over timescales of ≈2.5-5.5 years in the quasar rest frame. We carefully select acceleration candidates by requiring monolithic velocity shifts over the entire BAL trough, avoiding BALs with velocity shifts that might be caused by profile variability. The C iv BALs of two quasars show velocity shifts consistent with the expected signatures of BAL acceleration, and the BAL of one quasar shows a velocity-shift signature of deceleration. In our two acceleration candidates, we see evidence that the magnitude of the acceleration is not constant over time; the magnitudes of the change in acceleration for both acceleration candidates are difficult to produce with a standard disk-wind model or via geometric projection effects. We measure upper limits to acceleration and deceleration for 76 additional BAL troughs and find that the majority of BALs are stable to within about 3% of their mean velocities. The lack of widespread acceleration/deceleration could indicate that the gas producing most BALs is located at large radii from the central black hole and/or is not currently strongly interacting with ambient material within the host galaxy along our line of sight.

  18. Polarization and Structure of Broad Absorption Line Quasi-Stellar Objects

    NASA Astrophysics Data System (ADS)

    Ogle, Patrick Michael

    This thesis is a spectropolarimetric survey of broad absorption line quasi-stellar objects (BAL QSO). We observed 36 BAL QSO at the Palomar and W. M. Keck Observatories. BAL QSO have higher polarization than other quasars, reinforcing the view that they are normal quasars viewed from an equatorial aspect. However, there is a wide distribution of polarization values, which may be due to intrinsic differences in the geometry or optical depth to scattering. No correlations are found among emission line or broad absorption line properties and continuum polarization, suggesting that these properties are regulated by internal differences unrelated to viewing angle. The continuum polarization of BAL QSO is weakly wavelength-dependent after correction for emission line dilution. In most objects, the polarisation rises to the blue, suggesting that dust scattering or absorption may be important. Broad emission line photons are polarized less than the continuum; and the position angle of the electric vector is rotated with respect to the continuum. The semi-forbidden C III) emission line is polarized differently than the C IV emission line, suggesting resonance scattering in the C III) emission line region. Resonantly scattered photons from the broad absorption line region are detected at high velocities red-ward and blue-ward of the C IV line center in the spectra of some objects. These photons are negatively polarized with respect to the continuum photons, showing that the broad absorption line region and the continuum scattering region are oriented perpendicular to each other. The polarization increases in the BAL troughs, due mainly to partial coverage of the central source by the broad absorption line region. The geometry of the intervening BAL clouds is skewed with respect to the continuum scattering region, which results in position angle rotations in the BAL. The variation of polarization with velocity in the BAL is consistent with a non-radial, accelerating outflow

  19. A CHANDRA SURVEY OF THE X-RAY PROPERTIES OF BROAD ABSORPTION LINE RADIO-LOUD QUASARS

    SciTech Connect

    Miller, B. P.; Brandt, W. N.; Garmire, G. P.; Gibson, R. R.; Shemmer, O. E-mail: niel@astro.psu.edu E-mail: rgibson@astro.washington.edu

    2009-09-10

    This work presents the results of a Chandra study of 21 broad absorption line (BAL) radio-loud quasars (RLQs). We conducted a Chandra snapshot survey of 12 bright BAL RLQs selected from Sloan Digital Sky Survey Data/Faint Images of the Radio Sky data and possessing a wide range of radio and C IV absorption properties. Optical spectra were obtained nearly contemporaneously with the Hobby-Eberly Telescope; no strong flux or BAL variability was seen between epochs. In addition to the snapshot targets, we include in our sample nine additional BAL RLQs possessing archival Chandra coverage. We compare the properties of (predominantly high-ionization) BAL RLQs to those of non-BAL RLQs as well as to BAL radio-quiet quasars (RQQs) and non-BAL RQQs for context. All 12 snapshots and 8/9 archival BAL RLQs are detected, with observed X-ray luminosities less than those of non-BAL RLQs having comparable optical/UV luminosities by typical factors of 4.1-8.5. (BAL RLQs are also X-ray weak by typical factors of 2.0-4.5 relative to non-BAL RLQs having both comparable optical/UV and radio luminosities.) However, BAL RLQs are not as X-ray weak relative to non-BAL RLQs as are BAL RQQs relative to non-BAL RQQs. While some BAL RLQs have harder X-ray spectra than typical non-BAL RLQs, some have hardness ratios consistent with those of non-BAL RLQs, and there does not appear to be a correlation between X-ray weakness and spectral hardness, in contrast to the situation for BAL RQQs. RLQs are expected to have X-ray continuum contributions from both accretion-disk corona and small-scale jet emission. While the entire X-ray continuum in BAL RLQs cannot be obscured to the same degree as in BAL RQQs, we calculate that the jet is likely partially covered in many BAL RLQs. We comment briefly on implications for geometries and source ages in BAL RLQs.

  20. Monitoring the Variability of Intrinsic Absorption Lines in Quasar Spectra

    NASA Astrophysics Data System (ADS)

    Misawa, Toru; Charlton, Jane C.; Eracleous, Michael

    2014-09-01

    We have monitored 12 intrinsic narrow absorption lines (NALs) in five quasars and seven mini-broad absorption lines (mini-BALs) in six quasars for a period of 4-12 yr (1-3.5 yr in the quasar rest-frame). We present the observational data and the conclusions that follow immediately from them, as a prelude to a more detailed analysis. We found clear variability in the equivalent widths (EWs) of the mini-BAL systems but no easily discernible changes in their profiles. We did not detect any variability in the NAL systems or in narrow components that are often located at the center of mini-BAL profiles. Variations in mini-BAL EWs are larger at longer time intervals, reminiscent of the trend seen in variable BALs. If we assume that the observed variations result from changes in the ionization state of the mini-BAL gas, we infer lower limits to the gas density ~103-105 cm-3 and upper limits on the distance of the absorbers from the central engine of the order of a few kiloparsecs. Motivated by the observed variability properties, we suggest that mini-BALs can vary because of fluctuations of the ionizing continuum or changes in partial coverage while NALs can vary primarily because of changes in partial coverage. Based on data collected at Subaru telescope, which is operated by the National Astronomical Observatory of Japan. Based on observations obtained at the European Southern Observatory at La Silla, Chile in programs 65.O-0063(B), 65.O-0474(A), 67.A-0078(A), 68.A-0461(A), 69.A-0204(A), 70.B-0522(A), 072.A-0346(A), 076.A-0860(A), 079.B-0469(A), and 166.A-0106(A).

  1. THE INTRINSIC FRACTIONS AND RADIO PROPERTIES OF LOW-IONIZATION BROAD ABSORPTION LINE QUASARS

    SciTech Connect

    Dai Xinyu; Shankar, Francesco; Sivakoff, Gregory R.

    2012-10-01

    Low-ionization (Mg II, Fe II, and Fe III) broad absorption line quasars (LoBALs) probe a relatively obscured quasar population and could be at an early evolutionary stage for quasars. We study the intrinsic fractions of LoBALs using the Sloan Digital Sky Survey (SDSS), Two Micron All Sky Survey, and Faint Images of the Radio Sky at Twenty cm survey. We find that the LoBAL fractions of the near-infrared (NIR) and radio samples are approximately 5-7 times higher than those measured in the optical sample. This suggests that the fractions measured in the NIR and radio bands are closer to the intrinsic fractions of the populations, and that the optical fractions are significantly biased due to obscuration effects, similar to high-ionization broad absorption line quasars (HiBALs). Considering a population of obscured quasars that do not enter the SDSS, which could have a much higher LoBAL fraction, we expect that the intrinsic fraction of LoBALs could be even higher. We also find that the LoBAL fractions decrease with increasing radio luminosities, again, similarly to HiBALs. In addition, we find evidence for increasing fractions of LoBALs toward higher NIR luminosities, especially for FeLoBALs with a fraction of {approx}18% at M{sub K{sub s}}< -31 mag. This population of NIR-luminous LoBALs may be at an early evolutionary stage of quasar evolution. To interpret the data, we use a luminosity-dependent model for LoBALs that yields significantly better fits than those from a pure geometric model.

  2. Through BAL Quasars Brightly

    NASA Technical Reports Server (NTRS)

    Chartas, George

    2003-01-01

    We report on an observation of the broad absorption line (BAL) quasar PG 1115+080 performed with the XMM-Newton observatory. Spectral analysis reveals the second case of a relativistic X-ray-absorbing outflow in a BAL quasar. The first case was revealed in a recent observation of APM 08279+5255 with the Chandra X-Ray Observatory. As in the case of APM 08279+5255, the observed flux of PG 1115+080 is greatly magnified by gravitational lensing. The relatively high redshift (z=1.72) of the quasar places the redshifted energies of resonant absorption features in a sensitive portion of the XMM- Newton spectral response. The spectrum indicates the presence of complex low-energy absorption in the 0.2-0.6 keV observed energy band and high-energy absorption in the 2-5 keV observed energy band. The high-energy absorption is best modeled by two Gaussian absorption lines with rest-frame energies of 7.4 and 9.5 keV. Assuming that these two lines axe produced by resonant absorption due to Fe XXV, we infer that the X-ray absorbers are outflowing with velocities of approx. 0.10c and approx. 0.34c respectively. We have detected significant variability of the energies and widths of the X-ray BALs in PG 1115+080 and APM 08279+5255 over timescales of 19 and 1.8 weeks (proper time), respectively. The BAL variability observed from APM 08279+5255 supports our earlier conclusion that these absorbers are most likely launched at relatively small radii of less than 10(exp 16)(Mbh/M8)(sup 1/2) cm. A comparison of the ionization properties and column densities of the low-energy and high-energy absorbers indicates that these absorbers are likely distinct; however, higher spectral resolution is needed to confirm this result. Finally, we comment on prospects for constraining the kinematic and ionization properties of these X-ray BALs with the next generation of X-ray observatories.

  3. Investigating the radio-loud phase of broad absorption line quasars

    NASA Astrophysics Data System (ADS)

    Bruni, G.; González-Serrano, J. I.; Pedani, M.; Benn, C. R.; Mack, K.-H.; Holt, J.; Montenegro-Montes, F. M.; Jiménez-Luján, F.

    2014-09-01

    Context. Broad absorption lines (BALs) are present in the spectra of ~20% of quasars (QSOs); this indicates fast outflows (up to 0.2c) that intercept the observer's line of sight. These QSOs can be distinguished again into radio-loud (RL) BAL QSOs and radio-quiet (RQ) BAL QSOs. The first are very rare, even four times less common than RQ BAL QSOs. The reason for this is still unclear and leaves open questions about the nature of the BAL-producing outflows and their connection with the radio jet. Aims: We explored the spectroscopic characteristics of RL and RQ BAL QSOs with the aim to find a possible explanation for the rarity of RL BAL QSOs. Methods: We identified two samples of genuine BAL QSOs from SDSS optical spectra, one RL and one RQ, in a suitable redshift interval (2.5 < z < 3.5) that allowed us to observe the Mg ii and Hβ emission lines in the adjacent near-infrared (NIR) band. We collected NIR spectra of the two samples using the Telescopio Nazionale Galileo (TNG, Canary Islands). By using relations known in the literature, we estimated the black-hole mass, the broad-line region radius, and the Eddington ratio of our objects and compared the two samples. Results: We found no statistically significant differences from comparing the distributions of the cited physical quantities. This indicates that they have similar geometries, accretion rates, and central black-hole masses, regardless of whether the radio-emitting jet is present or not. Conclusions: These results show that the central engine of BAL QSOs has the same physical properties with and without a radio jet. The reasons for the rarity of RL BAL QSOs must reside in different environmental or evolutionary variables. Figure 3 is available in electronic form at http://www.aanda.org

  4. Extreme Bal quasars from the Sloan Digital Sky Survey

    SciTech Connect

    Patrick B. Hall et al.

    2002-10-11

    The Sloan Digital Sky Survey has discovered a population of broad absorption line quasars with various extreme properties. Many show absorption from metastable states of Fe II with varying excitations; several objects are almost completely absorbed bluewards of Mg II; at least one shows stronger absorption from Fe III than Fe II, indicating temperatures T > 35000 K in the absorbing region; and one object even seems to have broad H{beta} absorption. Many of these extreme BALs are also heavily reddened, though ''normal'' BALs (particularly LoBALs) from SDSS also show evidence for internal reddening.

  5. Broad Absorption Line Quasars and Galaxy Evolution

    NASA Astrophysics Data System (ADS)

    Wills, B. J.

    2009-12-01

    Luminous QSOs are signposts to galaxy evolution. Local supermassive black holes are the faded relics of quasars in their heyday at redshifts ˜2. Relationships between the masses of these local supermassive black holes and their host galaxy bulges reveal an intimate link, fundamental to galaxy evolution: the newly evolving galaxy fuels the seed black hole through its accretion disk and by loss of angular momentum and energy in the form of outflowing winds. As the central engine approaches Eddington luminosities, winds drive away dusty gas, revealing a luminous QSO and halting star formation in the galaxy bulge. Relativistic winds are manifested in powerful radio jets in ˜10% of quasars, and sub-relativistic winds are revealed by broad blueshifted absorption troughs in the “broad absorption line” (BAL) quasars. Historically, BALs avoid powerful radio quasars. Here we examine the BALs to investigate this inverse connection.

  6. Composite Spectra of Broad Absorption Line Quasars in SDSS-III BOSS

    NASA Astrophysics Data System (ADS)

    Herbst, Hanna; Hamann, Fred; Paris, Isabelle; Capellupo, Daniel M.

    2017-01-01

    We present preliminary results from a study of broad absorption line (BAL) quasars in the SDSS-III BOSS survey. We’re particularly interested in BALs because they arise from quasar outflows, which may be a source of feedback to the host galaxy. We analyze median composite spectra for BOSS QSOs in the redshift range 2.1 to 3.4 sorted by the strength of the BAL absorption troughs, parameterized by the Balnicity Index (BI), to study trends in the emission and absorption properties of BAL quasars. The wavelength coverage and high number of quasars observed in the BOSS survey allow us to examine BALs in the Lyman forest. Our main preliminary results when sorting the quasars by BI are 1) doublet absorption lines such as P V 1128A show a 1:1 ratio across all BI, indicating large column densities at all BI. This suggests that weaker BAL troughs result from smaller covering fractions rather than lower column densities. 2) The He II emission line, which is a measure of the far-UV/near-UV hardness of the ionizing continuum, is weaker in the larger BI composite spectra, indicating a far-UV spectral softening correlated with BI. This is consistent with the radiatively-driven BAL outflows being helped by intrinsically weaker ionizing continuum shapes (e.g., Baskin, Laor, and Hamann 2013). We also find a trend for slightly redder continuum slopes in the larger BI composite spectra, suggesting that the slope differences in the near-UV are also intrinsic.

  7. 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.

  8. A variable P v broad absorption line and quasar outflow energetics

    NASA Astrophysics Data System (ADS)

    Capellupo, D. M.; Hamann, F.; Barlow, T. A.

    2014-10-01

    Broad absorption lines (BALs) in quasar spectra identify high-velocity outflows that might exist in all quasars and could play a major role in feedback to galaxy evolution. The viability of BAL outflows as a feedback mechanism depends on their kinetic energies, as derived from the outflow velocities, column densities, and distances from the central quasar. We estimate these quantities for the quasar, Q1413+1143 (redshift ze = 2.56), aided by the first detection of P V λλ1118, 1128 BAL variability in a quasar. In particular, P V absorption at velocities where the C IV trough does not reach zero intensity implies that the C IV BAL is saturated and the absorber only partially covers the background continuum source (with characteristic size <0.01 pc). With the assumption of solar abundances, we estimate that the total column density in the BAL outflow is log NH ≳ 22.3 cm-2. Variability in the P V and saturated C IV BALs strongly disfavours changes in the ionization as the cause of the BAL variability, but supports models with high column density BAL clouds moving across our lines of sight. The observed variability time of 1.6 yr in the quasar rest frame indicates crossing speeds >750 km s-1 and a radial distance from the central black hole of ≲ 3.5 pc, if the crossing speeds are Keplerian. The total outflow mass is ˜4100 M⊙, the kinetic energy ˜4 × 1054 erg, and the ratio of the outflow kinetic energy luminosity to the quasar bolometric luminosity is ˜0.02 (at the minimum column density and maximum distance), which might be sufficient for important feedback to the quasar's host galaxy.

  9. Quasistellar Objects: Intervening Absorption Lines

    NASA Astrophysics Data System (ADS)

    Charlton, J.; Churchill, C.; Murdin, P.

    2000-11-01

    Every parcel of gas along the line of sight to a distant QUASAR will selectively absorb certain wavelengths of continuum light of the quasar due to the presence of the various chemical elements in the gas. Through the analysis of these quasar absorption lines we can study the spatial distributions, motions, chemical enrichment and ionization histories of gaseous structures from REDSHIFT five unti...

  10. FR-II Broad Absorption Line Quasars and the Life Cycle of Quasars

    SciTech Connect

    Gregg, M D; Becker, R H; de Vries, W

    2006-01-05

    By combining the Sloan Digitized Sky Survey Third Data Release quasar list with the VLA FIRST survey, we have identified five objects having both broad absorption lines in their optical spectra and FR-II radio morphologies. We identify an additional example of this class from the FIRST Bright Quasar Survey, J1408+3054. Including the original FR-II-BAL object, J1016+5209, brings the number of such objects to eight. These quasars are relatively rare; finding this small handful has required the 45,000-large quasar sample of SDSS. The FR-II-BAL quasars exhibit a significant anti-correlation between radio-loudness and the strength of the BAL features. This is easily accounted for by the evolutionary picture in which quasars emerge from cocoons of BAL-producing material which stifle the development of radio jets and lobes. There is no such simple explanation for the observed properties of FR-II-BALs in the unification-by-orientation model of quasars. The rarity of the FR-II-BAL class implies that the two phases do not coexist for very long in a single quasar, perhaps less than 10{sup 5} years, with the combined FR-II, high ionization broad absorption phase being even shorter by another factor of 10 or more.

  11. Photoionization-driven Absorption-line Variability in Balmer Absorption Line Quasar LBQS 1206+1052

    NASA Astrophysics Data System (ADS)

    Sun, Luming; Zhou, Hongyan; Ji, Tuo; Jiang, Peng; Liu, Bo; Liu, Wenjuan; Pan, Xiang; Shi, Xiheng; Wang, Jianguo; Wang, Tinggui; Yang, Chenwei; Zhang, Shaohua; Miller, Lauren P.

    2017-04-01

    In this paper we present an analysis of absorption-line variability in mini-BAL quasar LBQS 1206+1052. The Sloan Digital Sky Survey spectrum demonstrates that the absorption troughs can be divided into two components of blueshift velocities of ∼700 and ∼1400 km s‑1 relative to the quasar rest frame. The former component shows rare Balmer absorption, which is an indicator of high-density absorbing gas; thus, the quasar is worth follow-up spectroscopic observations. Our follow-up optical and near-infrared spectra using MMT, YFOSC, TSpec, and DBSP reveal that the strengths of the absorption lines vary for both components, while the velocities do not change. We reproduce all of the spectral data by assuming that only the ionization state of the absorbing gas is variable and that all other physical properties are invariable. The variation of ionization is consistent with the variation of optical continuum from the V-band light curve. Additionally, we cannot interpret the data by assuming that the variability is due to a movement of the absorbing gas. Therefore, our analysis strongly indicates that the absorption-line variability in LBQS 1206+1052 is photoionization driven. As shown from photoionization simulations, the absorbing gas with blueshift velocity of ∼700 km s‑1 has a density in the range of 109 to 1010 cm‑3 and a distance of ∼1 pc, and the gas with blueshift velocity of ∼1400 km s‑1 has a density of 103 cm‑3 and a distance of ∼1 kpc.

  12. Broad absorption line variability on multi-year timescales in a large quasar sample

    NASA Astrophysics Data System (ADS)

    Filiz Ak, Nurten

    Outflows launched near the central supermassive black holes (SMBHs) are a common and important component of active galactic nuclei (AGNs). Outflows in luminous AGNs (i.e., quasars) play a key role in mass accretion onto SMBH as well as in the feedback into host galaxies. The most prominent signature of such outflows appears as broad absorption lines (BALs) that are blueshifted from the emission line with a few thousands km s--1 velocities. In this dissertation, I place further constrains upon the size scale, internal structure, dynamics, and evolution of the outflows investigating profiles, properties, and variation characteristics of BAL troughs. I present observational results on BAL troughs in a large quasar sample utilizing spectroscopic observations from the Sloan Digital Sky Survey spanning on multi-year timescales. The results presented here, for the first time, provide a large and well-defined variability data base capable of discriminating between time-dependent hydrodynamic wind calculations in a statistically powerful manner. In a study of 582 quasars, I present 21 examples of BAL trough disappearance. Approximately 3.3% of BAL quasars show disappearing C IV trough on rest-frame timescales of 1.1--3.9 yr. BAL disappearance appears to occur mainly for shallow and weak or moderate-strength absorption troughs but not the strongest ones. When one BAL trough in a quasar spectrum disappears, the other present troughs usually weaken. Possible causes of such coordinated variations could be disk-wind rotation or variations of shielding gas that lead to variations of ionizing-continuum radiation. I present a detailed study on the variability of 428 C IV and 235 Si IV BAL troughs using a systematically observed sample of 291 BAL quasars. BAL variation distributions indicate that BAL disappearance is an extreme type of general BAL variability, rather than a qualitatively distinct phenomenon. The high observed frequency of BAL variability on multi-year timescales is

  13. The Level of Ionization and Chemical Composition of QSO BAL Regions

    NASA Astrophysics Data System (ADS)

    Kopko, M., Jr.; Turnshek, D. A.; Espey, B. R.

    1992-05-01

    We present results from our attempts to understand the level of ionization and chemical composition of the Broad Absorption Line (BAL) regions of QSOs. We discuss three aspects of the work: 1) We consider methods used to derive BAL region column densities as a function of outflow velocity from BAL profiles, discussing the problems associated with making assumptions about BAL region cloud sizes, covering factors, and internal kinematics (thermal versus turbulent velocities). 2) We apply these methods to a study of the ionization and chemical composition of QSO BAL regions using Ferland's photoionization code CLOUDY. 3) We present results for several BAL QSOs in our study, taking advantage of the presence of absorption from different ions of the same element to derive photoionization parameters. This allows us to derive more stringent constraints than has been possible in the past.

  14. The Nature of Low-ionization Broad Absorption Line Quasi-stellar Objects

    NASA Astrophysics Data System (ADS)

    Lazarova, Mariana Spasova

    The tight correlations between properties of galaxy bulges and their central supermassive black holes have been reproduced successfully in simulations of galaxy collisions if feedback processes are invoked. Mergers of gas-rich galaxies of comparable size have been shown to trigger starbursts, fuel the central black holes, and transform disks into ellipticals. Feedback from the black hole accretion in the form of extreme outflows has need suggested as the mechanism by which the black hole stop its own growth and quenches the star formation in the galaxy by expelling the gas supply. Such winds have been detected in Broad Absorption Line (BAL) QSOs. However, observational evidence that BAL QSOs may be an evolutionary link between mergers and QSO is missing. In this thesis, we provide the first detailed study of the spectral energy distributions and host galaxy morphologies of a statistically significant volume-limited sample of 22 optically-selected low-ionization Broad Absorption Line QSOs (LoBALs) at 0.5 < z < 0.6. By comparing their mid-IR spectral properties and far-IR SEDs with those of a control sample of 35 non-LoBALs (non-LoBALs) matched in Mi, we investigate the differences between the two populations in terms of their infrared emission and star formation activity. We model the SEDs and decouple the AGN and starburst contributions to the far-infrared luminosity in LoBALs and in non-LoBALs. We estimate star formation rates (SFRs) corrected for the AGN contribution to the FIR flux and find that LoBALs have comparable levels of star formation activity to non-LoBALs when considering the entire samples. Overall, our results show that there is no strong evidence from the mid- and far-IR properties that LoBALs are drawn from a different parent population than non-LoBALs. We conducted the first high-resolution morphological analysis of LoBALs using observations obtained with the Hubble Space Telescope Wide Field Camera 3 in two channels. Signs of recent or ongoing

  15. X-RAYS FROM A RADIO-LOUD COMPACT BROAD ABSORPTION LINE QUASAR 1045+352 AND THE NATURE OF OUTFLOWS IN RADIO-LOUD BROAD ABSORPTION LINE QUASARS

    SciTech Connect

    Kunert-Bajraszewska, Magdalena; Katarzynski, Krzysztof; Siemiginowska, Aneta; Janiuk, Agnieszka

    2009-11-10

    We present new results on X-ray properties of radio-loud broad absorption line (BAL) quasars and focus on broadband spectral properties of a high-ionization BAL (HiBAL) compact steep spectrum (CSS) radio-loud quasar 1045+352. This HiBAL quasar has a very complex radio morphology indicating either strong interactions between a radio jet and the surrounding interstellar medium or a possible re-start of the jet activity. We detected 1045+352 quasar in a short 5 ksec Chandra ACIS-S observation. We applied theoretical models to explain spectral energy distribution of 1045+352 and argue that non-thermal, inverse-Compton (IC) emission from the innermost parts of the radio jet can account for a large fraction of the observed X-ray emission. In our analysis, we also consider a scenario in which the observed X-ray emission from radio-loud BAL quasars can be a sum of IC jet X-ray emission and optically thin corona X-ray emission. We compiled a sample of radio-loud BAL quasars that were observed in X-rays to date and report no correlation between their X-ray and radio luminosity. However, the radio-loud BAL quasars show a large range of X-ray luminosities and absorption columns. This is consistent with the results obtained earlier for radio-quiet BAL quasars and may indicate an orientation effect in BAL quasars or more complex dependence between X-ray emission, radio emission, and an orientation based on the radio morphology.

  16. Broad Balmer-Line Absorption in SDSS J172341.10+555340.5

    NASA Astrophysics Data System (ADS)

    Aoki, Kentaro

    2010-10-01

    We present the discovery of Balmer-line absorption from Hα to H9 in an iron low-ionizaton broad absorption line (FeLoBAL) quasar, SDSS J172341.10+555340.5, by near-infrared spectroscopy with the Cooled Infrared Spectrograph and Camera for OHS (CISCO) attached to the Subaru Telescope. The redshift of the Balmer-line absorption troughs is 2.0530±0.0003, and it is blueshifted by 5370 km s-1 from the Balmer emission lines. It is more than 4000 km s-1 blueshifted from the previously known UV absorption lines. We detected relatively strong (EWrest = 20 Å) [OIII] emission lines that are similar to those found in other broad absorption line quasars with Balmer-line absorption. We also derived the column density of neutral hydrogen of 5.2 × 1017 cm-2 by using the curve of growth and taking account of Lyα trapping. We searched for UV absorption lines that had the same redshift with Balmer-line absorption, and found Ali III and Fe III absorption lines at z = 2.053 that correspond to previously unidentified absorption lines, and the presence of other blended troughs that were difficult to identify.

  17. Spectropolarimetry of PKS 0040-005 and the orientation of broad absorption line quasars

    NASA Astrophysics Data System (ADS)

    Brotherton, M. S.; De Breuck, C.; Schaefer, J. J.

    2006-10-01

    We have used the Very Large Telescope (VLT) to obtain spectropolarimetry of the radio-loud, double-lobed broad absorption line (BAL) quasar PKS 0040-005. We find that the optical continuum of PKS 0040-005 is intrinsically polarized at 0.7 per cent with an electric vector position angle nearly parallel to that of the large-scale radio axis. This result is naturally explained in terms of an equatorial scattering region seen at a small inclination, building a strong case that the BAL outflow is not equatorial. In conjunction with other recent results concerning BAL quasars, the era of simply characterizing these sources as `edge-on' is over. Based on observations collected at the European Southern Observatory, Paranal, project 71.B-0121(A). E-mail: mbrother@uwyo.edu (MSB); cdbreuc@eso.org (CDB); schaefjj@ufl.edu (JJS) ‡ ESO Visitor.

  18. Variation of Ionizing Continuum: The Main Driver of Broad Absorption Line Variability

    NASA Astrophysics Data System (ADS)

    He, Zhicheng; Wang, Tinggui; Zhou, Hongyan; Bian, Weihao; Liu, Guilin; Yang, Chenwei; Dou, Liming; Sun, Luming

    2017-04-01

    We present a statistical analysis of the variability of broad absorption lines (BALs) in quasars using the large multi-epoch spectroscopic data set of the Sloan Digital Sky Survey Data Release 12 (SDSS DR12). We divide the sample into two groups according to the pattern of the variation of C iv BAL with respect to that of a continuum: the equivalent widths (EW) of the BAL decreases (increases) when the continuum brightens (dims) as group T1; and the variation of the EW and the continuum in the opposite relation of group T2. We find that T2 has significantly ({P}{{T}}< {10}-6, Students T Test) higher EW ratios (R) of Si iv to C iv BAL than T1. Our result agrees with the prediction of photoionization models that {C}+3 column density increases (decreases) if there is a (or no) {C}+3 ionization front, while R decreases with the incident continuum. We show that BAL variabilities in at least 80% of quasars are driven by the variation of an ionizing continuum, while other models that predict uncorrelated BAL and continuum variability contribute less than 20%. Considering large uncertainty in the continuum flux calibration, the latter fraction may be much smaller. When the sample is binned into different time intervals between the two observations, we find significant difference in the distribution of R between T1 and T2 in all time-bins down to {{Δ }}T< 6 days, suggesting that the BAL outflow in a fraction of quasars has a recombination timescale of only a few days.

  19. Optical variability properties of mini-BAL and NAL quasars

    NASA Astrophysics Data System (ADS)

    Horiuchi, Takashi; Misawa, Toru; Morokuma, Tomoki; Koyamada, Suzuka; Takahashi, Kazuma; Wada, Hisashi

    2016-08-01

    While narrow absorption lines (NALs) are relatively stable, broad absorption lines (BALs) and mini-BAL systems usually show violent time variability within a few years via a mechanism that is not yet understood. In this study, we examine the variable ionization state (VIS) scenario as a plausible mechanism, as previously suspected. Over three years, we performed photometric monitoring observations of four mini-BAL and five NAL quasars at zem ˜ 2.0-3.1 using the 105 cm Kiso Schmidt Telescope in u, g, and i bands. We also performed spectroscopic monitoring observation of one of our mini-BAL quasars (HS 1603+3820) using the 188 cm Okayama Telescope over the same period as the photometric observations. Our main results are as follows: (1) Structure function (SF) analysis revealed that the quasar UV flux variability over three years was not large enough to support the VIS scenario, unless the ionization condition of outflow gas is very low. (2) There was no crucial difference between the SFs of mini-BAL and NAL quasars. (3) The variability of the mini-BAL and quasar light curves was weakly synchronized with a small time delay for HS 1603+3820. These results suggest that the VIS scenario may need additional mechanisms such as variable shielding by X-ray warm absorbers.

  20. Microlensing Constraints on Broad Absorption and Emission Line Flows in the Quasar H1413+117

    NASA Astrophysics Data System (ADS)

    O'Dowd, Matthew J.; Bate, Nicholas F.; Webster, Rachel L.; Labrie, Kathleen; Rogers, Joshua

    2015-11-01

    We present new integral field spectroscopy of the gravitationally lensed broad absorption line (BAL) quasar H1413+117, covering the ultraviolet restframe spectral range. We observe strong microlensing signatures in lensed image D, and we use this microlensing to simultaneously constrain both the broad emission and broad absorption line gas. The wavelength independence of image D magnifications across the broad emission lines (BELs) indicates a lower limit on the broad emission line region (BELR) size equal to the Einstein radius (ER) of the system: ≳11 {(< M> /{M}⊙ )}0.5 lt-day for a lens redshift of 1.4 and ≳15 {(< M> /{M}⊙ )}0.5 lt-day for zL = 0.94. Lensing simulations verify that the observed wavelength independence is very unlikely for BELRs with significant velocity stratification at size scales below an ER. We perform spectral decomposition to derive the intrinsic BEL and continuum spectrum, subject to BAL absorption. We reconstruct the intrinsic BAL absorption profile, whose features allow us to constrain outflow kinematics in the context of a disk-wind model. We find a very sharp, blueshifted onset of absorption of 1500 km s-1 in both C iv and N v, which may correspond to an inner edge of a disk-wind’s radial outflow. The lower ionization Si iv and Al iii have higher-velocity absorption onsets, consistent with a decreasing ionization parameter with radius in an accelerating outflow. There is evidence of strong absorption in the BEL component, which indicates a high covering factor for absorption over two orders of magnitude in outflow radius.

  1. The dependence of C IV broad absorption line properties on accompanying Si IV and Al III absorption: relating quasar-wind ionization levels, kinematics, and column densities

    SciTech Connect

    Filiz Ak, N.; Brandt, W. N.; Schneider, D. P.; Trump, J. R.; Hall, P. B.; Anderson, S. F.; Hamann, F.; Myers, Adam D.; Pâris, I.; Petitjean, P.; Ross, Nicholas P.; Shen, Yue; York, Don

    2014-08-20

    We consider how the profile and multi-year variability properties of a large sample of C IV Broad Absorption Line (BAL) troughs change when BALs from Si IV and/or Al III are present at corresponding velocities, indicating that the line of sight intercepts at least some lower ionization gas. We derive a number of observational results for C IV BALs separated according to the presence or absence of accompanying lower ionization transitions, including measurements of composite profile shapes, equivalent width (EW), characteristic velocities, composite variation profiles, and EW variability. We also measure the correlations between EW and fractional-EW variability for C IV, Si IV, and Al III. Our measurements reveal the basic correlated changes between ionization level, kinematics, and column density expected in accretion-disk wind models; e.g., lines of sight including lower ionization material generally show deeper and broader C IV troughs that have smaller minimum velocities and that are less variable. Many C IV BALs with no accompanying Si IV or Al III BALs may have only mild or no saturation.

  2. H{beta} LINE WIDTHS AS AN ORIENTATION INDICATOR FOR LOW-IONIZATION BROAD ABSORPTION LINE QUASARS

    SciTech Connect

    Punsly, Brian; Zhang Shaohua E-mail: brian.punsly@comdev-usa.co

    2010-12-20

    There is evidence from radio-loud quasars to suggest that the distribution of the H{beta} broad emission line (BEL) gas is arranged in a predominantly planar orientation, and this result may well also apply to radio-quiet quasars. This would imply that the observed FWHM of the H{beta} BELs is dependent on the orientation of the line of sight to the gas. If this view is correct then we propose that the FWHM can be used as a surrogate, in large samples, to determine the line of sight to the H{beta} BELs in broad absorption line quasars (BALQSOs). The existence of broad UV absorption lines (BALs) means that the line of sight to BALQSOs must also pass through the BAL out-flowing gas. It is determined that there is a statistically significant excess of narrow-line profiles in the SDSS DR7 archival spectra of low-ionization broad absorption line quasars (LoBALQSOs), indicating that BAL gas flowing close to the equatorial plane does not commonly occur in these sources. We also find that the data is not well represented by random lines of sight to the BAL gas. Our best fit indicates two classes of LoBALQSOs, the majority ({approx}2/3) are polar outflows that are responsible for the enhanced frequency of narrow-line profiles, and the remainder are equatorial outflows. We further motivated the line of sight explanation of the narrow-line excess in LoBALQSOs by considering the notion that the skewed distribution of line profiles is driven by an elevated Eddington ratio in BALQSOs. We constructed a variety of control samples comprised of non-LoBALQSOs matched to a de-reddened LoBALQSO sample in redshift, luminosity, black hole mass, and Eddington ratio. It is demonstrated that the excess of narrow profiles persists within the LoBALQSO sample relative to each of the control samples with no reduction of the statistical significance. Thus, we eliminate the possibility that the excess narrow lines seen in the LoBALQSOs arise from an enhanced Eddington ratio.

  3. VARIABLE REDDENING AND BROAD ABSORPTION LINES IN THE NARROW-LINE SEYFERT 1 GALAXY WPVS 007: AN ORIGIN IN THE TORUS

    SciTech Connect

    Leighly, Karen M.; Cooper, Erin; Grupe, Dirk; Terndrup, Donald M.; Komossa, S.

    2015-08-10

    We report the discovery of an occultation event in the low-luminosity narrow-line Seyfert 1 galaxy WPVS 007 in 2015 February and March. In concert with longer timescale variability, these observations place strong constraints on the nature and location of the absorbing material. Swift monitoring has revealed a secular decrease since ∼2010 accompanied by flattening of the optical and UV photometry that suggests variable reddening. Analysis of four Hubble Space Telescope COS observations since 2010, including a Director’s Discretionary time observation during the occultation, shows that the broad-absorption-line velocity offset and the C iv emission-line width both decrease as the reddening increases. The occultation dynamical timescale, the BAL variability dynamical timescale, and the density of the BAL gas show that both the reddening material and the broad-absorption-line gas are consistent with an origin in the torus. These observations can be explained by a scenario in which the torus is clumpy with variable scale height, and the BAL gas is blown from the torus material like spray from the crest of a wave. As the obscuring material passes into our line of sight, we alternately see high-velocity broad absorption lines and a clear view to the central engine, or low-velocity broad absorption lines and strong reddening. WPVS 007 has a small black hole mass, and correspondingly short timescales, and so we may be observing behavior that is common in BALQSOs, but is not typically observable.

  4. PG 1700 + 518 - a low-redshift, broad absorption line QSO

    SciTech Connect

    Pettini, M.; Boksenberg, A.

    1985-07-01

    The first high-resolution optical spectra and lower resolution UV spectra of PG 1700 + 518, the only known broad-absorption-line (BAL) QSO at low emission redshift (0.288) are presented. The optical data were obtained with the Isaac Newton Telescope on the island of La Palma and the UV data with the International Ultraviolet Explorer satellite. The outstanding feature of the optical spectrum is a strong, broad Mg II absorption trough, detached from the Mg II emission line and indicative of ejection velocities of between 7000 and 18,000 km/s. Also detected were narrow (FWHM = 350 km/s) Mg II absorption lines at absolute z = 0.2698, which are probably related to the mass ejection phenomenon. It is concluded that the emission-line spectrum is similar to that of other low-redshift QSOs although there are some obvious differences from typical BAL QSOs, most notably in the unusually low level of ionization of both emission-line and broad absorption line gas. 21 references.

  5. Radiation Pressure-Driven Magnetic Disk Winds in Broad Absorption Line Quasi-Stellar Objects

    NASA Technical Reports Server (NTRS)

    DeKool, Martin; Begelman, Mitchell C.

    1995-01-01

    We explore a model in which QSO broad absorption lines (BALS) are formed in a radiation pressure-driven wind emerging from a magnetized accretion disk. The magnetic field threading the disk material is dragged by the flow and is compressed by the radiation pressure until it is dynamically important and strong enough to contribute to the confinement of the BAL clouds. We construct a simple self-similar model for such radiatively driven magnetized disk winds, in order to explore their properties. It is found that solutions exist for which the entire magnetized flow is confined to a thin wedge over the surface of the disk. For reasonable values of the mass-loss rate, a typical magnetic field strength such that the magnetic pressure is comparable to the inferred gas pressure in BAL clouds, and a moderate amount of internal soft X-ray absorption, we find that the opening angle of the flow is approximately 0.1 rad, in good agreement with the observed covering factor of the broad absorption line region.

  6. Radiation Pressure--driven Magnetic Disk Winds in Broad Absorption Line Quasi-stellar Objects

    NASA Astrophysics Data System (ADS)

    de Kool, Martijn; Begelman, Mitchell C.

    1995-12-01

    We explore a model in which QSO broad absorption lines (BALs) are formed in a radiation pressure- driven wind emerging from a magnetized accretion disk. The magnetic field threading the disk material is dragged by the flow and is compressed by the radiation pressure until it is dynamically important and strong enough to contribute to the confinement of the BAL clouds. We construct a simple self-similar model for such radiatively driven magnetized disk winds, in order to explore their properties. It is found that solutions exist for which the entire magnetized flow is confined to a thin wedge over the surface of the disk. For reasonable values of the mass-loss rate, a typical magnetic field strength such that the magnetic pressure is comparable to the inferred gas pressure in BAL clouds, and a moderate amount of internal soft X-ray absorption, we find that the opening angle of the flow is approximately 0.1 rad, in good agreement with the observed covering factor of the broad absorption line region.

  7. VERY LARGE TELESCOPE SPECTROPOLARIMETRY OF BROAD ABSORPTION LINE QSOs

    SciTech Connect

    DiPompeo, M. A.; Brotherton, M. S.; De Breuck, C.

    2011-03-15

    We present spectropolarimetry of 19 confirmed and four possible bright, southern broad absorption line (BAL) quasars from the European Southern Observatory Very Large Telescope. A wide range of redshifts is covered in the sample (from 0.9 to 3.4), and both low- and high-ionization quasars are represented, as well as radio-loud and radio-quiet BALQSOs. We continue to confirm previously established spectropolarimetric properties of BALQSOs, including the generally rising continuum polarization with shorter wavelengths and comparatively large fraction with high broadband polarization (6 of 19 with polarizations >2%). Emission lines are polarized less than or similar to the continuum, except in a few unusual cases, and absorption troughs tend to have higher polarizations. A search for correlations between polarization properties has been done, identifying two significant or marginally significant correlations. These are an increase in continuum polarization with decreasing optical luminosity (increasing absolute B magnitude) and decreasing C IV emission-line polarization with increased continuum polarization.

  8. Do Atoms Really "Emit" Absorption Lines?

    ERIC Educational Resources Information Center

    Brecher, Kenneth

    1991-01-01

    Presents three absorption line sources that enhance student understanding of the phenomena associated with the interaction of light with matter and help dispel the misconception that atoms "emit" absorption lines. Sources include neodymium, food coloring and other common household liquids, and fluorescent materials. (MDH)

  9. Discovery of Broad Soft X-ray Absorption Lines from the Quasar Wind in PDS 456

    NASA Astrophysics Data System (ADS)

    Reeves, J. N.; Braito, V.; Nardini, E.; Behar, E.; O'Brien, P. T.; Tombesi, F.; Turner, T. J.; Costa, M. T.

    2016-06-01

    High-resolution soft X-ray spectroscopy of the prototype accretion disk wind quasar, PDS 456, is presented. Here, the XMM-Newton reflection grating spectrometer spectra are analyzed from the large 2013-2014 XMM-Newton campaign, consisting of five observations of approximately 100 ks in length. During the last observation (OBS. E), the quasar is at a minimum flux level, and broad absorption line (BAL) profiles are revealed in the soft X-ray band, with typical velocity widths of {σ }{{v}}˜ {{10,000}} km s-1. During a period of higher flux in the third and fourth observations (OBS. C and D, respectively), a very broad absorption trough is also present above 1 keV. From fitting the absorption lines with models of photoionized absorption spectra, the inferred outflow velocities lie in the range ˜ 0.1{--}0.2c. The absorption lines likely originate from He and H-like neon and L-shell iron at these energies. A comparison with earlier archival data of PDS 456 also reveals a similar absorption structure near 1 keV in a 40 ks observation in 2001, and generally the absorption lines appear most apparent when the spectrum is more absorbed overall. The presence of the soft X-ray BALs is also independently confirmed by an analysis of the XMM-Newton EPIC spectra below 2 keV. We suggest that the soft X-ray absorption profiles could be associated with a lower ionization and possibly clumpy phase of the accretion disk wind, where the latter is known to be present in this quasar from its well-studied iron K absorption profile and where the wind velocity reaches a typical value of 0.3c.

  10. X-ray-selected broad absorption line quasi-stellar objects

    NASA Astrophysics Data System (ADS)

    Page, M. J.; Carrera, F. J.; Ceballos, M.; Corral, A.; Ebrero, J.; Esquej, P.; Krumpe, M.; Mateos, S.; Rosen, S.; Schwope, A.; Streblyanska, A.; Symeonidis, M.; Tedds, J. A.; Watson, M. G.

    2017-02-01

    We study a sample of six X-ray-selected broad absorption line (BAL) quasi-stellar objects (QSOs) from the XMM-Newton Wide Angle Survey. All six objects are classified as BALQSOs using the classic balnicity index, and together they form the largest sample of X-ray-selected BALQSOs. We find evidence for absorption in the X-ray spectra of all six objects. An ionized absorption model applied to an X-ray spectral shape that would be typical for non-BAL QSOs (a power law with energy index α = 0.98) provides acceptable fits to the X-ray spectra of all six objects. The optical to X-ray spectral indices, αOX, of the X-ray-selected BALQSOs, have a mean value of <αOX> = 1.69 ± 0.05, which is similar to that found for X-ray-selected and optically selected non-BAL QSOs of a similar ultraviolet luminosity. In contrast, optically selected BALQSOs typically have much larger αOX and so are characterized as being X-ray weak. The results imply that X-ray selection yields intrinsically X-ray bright BALQSOs, but their X-ray spectra are absorbed by a similar degree to that seen in optically selected BALQSO samples; X-ray absorption appears to be ubiquitous in BALQSOs, but X-ray weakness is not. We argue that BALQSOs sit at one end of a spectrum of X-ray absorption properties in QSOs related to the degree of ultraviolet absorption in C IV 1550 Å.

  11. Weak hard X-ray emission from broad absorption line quasars: evidence for intrinsic X-ray weakness

    SciTech Connect

    Luo, B.; Brandt, W. N.; Scott, A. E.; Alexander, D. M.; Gandhi, P.; Stern, D.; Teng, S. H.; Arévalo, P.; Bauer, F. E.; Boggs, S. E.; Craig, W. W.; Christensen, F. E.; Comastri, A.; Farrah, D.; Hailey, C. J.; Harrison, F. A.; Koss, M.; Ogle, P.; Puccetti, S.; Saez, C.; and others

    2014-10-10

    We report NuSTAR observations of a sample of six X-ray weak broad absorption line (BAL) quasars. These targets, at z = 0.148-1.223, are among the optically brightest and most luminous BAL quasars known at z < 1.3. However, their rest-frame ≈2 keV luminosities are 14 to >330 times weaker than expected for typical quasars. Our results from a pilot NuSTAR study of two low-redshift BAL quasars, a Chandra stacking analysis of a sample of high-redshift BAL quasars, and a NuSTAR spectral analysis of the local BAL quasar Mrk 231 have already suggested the existence of intrinsically X-ray weak BAL quasars, i.e., quasars not emitting X-rays at the level expected from their optical/UV emission. The aim of the current program is to extend the search for such extraordinary objects. Three of the six new targets are weakly detected by NuSTAR with ≲ 45 counts in the 3-24 keV band, and the other three are not detected. The hard X-ray (8-24 keV) weakness observed by NuSTAR requires Compton-thick absorption if these objects have nominal underlying X-ray emission. However, a soft stacked effective photon index (Γ{sub eff} ≈ 1.8) for this sample disfavors Compton-thick absorption in general. The uniform hard X-ray weakness observed by NuSTAR for this and the pilot samples selected with <10 keV weakness also suggests that the X-ray weakness is intrinsic in at least some of the targets. We conclude that the NuSTAR observations have likely discovered a significant population (≳ 33%) of intrinsically X-ray weak objects among the BAL quasars with significantly weak <10 keV emission. We suggest that intrinsically X-ray weak quasars might be preferentially observed as BAL quasars.

  12. Weak Hard X-Ray Emission from Two Broad Absorption Line Quasars Observed with NuStar: Compton-Thick Absorption or Intrinsic X-Ray Weakness?

    NASA Technical Reports Server (NTRS)

    Luo, B.; Brandt, W. N.; Alexander, D. M.; Harrison, F. A.; Stern, D.; Bauer, F. E.; Boggs, S. E.; Christensen, F. E.; Comastri, A.; Craig, W. W..; Fabian, A. C.; Farrah, D.; Fiore, F.; Fuerst, F.; Grefenstette, B. W.; Hailey, C. J.; Hickox, R.; Madsen, K. K.; Matt, G.; Ogle, P.; Risaliti, G.; Saez, C.; Teng, S. H.; Walton, D. J.; Zhang, W. W.

    2013-01-01

    We present Nuclear Spectroscopic Telescope Array (NuSTAR) hard X-ray observations of two X-ray weak broad absorption line (BAL) quasars, PG 1004+130 (radio loud) and PG 1700+518 (radio quiet). Many BAL quasars appear X-ray weak, probably due to absorption by the shielding gas between the nucleus and the accretion-disk wind. The two targets are among the optically brightest BAL quasars, yet they are known to be significantly X-ray weak at rest-frame 2-10 keV (16-120 times fainter than typical quasars). We would expect to obtain approx. or equal to 400-600 hard X-ray (is greater than or equal to 10 keV) photons with NuSTAR, provided that these photons are not significantly absorbed N(sub H) is less than or equal to 10(exp24) cm(exp-2). However, both BAL quasars are only detected in the softer NuSTAR bands (e.g., 4-20 keV) but not in its harder bands (e.g., 20-30 keV), suggesting that either the shielding gas is highly Compton-thick or the two targets are intrinsically X-ray weak. We constrain the column densities for both to be N(sub H) 7 × 10(exp 24) cm(exp-2) if the weak hard X-ray emission is caused by obscuration from the shielding gas. We discuss a few possibilities for how PG 1004+130 could have Compton-thick shielding gas without strong Fe Ka line emission; dilution from jet-linked X-ray emission is one likely explanation. We also discuss the intrinsic X-ray weakness scenario based on a coronal-quenching model relevant to the shielding gas and disk wind of BAL quasars. Motivated by our NuSTAR results, we perform a Chandra stacking analysis with the Large Bright Quasar Survey BAL quasar sample and place statistical constraints upon the fraction of intrinsically X-ray weak BAL quasars; this fraction is likely 17%-40%.

  13. WEAK HARD X-RAY EMISSION FROM TWO BROAD ABSORPTION LINE QUASARS OBSERVED WITH NuSTAR: COMPTON-THICK ABSORPTION OR INTRINSIC X-RAY WEAKNESS?

    SciTech Connect

    Luo, B.; Brandt, W. N.; Alexander, D. M.; Hickox, R.; Harrison, F. A.; Fuerst, F.; Grefenstette, B. W.; Madsen, K. K.; Stern, D.; Bauer, F. E.; Boggs, S. E.; Craig, W. W.; Christensen, F. E.; Comastri, A.; Fabian, A. C.; Farrah, D.; Fiore, F.; Hailey, C. J.; Matt, G.; Ogle, P.; and others

    2013-08-01

    We present Nuclear Spectroscopic Telescope Array (NuSTAR) hard X-ray observations of two X-ray weak broad absorption line (BAL) quasars, PG 1004+130 (radio loud) and PG 1700+518 (radio quiet). Many BAL quasars appear X-ray weak, probably due to absorption by the shielding gas between the nucleus and the accretion-disk wind. The two targets are among the optically brightest BAL quasars, yet they are known to be significantly X-ray weak at rest-frame 2-10 keV (16-120 times fainter than typical quasars). We would expect to obtain Almost-Equal-To 400-600 hard X-ray ({approx}> 10 keV) photons with NuSTAR, provided that these photons are not significantly absorbed (N{sub H} {approx}< 10{sup 24} cm{sup -2}). However, both BAL quasars are only detected in the softer NuSTAR bands (e.g., 4-20 keV) but not in its harder bands (e.g., 20-30 keV), suggesting that either the shielding gas is highly Compton-thick or the two targets are intrinsically X-ray weak. We constrain the column densities for both to be N{sub H} Almost-Equal-To 7 Multiplication-Sign 10{sup 24} cm{sup -2} if the weak hard X-ray emission is caused by obscuration from the shielding gas. We discuss a few possibilities for how PG 1004+130 could have Compton-thick shielding gas without strong Fe K{alpha} line emission; dilution from jet-linked X-ray emission is one likely explanation. We also discuss the intrinsic X-ray weakness scenario based on a coronal-quenching model relevant to the shielding gas and disk wind of BAL quasars. Motivated by our NuSTAR results, we perform a Chandra stacking analysis with the Large Bright Quasar Survey BAL quasar sample and place statistical constraints upon the fraction of intrinsically X-ray weak BAL quasars; this fraction is likely 17%-40%.

  14. A survey of ultraviolet interstellar absorption lines

    NASA Technical Reports Server (NTRS)

    Bohlin, R. C.; Jenkins, E. B.; Spitzer, L., Jr.; York, D. G.; Hill, J. K.; Savage, B. D.; Snow, T. P., Jr.

    1983-01-01

    A telescope-spectrometer on the Copernicus spacecraft made possible the measurement of many ultraviolet absorption lines produced by the interstellar gas. The present survey provides data on ultraviolet absorption lines in the spectra of 88 early-type stars. The stars observed are divided into four classes, including reddened stars, unreddened bright stars, moderately reddened bright stars, and unreddened and moderately reddened faint stars. Data are presented for equivalent width, W, radial velocity V, and rms line width, D, taking into account some 10 to 20 lines of N I, O I, Si II, P II, S II, Cl I, Cl II, Mn II, Fe II, Ni II, Cu II, and H2. The data are based on multiple scans for each line. Attention is given to details of observations, the data reduction procedure, and the computation of equivalent width, mean velocity, and velocity dispersion.

  15. BAL QSOs AND EXTREME UFOs: THE EDDINGTON CONNECTION

    SciTech Connect

    Zubovas, Kastytis; King, Andrew

    2013-05-20

    We suggest a common physical origin connecting the fast, highly ionized winds (UFOs) seen in nearby active galactic nuclei (AGNs), and the slower and less ionized winds of broad absorption line (BAL) QSOs. The primary difference is the mass-loss rate in the wind, which is ultimately determined by the rate at which mass is fed toward the central supermassive black hole (SMBH) on large scales. This is below the Eddington accretion rate in most UFOs, and slightly super-Eddington in extreme UFOs such as PG1211+143, but ranges up to {approx}10-50 times this in BAL QSOs. For UFOs this implies black hole accretion rates and wind mass-loss rates which are at most comparable to Eddington, giving fast, highly ionized winds. In contrast, BAL QSO black holes have mildly super-Eddington accretion rates, and drive winds whose mass-loss rates are significantly super-Eddington, and so are slower and less ionized. This picture correctly predicts the velocities and ionization states of the observed winds, including the recently discovered one in SDSS J1106+1939. We suggest that luminous AGNs may evolve through a sequence from BAL QSO through LoBAL to UFO-producing Seyfert or quasar as their Eddington factors drop during the decay of a bright accretion event. LoBALs correspond to a short-lived stage in which the AGN radiation pressure largely evacuates the ionization cone, but before the large-scale accretion rate has dropped to the Eddington value. We show that sub-Eddington wind rates would produce an M-{sigma} relation lying above that observed. We conclude that significant SMBH mass growth must occur in super-Eddington phases, either as BAL QSOs, extreme UFOs, or obscured from direct observation.

  16. BAL QSOs and Extreme UFOs: The Eddington Connection

    NASA Astrophysics Data System (ADS)

    Zubovas, Kastytis; King, Andrew

    2013-05-01

    We suggest a common physical origin connecting the fast, highly ionized winds (UFOs) seen in nearby active galactic nuclei (AGNs), and the slower and less ionized winds of broad absorption line (BAL) QSOs. The primary difference is the mass-loss rate in the wind, which is ultimately determined by the rate at which mass is fed toward the central supermassive black hole (SMBH) on large scales. This is below the Eddington accretion rate in most UFOs, and slightly super-Eddington in extreme UFOs such as PG1211+143, but ranges up to ~10-50 times this in BAL QSOs. For UFOs this implies black hole accretion rates and wind mass-loss rates which are at most comparable to Eddington, giving fast, highly ionized winds. In contrast, BAL QSO black holes have mildly super-Eddington accretion rates, and drive winds whose mass-loss rates are significantly super-Eddington, and so are slower and less ionized. This picture correctly predicts the velocities and ionization states of the observed winds, including the recently discovered one in SDSS J1106+1939. We suggest that luminous AGNs may evolve through a sequence from BAL QSO through LoBAL to UFO-producing Seyfert or quasar as their Eddington factors drop during the decay of a bright accretion event. LoBALs correspond to a short-lived stage in which the AGN radiation pressure largely evacuates the ionization cone, but before the large-scale accretion rate has dropped to the Eddington value. We show that sub-Eddington wind rates would produce an M-σ relation lying above that observed. We conclude that significant SMBH mass growth must occur in super-Eddington phases, either as BAL QSOs, extreme UFOs, or obscured from direct observation.

  17. Variable Reddening and Broad Absorption Lines in the Narrow-line Seyfert 1 Galaxy WPVS 007: An Origin in the Torus

    NASA Astrophysics Data System (ADS)

    Leighly, Karen M.; Cooper, Erin; Grupe, Dirk; Terndrup, Donald M.; Komossa, S.

    2015-08-01

    We report the discovery of an occultation event in the low-luminosity narrow-line Seyfert 1 galaxy WPVS 007 in 2015 February and March. In concert with longer timescale variability, these observations place strong constraints on the nature and location of the absorbing material. Swift monitoring has revealed a secular decrease since ∼2010 accompanied by flattening of the optical and UV photometry that suggests variable reddening. Analysis of four Hubble Space Telescope COS observations since 2010, including a Director’s Discretionary time observation during the occultation, shows that the broad-absorption-line velocity offset and the C iv emission-line width both decrease as the reddening increases. The occultation dynamical timescale, the BAL variability dynamical timescale, and the density of the BAL gas show that both the reddening material and the broad-absorption-line gas are consistent with an origin in the torus. These observations can be explained by a scenario in which the torus is clumpy with variable scale height, and the BAL gas is blown from the torus material like spray from the crest of a wave. As the obscuring material passes into our line of sight, we alternately see high-velocity broad absorption lines and a clear view to the central engine, or low-velocity broad absorption lines and strong reddening. WPVS 007 has a small black hole mass, and correspondingly short timescales, and so we may be observing behavior that is common in BALQSOs, but is not typically observable. Based on observations made with the NASA/ESA Hubble Space Telescope, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associated with programs 11733, 13015, and 14058.

  18. Molecular absorption in transition region spectral lines

    NASA Astrophysics Data System (ADS)

    Schmit, D. J.; Innes, D.; Ayres, T.; Peter, H.; Curdt, W.; Jaeggli, S.

    2014-09-01

    Aims: We present observations from the Interface Region Imaging Spectrograph (IRIS) of absorption features from a multitude of cool atomic and molecular lines within the profiles of Si IV transition region lines. Many of these spectral lines have not previously been detected in solar spectra. Methods: We examined spectra taken from deep exposures of plage on 12 October 2013. We observed unique absorption spectra over a magnetic element which is bright in transition region line emission and the ultraviolet continuum. We compared the absorption spectra with emission spectra that is likely related to fluorescence. Results: The absorption features require a population of sub-5000 K plasma to exist above the transition region. This peculiar stratification is an extreme deviation from the canonical structure of the chromosphere-corona boundary. The cool material is not associated with a filament or discernible coronal rain. This suggests that molecules may form in the upper solar atmosphere on small spatial scales and introduces a new complexity into our understanding of solar thermal structure. It lends credence to previous numerical studies that found evidence for elevated pockets of cool gas in the chromosphere. Movies associated to Figs. 1 and 2 are available in electronic form at http://www.aanda.org

  19. Discovery of an X-ray Violently Variable Broad Absorption Line Quasar

    NASA Technical Reports Server (NTRS)

    Ghosh, Kajal K.; Gutierrez, Carlos M.; Punsly, Brian; Chevallier, Loic; Goncalves, Anabela C.

    2006-01-01

    In this letter, we report on a quasar that is violently variable in the X-rays, XVV. It is also a broad absorption line quasar (BALQSO) that exhibits both high ionization and low ionization UV absorption lines (LoBALQSO). It is very luminous in the X-rays (approximately 10(exp 46) ergs s(sup -l) over the entire X-ray band). Surprisingly, this does not over ionize the LoBAL outflow. The X-rays vary by a factor of two within minutes in the quasar rest frame, which is shorter than 1/30 of the light travel time across a scale length equal to the black hole radius. We concluded that the X-rays are produced in a relativistic jet beamed toward earth in which variations in the Doppler enhancement produce the XVV behavior.

  20. THE NATURE OF LoBAL QSOs. I. SEDs AND MID-INFRARED SPECTRAL PROPERTIES

    SciTech Connect

    Lazarova, Mariana S.; Canalizo, Gabriela; Lacy, Mark; Sajina, Anna E-mail: gabriela.canalizo@ucr.edu E-mail: Anna.Sajina@tufts.edu

    2012-08-10

    We have obtained Spitzer Infrared Spectrograph spectra and MIPS 24, 70, and 160 {mu}m photometry for a volume-limited sample of 22 Sloan Digital Sky Survey selected low-ionization broad absorption line (LoBALs) QSOs at 0.5 < z < 0.6. By comparing their mid-IR spectral properties and far-IR spectral energy distributions (SEDs) with those of a control sample of 35 non-LoBALs matched in M{sub i} , we investigate the differences between the two populations in terms of their infrared emission and star formation (SF) activity. Twenty-five percent of the LoBALs show polycyclic aromatic hydrocarbon features and 45% have weak 9.7 {mu}m silicate dust emission. We model the SEDs and decouple the active galactic nucleus (AGN) and starburst contributions to the far-infrared luminosity in LoBALs and in non-LoBALs. Their median total, starburst, and AGN infrared luminosities are comparable. Twenty percent (but no more than 60%) of the LoBALs and 26% of the non-LoBALs are ultraluminous infrared galaxies (L{sub IR} > 10{sup 12} L{sub Sun }). We estimate star formation rates (SFRs) corrected for the AGN contribution to the FIR flux and find that LoBALs have comparable levels of SF activity to non-LoBALs when considering the entire samples. However, the SFRs of the IR-luminous LoBALs are 80% higher than those of their counterparts in the control sample. The median contribution of SF to the total far-infrared flux in LoBALs and in non-LoBALs is estimated to be 40%-50%, in agreement with previous results for Palomar-Green (PG) QSOs. Overall, our results show that there is no strong evidence from the mid- and far-IR properties that LoBALs are drawn from a different parent population than non-LoBALs.

  1. Quasar Absorption Line Survey - Cycle 4 High

    NASA Astrophysics Data System (ADS)

    Bahcall, John

    1994-01-01

    The Absorption Line Survey of bright quasars provides a homogeneous data base for studying fundamental questions about the origin and evolution of gaseous systems in the universe. The initial results determine at small redshifts the number densities of Ly-ALPHA systems, of metal-lines and extragalactic halos, of Lyman-limit systems, of associated absorption systems, and the shapes and intensities of quasar emission lines and spectral energy distributions. The survey reveals that much of the sky is covered by high or very high velocity metal-line clouds present in the Galactic halo. A larger sample, which includes the requested Cycle 3 observations, is required to answer many important questions. For example, what is the correlation function of Ly-ALPHA systems at small redshifts? What fraction of the metal, the Ly-ALPHA, and the Ly-limit systems are associated with galaxies and what are the characteristic sizes of the outer gaseous regions of different types of galaxies? Do absorbing systems show evidence of the large-scale structure seen with galaxies and clusters of galaxies? The observations requested in Cycle 3 will extend the region of coverage of the Key Project sample from the redshift range of z = 0.0 to 1.0 (Cycles 1& 2) to z = 0.0 to 1.6 (Cycles 1-3). THIS FILE CONTAINS THE HIGH PRIORITY OBSERVATIONS FROM CYCLES 2 and 3 WHICH WERE NOT COMPLETED IN THOSE CYCLES.

  2. Dramatically Variable C IV Mini-Broad Absorption Line System in the Quasar HS 1603+3820

    NASA Astrophysics Data System (ADS)

    Misawa, T.; Eracleous, M.; Charlton, J. C.; Chartas, G.; Kashikawa, N.

    2008-10-01

    We observed the quasar HS 1603+3820 (z_{em} = 2.542, first discovered by Dobrzycki et al. 1996) six times over an interval of 4.2 yrs (1.2 yrs in the quasar rest frame) using the High Dispersion Spectrograph on Subaru telescope. The purpose was to study the mini-broad absorption line (mini-BAL; FWHM ˜ 1,000 km s^{-1}) that is blue-shifted from the quasar by ˜ 9,500 km s^{-1}. We found significant time variability, which supported the physical association of the mini-BAL gas with an outflow from the quasar. We have narrowed down the cause of the variability to two possible scenarios. We also used archival Chandra x-ray data to study the x-ray properties of this quasar. The results constrain the location of the absorbing gas relative to the overall outflow.

  3. XMM-NEWTON OBSERVATIONS OF THE RADIO-LOUD BROAD ABSORPTION LINE QUASAR FBQS J131213.5+231958

    SciTech Connect

    Mathur, Smita; Dai Xinyu E-mail: dai@nhn.ou.ed

    2010-12-15

    We present XMM-Newton observations of the broad absorption line (BAL) quasar FBQS J131213.5+231958. The X-ray spectrum of the source can be well described by an absorbed power-law model in which the absorber is either ionized or only partially covers the continuum source. This can explain the apparent lack of absorption observed in the Chandra spectrum with low signal-to-noise ratio. While the power-law slope of the spectrum is similar to that of non-BAL radio-loud quasars, the Eddington luminosity ratio is likely to be significantly higher than the mean. This shows that in high-mass black holes (BHs), high Eddington accretion may not result in as steep of a spectrum as in lower-mass BHs. This provides important constraints for accretion disk models. It also provides support to the idea that BAL quasars, at least their radio-loud subclass, represent an early evolutionary stage of quasars.

  4. A catalogue of absorption-line systems in QSO spectra

    NASA Astrophysics Data System (ADS)

    Ryabinkov, A. I.; Kaminker, A. D.; Varshalovich, D. A.

    2003-12-01

    We present a new catalog of absorption-line systems identified in the quasar spectra. It contains data on 821 QSOs and 8558 absorption systems comprising 16 139 absorption lines with measured redshifts in the QSO spectra. The catalog includes absorption-line systems consisting of lines of heavy elements, lines of neutral hydrogen, Lyman limit systems, damped Lyα absorption systems, and broad absorption-line systems. Using the data of the present catalog we also discuss redshift distributions of absorption-line systems. Tables 1 and 2 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/412/707

  5. Evidence for active galactic nucleus feedback in the broad absorption lines and reddening of MRK 231 {sup ,}

    SciTech Connect

    Leighly, Karen M.; Baron, Eddie; Lucy, Adrian B.; Terndrup, Donald M.; Dietrich, Matthias; Gallagher, Sarah C.

    2014-06-20

    We present the first J-band spectrum of Mrk 231, which reveals a large He I* λ10830 broad absorption line with a profile similar to that of the well-known Na I broad absorption line. Combining this spectrum with optical and UV spectra from the literature, we show that the unusual reddening noted by Veilleux et al. is explained by a reddening curve like those previously used to explain low values of total-to-selective extinction in Type Ia supernovae. The nuclear starburst may be the origin and location of the dust. Spatially resolved emission in the broad absorption line trough suggests nearly full coverage of the continuum emission region. The broad absorption lines reveal higher velocities in the He I* lines (produced in the quasar-photoionized H II region) compared with the Na I and Ca II lines (produced in the corresponding partially ionized zone). Cloudy simulations show that a density increase is required between the H II and partially ionized zones to produce ionic column densities consistent with the optical and IR absorption line measurements and limits, and that the absorber lies ∼100 pc from the central engine. These results suggest that the He I* lines are produced in an ordinary quasar BAL wind that impacts upon, compresses, and accelerates the nuclear starburst's dusty effluent (feedback in action), and the Ca II and Na I lines are produced in this dusty accelerated gas. This unusual circumstance explains the rarity of Na I absorption lines; without the compression along our line of sight, Mrk 231 would appear as an ordinary iron low-ionization, broad absorption line quasar.

  6. Fast outflows in broad absorption line quasars and their connection with CSS/GPS sources

    NASA Astrophysics Data System (ADS)

    Bruni , G.; Mack, K.-H.; Montenegro-Montes, F. M.; Brienza, M.; González-Serrano, J. I.

    2016-02-01

    Broad absorption line quasars are among the objects presenting the fastest outflows. The launching mechanism itself is not completely understood. Models in which they could be launched from the accretion disk, and then curved and accelerated by the effect of the radiation pressure, have been presented. We conducted an extensive observational campaign, from radio to optical band, to collect information about their nature and test the models present in the literature, the main dichotomy being between a young scenario and an orientation one. We found a variety of possible orientations, morphologies, and radio ages, not converging to a particular explanation for the BAL phenomenon. From our latest observations in the m- and mm-band, we obtained an indication of a lower dust abundance with respect to normal quasars, thus suggesting a possible feedback process on the host galaxy. Also, in the low-frequency regime we confirmed the presence of CSS components, sometime in conjunction with a GPS one already detected at higher frequencies. Following this, about 70 % of our sample turns out to be in a GPS or CSS+GPS phase. We conclude that fast outflows, responsible for the BAL features, can be more easily present among objects going through a restarting or just-started radio phase, where radiation pressure can substantially contribute to their acceleration.

  7. EMERGENCE OF A BROAD ABSORPTION LINE OUTFLOW IN THE NARROW-LINE SEYFERT 1 GALAXY WPVS 007

    SciTech Connect

    Leighly, Karen M.; Casebeer, Darrin A.; Hamann, Fred; Grupe, Dirk

    2009-08-10

    We report results from a 2003 Far Ultraviolet Spectroscopic Explorer (FUSE) observation and reanalysis of a 1996 Hubble Space Telescope (HST) observation of the unusual X-ray transient Narrow-line Seyfert 1 galaxy WPVS 007. The HST Faint Object Spectrograph (FOS) spectrum revealed mini-BALs (broad absorption lines) with V {sub max} {approx} 900 km s{sup -1} and FWHM {approx}550 km s{sup -1}. The FUSE spectrum showed that an additional BAL outflow with V {sub max} {approx} 6000 km s{sup -1} and FWHM {approx}3400 km s{sup -1} had appeared. WPVS 007 is a low-luminosity object in which such a high-velocity outflow is not expected; therefore, it is an outlier on the M{sub V} /v {sub max} relationship. Template spectral fitting yielded apparent ionic columns, and a Cloudy analysis showed that the presence of P V requires a high-ionization parameter log(U) {>=} 0 and high-column density log(N {sub H}) {>=} 23 assuming solar abundances and a nominal spectral energy distribution (SED) for low-luminosity NLS1s with {alpha} {sub ox} = -1.28. A recent long Swift observation revealed the first hard X-ray detection and an intrinsic (unabsorbed) {alpha} {sub ox} {approx} -1.9. Using this SED in our analysis yielded lower column density constraints (log(N {sub H}) {>=} 22.2 for Z = 1, or log(N {sub H}) {>=} 21.6 if Z = 5). The X-ray weak continuum, combined with X-ray absorption consistent with the UV lines, provides the best explanation for the observed Swift X-ray spectrum. The large column densities and velocities implied by the UV data in any of these scenarios could be problematic for radiative acceleration. We also point out that since the observed P V absorption can be explained by lower total column densities using an intrinsically X-ray weak spectrum, we might expect to find P V absorption preferentially more often (or stronger) in quasars that are intrinsically X-ray weak.

  8. The radio core and jet in the broad absorption-line quasar PG 1700+518

    NASA Astrophysics Data System (ADS)

    Yang, J.; Wu, F.; Paragi, Z.; An, T.

    2012-01-01

    The blueshifted broad absorption lines (BAL) or troughs are observed in active galactic nuclei (AGNs) when our line of sight is intercepted by a high-speed outflow (wind), likely originating in the accretion disc. The outflow or wind can shed light on the internal structure obscured by the AGN torus. Recently, it has been shown that this outflow is rotating in the BAL quasar PG 1700+518, further supporting the accretion disc origin of the wind. With the purpose of giving independent constraints on the wind geometry, we performed high-resolution European very long baseline interferometry (VLBI) Network (EVN) observations at 1.6 GHz in 2010. Combining the results with the Very Large Array (VLA) archival data at 8.4 GHz, we present its jet structure on scales of parsec (pc) to kiloparsec (kpc) for the first time. The source shows two distinct jet features in east-west direction with a separation of around 4 kpc. The eastern feature, which has so far been assumed to hide the core, is a kpc-scale hotspot, which is completely resolved out in the EVN image. In the western jet feature, we find a compact jet component, which pinpoints the position of the central black hole in the galaxy. Jet components on both sides of the core are additionally detected in the north-west-south-east direction, and they show a symmetric morphology on scale of <1 kpc. This two-sided jet feature is not common in the known BAL quasars and indicates that the jet axis is far away from the line of sight. Furthermore, it is nearly parallel to the scattering plane revealed earlier by optical polarimetry. By analogy to polar-scattered Seyfert 1 galaxies, we conclude that the jet likely has a viewing angle around 45°. The analogy is further supported by the recent report of significant cold absorption in the soft X-rays, a nearly unique feature to polar-scattered Seyfert galaxies. Finally, our observations have confirmed the earlier finding that the majority of radio emission in this galaxy arises

  9. Results of Monitoring the Dramatically Variable C IV Mini-Broad Absorption Line System in the Quasar HS 1603+3820

    NASA Astrophysics Data System (ADS)

    Misawa, Toru; Eracleous, Michael; Charlton, Jane C.; Kashikawa, Nobunari

    2007-05-01

    We present six new and two previously published high-resolution spectra of the quasar HS 1603+3820 (zem=2.542) taken over an interval of 4.2 yr (1.2 yr in the quasar rest frame). The observations were made with the High Dispersion Spectrograph on the Subaru telescope and the Medium Resolution Spectrograph on the Hobby-Eberly Telescope. The purpose was to study the narrow absorption lines (NALs). We use time variability and coverage fraction analysis to separate intrinsic absorption lines, which are physically related to the quasar, from intervening absorption lines. By fitting models to the line profiles, we derive the parameters of the respective absorbers as a function of time. Only the mini-BAL system at zabs~2.43 (vshift~9500 km s-1) shows both partial coverage and time variability, although two NAL systems possibly show evidence of partial coverage. We find that all the troughs of the mini-BAL system vary in concert and its total equivalent width variations resemble those of the coverage fraction. However, no other correlations are seen between the variations of different model parameters. Thus, the observed variations cannot be reproduced by a simple change of ionization state or by motion of a homogeneous parcel of gas across the cylinder of sight. We propose that the observed variations are a result of rapid continuum fluctuations, coupled with coverage fraction fluctuations caused by a clumpy screen of variable optical depth located between the continuum source and the mini-BAL gas. An alternative explanation is that the observed partial coverage signature is the result of scattering of continuum photons around the absorber, thus the equivalent width of the mini-BAL can vary as the intensity of the scattered continuum changes. Based on data collected at the Subaru telescope, which is operated by the National Astronomical Observatory of Japan.

  10. Discovery of a z=0.65 Post-Starburst BAL Quasar in the DES Supernova Fields

    SciTech Connect

    Mudd, Dale; et al.

    2016-06-08

    We present the discovery of a z=0.65 low-ionization broad absorption line (LoBAL) quasar in a post-starburst galaxy in data from the Dark Energy Survey (DES) and spectroscopy from the Australian Dark Energy Survey (OzDES). LoBAL quasars are a minority of all BALs, and rarer still is that this object also exhibits broad FeII (an FeLoBAL) and Balmer absorption. This is the first BAL quasar that has signatures of recently truncated star formation, which we estimate ended about 40 Myr ago. The characteristic signatures of an FeLoBAL require high column densities, which could be explained by the emergence of a young quasar from an early, dust-enshrouded phase, or by clouds compressed by a blast wave. The age of the starburst component is comparable to estimates of the lifetime of quasars, so if we assume the quasar activity is related to the truncation of the star formation, this object is better explained by the blast wave scenario.

  11. Toward a Complete Picture of Quasar Outflows: from BALs to mini-BALs

    NASA Astrophysics Data System (ADS)

    Moravec, Emily; Hamann, Fred; Capellupo, Daniel M.; McGraw, Sean; Shields, Joseph C.; Rodriguez Hidalgo, Paola

    2016-01-01

    Accretion disk outflows are important for galaxy evolution and an integral part of the quasar phenomenon, but they remain poorly understood. In order to construct a more complete picture of the quasar phenomenon, we need to understand the full range of different types of quasar outflows and how they correlate with one another. We examine seven SDSS quasars with CIV 1548,1551 Å outflow lines that span a range from strong BALs to weak mini-BALs. They have moderate redshifts (1.68 < z < 1.91) to minimize contamination from the Lyα forest while still allowing measurements of CIV from the ground and other important lines like OVI 1031,1038 Å and PV 1118,1128 Å with HST. We use archival SDSS and BOSS spectra in combination with HST COS G230L observations and multi-epoch ground-based spectra obtained at the MDM and Kitt Peak observatories to measure a variety of ions across the rest UV wavelength range. Our preliminary analysis shows OVI is present and stronger than CIV in all seven quasars. In one case, we detect an OVI mini-BAL with no accompanying CIV, requiring a highly-ionized outflow. In the strongest BAL quasar, we detect resolved PV doublet absorption that requires PV optical depths > 3 and in outflow gas with a line-of-sight covering fraction of only 0.27. Thus, the total column density in this outflow component might exceed N_H > 1023 cm-2 which has important consequences for the outflow kinetic energies and feedback. The multi-epoch CIV data reveal CIV outflow variability in all seven quasars; four become weaker, one becomes stronger, and two become both stronger and weaker over the different epochs. This variability happens across time scales of ~1-12 years in the quasar rest frames which is consistent with outflow locations close to the central quasar engines. We use these and other results to constrain the ionization, column density, and location of the absorbers with the broader goals of understanding accretion physics, the integrated structure of

  12. The Early Universe Probed by QSO Absorption Lines

    NASA Astrophysics Data System (ADS)

    Misawa, Toru; Iye, Masanori

    2000-12-01

    High-z QSOs are valuable probes of the early universe and provide us information on the era of galaxy formation. QSOs can also be used as background sources against intervening objects such as proto-galactic clouds and faint foreground galaxies. These intervening objects produce absorption lines in the spectra of background QSOs. Gas clouds producing metal absorption lines are thought to exist in the halos of intervening galaxies and are used to evaluate the metal abundances of galaxies at high redshifts. In the course of studying the evolution of metal absorption lines, it was found that the number of absorbers per unit redshift interval increases in the vicinity of QSOs, especially of radio-loud QSOs. The reason of such an excess of metal absorption lines remains still unclear. In this paper, the authors review the absorption properties and enigmas of quasar absorption lines.

  13. Ultraviolet interstellar absorption lines from low-z galaxies

    NASA Astrophysics Data System (ADS)

    Sahu, M. S.

    1997-05-01

    The importance of studying absorption lines from z<<0.1 galaxies are discussed. The Mg II λλ2796 and 2803 Å doublet absorption is sensitive to low column density gas and has been used to search for absorption lines from low-z galaxies. Recent studies of abundances and depletion patterns toward the Small Magellanic Cloud (Welty et al. 1997) and the NGC 1705 sightline (Sahu & Blades, 1997) are reviewed.

  14. EVIDENCE FOR PHOTOIONIZATION-DRIVEN BROAD ABSORPTION LINE VARIABILITY

    SciTech Connect

    Wang, Tinggui; Yang, Chenwei; Wang, Huiyuan; Ferland, Gary

    2015-12-01

    We present a qualitative analysis of the variability of quasar broad absorption lines using the large multi-epoch spectroscopic data set of the Sloan Digital Sky Survey Data Release 10. We confirm that variations of absorption lines are highly coordinated among different components of the same ion or the same absorption component of different ions for C iv, Si iv, and N v. Furthermore, we show that the equivalent widths (EWs) of the lines decrease or increase statistically when the continuum brightens or dims. This is further supported by the synchronized variations of emission and absorption-line EWs when the well-established intrinsic Baldwin effect for emission lines is taken into account. We find that the emergence of an absorption component is usually accompanied by the dimming of the continuum while the disappearance of an absorption-line component is accompanied by the brightening of the continuum. This suggests that the emergence or disappearance of a C iv absorption component is only the extreme case, when the ionic column density is very sensitive to continuum variations or the continuum variability the amplitude is larger. These results support the idea that absorption-line variability is driven mainly by changes in the gas ionization in response to continuum variations, that the line-absorbing gas is highly ionized, and in some extreme cases, too highly ionized to be detected in UV absorption lines. Due to uncertainties in the spectroscopic flux calibration, we cannot quantify the fraction of quasars with asynchronized continuum and absorption-line variations.

  15. Time-Variable Complex Metal Absorption Lines in the Quasar HS 1603+3820

    NASA Astrophysics Data System (ADS)

    Misawa, Toru; Eracleous, Michael; Charlton, Jane C.; Tajitsu, Akito

    2005-08-01

    We present a new spectrum of the quasar HS 1603+3820 taken 1.28 yr (0.36 yr in the quasar rest frame) after a previous observation with Subaru+HDS. The new spectrum enables us to search for time variability as an identifier of intrinsic narrow absorption lines (NALs). This quasar shows a rich complex of C IV NALs within 60,000 km s-1 of the emission redshift. On the basis of covering factor analysis, Misawa et al. found that the C IV NAL system at zabs=2.42-2.45 (system A, at a shift velocity of vsh=8300-10,600 km s-1 relative to the quasar) was intrinsic to the quasar. With our new spectrum, we perform time variability analysis, as well as covering factor analysis, to separate intrinsic NALs from intervening NALs for eight C IV systems. Only system A, which was identified as an intrinsic system in the earlier paper by Misawa et al., shows a strong variation in line strength (Wobs~10.4-->19.1 Å). We speculate that a broad absorption line (BAL) could be forming in this quasar (i.e., many narrower lines will blend together to make a BAL profile). We illustrate the plausibility of this suggestion with the help of a simulation in which we vary the column densities and covering factors of the NAL complex. Under the assumption that a change of ionization state causes the variability, a lower limit can be placed on the electron density (ne>~3×104cm-3) and an upper limit on the distance from the continuum source (r<=6 kpc). On the other hand, if the motion of clumpy gas causes the variability (a more likely scenario), the crossing velocity and the distance from the continuum source are estimated to be vcross>8000 km s-1 and r<3 pc. In this case, the absorber does not intercept any flux from the broad emission line region, but only flux from the UV continuum source. If we adopt the dynamical model of Murray et al., we can obtain a much more strict constraint on the distance of the gas parcel from the continuum source, r<0.2 pc. Based on data collected at the Subaru

  16. Monitoring of a Dramatically Variable C IV Mini-BAL in the Quasar HS1603+3820

    NASA Astrophysics Data System (ADS)

    Misawa, Toru; Eracleous, M.; Charlton, J. C.; Kashikawa, N.

    2006-12-01

    We present eight high-resolution spectra of an optically bright quasar, HS1603+3820 (z_em=2.542), taken over an interval of 4.2 years (1.2 years in the quasar rest frame) with Subaru Telescope and Hobby-Eberly Telescope, for the purpose of monitoring absorption lines that are physically associated to the quasar. Among eight C IV absorption systems in this quasar spectrum, only one mini-BAL system at z_abs 2.43, which was already identified as an intrinsic system based on partial coverage analysis (Misawa et al. 2003,2005), showed dramatic time variability. We fitted Voigt profiles to the mini-BAL, and found that there were no clear correlations between the fit parameters such as the column density, Doppler parameter, and coverage fraction. This result suggests that the mini-BAL absorber has an inhomogeneous internal structure. Another important observational clue is that all absorption components in the system varied in concert, which suggests the observed time variability was due to a change of the ionization conditions (not due to the gas motion) in the mini-BAL absorber. Because such rapid UV continuum variability is not expected in luminous quasars such as our target, we suggest that a variable screen of material between the quasar continuum source and the absorber is the cause of the changes in the ionization state of the mini-BAL system. We acknowledge support from NASA grant NAG5-10817.

  17. On the identification of deuterium lines in QSO absorption systems

    NASA Astrophysics Data System (ADS)

    Levshakov, S. A.; Takahara, F.

    1996-07-01

    The ambiguity of identification of deuterium lines in QSO absorption systems is considered, under the assumption that the D I and H I absorption lines are formed in turbulent media with a finite correlation length of the stochastic velocity field. The relative shift of the D I and H I lines is shown to vary over the range +/-(4-8) km s^- 1^ for a cloud model with hydrogen column density N_HI_ = 10^17^ cm^-2^, the ratio D/H = 10^-4^, and kinetic temperature T_kin_ = 10^4^ K. The variations in the relative shift of the deuterium lines are fundamental in character and result from the stochastic nature of the formation of absorption lines in turbulent media

  18. Double troughs in broad absorption line quasars and Ly-alpha-N V line-locking

    NASA Technical Reports Server (NTRS)

    Korista, Kirk T.; Voit, G. M.; Morris, Simon L.; Weymann, Ray J.

    1993-01-01

    It was investigated whether the double trough (DT) structure in the mean C IV BAL trough reported by Weymann et al. (1991) is real or due to statistical fluctuations of BAL troughs over random outflow velocities in a limited sample. A sample of 72 BAL QSOs with C IV BAL troughs was analyzed. It is found that only 22 percent of the sample explicitly exhibits the DT feature; when present the DTs are deep. A Monte Carlo simulation of the mean C IV BAL suggests that the DT feature is real at only the 95-98 percent level.

  19. Quasar Absorption Lines and SDSS Galaxies

    NASA Astrophysics Data System (ADS)

    Shoemaker, Emileigh Suzanne; Scott, Jennifer E.; Oldak, Katarzyna

    2017-01-01

    We present the results of a study of the sightlines of 45 low redshift quasars (0.06 < z < 0.85) observed with HST/COS that lie within the footprint of the Sloan Digital Sky Survey. We use both the SDSS DR12 galaxy photometric data, including photometric redshifts, and the measured properties of the absorbers along with the known absorption characteristics of the intergalactic medium and the circumgalactic medium of galaxies to assign the most probable galaxy matches for each absorber in the sample, using estimated galaxy luminosities and virial radii as a discriminator. We show that the scheme can recover known galaxy-absorber matches found from spectroscopic data and thus provides a method for identifying likely pairs in photometric data sets as well as targets for spectroscopic follow up.

  20. Searching for Variability of NV Intrinsic Narrow Absorption Line Systems

    NASA Astrophysics Data System (ADS)

    Rodruck, Michael; Charlton, Jane C.; Ganguly, Rajib

    2017-01-01

    The majority of quasar absorption line systems with NV detected are found within the associated region (within 5000km/s of the quasar redshift) and many/most are believed to be related to the quasar accretion disk wind or outflows. The most definite evidence that these NV absorbers are "intrinsic" is partial covering of the quasar continuum source and/or broad line region. Over 50 quasars containing NV narrow absorption lines have observations obtained at different times with the Keck/HIRES and the VLT/UVES spectrographs at high resolution. The interval between these observations range from months to a decade in the quasar rest frame. While variability is common for intrinsic broad and mini-broad absorption lines, intrinsic narrow absorption lines have been found to be less likely to vary, though systematic studies with large, high quality datasets have been limited. The variability timescales are useful for deriving gas densities and thus the distances from the central engines. This is important in mapping the quasar surroundings, understanding the accretion disk wind mechanism, and assessing the effect the wind has on the galaxy surroundings. We report on the results of a systematic study of variability of NV NALs, exploiting the overlap of targets for observations in the archives of Keck and VLT, and discuss the consequences for interpretation of the origin of intrinsic narrow absorption lines.

  1. PG 1411 + 442 - The nearest broad absorption line quasar

    NASA Technical Reports Server (NTRS)

    Malkan, Matthew A.; Green, Richard F.; Hutchings, John B.

    1987-01-01

    IUE observations reveal strong, moderately broad absorption troughs in the blue wings of the C IV and N V emission lines of the quasar PG 1411 + 442. No absorption from weakly ionized gas is detected. The emission-line strengths and overall shape of the ultraviolet/optical/near-infrared/far-infrared continuum of the new broad absorption line quasar are within the range normally measured in quasars. Its redshift is low enough to allow the morphology of the host galaxy to be studied in deep broad-band and intermediate-band CCD images. The galaxy appears to be a large spiral with a very long arm or tail. The inclination angle is 57 deg, which rules out the possibility that the line of sight to the nucleus intersects a large path length in a galactic disk.

  2. Active Galactic Nuclei Probed by QSO Absorption Lines

    NASA Astrophysics Data System (ADS)

    Misawa, Toru

    2007-07-01

    Quasars are the extremely bright nuclei found in about 10% of galaxies. A variety of absorption features (known collectively as quasar absorption lines) are detected in the rest-frame UV spectra of these objects. While absorption lines that have very broad widths originate in gas that is probably physocally related to the quasars, narrow absorption lines (NALs) were thought to arise in galaxies and/or in the intter-alacttic medium between the quasars and us. Using high-resolution spectra of quasars, it is found that a substantial fraction of NALs arise in gas in the immediate vicinity of the quasars. A dramatically variable, moderately-broad absorption line in the spectrum of the quasar HS 1603+3820l is also found. The variability of this line is monitored in a campaign with Subaru telescope. These observational results are compared to models for outflows from the quasars, specifically, models for accretion disk winds and evaporating obscuring tori. It is quite important to determine the mechanism of outflow because of its cosmological implications. The outflow could expel angular momentum from the accretion disk and enable quasars to accrete and shine. In addition, the outflow may also regulate star formation in the early stages of the assembly of the host galaxy and enrich the interstellar and intergalactic medium with metals.

  3. Broad Absorption Line Quasar catalogues with Supervised Neural Networks

    SciTech Connect

    Scaringi, Simone; Knigge, Christian; Cottis, Christopher E.; Goad, Michael R.

    2008-12-05

    We have applied a Learning Vector Quantization (LVQ) algorithm to SDSS DR5 quasar spectra in order to create a large catalogue of broad absorption line quasars (BALQSOs). We first discuss the problems with BALQSO catalogues constructed using the conventional balnicity and/or absorption indices (BI and AI), and then describe the supervised LVQ network we have trained to recognise BALQSOs. The resulting BALQSO catalogue should be substantially more robust and complete than BI-or AI-based ones.

  4. AFGL atmospheric absorption line parameters compilation - 1982 edition

    NASA Astrophysics Data System (ADS)

    Rothman, L. S.; Gamache, R. R.; Barbe, A.; Goldman, A.; Gillis, J. R.; Brown, L. R.; Toth, R. A.; Flaud, J.-M.; Camy-Peyret, C.

    1983-08-01

    The latest edition of the AFGL atmospheric absorption line parameters compilation for the seven most active infrared terrestrial absorbers is described. Major modifications to the atlas for this edition include updating of water-vapor parameters from 0 to 4300 per cm, improvements to line positions for carbon dioxide, substantial modifications to the ozone bands in the middle to far infrared, and improvements to the 7- and 2.3-micron bands of methane. The atlas now contains about 181,000 rotation and vibration-rotation transitions between 0 and 17,900 per cm. The sources of the absorption parameters are summarized.

  5. XMM-Newton Spectroscopy of the X-ray Detected Broad Absorption Line QSO CSO 755

    NASA Technical Reports Server (NTRS)

    Brandt, Niel

    2005-01-01

    We present the results from XMM-Newton observations of the highly optically polarized broad absorption line quasar (BALQSO) CSO 755. By analyzing its X-ray spectrum with a total of approximately 3000 photons we find that this source has an X-ray continuum of "typical" radio-quiet quasars, with a photon index of Gamma=1.83, and a rather flat (X-ray bright) intrinsic optical-to-X-ray spectral slope of alpha_ox=- 1.51. The source shows evidence for intrinsic absorption, and fitting the spectrum with a neutral-absorption model gives a column density of N_H approximately 1.2x10^22 cm^{-2}; this is among the lowest X-ray columns measured for BALQSOs. We do not detect, with high significance, any other absorption features in the X-ray spectrum. Upper limits we place on the rest-frame equivalent width of a neutral (ionized) Fe K-alpha line, less than =180 eV (less than =120 eV), and on the Compton-reflection component parameter, R less than =0.2, suggest that most of the X-rays from the source are directly observed rather than being scattered or reflected; this is also supported by the relatively flat intrinsic alpha ox we measure. The possibility that most of the X-ray flux is scattered due to the high level of UV-optical polarization is ruled out. Considering data for 46 BALQSOs from the literature, including CSO 755, we have found that the UV-optical continuum polarization level of BALQSOs is not correlated with any of their X-ray properties. A lack of significant short-term and long-term X-ray flux variations in the source may be attributed to a large black-hole mass in CSO 755. We note that another luminous BALQSO, PG 2112+059, has both similar shallow C IV BALs and moderate X-ray absorption.

  6. Radiation pressure confinement - IV. Application to broad absorption line outflows

    NASA Astrophysics Data System (ADS)

    Baskin, Alexei; Laor, Ari; Stern, Jonathan

    2014-12-01

    A fraction of quasars present broad absorption lines, produced by outflowing gas with typical velocities of 3000-10 000 km s-1. If the outflowing gas fills a significant fraction of the volume where it resides, then it will be highly ionized by the quasar due to its low density, and will not produce the observed UV absorption. The suggestion that the outflow is shielded from the ionizing radiation was excluded by recent observations. The remaining solution is a dense outflow with a filling factor f < 10-3. What produces such a small f? Here, we point out that radiation pressure confinement (RPC) inevitably leads to gas compression and the formation of dense thin gas sheets/filaments, with a large gradient in density and ionization along the line of sight. The total column of ionized dustless gas is a few times 1022 cm-2, consistent with the observed X-ray absorption and detectable P V absorption. The predicted maximal columns of various ions show a small dependence on the system parameters, and can be used to test the validity of RPC as a solution for the overionization problem. The ionization structure of the outflow implies that if the outflow is radiatively driven, then broad absorption line quasars should have L/L_Eddgtrsim 0.1.

  7. Redshifted 21cm Line Absorption by Intervening Galaxies

    NASA Astrophysics Data System (ADS)

    Briggs, F. H.

    The present generation of radio telescopes, combined with powerful new spectrometers, is opening a new age of redshifted radio absorption-line studies. Out-fitting of arrays of antennas, such as the European VLBI Network and the upgraded VLA, with flexibly tuned receivers, will measure sizes and kinematics of intervening galaxies as a function of cosmic time.

  8. Broad Balmer Absorption Line Variability: Evidence of Gas Transverse Motion in the QSO SDSS J125942.80+121312.6

    NASA Astrophysics Data System (ADS)

    Shi, Xiheng; Zhou, Hongyan; Shu, Xinwen; Zhang, Shaohua; Ji, Tuo; Pan, Xiang; Sun, Luming; Zhao, Wen; Hao, Lei

    2016-03-01

    We report on the discovery of broad Balmer absorption lines variability in the QSO SDSS J125942.80+121312.6, based on the optical and near-infrared spectra taken from the SDSS-I, SDSS-III Baryon Oscillation Spectroscopic Survey (BOSS), and TripleSpec observations over a timescale of 5.8 years in the QSO's rest-frame. The blueshifted absorption profile of Hβ shows a variation of more than 5σ at a high velocity portion (\\gt 3000 {km} {{{s}}}-1) of the trough. We perform a detailed analysis for the physical conditions of the absorber using Balmer lines as well as metastable He i and optical Fe ii absorptions (λ4233 from b4P5/2 level and λ5169 from a6S5/2) at the same velocity. These Fe ii lines are identified in the QSO spectra for the first time. According to the photoionization simulations, we estimate a gas density of n({{H}})≈ {10}9.1 {{cm}}-3 and a column density of {N}{col}({{H}})≈ {10}23 {{cm}}-2 for the BOSS data, but the model fails to predict the variations of ionic column densities between the SDSS and BOSS observations if changes in ionizing flux are assumed. We thus propose transverse motion of the absorbing gas being the cause of the observed broad Balmer absorption line variability. In fact, we find that the changes in covering factors of the absorber can well-reproduce all of the observed variations. The absorber is estimated ∼0.94 pc away from the central engine, which is where the outflow likely experiences deceleration due to the collision with the surrounding medium. This scheme is consistent with the argument that LoBAL QSOs may represent the transition from obscured star-forming galaxies to classic QSOs.

  9. SDSS J163459.82+204936.0: A Ringed Infrared-luminous Quasar with Outflows in Both Absorption and Emission Lines

    NASA Astrophysics Data System (ADS)

    Liu, Wen-Juan; Zhou, Hong-Yan; Jiang, Ning; Wu, Xufen; Lyu, Jianwei; Shi, Xiheng; Shu, Xinwen; Jiang, Peng; Ji, Tuo; Wang, Jian-Guo; Wang, Shu-Fen; Sun, Luming

    2016-05-01

    SDSS J163459.82+204936.0 is a local (z = 0.1293) infrared-luminous quasar with L IR = 1011.91 {L}⊙ . We present a detailed multiwavelength study of both the host galaxy and the nucleus. The host galaxy, appearing as an early-type galaxy in the optical images and spectra, demonstrates violent, obscured star formation activities with SFR ≈ 140 {M}⊙ yr-1, estimated from either the polycyclic aromatic hydrocarbon emission or IR luminosity. The optical to NIR spectra exhibit a blueshifted narrow cuspy component in Hβ, He i λλ5876, 10830, and other emission lines consistently with an offset velocity of ≈900 {km} {{{s}}}-1, as well as additional blueshifting phenomena in high-ionization lines (e.g., a blueshifted broad component of He i λ10830 and the bulk blueshifting of [O iii]λ5007), while there exist blueshifted broad absorption lines (BALs) in Na i D and He i λλ3889, 10830, indicative of the active galactic nucleus outflows producing BALs and emission lines. Constrained mutually by the several BALs in the photoionization simulations with Cloudy, the physical properties of the absorption line outflow are derived as follows: density 104 < n H ≲ 105 cm-3, ionization parameter 10-1.3 ≲ U ≲ 10-0.7 , and column density 1022.5 ≲ N H ≲ 1022.9 cm-2, which are similar to those derived for the emission line outflows. This similarity suggests a common origin. Taking advantages of both the absorption lines and outflowing emission lines, we find that the outflow gas is located at a distance of ˜48-65 pc from the nucleus and that the kinetic luminosity of the outflow is 1044-1046 {erg} {{{s}}}-1. J1634+2049 has a off-centered galactic ring on the scale of ˜30 kpc that is proved to be formed by a recent head-on collision by a nearby galaxy for which we spectroscopically measure the redshift. Thus, this quasar is a valuable object in the transitional phase emerging out of dust enshrouding as depicted by the co-evolution scenario invoking galaxy merger (or

  10. A SURVEY OF ALKALI LINE ABSORPTION IN EXOPLANETARY ATMOSPHERES

    SciTech Connect

    Jensen, Adam G.; Redfield, Seth; Endl, Michael; Cochran, William D.; Koesterke, Lars; Barman, Travis S. E-mail: sredfield@wesleyan.edu E-mail: wdc@astro.as.utexas.edu E-mail: barman@lowell.edu

    2011-12-20

    We obtained over 90 hr of spectroscopic observations of four exoplanetary systems with the Hobby-Eberly Telescope. Observations were taken in transit and out of transit, and we analyzed the differenced spectra-i.e., the transmission spectra-to inspect it for absorption at the wavelengths of the neutral sodium (Na I) doublet at {lambda}{lambda}5889, 5895 and neutral potassium (K I) at {lambda}7698. We used the transmission spectrum at Ca I {lambda}6122-which shows strong stellar absorption but is not an alkali metal resonance line that we expect to show significant absorption in these atmospheres-as a control line to examine our measurements for systematic errors. We use an empirical Monte Carlo method to quantify these systematic errors. In a reanalysis of the same data set using a reduction and analysis pipeline that was derived independently, we confirm the previously seen Na I absorption in HD 189733b at a level of (- 5.26 {+-} 1.69) Multiplication-Sign 10{sup -4} (the average value over a 12 A integration band to be consistent with previous authors). Additionally, we tentatively confirm the Na I absorption seen in HD 209458b (independently by multiple authors) at a level of (- 2.63 {+-} 0.81) Multiplication-Sign 10{sup -4}, though the interpretation is less clear. Furthermore, we find Na I absorption of (- 3.16 {+-} 2.06) Multiplication-Sign 10{sup -4} at <3{sigma} in HD 149026b; features apparent in the transmission spectrum are consistent with real absorption and indicate this may be a good target for future observations to confirm. No other results (Na I in HD 147506b and Ca I and K I in all four targets) are significant to {>=}3{sigma}, although we observe some features that we argue are primarily artifacts.

  11. Oscillator strength measurements of atomic absorption lines from stellar spectra

    NASA Astrophysics Data System (ADS)

    Lobel, Alex

    2011-05-01

    Herein we develop a new method to determine oscillator strength values of atomic absorption lines with state-of-the-art detailed spectral synthesis calculations of the optical spectrum of the Sun and of standard spectral reference stars. We update the log(gf) values of 911 neutral lines observed in the KPNO-FTS flux spectrum of the Sun and high-resolution echelle spectra (R = 80 000) of Procyon (F5 IV-V) and Eps Eri (K2 V) observed with large signal-to-noise (S/N) ratios of 2000 using the new Mercator-Hermes spectrograph at La Palma Observatory (Spain). We find for 483 Fe I, 85 Ni I, and 51 Si I absorption lines in the sample a systematic overestimation of the literature log(gf) values with central line depths below 15%. We employ a curve-of-growth analysis technique to test the accuracy of the new oscillator strength values and compare calculated equivalent line widths to the Moore, Minnaert, and Houtgast atlas of the Sun. The online SpectroWeb database at http://spectra.freeshell.org interactively displays the observed and synthetic spectra and provides the new log(gf) values together with important atomic line data. The graphical database is under development for stellar reference spectra of every spectral sub-class observed with large spectral resolution and S/N ratios.

  12. Time-dependent excitation and ionization modelling of absorption-line variability due to GRB 080310

    NASA Astrophysics Data System (ADS)

    Vreeswijk, P. M.; Ledoux, C.; Raassen, A. J. J.; Smette, A.; De Cia, A.; Woźniak, P. R.; Fox, A. J.; Vestrand, W. T.; Jakobsson, P.

    2013-01-01

    We model the time-variable absorption of Fe II, Fe III, Si II, C II and Cr II detected in Ultraviolet and Visual Echelle Spectrograph (UVES) spectra of gamma-ray burst (GRB) 080310, with the afterglow radiation exciting and ionizing the interstellar medium in the host galaxy at a redshift of z = 2.42743. To estimate the rest-frame afterglow brightness as a function of time, we use a combination of the optical VRI photometry obtained by the RAPTOR-T telescope array, which is presented in this paper, and Swift's X-Ray Telescope (XRT) observations. Excitation alone, which has been successfully applied for a handful of other GRBs, fails to describe the observed column density evolution in the case of GRB 080310. Inclusion of ionization is required to explain the column density decrease of all observed Fe II levels (including the ground state 6D9/2) and increase of the Fe III 7S3 level. The large population of ions in this latter level (up to 10% of all Fe III) can only be explained through ionization of Fe II, as a large fraction of the ionized Fe II ions (we calculate 31% using the Flexible Atomic and Cowan codes) initially populate the 7S3 level of Fe III rather than the ground state. This channel for producing a significant Fe III 7S3 level population may be relevant for other objects in which absorption lines from this level, the UV34 triplet, are observed, such as broad absorption line (BAL) quasars and η Carinae. This provides conclusive evidence for time-variable ionization in the circumburst medium, which to date has not been convincingly detected. However, the best-fit distance of the neutral absorbing cloud to the GRB is 200-400 pc, i.e. similar to GRB-absorber distance estimates for GRBs without any evidence for ionization. We find that the presence of time-varying ionization in GRB 080310 is likely due to a combination of the super-solar iron abundance ([Fe/H] = +0.2) and the low H I column density (log N(H i) = 18.7) in the host of GRB 080310. Finally

  13. Terminal Velocity Infall in QSO Absorption Line Halos

    NASA Astrophysics Data System (ADS)

    Benjamin, Robert A.

    We explore the hypothesis that clouds detected in quasar absorption line systems are falling at a terminal velocity toward the center of high redshift gaseous galactic halos. Since both the ionization level and terminal velocity of halo clouds increase with increasing distance from the central galaxy, velocity resolved profiles of highly ionized gas are predicted to have a greater width than low ionization gas. A line of sight passing through the center of gaseous halo (an idealized damped Ly alpha system), yields low ionization absorption at the velocity of the galaxy, flanked by high ionization on either side. Reasonable halo parameters yield total velocity extents for C IV of Delta v_{C IV}=100-200 km s^{-1}, in agreement with many systems observed by Lu et al (1997). The remaining systems may better described by the rotating disk model of Prochaska & Wolfe (1998). Finally, observational tests are suggested for verifying or falsifying the terminal velocity hypothesis for these systems.

  14. Mapping of the Local Interstellar Medium using Absorption Line Spectroscopy

    NASA Astrophysics Data System (ADS)

    Penprase, Bryan Edward

    2017-01-01

    Using the Yale SMARTS 1.5-meter telescope at CTIO and the CHIRON spectrograph, we have developed a program for mapping the local interstellar medium using a sample of over 200 newly observed B stars previously unobserved using Na I absorption lines. This sample includes stars that extend out to map beyond the local bubble to 500 pc. The sample has been observed using high resolution absorption lines, and when combined with previously observed stars with Na I and Ca II data provides a more complete picture of the local ISM than previous surveys. The distances to the stars using the new GAIA database also allows for more accurate determination of distances to features in the lcoal ISM, and new maps of the structure of the ISM hav been prepared with the data.

  15. AFGL atmospheric absorption line parameters compilation - 1980 version

    NASA Astrophysics Data System (ADS)

    Rothman, L. S.

    1981-03-01

    A new version of the AFGL atmospheric absorption line parameters compilation is now available. Major modifications since the last edition of 1978 include the strongest bands of water vapor, updated line positions for carbon dioxide, improved ozone parameters in the 5- and 10 micron regions, and updated and additional data for methane in the 3.5- and 7.7 micron regions. The atlas now contains over 159,000 rotational and vibration-rotation transitions from 0.3 to 17,880 per cm.

  16. Observational Cosmology Using Absorption Lines in Quasar Spectra

    NASA Astrophysics Data System (ADS)

    Aghaee, A.

    2016-09-01

    Distant, highly luminous quasars are important cosmological probes for a variety of astrophysical questions: the first generation of galaxies, the star formation history and metal enrichment in the early Universe, the growth of the first super massive black holes (SMBHs), the role of feedback from quasars and SMBHs in galaxy evolution, the epoch of reionization, etc. In addition, they are used as background illuminating source that reveal any object located by chance on the line of sight. I will present our group works in these issues that can be done using absorption lines in the quasar spectra.

  17. Pressure dependence of Se absorption lines in AlSb

    SciTech Connect

    Hsu, L. |; Haller, E.E.; Ramdas, A.K.

    1996-09-01

    Using far infrared absorption spectroscopy, the authors have investigated electronic transition spectra of Se donors in AlSb as a function of hydrostatic pressure. At least two distinct ground to bound excited state transition lines, which depend quadratically on the pressure, can be seen. At pressures between 30 and 50 kbar, evidence of an anti-crossing between one of the electronic transitions and a peak which they attribute to the 2 zone center LO phonon mode can be seen.

  18. The Physical Constraints on a New LoBAL QSO at z = 4.82

    NASA Astrophysics Data System (ADS)

    Yi, Weimin; Green, Richard; Bai, Jin-Ming; Wang, Tinggui; Grier, Catherine J.; Trump, Jonathan R.; Brandt, William N.; Zuo, Wenwen; Yang, Jinyi; Wang, Feige; Yang, Chenwei; Wu, Xue-Bing; Zhou, Hongyan; Fan, Xiaohui; Jiang, Linhua; Yang, Qian; Varricatt, Watson; Kerr, Tom; Milne, Peter; Benigni, Sam; Wang, Jian-Guo; Zhang, Jujia; Wang, Fang; Wang, Chuan-Jun; Xin, Yu-Xin; Fan, Yu-Feng; Chang, Liang; Zhang, Xiliang; Lun, Bao-Li

    2017-04-01

    Very few low-ionization broad absorption line (LoBAL) QSOs have been found at high redshifts, to date. One high-redshift LoBAL QSO, J0122+1216, was recently discovered by the Lijiang 2.4 m Telescope, with an initial redshift determination of 4.76. Aiming to investigate its physical properties, we carried out follow-up observations in the optical and near-IR spectroscopy. Near-IR spectra from UKIRT and P200 confirm that it is a LoBAL, with a new redshift determination of 4.82 ± 0.01 based on the Mg ii emission-line. The new Mg ii redshift determination reveals strong blueshifts and asymmetry of the high-ionization emission lines. We estimate a black hole mass of ∼2.3 × 109 M ⊙ and Eddington ratio of ∼1.0 according to the empirical Mg ii-based single-epoch relation and bolometric correction factor. It is possible that strong outflows are the result of an extreme quasar environment driven by the high Eddington ratio. A lower limit on the outflowing kinetic power (>0.9% L Edd) is derived from both emission and absorption lines, indicating that these outflows play a significant role in the feedback process that regulates the growth of its black hole, as well as host galaxy evolution.

  19. Multicomponent Analysis of the UV Si IV and C IV Broad Absorption Troughs in BALQSO Spectra: The Examples of J01225 + 1339 and J02287 + 0002

    NASA Astrophysics Data System (ADS)

    Stathopoulos, D.; Danezis, E.; Lyratzi, E.; Antoniou, A.; Tzimeas, D.

    2015-12-01

    Broad Absorption Line QSOs (BALQSOs) are a subtype of radio-quite QSOs that exhibit complex and unusually broad (FWHM ≥ 2,000 km/s) absorption lines. The existence of these lines in BALQSO spectra raises some questions with respect to the properties, the physical conditions and kinematics of the BAL material as well as the morphology of BAL troughs. In this study, taking into consideration the clumpy structure of the AGN outflow winds, we propose a physical model in order to explain the formation of BAL troughs and we give the mathematical description of this model. We also propose a method for analyzing spectroscopically the BAL profiles in the UV region of the electromagnetic spectrum. This method consists of the criteria we set during the fitting process of BAL troughs. The purpose of these criteria is to enable us to determine the exact number of components needed to simulate accurately the BAL troughs and guarantee the uniqueness of the fit. We give an application of the model and the method for Si IV and C IV resonance lines in the case of two BALQSOs. From the analysis, we conclude that the BAL material is in the form of clouds (density enhancements) that move radially and intercept the line-of-sight to the central continuum source. Using our method, we find the number of absorption components needed to simulate the BAL profiles, which means the number of clouds in the line-of-sight. We calculate the velocity shifts, the FWHM and the optical depths of the absorption components of BALs and we propose an internal structure for these clouds. Finally, we give some correlations between the properties of absorption components of Si IV and C IV.

  20. Interpreting the convergence of Lyman series absorption lines

    NASA Technical Reports Server (NTRS)

    Jenkins, Edward B.

    1990-01-01

    Spectra of quasars at high z often show absorption at the Lyman limit from intervening gas systems at intermediate z having N(H) approx. greater than 10(exp 7) cm(-2). In some circumstances, N(H) can be determined by measuring the strength of the Lyman limit absorption or the damping wings of Lyman - alpha. With a spectrum taken at low wavelength resolution, say, lambda/delta lambda approx. 10(exp 3), it is usually not possible to distinguish individual Lyman series lines near the limit, yet one can still discern how rapidly the average intensity drops off as the limit is approached from the long wavelength side. The purpose here is to point out the information which is available from measurements of this series convergence.

  1. Thomson Thick X-Ray Absorption in a Broad Absorption Line Quasar, PG 0946+301.

    PubMed

    Mathur; Green; Arav; Brotherton; Crenshaw; deKool; Elvis; Goodrich; Hamann; Hines; Kashyap; Korista; Peterson; Shields; Shlosman; van Breugel W; Voit

    2000-04-20

    We present a deep ASCA observation of a broad absorption line quasar (BALQSO) PG 0946+301. The source was clearly detected in one of the gas imaging spectrometers, but not in any other detector. If BALQSOs have intrinsic X-ray spectra similar to normal radio-quiet quasars, our observations imply that there is Thomson thick X-ray absorption (NH greater, similar1024 cm-2) toward PG 0946+301. This is the largest column density estimated so far toward a BALQSO. The absorber must be at least partially ionized and may be responsible for attenuation in the optical and UV. If the Thomson optical depth toward BALQSOs is close to 1, as inferred here, then spectroscopy in hard X-rays with large telescopes like XMM would be feasible.

  2. BAL PHOSPHORUS ABUNDANCE AND EVIDENCE FOR IMMENSE IONIC COLUMN DENSITIES IN QUASAR OUTFLOWS: VLT/X-SHOOTER OBSERVATIONS OF QUASAR SDSS J1512+1119

    SciTech Connect

    Borguet, Benoit C. J.; Edmonds, Doug; Arav, Nahum; Chamberlain, Carter; Benn, Chris

    2012-10-10

    We present spectroscopic analysis of the broad absorption line (BAL) outflow in quasar SDSS J1512+1119. In particular, we focus our attention on a kinematic component in which we identify P V and S IV/S IV* absorption troughs. The shape of the unblended phosphorus doublet troughs and the three S IV/S IV* troughs allow us to obtain reliable column density measurements for these two ions. Photoionization modeling using these column densities and those of He I* constrain the abundance of phosphorus to the range of 0.5-4 times the solar value. The total column density, ionization parameter, and metallicity inferred from the P V and S IV column densities lead to large optical depth values for the common transition observed in BAL outflows. We show that the true C IV optical depth is {approx}1000 times greater in the core of the absorption profile than the value deduced from its apparent optical depth.

  3. GEMINI 3D spectroscopy of BAL + IR + FeII QSOs - I. Decoupling the BAL, QSO, starburst, NLR, supergiant bubbles and galactic wind in Mrk 231

    NASA Astrophysics Data System (ADS)

    Lipari, S.; Sanchez, S. F.; Bergmann, M.; Terlevich, R.; Garcia-Lorenzo, B.; Punsly, B.; Mediavilla, E.; Taniguchi, Y.; Ajiki, M.; Zheng, W.; Acosta, J.; Jahnke, K.

    2009-02-01

    In this paper we present the first results of a study of BAL QSOs (at low and high redshift), based on very deep Gemini GMOS integral field spectroscopy. In particular, the results obtained for the nearest BAL IR-QSO Mrk 231 are presented. For the nuclear region of Mrk 231, the QSO and host galaxy components were modelled, using a new technique of decoupling 3D spectra. From this study, the following main results were found: (i) in the pure host galaxy spectrum an extreme nuclear starburst component was clearly observed, as a very strong increase in the flux, at the blue wavelengths; (ii) the BAL system I is observed in the spectrum of the host galaxy; (iii) in the clean/pure QSO emission spectrum, only broad lines were detected. 3D GMOS individual spectra (specially in the near-infrared CaII triplet) and maps confirm the presence of an extreme and young nuclear starburst (8 < age < 15 Myr), which was detected in a ring or toroid with a radius r = 0.3arcsec ~ 200 pc, around the core of the nucleus. The extreme continuum blue component was detected only to the south of the core of the nucleus. This area is coincident with the region where we previously suggested that the galactic wind is cleaning the nuclear dust. Very deep 3D spectra and maps clearly show that the BAL systems I and II - in the strong `absorption lines' NaIDλ5889-95 and CaII Kλ3933 - are extended (reaching ~1.4-1.6 arcsec ~ 1.2-1.3 kpc, from the nucleus) and clearly elongated at the position angle (PA) close to the radio jet PA, which suggest that the BAL systems I and II are `both' associated with the radio jet. The physical properties of the four expanding nuclear bubbles were analysed, using the GMOS 3D spectra and maps. In particular, we found strong multiple LINER/OF emission-line systems and Wolf-Rayet features in the main knots of the more external super bubble S1 (r = 3.0 kpc). The kinematics of these knots - and the internal bubbles - suggest that they are associated with an area of

  4. ORIGIN OF THE COMPLEX RADIO STRUCTURE IN BAL QSO 1045+352

    SciTech Connect

    Kunert-Bajraszewska, Magdalena; Gawronski, Marcin P.; Janiuk, Agnieszka; Siemiginowska, Aneta

    2010-08-01

    We present new, more sensitive, high-resolution radio observations of a compact broad absorption line (BAL) quasar, 1045+352, made with the EVN+MERLIN at 5 GHz. These observations allowed us to trace the connection between the arcsecond structure and the radio core of the quasar. The radio morphology of 1045+352 is dominated by a knotty jet showing several bends. We discuss possible scenarios that could explain such a complex morphology: galaxy merger, accretion disk instability, precession of the jet, and jet-cloud interactions. It is possible that we are witnessing an ongoing jet precession in this source due to internal instabilities within the jet flow; however, a dense environment detected in the submillimeter band and an outflowing material suggested by the X-ray absorption could strongly interact with the jet. It is difficult to establish the orientation between the jet axis and the observer in 1045+352 because of the complex structure. Nevertheless, taking into account the most recent inner radio structure, we conclude that the radio jet is oriented close to the line of sight, which can mean that the opening angle of the accretion disk wind can be large in this source. We also suggest that there is no direct correlation between the jet-observer orientation and the possibility of observing BALs.

  5. Origin of the Complex Radio Structure in BAL QSO 1045+352

    NASA Astrophysics Data System (ADS)

    Kunert-Bajraszewska, Magdalena; Janiuk, Agnieszka; Gawroński, Marcin P.; Siemiginowska, Aneta

    2010-08-01

    We present new, more sensitive, high-resolution radio observations of a compact broad absorption line (BAL) quasar, 1045+352, made with the EVN+MERLIN at 5 GHz. These observations allowed us to trace the connection between the arcsecond structure and the radio core of the quasar. The radio morphology of 1045+352 is dominated by a knotty jet showing several bends. We discuss possible scenarios that could explain such a complex morphology: galaxy merger, accretion disk instability, precession of the jet, and jet-cloud interactions. It is possible that we are witnessing an ongoing jet precession in this source due to internal instabilities within the jet flow; however, a dense environment detected in the submillimeter band and an outflowing material suggested by the X-ray absorption could strongly interact with the jet. It is difficult to establish the orientation between the jet axis and the observer in 1045+352 because of the complex structure. Nevertheless, taking into account the most recent inner radio structure, we conclude that the radio jet is oriented close to the line of sight, which can mean that the opening angle of the accretion disk wind can be large in this source. We also suggest that there is no direct correlation between the jet-observer orientation and the possibility of observing BALs.

  6. Variability of QSOs with variable regions in broad absorption troughs from the Sloan Digital Sky Survey

    NASA Astrophysics Data System (ADS)

    He, Zhi-Cheng; Bian, Wei-Hao; Ge, Xue; Jiang, Xiao-Lei

    2015-12-01

    The variability of broad absorption lines (BALs) is investigated for a sample of 188 BAL quasars (QSOs) (z > 1.7) with at least two epoch observations from the Sloan Digital Sky Survey Data Release 7, covering a time-scale of about 0.001-3 yr in the rest frame. Considering only the longest time-scale between epochs for each QSO, 73 variable regions in the C IV BAL troughs are detected for 43 BAL QSOs. The proportion of BAL QSOs showing variable regions increases with longer time-interval than about 1 yr in the rest frame. The velocity width of variable regions is narrow compared to the BAL-trough outflow velocity. For 43 BAL QSOs with variable regions, it is found that there is a medium strong correlation between the variation of the continuum luminosity at 1500 Å and the variation of the spectral index. With respect to the total 188 QSOs, a larger proportion of BAL QSOs with variable regions appears bluer during their brighter phases, which implies that the origin of BAL variable regions is related to the central accretion process. For 43 BAL QSOs with variable regions, it is possible that there is a negative medium strong correlation between the absolute variation of the equivalent width and the Mg II-based black hole mass, and a medium strong correlation between the maximum outflow velocity of variable regions and the Eddington ratio. These results imply a connection between the BAL-trough variation and the central accretion process.

  7. The Physical Nature of Polar Broad Absorption Line Quasars

    NASA Technical Reports Server (NTRS)

    Ghost, Kajal; Punsly, Brian

    2007-01-01

    It has been shown based on radio variability arguments that some BALQSOs (broad absorption line quasars) are viewed along the polar axis (o rthogonal to accretion disk) in the recent article of Zhou et a. Thes e arguments are based on the brightness temperature, T(sub b) exceedi ng 10(exp 12) K which leads to the well-known inverse Compton catastr ophe unless the radio jet is relativistic and is viewed along its axi s. In this letter, we expand the Zhou et al sample of polar BALQSOs u sing their techniques applied to SDSS DR5. In the process, we clarify a mistake in their calculation of brightness temperature. The expanded sample of high T(sub b) BALQSOS, has an inordinately large fraction of LoBALQSOs (low ionization BALQSOs). We consider this an important clue to understanding the nature of the polar BALQSOs. This is expec ted in the polar BALQSO analytical/numerical models of Punsly that pr edicted that LoBALQSOs occur when the line of sight is very close to the polar axis, where the outflow density is the highest.

  8. Anomalous absorption line in the magneto-optical response of graphene.

    PubMed

    Gusynin, V P; Sharapov, S G; Carbotte, J P

    2007-04-13

    The intensity as well as position in energy of the absorption lines in the infrared conductivity of graphene, both exhibit features that are directly related to the Dirac nature of its quasiparticles. We show that the evolution of the pattern of absorption lines as the chemical potential is varied encodes the information about the presence of the anomalous lowest Landau level. The first absorption line related to this level always appears with full intensity or is entirely missing, while all other lines disappear in two steps. We demonstrate that if a gap develops, the main absorption line splits into two provided that the chemical potential is greater than or equal to the gap.

  9. DISCOVERY OF THE TRANSITION OF A MINI-BROAD ABSORPTION LINE INTO A BROAD ABSORPTION LINE IN THE SDSS QUASAR J115122.14+020426.3

    SciTech Connect

    Hidalgo, Paola Rodriguez; Eracleous, Michael; Charlton, Jane; Hamann, Fred; Murphy, Michael T.; Nestor, Daniel

    2013-09-20

    We present the detection of a rare case of dramatic strengthening in the UV absorption profiles in the spectrum of the quasar J115122.14+020426.3 between observations {approx}2.86 yr apart in the quasar rest frame. A spectrum obtained in 2001 by the Sloan Digital Sky Survey shows a C IV ''mini-broad'' absorption line (FWHM = 1220 km s{sup -1}) with a maximum blueshift velocity of {approx}9520 km s{sup -1}, while a later spectrum from the Very Large Telescope shows a significantly broader and stronger absorption line, with a maximum blueshift velocity of {approx}12, 240 km s{sup -1} that qualifies as a broad absorption line. A similar variability pattern is observed in two additional systems at lower blueshifted velocities and in the Ly{alpha} and N V transitions as well. One of the absorption systems appears to be resolved and shows evidence for partial covering of the quasar continuum source (C{sub f} {approx} 0.65), indicating a transverse absorber size of, at least, {approx}6 Multiplication-Sign 10{sup 16} cm. In contrast, a cluster of narrower C IV lines appears to originate in gas that fully covers the continuum and broad emission line sources. There is no evidence for changes in the centroid velocity of the absorption troughs. This case suggests that at least some of the absorbers that produce ''mini-broad'' and broad absorption lines in quasar spectra do not belong to intrinsically separate classes. Here, the ''mini-broad'' absorption line is most likely interpreted as an intermediate phase before the appearance of a broad absorption line due to their similar velocities. While the current observations do not provide enough constraints to discern among the possible causes for this variability, future monitoring of multiple transitions at high resolution will help achieve this goal.

  10. A Kennicutt-Schmidt Law for Intervening Absorption Line Systems

    NASA Astrophysics Data System (ADS)

    Chelouche, Doron; Bowen, David V.

    2010-10-01

    We argue that most strong intervening metal absorption line systems, where the rest equivalent width of the Mg II λ2796 line is >0.5 Å, are interstellar material in, and outflowing from, star-forming disks. We show that a version of the Kennicutt-Schmidt law is readily obtained if the Mg II equivalent widths are interpreted as kinematic broadening from absorbing gas in outflowing winds originating from star-forming galaxies. Taking a phenomenological approach and using a set of observational constraints available for star-forming galaxies, we are able to account for the density distribution of strong Mg II absorbers over cosmic time. The association of intervening material with star-forming disks naturally explains the metallicity and dust content of strong Mg II systems, as well as their high H I column densities, and does not require the advection of metals from compact star-forming regions into the galaxy halos to account for the observations. We find that galaxies with a broad range of luminosities can give rise to absorption of a given rest equivalent width and discuss possible observational strategies to better quantify true galaxy-absorber associations and further test our model. We show that the redshift evolution in the density of absorbers closely tracks the star formation history of the universe and that strong intervening systems can be used to directly probe the physics of both bright and faint galaxies over a broad redshift range. In particular, in its simplest form, our model suggests that many of the statistical properties of star-forming galaxies and their associated outflows have not evolved significantly since z ~ 2. By identifying strong intervening systems with galaxy disks and quantifying a version of the Kennicutt-Schmidt law that applies to them, a new probe of the interstellar medium is found which provides complementary information to that obtained through emission studies of galaxies. Implications of our results for galaxy feedback and

  11. Discovery of Hα Absorption in the Unusual Broad Absorption Line Quasar SDSS J083942.11+380526.3

    NASA Astrophysics Data System (ADS)

    Aoki, Kentaro; Iwata, Ikuru; Ohta, Kouji; Ando, Masataka; Akiyama, Masayuki; Tamura, Naoyuki

    2006-11-01

    We discovered Hα absorption in the broad Hα emission line of an unusual broad absorption line quasar, SDSS J083942.11+380526.3, at z=2.318, through near-infrared spectroscopy with the Cooled Infrared Spectrograph and Camera for OHS (CISCO) on the Subaru telescope. The presence of nonstellar Hα absorption is known only in the Seyfert galaxy NGC 4151 to date; thus, our discovery is the first case for quasars. The Hα absorption line is blueshifted by 520 km s-1 relative to the Hα emission line, and its redshift almost coincides with those of UV low-ionization metal absorption lines. The width of the Hα absorption (~340 km s-1) is similar to those of the UV low-ionization absorption lines. These facts suggest that the Hα and low-ionization metal absorption lines are produced by the same low-ionization gas, which has a substantial amount of neutral gas. The column density of the neutral hydrogen is estimated to be ~1018 cm-2 by assuming a gas temperature of 10,000 K from the analysis of the curve of growth. The continuum spectrum is reproduced by a reddened [E(B-V)~0.15 mag for the SMC-like reddening law] composite quasar spectrum. Furthermore, the UV spectrum of SDSS J083942.11+380526.3 shows a remarkable similarity to that of NGC 4151 in its low state, suggesting that the physical condition of the absorber in SDSS J083942.11+380526.3 is similar to that of NGC 4151 in the low state. As proposed for NGC 4151, SDSS J083942.11+380526.3 may also be seen through the edge of the obscuring torus. Based in part on data collected at Subaru Telescope, which is operated by the National Astronomical Observatory of Japan.

  12. Interstellar absorption lines in the spectrum of Gamma Velorum

    NASA Technical Reports Server (NTRS)

    Morton, D. C.; Bhavsar, S. P.

    1979-01-01

    Copernicus scans of selected interstellar absorption lines in the UV spectrum of Gamma Vel are analyzed, together with ground-based data, to obtain column densities for various ion states of C, N, O, Na, Mg, Al, Si, P, S, Cl, Ar, Ca, Mn, Fe, and CO. N I and O I are fitted to a single empirical curve of growth with a velocity parameter (b) of 8 km/s; Mg II, Si II, P II, S II, Mn II, and Fe II are fitted to another curve with b between 3 and 9 km/s. Abundance determinations relative to H I show that: (1) C, N, P, S, and Ar are probably close to their solar values; (2) O may be depleted by about a factor of 2; (3) Mg, Al, Si, Cl, Mn, and Fe are depleted by a factor of 4 or more: (4) Al is depleted by at least a factor of 10 in the H II region; and (5) both N V and O VI are present, but not C IV. The N V/O VI ratio implies that the electron temperature in the H II region is about 275,000 K.

  13. Probing Quasar Winds Using Intrinsic Narrow Absorption Lines

    NASA Astrophysics Data System (ADS)

    Culliton, Christopher S.; Charlton, Jane C.; Eracleous, Michael; Roberts, Amber; Ganguly, Rajib; Misawa, Toru; Muzahid, Sowgat

    2017-01-01

    Quasar outflows are important for understanding the accretion and growth processes of the central black hole. Furthermore, outflows potentially have a role in providing feedback to the galaxy, and halting star formation and infall of gas. The geometry and density of these outflows remain unknown, especially as a function of ionization and velocity. Having searched ultraviolet spectra at both high redshift (VLT/UVES; 1.4absorption lines (NALs) that are intrinsic to (physically associated with) the quasar. We identify intrinsic NALs with a wide range of properties, including ejection velocity, coverage fraction, and ionization level. We also consider the incidence of intrinsic absorbers as a function of quasar properties (optical, radio and X-ray fluxes), and find that radio properties and quasar orientation are influential in determining if a quasar is likely to host an intrinsic system. We find that there is a continuum of properties within the intrinsic NAL sample, rather than discrete families, ranging from partially covered CIV systems with black Lya and with a separate low ionization gas phase to partially covered NV systems with partially covered Lya and without detected low ionization gas. Additionally, we construct a model describing the spatial distributions, geometries, and varied ionization structures of intrinsic NALs.

  14. Studying the complex absorption profiles of Si IV in 21 HiBALQSO spectra

    NASA Astrophysics Data System (ADS)

    Stathopoulos, D.; Danezis, E.; Lyratzi, E.; Antoniou, A.; Popović, L. Č.; Tzimeas, D.; Dimitrijević, M. S.

    2014-12-01

    We investigate the physical conditions and kinematics of broad absorption line region clouds of Si IV in 21 HiBAL Quasars. We use the Danezis et al. method [1], [2], [3] in order to fit and analyze the broad absorption troughs of Si IV resonance lines in the UV region of the electromagnetic spectrum. We find that the BAL flow is not smooth but instead plasma clouds are formed in it. BAL troughs present multicomponent structure which indicates the existence of more than one absorbing cloud in the line of sight, where every absorbing cloud produces a Si IV doublet. We show that the blending of these doublets produces the apparent broad absorption troughs we observe. One of our main achievements is that we managed to decompose and deblend each complex absorption trough to the individual doublets that it consists of. Apart from that, we succeeded in deblending the resonance lines of every doublet. By achieving accurate fits to the BAL troughs we calculated some physical and kinematical parameters that describe the plasma clouds in the line of sight. These parameters are: the radial outflow velocities of the clouds, the random velocities of ions inside each plasma cloud, the apparent optical depth in the center of every absorption component, the FWHM and the equivalent width. As a final step we correlate these physical parameters in order to draw useful conclusions.

  15. BAL OUTFLOW CONTRIBUTION TO AGN FEEDBACK: FREQUENCY OF S IV OUTFLOWS IN THE SDSS

    SciTech Connect

    Dunn, Jay P.; Arav, Nahum; Laughlin, Courtney; Edmonds, Doug; Aoki, Kentaro; Wilkins, Ashlee; Bautista, Manuel E-mail: arav@vt.edu E-mail: kentaro.aoki@hawaiiantel.net E-mail: manuel.bautista@wmich.edu

    2012-05-10

    We present a study of broad absorption line (BAL) quasar outflows that show S IV {lambda}1063 and S IV* {lambda}1073 troughs. The fractional abundances of S IV and C IV peak at similar value of the ionization parameter, implying that they arise from the same physical component of the outflow. Detection of the S IV* troughs will allow us to determine the distance to this gas with higher resolution and higher signal-to-noise spectra, therefore providing the distance and energetics of the ubiquitous C IV BAL outflows. In our bright sample of 156 SDSS quasars, 14% show C IV and 1.9% S IV troughs, which are consistent with a fainter magnitude sample with twice as many objects. One object in the fainter sample shows evidence of a broad S IV trough without any significant trough present from the excited state line, which implies that this outflow could be at a distance of several kpc. Given the fractions of C IV and S IV, we establish firm limits on the global covering factor on S IV that ranges from 2.8% to 21% (allowing for the k-correction). Comparison of the expected optical depth for these ions with their detected percentage suggests that these species arise from common outflows with a covering factor closer to the latter.

  16. Nustar Reveals an Intrinsically X-ray Weak Broad Absorption Line Quasar in the Ultraluminous Infrared Galaxy Markarian 231

    NASA Technical Reports Server (NTRS)

    Teng, Stacy H.; Brandt. W. N.; Harrison, F. A.; Luo, B.; Alexander, D. M.; Bauer, F. E.; Boggs, S. E.; Christensen, F. E.; Comastri, A.; Craig, W. W.; Fabian, A. C.; Farrah, D.; Fiore, F.; Gandhi, P.; Grefenstette, B. W.; Hailey, C. J.; Hickox, R. C.; Madsen, K. K.; Ptak, A. F.; Rigby, Jane Rebecca; Risaliti, G.; Saz, C.; Stern, D.; Veilleux, S.; Walton, D. J.; Wik, D. R.; Zhang, W. W.

    2014-01-01

    We present high-energy (3-30 keV) NuSTAR observations of the nearest quasar, the ultraluminous infrared galaxy (ULIRG) Markarian 231 (Mrk 231), supplemented with new and simultaneous low-energy (0.5-8 keV) data from Chandra. The source was detected, though at much fainter levels than previously reported, likely due to contamination in the large apertures of previous non-focusing hard X-ray telescopes. The full band (0.5-30 keV) X-ray spectrum suggests the active galactic nucleus (AGN) in Mrk 231 is absorbed by a patchy and Compton-thin N(sub H) approx. 1.2(sup +0.3) sub-0.3) x 10(exp 23) / sq cm) column. The intrinsic X-ray luminosity L(sub 0.5-30 Kev) approx. 1.0 x 10(exp 43) erg /s) is extremely weak relative to the bolometric luminosity where the 2-10 keV to bolometric luminosity ratio is approx. 0.03% compared to the typical values of 2-15%. Additionally, Mrk 231 has a low X-ray-to-optical power law slope alpha(sub 0X) approx. -1.7. It is a local example of a low-ionization broad absorption line (LoBAL) quasar that is intrinsically X-ray weak. The weak ionizing continuum may explain the lack of mid-infrared [O IV], [Ne V], and [Ne VI] fine-structure emission lines which are present in sources with otherwise similar AGN properties. We argue that the intrinsic X-ray weakness may be a result of the super-Eddington accretion occurring in the nucleus of this ULIRG, and may also be naturally related to the powerful wind event seen in Mrk 231, a merger remnant escaping from its dusty cocoon.

  17. What Drives the Outflows in Broad Absorption Line QSOs?

    NASA Technical Reports Server (NTRS)

    Begelman, Mitchell C.

    1997-01-01

    We have made progress in the areas related to the propulsion and confinement of gas responsible for broad absorption troughts in QSOs: Radiative Acceleration in BALQSOs; The "Ghost" of Lyman (alpha); and Magnetic Confinement of Absorbing Gas.

  18. The Hubble Space Telescope Quasar Absorption Line Key Project: The Unusual Absorption-Line System in the Spectrum of PG 2302+029---Ejected or Intervening?

    NASA Astrophysics Data System (ADS)

    Jannuzi, B. T.; Hartig, G. F.; Kirhakos, S.; Sargent, W. L. W.; Turnshek, D. A.; Weymann, R. J.; Bahcall, J. N.; Bergeron, J.; Boksenberg, A.; Savage, B. D.; Schneider, D. P.; Wolfe, A. M.

    1996-10-01

    We report the discovery of a high-ionization broad absorption line system at a redshift of zabs = 0.695 in the spectrum of the zem = 1.052 radio-quiet quasar PG 2302+029. Broad absorption with FWHM from 3000 to 5000 km s-1 is detected from C IV, N V, and O VI in Hubble Space Telescope (HST) Faint Object Spectrograph spectra of the quasar. A narrow-line system (FWHM ~ 250 km s-1) at zabs = 0.7016 is resolved from the broad blend and includes absorption by Ly alpha and the C IV, N V, and O VI doublets. No absorption by low-ionization metal species (e.g., Si II and Mg II) is detected in the HST or ground-based spectra for either the broad or the narrow system. The centroids of the broad system lines are displaced by ~56,000 km s-1 to the blue of the quasar's broad emission lines. The reddest extent of the broad-line absorption is more than 50,000 km s-1 from the quasar. The properties of this system are unprecedented, whether it is an intervening or an ejected system.

  19. The Hubble Space Telescope Quasar Absorption Line Key Project: The Unusual Absorption-Line System in the Spectrum of PG 2302+029--Ejected or Intervening?

    NASA Technical Reports Server (NTRS)

    Jannuzi, B. T.; Hartig, G. F.; Kirhakos, S.; Sargent, W. L. W.; Turnshek, D. A.; Weymann, R. J.; Bahcall, J. N.; Bergeron, J.; Boksenberg, A.; Savage, B. D.; Schneider, D. P.; Wolfe, A. M.

    1996-01-01

    We report the discovery of a high-ionization broad absorption line system at a redshift of z(sub abs) = 0.695 in the spectrum of the z(sub em) = 1.052 radio-quiet quasar PG 2302+029. Broad absorption with FWHM from 3000 to 5000 km/s is detected from C iv, N v, and O vi in Hubble Space Telescope (HST) Faint Object Spectrograph spectra of the quasar. A narrow-line system (FWHM approx. 250 km/s) at z(sub abs) = 0.7016 is resolved from the broad blend and includes absorption by Ly alpha and the C iv, N v, and O vi doublets. No absorption by low-ionization metal species (e.g., Si II and Mg II) is detected in the HST or ground-based spectra for either the broad or the narrow system. The centroids of the broad system lines are displaced by approx. 56,000 km/s to the blue of the quasar's broad emission lines. The reddest extent of the broad-line absorption is more than 50,000 km/s from the quasar. The properties of this system are unprecedented, whether it is an intervening or an ejected system.

  20. [A line-by-line trace gas absorption model and its application in NDIR gas detection technology].

    PubMed

    Fang, Jing; Liu, Wen-qing; Zhang, Tian-shu

    2008-06-01

    An accurate line-by-line integral trace gas absorption model is presented in the present article. It is for mid-infrared band and can be used in the study on and application to detecting trace gas (or pollution gas). First of all, two algorithms of trace gas radioactive properties, line-by-line integral method and band model method, were introduced. The merits and demerits of each were compared. Several recent developed line-by-line integral calculation models were also introduced. Secondly, the basic principle of line-by-line integral trace gas absorption calculation model was described in detail. The absorption coefficient is a function of temperature, frequency (wave number), pressure, gas volume mixing ratio and constants associated with all contributing line transitions. The average monochromatic absorption coefficient at a given frequency of a given gas species can be written as the product of the number density of the molecular species to which the spectral line belongs, the line intensity and a line shape factor. Efficient calculation of the line shape factor may be required for different atmospheric conditions. In the lower atmosphere, the shape of spectral lines is dominated by pressure broadening and can be represented most simply by the Lorentz line shape factor. At high altitudes, the shape of spectral lines is governed by Doppler broadening At intermediate altitudes, they can be modeled using the Voigt line shape factor, a convolution of the Lorentz and Doppler line shape factors. Finally, in the section of experiment, the results calculated by model were compared with that measured by Fourier transform infrared spectrometer. As an instance, the model was applied to the detectors design of NDIR (non-dispersive infrared) technology and the relationship between signal intensity of detectors and concentration of CO2/CO was simulated by model. Available concentration range of detector was given by calculating the results of the model. It is based on

  1. Effect of a progressive sound wave on the profiles of spectral lines. 2: Asymmetry of faint Fraunhofer lines. [absorption spectra

    NASA Technical Reports Server (NTRS)

    Kostyk, R. I.

    1974-01-01

    The absorption coefficient profile was calculated for lines of different chemical elements in a medium with progressive sound waves. Calculations show that (1) the degree and direction of asymmetry depend on the atomic ionization potential and the potential of lower level excitation of the individual line; (2) the degree of asymmetry of a line decreases from the center toward the limb of the solar disc; and (3) turbulent motions 'suppress' the asymmetry.

  2. Study of Water Absorption Lines in the Near Infrared

    DTIC Science & Technology

    1975-02-17

    the absorption coefficient is better approximated by the sum of Matcha -N«. oec short range contribution and W-BB dispersion contribution. The...and W. Byers Brown, Molecular Physics 2S, 1105 (1973). 5. R. L. Matcha and R. K. Nesbet, Phys. Rev. 1_6_0, 72 (1967). I H. B. Levine, Phys. Rev...reasurcrents of Ouren, ^eltqen Gaide, Helbing and Pauly. The dipole moment function is taken from ab initio 9 calculations of Matcha and Nesbet. With

  3. Investigation of Impact Load Absorption through Suspension Line Elongation

    DTIC Science & Technology

    1952-12-01

    16 1. Charts . . ’ . . . .. . . 16 2. glong~tion Ratin of Li; Goups . . . 163. Graphs . .. .. .. .. .. .. .. ... . 16 SECTION IV - DISCUSSION OF...Tester . ...................... z14 Figure 16 . Frazier Air Porosity Tester in Use ....... 215 Figure 17. 30 ft., Extended Skirt CsnoW’ in Deployment Bag...line than on canopies strung with high elongation line. WMADR 5&~5T 1 CONCLUSIONS; 15. Nylon is superior to fortisan in shock absorbing capacity. 16

  4. Effects of velocity averaging on the shapes of absorption lines

    NASA Technical Reports Server (NTRS)

    Pickett, H. M.

    1980-01-01

    The velocity averaging of collision cross sections produces non-Lorentz line shapes, even at densities where Doppler broadening is not apparent. The magnitude of the effects will be described using a model in which the collision broadening depends on a simple velocity power law. The effect of the modified profile on experimental measures of linewidth, shift and amplitude will be examined and an improved approximate line shape will be derived.

  5. Probing low-redshift galaxies using quasar absorption lines with an emphasis on Ca II absorption

    NASA Astrophysics Data System (ADS)

    Sardane, Gendith M.

    2016-05-01

    We searched for intervening CaII absorption in nearly 95,000 quasar spectra with i≤20 from the Sloan Digital Sky Survey(SDSS) data releases DR7+DR9. Our identification of >400 CaII systems is the largest compilation of CaII absorbers in a blind search. (Abstract shortened by ProQuest.).

  6. On-Line Wavelength Calibration of Pulsed Laser for CO2 Differential Absorption LIDAR

    NASA Astrophysics Data System (ADS)

    Xiang, Chengzhi; Ma, Xin; Han, Ge; Liang, Ailin; Gong, Wei

    2016-06-01

    Differential absorption lidar (DIAL) remote sensing is a promising technology for atmospheric CO2 detection. However, stringent wavelength accuracy and stability are required in DIAL system. Accurate on-line wavelength calibration is a crucial procedure for retrieving atmospheric CO2 concentration using the DIAL, particularly when pulsed lasers are adopted in the system. Large fluctuations in the intensities of a pulsed laser pose a great challenge for accurate on-line wavelength calibration. In this paper, a wavelength calibration strategy based on multi-wavelength scanning (MWS) was proposed for accurate on-line wavelength calibration of a pulsed laser for CO2 detection. The MWS conducted segmented sampling across the CO2 absorption line with appropriate number of points and range of widths by using a tunable laser. Complete absorption line of CO2 can be obtained through a curve fitting. Then, the on-line wavelength can be easily found at the peak of the absorption line. Furthermore, another algorithm called the energy matching was introduced in the MWS to eliminate the backlash error of tunable lasers during the process of on-line wavelength calibration. Finally, a series of tests was conducted to elevate the calibration precision of MWS. Analysis of tests demonstrated that the MWS proposed in this paper could calibrate the on-line wavelength of pulsed laser accurately and steadily.

  7. Quasar emission lines as probes of orientation: implications for disc wind geometries and unification

    NASA Astrophysics Data System (ADS)

    Matthews, J. H.; Knigge, C.; Long, K. S.

    2017-01-01

    The incidence of broad absorption lines (BALs) in quasar samples is often interpreted in the context of a geometric unification model consisting of an accretion disc and an associated outflow. We use the the Sloan Digital Sky Survey (SDSS) quasar sample to test this model by examining the equivalent widths (EWs) of C IV 1550 Å, Mg II 2800 Å, [O III] 5007 Å and C III] 1909 Å. We find that the emission line EW distributions in BAL and non-BAL quasars are remarkably similar - a property that is inconsistent with scenarios in which a BAL outflow rises equatorially from a geometrically thin, optically thick accretion disc. We construct simple models to predict the distributions from various geometries; these models confirm the above finding and disfavour equatorial geometries. We show that obscuration, line anisotropy and general relativistic effects on the disc continuum are unlikely to hide an EW inclination dependence. We carefully examine the radio and polarisation properties of BAL quasars. Both suggest that they are most likely viewed (on average) from intermediate inclinations, between type 1 and type 2 AGN. We also find that the low-ionization BAL quasars in our sample are not confined to one region of `Eigenvector I' parameter space. Overall, our work leads to one of the following conclusions, or some combination thereof: (i) the continuum does not emit like a geometrically thin, optically thick disc; (ii) BAL quasars are viewed from similar angles to non-BAL quasars, i.e. low inclinations; (iii) geometric unification does not explain the fraction of BALs in quasar samples.

  8. Ultraviolet absorption lines associated with the Vela supernova remnant

    NASA Technical Reports Server (NTRS)

    Jenkins, E. B.; Wallerstein, G.; Silk, J.

    1976-01-01

    Two stars behind the Vela supernova remnant and two stars offset from the remnant have been observed with the UV spectrometer aboard the Copernicus satellite. Over 200 interstellar atomic and molecular absorption features between 1000 and 1400 A have been identified and measured for radial velocity and equivalent width. In many cases, additional information was obtained by studying the detailed shapes of the recorded profiles. Most of the stars show several absorption components, with clouds of the highest radial velocity appearing in the spectra of stars behind the remnant. For each component, column densities were derived using velocity dispersion parameters which yielded the most self-consistent results. Qualitatively, the gas toward the remnant exhibits a number of unusual properties, when compared with normal interstellar material. First, abnormally high radial velocities were evident. Second, the degree of ionization of some elements suggested the existence of ionizing processes significantly more potent than those found in general regions of space. Finally, an investigation of electron densities shows that much of the gas, especially that at high velocity, must exist in the form of relatively thin sheets or filaments. If cosmic abundances prevail, the column densities of high-velocity excited material suggest that H-alpha emission measures could be as large as 100 sq cm/cu pc.

  9. Detectability of cold streams into high-redshift galaxies by absorption lines

    NASA Astrophysics Data System (ADS)

    Goerdt, Tobias; Dekel, Avishai; Sternberg, Amiel; Gnat, Orly; Ceverino, Daniel

    2012-08-01

    Cold gas streaming along the dark matter filaments of the cosmic web is predicted to be the major source of fuel for disc buildup, violent disc instability and star formation in massive galaxies at high redshift. We investigate to what extent such cold gas is detectable in the extended circumgalactic environment of galaxies via Lyα absorption and selected low-ionization metal absorption lines. We model the expected absorption signatures using high-resolution zoom-in adaptive mesh refinement cosmological simulations. In the post-processing, we distinguish between self-shielded gas and unshielded gas. In the self-shielded gas, which is optically thick to Lyman continuum radiation, we assume pure collisional ionization for species with an ionization potential greater than 13.6 eV. In the optically-thin, unshielded gas, these species are also photoionized by the metagalactic radiation. In addition to absorption of radiation from background quasars, we compute the absorption line profiles of radiation emitted by the galaxy at the centre of the same halo. We predict the strength of the absorption signal for individual galaxies without stacking. We find that the Lyα absorption profiles produced by the streams are consistent with observations of absorption and emission Lyα profiles in high-redshift galaxies. Due to the low metallicities in the streams, and their low covering factors, the metal absorption features are weak and difficult to detect.

  10. Synthetic absorption lines for a clumpy medium: a spectral signature for cloud acceleration in AGN?

    NASA Astrophysics Data System (ADS)

    Waters, Tim; Proga, Daniel; Dannen, Randall; Kallman, Timothy R.

    2017-01-01

    There is increasing evidence that the highly ionised multiphase components of AGN disc winds may be due to thermal instability. The ions responsible for forming the observed X-ray absorption lines may only exist in relatively cool clumps that can be identified with the so-called `warm absorbers'. Here we calculate synthetic absorption lines for such warm absorbers from first principles by combining 2D hydrodynamic solutions of a two-phase medium with a dense grid of photoionization models to determine the detailed ionization structure of the gas. Our calculations reveal that cloud disruption, which leads to a highly complicated velocity field (i.e. a clumpy flow), will only mildly affect line shapes and strengths when the warm gas becomes highly mixed but not depleted. Prior to complete disruption, clouds which are optically thin to the driving UV resonance lines will cause absorption at an increasingly blueshifted line of sight velocity as they are accelerated. This behavior will imprint an identifiable signature on the line profile if warm absorbers are enshrouded in an even broader absorption line produced by a high column of intercloud gas. Interestingly, we show that it is possible to develop a spectral diagnostic for cloud acceleration by differencing the absorption components of a doublet line, a result which can be qualitatively understood using a simple partial covering model. Our calculations also permit us to comment on the spectral differences between cloud disruption and ionization changes driven by flux variability. Notably, cloud disruption offers another possibility for explaining absorption line variability.

  11. Improved And Quality Assessed Emission And Absorption Line Measurements In Sloan Digital Sky Survey Galaxies

    NASA Astrophysics Data System (ADS)

    Oh, Kyuseok; Sarzi, M.; Schawinski, K.; Yi, S. K.

    2011-01-01

    We have established a new database of absorption and emission line measurements from the Sloan Digital Sky Survey 7th data release for the galaxies within a redshift of 0.2. This work used publicly available codes, pPXF(penalized pixel-fitting) and GANDALF(gas and absorption line fitting), to achieve robust spectral fits and reliable measurements. The absorption line strengths measured by SDSS pipeline are seriously contaminated by emission fill-in. We effectively separate emission lines from absorption lines. For instance, this work successfully extract [NI] doublet from Mgb and it leads to more realistic result of alpha enhancement on late-type galaxies compared to the previous database. Besides accurately measuring line strengths, the database will be provided with new parameters that are indicative of line strength measurement quality. Users can build a subset of database optimal for their studies using specific cuts in the fitting quality parameters as well as empirical signal-to-noise. Applying these parameters, we found galaxies with dramatically broad line regions among the galaxies with poor fitting quality parameters. We applied a new continuum finding prescriptions to newly identified BLRs and they turned out to be Seyfert I nuclei.

  12. Line shape of 57Co sources exhibiting self absorption

    NASA Astrophysics Data System (ADS)

    Spiering, H.; Ksenofontov, V.; Leupold, O.; Kusz, J.; Deák, L.; Németh, Z.; Bogdán, C.; Bottyán, L.; Nagy, D. L.

    2016-12-01

    The effect of selfabsorption in Mössbauer sources is studied in detail. Spectra were measured using an old 57 C o/ R h source of 74 M B q activity with an original activity of ca. 3.7 G B q and a 0.15 G B q 57 C o/ α - F e source magnetized by an in-plane magnetic field of 0.2 T. The 57 C o/ α - F e source of a thickness of 25 μ was used both from the active and the inactive side giving cause to very different selfabsorption effects. The absorber was a single crystal of ferrous ammonium sulphate hexahydrate (FAS). Its absorption properties were taken over from a detailed study (Bull et al., Hyperfine Interact. 94(1-3), 1; Spiering et al. 2). FAS (space group P21/c) crystallizes as flat plates containing the (overline {2}01) plane. The γ-direction was orthogonal to the crystal plate. The 57 C o atoms of the 57 C o/ R h source were assumed to be homogeneously distributed over a 6 μ thick Rh foil and to follow a one dimensional diffusion profile in the 25 μ Fe-foil. The diffusion length was fitted to 10 μ. The theory follows the Blume-Kistner equations for forward scattering (Blume and Kistner, Phys. Rev. 171, 417, 3) by integrating over the source sampled up to 128 layers.

  13. A method for measuring magnetic fields in sunspots using Zeeman-broadened absorption lines

    NASA Astrophysics Data System (ADS)

    Oostra, Benjamin

    2017-04-01

    We present measurements of magnetic fields in several sunspots using high-resolution spectra obtained with the ESPARTACO spectrograph at the Universidad de los Andes, with the aim to explore experimental possibilities for students. Because the Zeeman line splitting is smaller than the line width, our work only observes broadened absorption lines. This broadening, however, can be measured and suitably modeled, giving realistic quantitative results.

  14. The Unusual Absorption Line System of PG 2302+029 -- Ejected or Intervening?

    NASA Astrophysics Data System (ADS)

    Jannuzi, Buell

    1997-07-01

    A high-ionization broad absorption line system {C IV, N V, and O VI doublets; FWHM 3, 000 to 5, 000 km s^-1; z_rmabs=0.7} in the HST FOS UV spectrum of PG 2302+029 {z=1.052} has unprecedented properties. A distinct narrow line system {FWHM <250 km s^-1, z_abs=0.702} is also resolved within the broad system. If produced by material intrinsic to the quasar then the absorbing gas has been ejected from the quasar at more than sim56, 000 km s^-1. This extremely large ejection velocity as well as its ``detached'' nature {the reddest extent of the broad line absorption is more than 50, 000 km s^-1 from the quasar rest frame} would be unlike any known intrinsic absorber in QSOs. Alternatively, the broad and narrow systems could be produced by gas in a foreground cluster or super-cluster of galaxies. However, previous examples of such absorption have always included absorption by low-ionization species {e.g. Mg II, Si II}, which are not detected in the PG 2302+029 systems. We will undertake STIS and WFPC2 observations designed to help to identify the cause of this absorption system and allow us to determine whether the system is an extreme example of previously known classes of quasar absorption lines or represents an entirely new phenomenon.

  15. An X-ray-absorbed radio-quiet QSO with an intervening strong metal absorption-line system

    NASA Astrophysics Data System (ADS)

    Page, M. J.; Mittaz, J. P. D.; Carrera, F. J.

    2000-02-01

    We find evidence for significant X-ray absorption in the QSO RXJ005734.78-272827.4, along with strong absorption lines in its optical spectrum. We propose that the absorption lines are due to an intervening metal-line system at a redshift of z=0.628, and show that this intervening system is also the probable cause of the X-ray absorption. The intervening absorber is inferred to have an X-ray column of ~1022cm-2. This is the first time that an absorption-line system has been identified with an X-ray absorber in a radio-quiet object.

  16. DISENTANGLING THE CIRCUMNUCLEAR ENVIRONS OF CENTAURUS A. II. ON THE NATURE OF THE BROAD ABSORPTION LINE

    SciTech Connect

    Espada, D.; Matsushita, S.; Sakamoto, K.; Peck, A. B.; Henkel, C.; Iono, D.; Israel, F. P.; Muller, S.; Petitpas, G.; Pihlstroem, Y.; Taylor, G. B.; Trung, D. V.

    2010-09-01

    We report on atomic gas (H I) and molecular gas (as traced by CO(2-1)) redshifted absorption features toward the nuclear regions of the closest powerful radio galaxy, Centaurus A (NGC 5128). Our H I observations using the Very Long Baseline Array allow us to discern with unprecedented sub-parsec resolution H I absorption profiles toward different positions along the 21 cm continuum jet in the inner 0.''3 (or 5.4 pc). In addition, our CO(2-1) data obtained with the Submillimeter Array probe the bulk of the absorbing molecular gas with little contamination by emission, which was not possible with previous CO single-dish observations. We shed light on the physical properties of the gas in the line of sight with these data, emphasizing the still open debate about the nature of the gas that produces the broad absorption line ({approx}55 km s{sup -1}). First, the broad H I line is more prominent toward the central and brightest 21 cm continuum component than toward a region along the jet at a distance {approx}20 mas (or 0.4 pc) further from the nucleus. This indicates that the broad absorption line arises from gas located close to the nucleus, rather than from diffuse and more distant gas. Second, the different velocity components detected in the CO(2-1) absorption spectrum match well with other molecular lines, such as those of HCO{sup +}(1-0), except the broad absorption line that is detected in HCO{sup +}(1-0) (and most likely related to that of the H I). Dissociation of molecular hydrogen due to the active galactic nucleus seems to be efficient at distances r {approx}< 10 pc, which might contribute to the depth of the broad H I and molecular lines.

  17. Low-redshift Lyman-alpha absorption lines and the dark matter halos of disk galaxies

    NASA Technical Reports Server (NTRS)

    Maloney, Philip

    1992-01-01

    Ultraviolet observations of the low-redshift quasar 3C 273 using the Hubble Space Telescope have revealed many more Lyman-alpha absorption lines than would be expected from extrapolation of the absorption systems seen toward QSOs at z about 2. It is shown here that these absorption lines can plausibly be produced by gas at large radii in the disks of spiral and irregular galaxies; the gas is confined by the dark matter halos and ionized and heated by the extragalactic radiation field. This scenario does not require the extragalactic ionizing radiation field to decline as rapidly with decreasing z as the QSO emissivity. Observations of Ly-alpha absorption through the halos of known galaxies at low redshift will constrain both the extragalactic background and the properties of galactic halos.

  18. EMPIRICAL LINE LISTS AND ABSORPTION CROSS SECTIONS FOR METHANE AT HIGH TEMPERATURES

    SciTech Connect

    Hargreaves, R. J.; Bernath, P. F.; Dulick, M.; Bailey, J.

    2015-11-01

    Hot methane is found in many “cool” sub-stellar astronomical sources including brown dwarfs and exoplanets, as well as in combustion environments on Earth. We report on the first high-resolution laboratory absorption spectra of hot methane at temperatures up to 1200 K. Our observations are compared to the latest theoretical spectral predictions and recent brown dwarf spectra. The expectation that millions of weak absorption lines combine to form a continuum, not seen at room temperature, is confirmed. Our high-resolution transmittance spectra account for both the emission and absorption of methane at elevated temperatures. From these spectra, we obtain an empirical line list and continuum that is able to account for the absorption of methane in high temperature environments at both high and low resolution. Great advances have recently been made in the theoretical prediction of hot methane, and our experimental measurements highlight the progress made and the problems that still remain.

  19. Metal-line absorption at Zabs approximately Zem from associated galaxies

    NASA Astrophysics Data System (ADS)

    Ellingson, E.; Yee, H. K. C.; Bechtold, Jill; Dobrzycki, Adam

    1994-04-01

    For a preliminary study of whether C IV absorption at Zabs approximately Zem is related to associated galaxy companions, we have collected data from a sample of 10 quasars with 0.15 less than z less than 0.65 for which high-resolution optical and UV spectroscopy is available from the literature, and for which we have deep optical images and limited spectroscopy. We also present new optical spectra for two of our samples. Four of these quasars have associated C IV absorption systems. In thes four fields, there are eight galaxies with Mr less than -19.0 mag within 35 kpc of the quasar (projected distance, assuming they are at the quasar redshift), which may be candidates for the associated C IV absorption. This observed density of galaxies near quasars with associated C IV absorption is significantly greater than that for a control sample of quasars chosen from the literature. This result suggests that galaxies near the quasar line of sight may be linked with associated C IV absorption. None of these quasars show associated Mg II absorption, despite the presence of galaxies very near the line of sight, suggesting a Mg II 'proximity effect,' where ionizing flux from the quasar destroys the Mg(+) from at least the outer parts of the galaxies. Three quasars are located in rich galaxy clusters, but none of these quasars are found to have associated C IV absorption. This suggests that galaxies in rich clusters associated with quasars are less likely to be metal-line absorbers. It is plausible that the extended galaxy halos which may be responsible for the absorptions are stripped from galaxies in these dense environments. While it seems that at Z approximately 0.6 rich clusters do not cause them, associated C IV absorption systems at higher redshift may be explained by associated clusters if there has been evolution in the properties of galaxy halos in dense environments.

  20. Radiatively driven winds for different power law spectra. [for explaining narrow and broad quasar absorption lines

    NASA Technical Reports Server (NTRS)

    Beltrametti, M.

    1980-01-01

    The analytic solutions for radiatively driven winds are given for the case in which the winds are driven by absorption of line and continuum radiation. The wind solutions are analytically estimated for different parameters of the central source and for different power law spectra. For flat spectra, three sonic points can exist; it is shown, however, that only one of these sonic points is physically realistic. Parameters of the central source are given which generate winds of further interest for explaining the narrow and broad absorption lines in quasars. For the quasar model presented here, winds which could give rise to the narrow absorption lines are generated by central sources with parameters which are not realistic for quasars.

  1. Narrow absorption lines with two observations from the Sloan Digital Sky Survey

    NASA Astrophysics Data System (ADS)

    Chen, Zhi-Fu; Gu, Qiu-Sheng; Chen, Yan-Mei; Cao, Yue

    2015-07-01

    We assemble 3524 quasars from the Sloan Digital Sky Survey (SDSS) with repeated observations to search for variations of the narrow C IV λ λ 1548,1551 and Mg II λ λ 2796,2803 absorption doublets in spectral regions shortward of 7000 Å in the observed frame, which corresponds to time-scales of about 150-2643 d in the quasar rest frame. In these quasar spectra, we detect 3580 C IV absorption systems with zabs = 1.5188-3.5212 and 1809 Mg II absorption systems with zabs = 0.3948-1.7167. In term of the absorber velocity (β) distribution in the quasar rest frame, we find a substantial number of C IV absorbers with β < 0.06, which might be connected to absorption of quasar outflows. The outflow absorption peaks at υ ≈ 2000 km s^{-1} and drops rapidly below this peak value. Among 3580 C IV absorption systems, 52 systems (˜1.5 per cent) show obvious variations in equivalent widths in the absorber rest frame (Wr): 16 enhanced, 16 emerged, 12 weakened and 8 disappeared systems, respectively. We find that changes in Wrλ1548 are related neither to the time-scales of the two SDSS observations nor to absorber velocities in the quasar rest frame. Variable absorption in low-ionization species is important to constrain the physical conditions of the absorbing gas. There are two variable Mg II absorption systems measured from SDSS spectra detected by Hacker et al. However, in our Mg II absorption sample, we find that neither shows variable absorption with confident levels of >4σ for λ2796 lines and >3σ for λ2803 lines.

  2. A ghostly damped Ly α system revealed by metal absorption lines

    NASA Astrophysics Data System (ADS)

    Fathivavsari, H.; Petitjean, P.; Zou, S.; Noterdaeme, P.; Ledoux, C.; Krühler, T.; Srianand, R.

    2017-03-01

    We report the discovery of the first 'ghostly' damped Ly α absorption system (DLA), which is identified by the presence of absorption from strong low-ion species at zabs = 1.704 65 along the line of sight to the quasar SDSS J113341.29-005740.0 with zem = 1.704 41. No Ly α absorption trough is seen associated with these absorptions because the DLA trough is filled with the leaked emission from the broad emission-line region of the quasar. By modelling the quasar spectrum and analysing the metal lines, we derive log N(H I)(cm-2) ∼21.0 ± 0.3. The DLA cloud is small (≤0.32 pc), thus not covering entirely the broad-line region and is located at ≥39 pc from the central active galactic nucleus (AGN). Although the DLA is slightly redshifted relative to the quasar, its metallicity ([S/H] = -0.41 ± 0.30) is intermediate between what is expected from infalling and outflowing gas. It could be possible that the DLA is part of some infalling material accreting on to the quasar host galaxy through filaments, and that its metallicity is raised by mixing with the enriched outflowing gas emanating from the central AGN. Current DLA surveys miss these 'ghostly' DLAs, and it would be important to quantify the statistics of this population by searching the Sloan Digital Sky Survey (SDSS) data base using metal absorption templates.

  3. Resolution Effects on Quasar Absorption Line Studies of ΛCDM Simulations

    NASA Astrophysics Data System (ADS)

    Kacprzak, Glenn; Ceverino, D.; Churchill, C. W.; Murphy, M. T.; Evans, J. L.

    2009-01-01

    The technique of using background quasars to study absorption lines produced by gaseous halos of foreground galaxies provides a uniquely powerful tool to probe the gas-galaxy and IGM interface. With absorption lines, we are capable of studying the kinematic, chemical, and ionization conditions of galactic halos over all redshifts out to projected galactocentric radii of several 100 kpc. However, interpreting these data can be difficult. We have recently begun to produce similar absorption line observations of galaxies and their gaseous halos in LCDM cosmological simulations in order to constrain the dynamic interaction of the galaxy/halo/cosmic web environment and the distribution of gas within halos. The simulations are performed using the Eulerian Gasdynamics plus N-body Adaptive Refinement Tree (ART) code, were the highest resolution gas cells are 20-100 pc. However, absorption lines are primarily produced/observed in the halos of galaxies where the resolution is lower. Here, we quantify how varying the resolution affects the measured absorption velocity spreads, number of clouds, and covering fractions of halo gas within the simulated galaxies. This is an important step toward understanding the interplay between halo gas kinematics and small scale structure. It is crucial that we understand these effects in order to correctly interpret our observations.

  4. VizieR Online Data Catalog: QSOs narrow absorption line variability (Hacker+, 2013)

    NASA Astrophysics Data System (ADS)

    Hacker, T. L.; Brunner, R. J.; Lundgren, B. F.; York, D. G.

    2013-06-01

    Catalogues of 2,522 QAL systems and 33 variable NAL systems detected in SDSS DR7 quasars with repeat observations. The object identifiers, position coordinates, and plate-MJD-fibre designations are taken from the SpecObjAll table in the SDSS Catalogue Archive Server (CAS) while the quasar redshifts (zqso) are from Hewett & Wild (2010, Cat. J/MNRAS/405/2302). The absorption system redshift (zabs), system grade, and detected lines are outputs of the York et al. (2013, in. prep.) QAL detection pipeline. Some absorption lines are flagged based on alternate identifications (a), proximity of masked pixels (b), or questionable continuum fits (c). (3 data files).

  5. Absorption Spectra of Broadened Sodium Resonance Lines in Presence of Rare Gases

    SciTech Connect

    Chung, H-K; Shurgalin, M; Babb, J F

    2002-09-11

    The pressure broadening of alkali-metal lines is a fundamental problem with numerous applications. For example, the sodium resonance lines broadened by xenon are important in the production of broad spectra emitted in the HPS (High-Pressure Sodium) lamp and they potentially can be used for gas condition diagnostics. Broadened absorption lines of alkali-metal atoms are prominent in the optical spectra of brown dwarfs and understanding the broadening mechanism will help elucidate the chemical composition and atmospheric properties of those stars. The far-line wing spectra of sodium resonance lines broadened by rare gases are found to exhibit molecular characteristics such as satellites and hence the total absorption coefficients for vapors of Na atoms and perturbing rare gas atoms can be modeled as Na-RG (rare gas) molecular absorption spectra. In this work, using carefully chosen interatomic potentials for Na-RG molecules we carry out quantum-mechanical calculations for reduced absorption coefficients for vapors composed of Na-He, Na-Ar, and Na-Xe. Calculated spectra are compared to available experimental results and the agreement is good in the measured satellite positions and shapes.

  6. New aspects of absorption line formation in intervening turbulent clouds - I. General principles

    NASA Astrophysics Data System (ADS)

    Levshakov, Sergei A.; Kegel, Wilhelm H.

    1997-07-01

    We study the formation of absorption lines in intervening clouds with stochastic velocity fields, accounting for the fact that actually only one line of sight is observed. Our results show that the introduction of the finite velocity correlation length leads to a new type of absorption line profiles which are asymmetric in general, may have different shifts of the centres of gravity, and look like barely resolved blends, i.e. could be interpreted in a standard Voigt fitting analysis as being caused by several independent clouds with different physical parameters. Numerical results are presented for the HI Lyalpha line with N_Hi=10^12,10^14,10^15 and 10^16cm^-2, T_kin=10^4 K, and different sets of turbulent parameters. The intensity fluctuations within the line profile caused by `turbulent noise' are investigated and the confidence belts for the absorption lines are calculated. We conclude that an exact measurement of the column densities of the absorbing atoms N_a from the observed values of the optical depths tau lambda is actually impossible for the case of the correlated velocity field. One can only determine a range of values within which N_a is to be found with a certain probability.

  7. Variability of the broad absorption lines in the QSO UM 232

    NASA Technical Reports Server (NTRS)

    Barlow, Thomas A.; Junkkarinen, Vesa T.; Burbidge, E. Margaret

    1989-01-01

    Low-resolution spectra of UM 232 taken in 1978, 1979, and 1988 at Lick Observatory are presented. Large changes in the Si IV lambda 1397, CIV lambda 1549, and Al III lambda 1857 broad absorption lines are apparent. The decrease in column density in all three ions and an observed brightening of the QSO suggests that these changes are due to an increase in the ionization level driven by an increase in the central source luminosity. This mechanism has been proposed by Smith and Penston to explain small changes in the absorption spectrum of the QSO 1246-057. The spectra of UM 232 show that the fractional decrease in optical depth is smaller at higher outflow velocies. The structure of the broad absorption-line region (BALR) is investigted by estimating an ionization parameter for each ion species as a function of velocity.

  8. 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.

  9. Archival research on absorption lines in violently star-forming galaxies

    NASA Technical Reports Server (NTRS)

    Gallagher, J. S.

    1989-01-01

    A computerized analysis of a starburst model is discussed. The model proposes that the absorption line equivalent width should scale with the level of star forming activity. Archival International Ultraviolet Explorer (IUE) data on IUE spectra of luminous blue galaxies were compared with previous IUE observations of extragalactic HII regions and low luminosity galaxies. The comparisons are summarized and causes for offsets are discussed.

  10. A summary of transition probabilities for atomic absorption lines formed in low-density clouds

    NASA Technical Reports Server (NTRS)

    Morton, D. C.; Smith, W. H.

    1973-01-01

    A table of wavelengths, statistical weights, and excitation energies is given for 944 atomic spectral lines in 221 multiplets whose lower energy levels lie below 0.275 eV. Oscillator strengths were adopted for 635 lines in 155 multiplets from the available experimental and theoretical determinations. Radiation damping constants also were derived for most of these lines. This table contains the lines most likely to be observed in absorption in interstellar clouds, circumstellar shells, and the clouds in the direction of quasars where neither the particle density nor the radiation density is high enough to populate the higher levels. All ions of all elements from hydrogen to zinc are included which have resonance lines longward of 912 A, although a number of weaker lines of neutrals and first ions have been omitted.

  11. Candidate Hα emission and absorption line sources in the Galactic Bulge Survey

    NASA Astrophysics Data System (ADS)

    Wevers, T.; Jonker, P. G.; Nelemans, G.; Torres, M. A. P.; Groot, P. J.; Steeghs, D.; Maccarone, T. J.; Hynes, R. I.; Heinke, C.; Britt, C.

    2017-04-01

    We present a catalogue of candidate Hα emission and absorption line sources and blue objects in the Galactic Bulge Survey (GBS) region. We use a point source catalogue of the GBS fields (two strips of (l × b) = (6° × 1°) centred at b = 1.5° above and below the Galactic Centre), covering the magnitude range 16 ≤ r΄ ≤ 22.5. We utilize (r΄ - i΄, r΄ - Hα) colour-colour diagrams to select Hα emission and absorption line candidates, and also identify blue objects (compared to field stars) using the r΄ - i΄ colour index. We identify 1337 Hα emission line candidates and 336 Hα absorption line candidates. These catalogues likely contain a plethora of sources, ranging from active (binary) stars, early-type emission line objects, cataclysmic variables (CVs) and low-mass X-ray binaries (LMXBs) to background active galactic nuclei (AGN). The 389 blue objects we identify are likely systems containing a compact object, such as CVs, planetary nebulae and LMXBs. Hot subluminous dwarfs (sdO/B stars) are also expected to be found as blue outliers. Cross-matching our outliers with the GBS X-ray catalogue yields 16 sources, including 7 (magnetic) CVs and 1 qLMXB candidate among the emission line candidates and 1 background AGN for the absorption line candidates. One of the blue outliers is a high-state AM CVn system. Spectroscopic observations combined with the multiwavelength coverage of this area, including X-ray, ultraviolet and (time-resolved) optical and infrared observations, can be used to further constrain the nature of individual sources.

  12. Atlas of absorption lines from 0 to 17 900 cm(-1)

    NASA Technical Reports Server (NTRS)

    Park, J. H.; Rothman, L. S.; Rinsland, C. P.; Smith, M. A. H.; Richardson, D. J.; Larsen, J. C.

    1981-01-01

    Plots of absorption line strength versus line position for wavenumbers from 0 to 17,900 cm(-1) are shown for 20 atmospheric gases (H2O, CO2, O3, N2O, CO, CH4, O2, NO, SO2, NO2, NH3, HNO3, OH, HF, HCl, HBr, HI, ClO, OCS, H2CO). Also shown are similar plots of lower-state energy values for adsorption lines for the strongly adsorbing atmospheric gases (H2O, CO2, O3, and CH4) for wavenumbers from 0 to 5000 cm(-1).

  13. Correlations between different line-forming regions in quasar environments

    NASA Astrophysics Data System (ADS)

    Chen, Chen; Hamann, Fred; Lundgren, Britt

    2017-01-01

    The early stage of massive galaxy evolution can involve outflows driven by a starburst or a central quasar plus cold mode accretion (infall) adding to the mass build-up in the galaxies. We are using SDSS-BOSS DR12 database to study the nature of infall and outflows in quasar environments by examining the relationships of their narrow absorption lines (NALs) at positive and negative velocity shifts to other quasar properties such as their broad absorption line (BAL) outflows, emission line characteristics, radio-loudness, and reddening by dust. We also test for extreme high-velocity NAL outflows (with speeds 0.1-0.2c) based on relationships to low-speed NALs and quasar properties, and we perform detailed analyses of particular cases of rich multi-component NAL complexes that might result from high-speed quasar outflows shredding and dispersing interstellar clouds in the host galaxies. Our results show that low-velocity NALs and rich NAL complexes correlate strongly with BALs, suggesting a physical relationship. Infalling systems are less common in quasars with BALs, suggesting that BAL outflows can halt or disrupt gas accretion. The extreme high-velocity NALs (at 0.1-0.2c) show a weak relationship to BALs and a strong dependence on low-velocity NALs, indicating that a significant fraction of these systems is ejected from the quasars (and are *not* unrelated intervening clouds). We find no correlations between radio flux and low-velocity NALs, infalling systems, or rich complexes, which indicates that none of these features are closely tied to quasar radio properties. We analyze the relationship of the N V/C IV line strengths (a possible abundance/metallicity probe) in emission versus absorption lines and find no correlation between them.

  14. The Connection between Galaxies and Intergalactic Absorption Lines at Redshift 2<~z<~3

    NASA Astrophysics Data System (ADS)

    Adelberger, Kurt L.; Shapley, Alice E.; Steidel, Charles C.; Pettini, Max; Erb, Dawn K.; Reddy, Naveen A.

    2005-08-01

    Absorption-line spectroscopy of 23 background QSOs and numerous background galaxies has let us measure the spatial distribution of metals and neutral hydrogen around 1044 UV-selected galaxies at redshifts 1.8<~z<~3.3. The typical galaxy is surrounded to radii r~40 proper kpc by gas that has a large velocity spread (Δv>260 km s-1) and produces very strong absorption lines (NCIV>>1014 cm-2) in the spectra of background objects. These absorption lines are almost as strong as those produced by a typical galaxy's own interstellar gas. Absorption with an average column density of NCIV~=1014 cm-2 extends out to ~80 kpc, a radius large enough to imply that most strong intergalactic C IV absorption is associated with star-forming galaxies like those in our sample. Our measurement of the galaxy-C IV spatial correlation function shows that even the weakest detectable C IV systems are found in the same regions as galaxies; we find that the cross-correlation length increases with C IV column density and is similar to the galaxy autocorrelation length (r0~4 h-1 Mpc) for NCIV>~1012.5 cm-2. Distortions in the redshift-space galaxy-C IV correlation function on small scales may imply that some of the C IV systems have large peculiar velocities. Four of the five detected O VI absorption systems in our sample lie within 400 proper kpc of a known galaxy. Strong Lyα absorption is produced by the intergalactic gas within 1 h-1 comoving Mpc of most galaxies, but for a significant minority (~1/3) the absorption is weak or absent. This is not observed in smooth-particle hydrodynamic simulations that omit the effects of ``feedback'' from galaxy formation. We were unable to identify any statistically significant differences in age, dust reddening, environment, or kinematics between galaxies with weak nearby H I absorption and the rest, although galaxies with weak absorption may have higher star formation rates. Galaxies near intergalactic C IV systems appear to reside in relatively dense

  15. Absorption line profiles in a companion spectrum of a mass losing cool supergiant

    NASA Technical Reports Server (NTRS)

    Rodrigues, Liliya L.; Boehm-Vitense, Erika

    1990-01-01

    Cool star winds can best be observed in resonance absorption lines seen in the spectrum of a hot companion, due to the wind passing in front of the blue star. We calculated absorption line profiles that would be seen in the ultraviolet part of the blue companion spectrum. Line profiles are derived for different radial dependences of the cool star wind and for different orbital phases of the binary. Bowen and Wilson find theoretically that stellar pulsations drive mass loss. We therefore apply our calculations to the Cepheid binary S Muscae which has a B5V companion. We find an upper limit for the Cepheid mass loss of M less than or equal to 7 x 10(exp -10) solar mass per year provided that the stellar wind of the companion does not influence the Cepheid wind at large distances.

  16. Tracing the outflow of a z = 0.334 FeLoBAL: New constraints from low-ionization absorbers in FBQS J1151+3822

    SciTech Connect

    Lucy, Adrian B.; Leighly, Karen M.; Terndrup, Donald M.; Dietrich, Matthias; Gallagher, Sarah C.

    2014-03-01

    We show for the first time that FBQS J1151+3822 is an iron low-ionization broad absorption line quasar (FeLoBAL QSO), the second-brightest and second-closest known example of this class. He I* and Fe II together act as an effective analytical tool, allowing us to obtain useful kinematic constraints from photoionization models of the outflow without needing to assume any particular acceleration model. The main outflow's log ionization parameter is –1.5, the log hydrogen density (cm{sup –3}) 5.5-8, the log hydrogen column density (cm{sup –2}) 21.7-21.9, the absorption radius 7.2-127 pc, and the kinetic luminosity is 0.16%-4.5% of the bolometric luminosity. We obtain line-of-sight covering fractions of ∼0.25 for strong Fe II, ∼0.5 for He I*, and ∼0.6 for Mg II. Narrower and shallower absorption lines from weaker Fe II and Mn II with an outflow velocity of ∼3400 km s{sup –1} have appeared between 2005 and 2011, suggesting that dense cores may have condensed inside the main outflow. Consideration of the literature might suggest that the FBQS J1151+3822 outflow is a member of a rare and distinct subclass of FeLoBALs with high densities and correspondingly small absorption radii. We find, however, that such outflows are not necessarily a distinct subclass, and that their apparent rarity could be a symptom of selection bias in studies using density-sensitive lines.

  17. XMM-Newton Observation of Fe K(alpha) Emission from a BAL QSO: Mrk 231

    NASA Technical Reports Server (NTRS)

    Turner, T. J.; Kraemer, S. B.

    2003-01-01

    We present results from a 20 ksec XMM-Newton observation of Mrk 231. EPIC spectral data reveal strong line emission due to Fe K alpha, which has rarely been detected in this class, as BAL QSOs are very faint in the X-ray band. The line energy is consistent with an origin in neutral Fe. The width of the line is equivalent to a velocity dispersion approximately 18,000 kilometers per second and thus the line may be attributed to transmission and/or reflection from a distribution of emitting clouds. If, instead, the line originates in the accretion disk then the line strength and flat X-ray continuum support some contribution from a reflected component, although the data disfavor a model where the hard X-ray band is purely reflected X-rays. The line parameters are similar to those obtained for the Fe Ka line detected in another BAL QSO, H1413 + 117.

  18. Multiple Velocity Components in the CIV Absorption Line of NGC5548

    NASA Astrophysics Data System (ADS)

    Mathur, S.; Elvis, M.; Wilkes, B. J.

    1998-12-01

    The bright, variable, Seyfert 1 galaxy NGC 5548 has been extensively studied at many wavelengths. It has been a target of reverberation mapping experiments in the optical and UV (Peterson et al. 1992, Clavel et al. 1991, Korista et al. 1995). These have led to the accurate determination of the physical size of the BELR. The UV spectrum also shows absorption lines (Shull & Sachs 1993, Mathur, Elvis & Wilkes 1995 (MEW95)). Recently, based on ASCA and HST FOS data, MEW95 showed that the ionizaed X-ray and UV absorption in NGC5548 is likely to originate in the same material. We have now obtained high resolution GHRS spectrum around the CIV line. We find that the absorption line splits into multiple velocity components. The X-ray absorber would be associated with one of these components. We also have a tentative evidence for inflow based on the redshifted absorption component. This is in accord with the radial infall in NGC 5548 found by Done & Krolik (1996) based on the kinematic model of the BELR.

  19. The Herbig AE star AB AUR - absorption along the line of sight and chromospheric emission

    NASA Astrophysics Data System (ADS)

    Felenbok, P.; Praderie, F.; Talavera, A.

    1983-11-01

    The H-alpha, He I 5876 A, Na I 5890 A, Ca II IR triplet, and P14-P16 Paschen lines of AB Aur are all brighter than the nearby continuum. The emission lines are examined with regard to their origin as either recombination or chromospheric emission. While He I and H-alpha could be formed simultaneously by recombination under certain circumstances, a deep chromosphere would account for He I 5876, for the Paschen lines in emission, and perhaps even for the Ca II IR triplet in emission. A deep chromosphere would also explain why higher Balmer lines are in absorption and why the Ca II resonance lines have only an autoreversed emission core, despite not being fully in emission.

  20. Selection of the optimal combination of water vapor absorption lines for detection of temperature in combustion zones of mixing supersonic gas flows by diode laser absorption spectrometry

    NASA Astrophysics Data System (ADS)

    Mironenko, V. R.; Kuritsyn, Yu. A.; Bolshov, M. A.; Liger, V. V.

    2016-12-01

    Determination of a gas medium temperature by diode laser absorption spectrometry (DLAS) is based on the measurement of integral intensities of the absorption lines of a test molecule (generally water vapor molecule). In case of local thermodynamic equilibrium temperature is inferred from the ratio of the integral intensities of two lines with different low energy levels. For the total gas pressure above 1 atm the absorption lines are broadened and one cannot find isolated well resolved water vapor absorption lines within relatively narrow spectral interval of fast diode laser (DL) tuning range (about 3 cm-1). For diagnostics of a gas object in the case of high temperature and pressure DLAS technique can be realized with two diode lasers working in different spectral regions with strong absorption lines. In such situation the criteria of the optimal line selection differs significantly from the case of narrow lines. These criteria are discussed in our work. The software for selection the optimal spectral regions using the HITRAN-2012 and HITEMP data bases is developed. The program selects spectral regions of DL tuning, minimizing the error of temperature determination δT/T, basing on the attainable experimental error of line intensity measurement δS. Two combinations of optimal spectral regions were selected - (1.392 & 1.343 μm) and (1.392 & 1.339 μm). Different algorithms of experimental data processing are discussed.

  1. [Laser induced breakdown spectra of coal sample and self-absorption of the spectral line].

    PubMed

    Zhang, Gui-yin; Ji, Hui; Jin, Yi-dong

    2014-12-01

    The LIBS of one kind of household fuel coal was obtained with the first harmonic output 532 nm of an Nd·YAG laser as radiation source. With the assignment of the spectral lines, it was found that besides the elements C, Si, Mg, Fe, Al, Ca, Ti, Na and K, which are reported to be contained in coal, the presented sample also contains trace elements, such as Cd, Co, Hf, Ir, Li, Mn, Ni, Rb, Sr, V, W, Zn, Zr etc, but the spectral lines corresponding to O and H elements did not appear in the spectra. This is owing to the facts that the transition probability of H and O atoms is small and the energy of the upper level for transition is higher. The results of measurement also show that the intensity of spectral line increases with the laser pulse energy and self-absorption of the spectral lines K766.493 nm and K769.921 nm will appear to some extent. Increasing laser energy further will make self-absorption more obvious. The presence of self-absorption can be attributed to two factors. One is the higher transition rate of K atoms, and the other is that the increase in laser intensity induces the enhancement of the particle number density in the plasma.

  2. THE PHYSICAL CONDITIONS OF THE INTRINSIC N V NARROW ABSORPTION LINE SYSTEMS OF THREE QUASARS

    SciTech Connect

    Wu Jian; Charlton, Jane C.; Misawa, Toru; Eracleous, Michael; Ganguly, Rajib E-mail: misawatr@shinshu-u.ac.j

    2010-10-20

    We employ detailed photoionization models to infer the physical conditions of intrinsic narrow absorption line systems found in high-resolution spectra of three quasars at z = 2.6-3.0. We focus on a family of intrinsic absorbers characterized by N V lines that are strong relative to the Ly{alpha} lines. The inferred physical conditions are similar for the three intrinsic N V absorbers, with metallicities greater than 10 times the solar value (assuming a solar abundance pattern), and with high ionization parameters (log U {approx} 0). Thus, we conclude that the unusual strength of the N V lines results from a combination of partial coverage, a high ionization state, and high metallicity. We consider whether dilution of the absorption lines by flux from the broad emission line region can lead us to overestimate the metallicities and we find that this is an unlikely possibility. The high abundances that we infer are not surprising in the context of scenarios in which metal enrichment takes place very early on in massive galaxies. We estimate that the mass outflow rate in the absorbing gas (which is likely to have a filamentary structure) is less than a few M{sub sun} yr{sup -1} under the most optimistic assumptions, although it may be embedded in a much hotter, more massive outflow.

  3. The Suzaku Observation of NGC 3516: Complex Absorption and the Broad and Narrow Fe K Lines

    NASA Technical Reports Server (NTRS)

    Markowitz, Alex; Reeves, James N.; Miniutti, Giovanni; Serlemitsos, Peter; Kunieda, Hideyo; Taqoob, Tahir; Fabian, Andrew C.; Fukazawa, Yasushi; Mushotzky, Richard; Okajima, Takashi; Gallo, Luigi; Awaki, Hisamitsu; Griffiths, Richard E.

    2007-01-01

    We present results from a 150 ksec Suzaku observation of the Seyfert 1 NGC 3516 in October 2005. The source was in a relatively highly absorbed state. Our best-fit model is consistent with partial covering by a lowly-ionized absorber with a column density near 5x10(exp 22) cm(exp -2) and with a covering fraction 96-100 percent. Narrow K-shell absorption features due to He- and H-like Fe confirm the presence of a high-ionization absorbing component as well. A broad Fe K(alpha) diskline is required in all fits, even after the complex absorption is taken into account; an additional partial-covering component is an inadequate substitute for the continuum curvature associated with the broad line. The narrow Fe Ka line at 6.4 keV is resolved, yielding a velocity width commensurate with the optical Broad Line Region. The strength of the Compton reflection hump suggests a contribution mainly from the broad Fe line origin. We include in our model soft band emission lines from He- and H-like ions and radiative recombination lines, consistent with photo-ionization, though a small contribution from collisional ionization is possible.

  4. Dust depletion of Ca and Ti in QSO absorption-line systems

    NASA Astrophysics Data System (ADS)

    Guber, C. R.; Richter, P.

    2016-06-01

    Aims: To explore the role of titanium- and calcium-dust depletion in gas in and around galaxies, we systematically study Ti/Ca abundance ratios in intervening absorption-line systems at low and high redshift. Methods: We investigate high-resolution optical spectra obtained by the UVES instrument at the Very Large Telescope (VLT) and spectroscopically analyze 34 absorption-line systems at z ≤ 0.5 to measure column densities (or limits) for Ca ii and Ti ii. We complement our UVES data set with previously published absorption-line data on Ti/Ca for redshifts up to z ~ 3.8. Our absorber sample contains 110 absorbers including damped Lyman α systems (DLAs), sub-DLAs, and Lyman-Limit systems (LLS). We compare our Ti/Ca findings with results from the Milky Way and the Magellanic Clouds and discuss the properties of Ti/Ca absorbers in the general context of quasar absorption-line systems. Results: Our analysis indicates that there are two distinct populations of absorbers with either high or low Ti/Ca ratios with a separation at [Ti/Ca] ≈ 1. While the calcium-dust depletion in most of the absorbers appears to be severe, the titanium depletions are mild in systems with high Ti/Ca ratios. The derived trend indicates that absorbers with high Ti/Ca ratios have dust-to-gas ratios that are substantially lower than in the Milky Way. We characterize the overall nature of the absorbers by correlating Ti/Ca with other observables (e.g., metallicity, velocity-component structure) and by modeling the ionization properties of singly-ionized Ca and Ti in different environments. Conclusions: We conclude that Ca ii and Ti ii bearing absorption-line systems trace predominantly neutral gas in the disks and inner halo regions of galaxies, where the abundance of Ca and Ti reflects the local metal and dust content of the gas. Our study suggests that the Ti/Ca ratio represents a useful measure for the gas-to-dust ratio and overall metallicity in intervening absorption-line systems.

  5. Interstellar Absorption Lines in the Spectrum of the Starburst Galaxy NGC 1705

    NASA Astrophysics Data System (ADS)

    Sahu, M. S.

    1998-09-01

    A Goddard High Resolution Spectrograph archival study of the interstellar absorption lines in the line of sight to the H i-rich, starburst dwarf galaxy NGC 1705 in the 1170 to 1740 Å range at ~120 km s^-1 resolution is presented. The absorption features arising because of photospheric lines are distinctly different from the interstellar lines: the photospheric lines are weak, broad (equivalent widths >1 Å), asymmetric, and centered around the systemic LSR velocity of NGC 1705 (~610 km s^-1). The interstellar lines consist of three relatively narrow components at LSR velocities of -20, 260, and 540 km s^-1, and include absorption by neutral atoms (N i lambda1200 triplet and O i lambda1302), singly ionized atoms (Si ii lambdalambda1190, 1193, 1260, 1304, and 1526, S ii lambda1253, C ii lambda1334, C ii^* lambda1336, Fe ii lambda1608, and Al ii lambda1670), and atoms in higher ionization states (Si iii lambda1206, Si iv lambdalambda1393, 1402, and C iv lambdalambda1548, 1550). The Si iv and C iv absorption features have both interstellar and photospheric contributions. In an earlier study, Sahu & Blades identified the absorption system at -20 km s^-1 with Milky Way disk/halo gas, and the 260 km s^-1 system with a small, isolated high-velocity cloud HVC 487, which is probably associated with Magellanic Stream gas. The 540 km s^-1 absorption system is associated with a kiloparsec-scale expanding, ionized supershell centered on the super-star cluster NGC 1705-1. The analysis presented in this paper consists of (1) a list of all interstellar absorption features with greater than 3 sigma significance and their measured equivalent widths, (2) plots of the lines in the various atomic species together with the results of nonlinear least-squares fit profiles to the observed data, and (3) unpublished 21 cm maps from the Wakker & van Woerden survey showing the large-scale H i distribution in the region near the NGC 1705 sight line and HVC 487. Furthermore, weak N i lambda1200

  6. Comparison of line-by-line and band models of near-IR methane absorption applied to outer planet atmospheres

    NASA Astrophysics Data System (ADS)

    Sromovsky, L. A.; Fry, P. M.; Boudon, V.; Campargue, A.; Nikitin, A.

    2012-03-01

    Recent improvements in high spectral resolution measurements of methane absorption at wavenumbers between 4800 cm-1 and 7919 cm-1 have greatly increased the number of lines with known lower state energies, the number of weak lines, and the number of lines observed at low temperatures (Campargue, A., Wang, L., Kassi, S., Mašát, M., Votava, O. [2010]. J. Quant. Spectrosc. Radiat. Trans. 111, 1141-1151; Campargue, A., Wang, L., Liu, A.W., Hu, S.M., Kassi, S. [2010]. Chem. Phys. 373, 203-210; Mondelain, D., Kassi, S., Wang, L.C. [2011]. Phys. Chem. Chem. Phys. 13, 7985-7996; Nikitin, A.V. et al. [2011a]. J. Mol. Spectrosc. 268, 93-106; Nikitin, A.V. et al. [2010]. J. Quant. Spectrosc. Radiat. Trans. 111, 2211-2224; Wang, L., Kassi, S., Campargue, A. [2010]. J. Quant. Spectrosc. Radiat. Trans. 111, 1130-1140; Wang, L., Kassi, S., Liu, A.W., Hu, S.M., Campargue, A. [2011]. J. Quant. Spectrosc. Radiat. Trans. 112, 937-951), making it possible to fit near-IR spectra of Titan using line-by-line calculations instead of band models (Bailey, J., Ahlsved, L., Meadows, V.S. [2011]. Icarus 213, 218-232; de Bergh, C. et al. [2011]. Planet. Space Sci. doi:10.1016/j.pss.2011.05.003). Using these new results, we compiled an improved line list relative that used by Bailey et al. by updating several spectral regions with either calculated or more recently measured line parameters, revising lower state energy estimates for lines lacking them, and adding room temperature lines to make the list applicable over a wider range of temperatures. We compared current band models with line-by-line calculations using this new line list, both to assess the behavior of band models, and to identify remaining issues with line-by-line calculations when applied to outer planet atmospheres and over a wider range of wavelengths. Comparisons were made for a selection of uniform paths representing outer planet conditions and for representative non-uniform paths within the atmospheres of Uranus, Saturn

  7. The Hubble Space Telescope quasar absorption line key project. III - First observational results on Milky Way gas

    NASA Technical Reports Server (NTRS)

    Savage, Blair D.; Lu, Limin; Bahcall, John N.; Bergeron, Jacqueline; Boksenberg, Alec; Hartig, George F.; Jannuzi, Buell T.; Kirhakos, Sofia; Lockman, Felix J.; Sargent, W. L. W.

    1993-01-01

    Absorption lines found near zero redshift due to Milky Way disk and halo gas in the spectra of 15 quasars observed with the Faint Object Spectrograph (FOS) of the HST at a resolution of about 230 km/s are reported. Results show that Milky Way absorption lines comprise about 44 percent of all absorption lines seen in the first group of Key Project FOS spectra. Milky Way lines were observed for 3C 273 and H1821 + 643. Limits to the Mg-to-H abundance ratio obtained for very high velocity Mg II absorption detections imply gas-phase Mg abundances for the very high velocity gas ranging from more than 0.059 to more than 0.32 times the solar abundance. In all cases where high-velocity H I emission is seen, corresponding high-velocity metal-line absorption is observed.

  8. High-resolution optical and ultraviolet absorption-line studies of interstellar gas

    NASA Technical Reports Server (NTRS)

    Cowie, Lennox L.; Songaila, Antoinette

    1986-01-01

    Recent progress in the characterization of the interstellar medium (ISM) by means of optical and UV spectral data is summarized. The gas is studied by focusing on background stars whose spectra can be accurately modeled to provide the light source for the absorption-line scans. The capabilities of earth- and space-based instruments which have been and are used for the surveys are delineated. The distributions of diffuse gas densities and characteristics of the cold, warm and hot gas in the Galaxy are described in terms of the elemental abundances, kinetics and distributions of the gas. Particular note is taken of gas in the solar neighborhood and around SNR, and of absorption-line data of cosmological significance.

  9. Locking distributed feedback laser diode frequency to gas absorption lines based on genetic programming

    NASA Astrophysics Data System (ADS)

    Quan, Wei; Li, Guanghui; Fang, Zishan; Zhai, Yueyang; Li, Xinyi; Liu, Feng

    2017-01-01

    Distributed feedback laser is widely used as the pump beam and probe beam in atomic physical and quantum experiments. As the frequency stability is a vital characteristic to the laser diode in these experiments, a saturated absorption frequency stabilization method assisted with the function of current and frequency is proposed. The relationship between the current and frequency is acquired based on the genetic programming (GP) algorithm. To verify the feasibility of the method, the frequency stabilization system is comprised of two parts that are modeling the relation between the current and frequency by GP and processing the saturated absorption signal. The results of the frequency stabilization experiment proved that this method can not only narrow the frequency searching range near the atomic line center but also compensate for the phase delay between the saturated absorption peak and the zero crossing point of the differential error signal. The reduced phase delay increases the locking probability and makes the wavelength drift only 0.015 pm/h, which converted to frequency drift is 7 MHz/h after frequency locking on the Rb absorption line.

  10. Neutral atomic absorption lines and far-UV extinction: Possible implications for depletions and grain parameters

    NASA Technical Reports Server (NTRS)

    Welty, Daniel E.

    1990-01-01

    Researchers examine nine lines of sight within the Galaxy and one in the Large Magellanic Cloud (LMC) for which data on both neutral atomic absorption lines (Snow 1984; White 1986; Welty, Hobbs, and York 1989) and far UV extinction (Bless and Savage 1972; Jenkins, Savage, and Spitzer 1986) are available, in order to test the assumption that variations in gamma/alpha will cancel in taking ratios of the ionization balance equation, and to try to determine to what extent that assumption has affected the aforementioned studies of depletions and grain properties.

  11. Neutral atomic absorption lines and far-UV extinction: Possible implications for depletions and grain parameters

    NASA Astrophysics Data System (ADS)

    Welty, Daniel E.

    1990-07-01

    Researchers examine nine lines of sight within the Galaxy and one in the Large Magellanic Cloud (LMC) for which data on both neutral atomic absorption lines (Snow 1984; White 1986; Welty, Hobbs, and York 1989) and far UV extinction (Bless and Savage 1972; Jenkins, Savage, and Spitzer 1986) are available, in order to test the assumption that variations in gamma/alpha will cancel in taking ratios of the ionization balance equation, and to try to determine to what extent that assumption has affected the aforementioned studies of depletions and grain properties.

  12. Wavelength Locking to CO2 Absorption Line-Center for 2-Micron Pulsed IPDA Lidar Application

    NASA Technical Reports Server (NTRS)

    Refaat, Tamer F.; Petros, Mulugeta; Antill, Charles W.; Singh, Upendra N.; Yu, Jirong

    2016-01-01

    An airborne 2-micron triple-pulse integrated path differential absorption (IPDA) lidar is currently under development at NASA Langley Research Center (LaRC). This IPDA lidar system targets both atmospheric carbon dioxide (CO2) and water vapor (H2O) column measurements. Independent wavelength control of each of the transmitted laser pulses is a key feature for the success of this instrument. The wavelength control unit provides switching, tuning and locking for each pulse in reference to a 2-micron CW (Continuous Wave) laser source locked to CO2 line-center. Targeting the CO2 R30 line center, at 2050.967 nanometers, a wavelength locking unit has been integrated using semiconductor laser diode. The CO2 center-line locking unit includes a laser diode current driver, temperature controller, center-line locking controller and CO2 absorption cell. This paper presents the CO2 center-line locking unit architecture, characterization procedure and results. Assessment of wavelength jitter on the IPDA measurement error will also be addressed by comparison to the system design.

  13. Surprises from a Deep ASCA Spectrum of the Broad Absorption Line Quasar PHL 5200

    NASA Technical Reports Server (NTRS)

    Mathur, Smita; Matt, G.; Green, P. J.; Elvis, M.; Singh, K. P.

    2002-01-01

    We present a deep (approx. 85 ks) ASCA observation of the prototype broad absorption line quasar (BALQSO) PHL 5200. This is the best X-ray spectrum of a BALQSO yet. We find the following: (1) The source is not intrinsically X-ray weak. (2) The line-of-sight absorption is very strong, with N(sub H) = 5 x 10(exp 23)/sq cm. (3) The absorber does not cover the source completely; the covering fraction is approx. 90%. This is consistent with the large optical polarization observed in this source, implying multiple lines of sight. The most surprising result of this observation is that (4) the spectrum of this BALQSO is not exactly similar to other radio-quiet quasars. The hard X-ray spectrum of PHL 5200 is steep, with the power-law spectral index alpha approx. 1.5. This is similar to the steepest hard X-ray slopes observed so far. At low redshifts, such steep slopes are observed in narrow-line Seyfert 1 (NLS1) galaxies, believed to be accreting at a high Eddington rate. This observation strengthens the analogy between BALQSOs and NLS1 galaxies and supports the hypothesis that BALQSOs represent an early evolutionary state of quasars. It is well accepted that the orientation to the line of sight determines the appearance of a quasar: age seems to play a significant role as well.

  14. Simulation studies of multi-line line-of-sight tunable-diode-laser absorption spectroscopy performance in measuring temperature probability distribution function

    NASA Astrophysics Data System (ADS)

    Zhang, Guang-Le; Liu, Jian-Guo; Kan, Rui-Feng; Xu, Zhen-Yu

    2014-12-01

    Line-of-sight tunable-diode-laser absorption spectroscopy (LOS-TDLAS) with multiple absorption lines is introduced for non-uniform temperature measurement. Temperature binning method combined with Gauss—Seidel iteration method is used to measure temperature probability distribution function (PDF) along the line-of-sight (LOS). Through 100 simulated measurements, the variation of measurement accuracy is investigated with the number of absorption lines, the number of temperature bins and the magnitude of temperature non-uniformity. A field model with 2-T temperature distribution and 15 well-selected absorption lines are used for the simulation study. The Gauss—Seidel iteration method is discussed for its reliability. The investigation result about the variation of measurement accuracy with the number of temperature bins is different from the previous research results.

  15. [The development of acetylene on-line monitoring technology based on laser absorption spectrum].

    PubMed

    He, Ying; Zhang, Yu-jun; Kan, Rui-feng; Xia, Hui; Wang, Min; Cui, Xiao-juan; Chen, Jiu-ying; Chen, Dong; Liu, Wen-qing; Liu, Jian-guo

    2008-10-01

    As one of the materials in organic chemical industry, acetylene has been used in many aspects of chemical industry. But acetylene is a very dangerous inflammable and explosive gas, so it needs in-situ monitoring during industrial storage and production. Tunable diode laser absorption spectroscopy (TDLAS) technology has been widely used in atmospheric trace gases detection, because it has a lot of advantageous characteristics, such as high sensitivity, good selectivity, and rapid time response. The distribution characteristics of absorption lines of acetylene in near infrared band were studied, and then the system designing scheme of acetylene on-line monitoring based on near infrared tunable diode laser absorption spectroscopy technology was discussed in detail. Moreover, the system of experiment measurement was set up and the method of signal detection and the algorithm of concentration inversion were studied. In addition, the sample cell with a path length of 10 cm, and the acetylene of different known concentrations were measured. As a result, the detection limit obtained reached 1.46 cm3 x m(-3). Finally the dynamic detection experiment was carried out, and the measurement result is stable and reliable, so the design of the system is practicable through experiment analysis. On-line acetylene leakage monitoring system was developed based on the experiment, and it is suitable for giving a leakage alarm of acetylene during its storage, transportation and use.

  16. Constraining the variation of the fine-structure constant with observations of narrow quasar absorption lines

    SciTech Connect

    Songaila, A.; Cowie, L. L.

    2014-10-01

    The unequivocal demonstration of temporal or spatial variability in a fundamental constant of nature would be of enormous significance. Recent attempts to measure the variability of the fine-structure constant α over cosmological time, using high-resolution spectra of high-redshift quasars observed with 10 m class telescopes, have produced conflicting results. We use the many multiplet (MM) method with Mg II and Fe II lines on very high signal-to-noise, high-resolution (R = 72, 000) Keck HIRES spectra of eight narrow quasar absorption systems. We consider both systematic uncertainties in spectrograph wavelength calibration and also velocity offsets introduced by complex velocity structure in even apparently simple and weak narrow lines and analyze their effect on claimed variations in α. We find no significant change in α, Δα/α = (0.43 ± 0.34) × 10{sup –5}, in the redshift range z = 0.7-1.5, where this includes both statistical and systematic errors. We also show that the scatter in measurements of Δα/α arising from absorption line structure can be considerably larger than assigned statistical errors even for apparently simple and narrow absorption systems. We find a null result of Δα/α = (– 0.59 ± 0.55) × 10{sup –5} in a system at z = 1.7382 using lines of Cr II, Zn II, and Mn II, whereas using Cr II and Zn II lines in a system at z = 1.6614 we find a systematic velocity trend that, if interpreted as a shift in α, would correspond to Δα/α = (1.88 ± 0.47) × 10{sup –5}, where both results include both statistical and systematic errors. This latter result is almost certainly caused by varying ionic abundances in subcomponents of the line: using Mn II, Ni II, and Cr II in the analysis changes the result to Δα/α = (– 0.47 ± 0.53) × 10{sup –5}. Combining the Mg II and Fe II results with estimates based on Mn II, Ni II, and Cr II gives Δα/α = (– 0.01 ± 0.26) × 10{sup –5}. We conclude that spectroscopic measurements of

  17. Constraining the Variation of the Fine-structure Constant with Observations of Narrow Quasar Absorption Lines

    NASA Astrophysics Data System (ADS)

    Songaila, A.; Cowie, L. L.

    2014-10-01

    The unequivocal demonstration of temporal or spatial variability in a fundamental constant of nature would be of enormous significance. Recent attempts to measure the variability of the fine-structure constant α over cosmological time, using high-resolution spectra of high-redshift quasars observed with 10 m class telescopes, have produced conflicting results. We use the many multiplet (MM) method with Mg II and Fe II lines on very high signal-to-noise, high-resolution (R = 72, 000) Keck HIRES spectra of eight narrow quasar absorption systems. We consider both systematic uncertainties in spectrograph wavelength calibration and also velocity offsets introduced by complex velocity structure in even apparently simple and weak narrow lines and analyze their effect on claimed variations in α. We find no significant change in α, Δα/α = (0.43 ± 0.34) × 10-5, in the redshift range z = 0.7-1.5, where this includes both statistical and systematic errors. We also show that the scatter in measurements of Δα/α arising from absorption line structure can be considerably larger than assigned statistical errors even for apparently simple and narrow absorption systems. We find a null result of Δα/α = (- 0.59 ± 0.55) × 10-5 in a system at z = 1.7382 using lines of Cr II, Zn II, and Mn II, whereas using Cr II and Zn II lines in a system at z = 1.6614 we find a systematic velocity trend that, if interpreted as a shift in α, would correspond to Δα/α = (1.88 ± 0.47) × 10-5, where both results include both statistical and systematic errors. This latter result is almost certainly caused by varying ionic abundances in subcomponents of the line: using Mn II, Ni II, and Cr II in the analysis changes the result to Δα/α = (- 0.47 ± 0.53) × 10-5. Combining the Mg II and Fe II results with estimates based on Mn II, Ni II, and Cr II gives Δα/α = (- 0.01 ± 0.26) × 10-5. We conclude that spectroscopic measurements of quasar absorption lines are not yet capable of

  18. Collisional Line-Shape and Line-Mixing Parameters for CO(2) Absorption near 3340 cm(-1): Measurements and Modeling

    NASA Astrophysics Data System (ADS)

    Buldyreva, Jeanna; Auwera, Jean Vander

    2014-06-01

    class="MsoNormal">The present work is focused on the determination of line-shape parameters for one of the 12C16O2 bands detectable by the SOIR (Solar Occultation in the InfraRed) instrument onboard the ESA Venus Express spacecraft, namely the 21102 - 00001 band located near 3340 cm-1. High-resolution Fourier transform spectra of this band have been recorded at sub-atmospheric pressures and analyzed to extract isolated-line intensities and collisional parameters as well as first-order line-mixing coefficients. Voigt, hard-collision Rautian and Sobel'man, and quadratic-speed-dependent Voigt profiles have been used. The retrieved parameters are compared with previous data available in the literature and with theoretical estimates obtained by an Energy-Corrected Sudden approach (generally, non-Markovian) employing a symmetric metric in the Liouville space. The same approach, supplied with additional hypotheses for basic transition rates for the hot bands, has also been used to model the complete band shapes. The need for accounting of line-narrowing effects at sub-atmospheric pressures has been evidenced from comparison with the recorded spectra, and some improvements have been introduced in the relaxation matrix model, leading to a good agreement of calculated and measured absorptions from nearly Doppler pressure regime to nearly atmospheric pressure.

  19. WAVELENGTH MEASUREMENTS OF K TRANSITIONS OF OXYGEN, NEON, AND MAGNESIUM WITH X-RAY ABSORPTION LINES

    SciTech Connect

    Liao Jinyuan; Zhang Shuangnan; Yao Yangsen

    2013-09-10

    Accurate atomic transition data are important in many astronomical research areas, especially for studies of line spectroscopy. Whereas transition data of He-like and H-like ions (i.e., ions in high-charge states) have been accurately calculated, the corresponding data of K transitions of neutral or low-ionized metal elements are still very uncertain. Spectroscopy of absorption lines produced in the interstellar medium (ISM) has been proven to be an effective way to measure the central wavelengths of these atomic transitions. In this work, we analyze 36 Chandra High Energy Transmission Grating observations to search for and measure the ISM absorption lines along sight lines to 11 low-mass X-ray binaries. We correct the Galactic rotation velocity to the rest frame for every observation and then use two different methods to merge all the corrected spectra to a co-added spectrum. However, the co-added spectra obtained by this method exhibit biases, toward to either observations with high counts or lines with high signal-to-noise ratios. We do a Bayesian analysis of several significantly detected lines to obtain the systematic uncertainty and the bias correction for other lines. Compared to previous studies, our results improve the wavelength accuracy by a factor of two to five and significantly reduce the systematic uncertainties and biases. Several weak transitions (e.g., 1s-2p of Mg IV and Mg V; 1s-3p of Mg III and Mg V) are also detected for the first time, albeit with low significance; future observations with improved accuracy are required to confirm these detections.

  20. Absorption Line Analysis to Interprete and Constrain Cosmological Simulations of Galaxy Evolution with Feedback

    NASA Astrophysics Data System (ADS)

    Churchill, Christopher

    2011-10-01

    The mammoth challenge for contemporary studies of galaxy formation and evolution are to establish detailed models in the cosmological context in which both the few parsec scale physics within galaxies are self-consistently unified and made consistent with the observed universe of galaxies. They key diagnostics reside with the gas physics, which dictate virtually every aspect of galaxy formation and evolution. The small scale physics includes stellar feedback, gas cooling, heating, and advection and the multiphase interstellar medium; the large scale physics includes intergalactic accretion, local merging, effects of supernovae driven winds, and the development of extended metal-enriched gas halos.Absorption line data have historically proven to be {and shall in the future} virtually the most powerful tool for understanding gas physics on all spatial scales over the majority of the age of the universe- the key to success. Simply stated, absorption lines are one of astronomy's most powerful observational windows on the universe {galaxy formation, galaxy winds, IGM metal enrichment, etc.}. The high quality and vast numbers of absorption line data {obtained with HST and FUSE} probe a broad range of gas structures {ISM, HVCs, halos, IGM} over the full cosmic span when galaxies are actively evolving.We propose to use LCDM hydrodynamic cosmological simulations employing a Eulerian Gasdynamics plus N-body Adaptive Refinement Tree {ART} code to develop and refine our understanding of stellar feedback physics and its role in governing the gas physics that regulates the evolution of galaxies and the IGM. We aim to substantially progress our understanding of all possible gas phases embedded within and extending far from galaxies. Our methodology is to apply a series of quantitative observational constraints from absorption line systems to better understand extended galaxy halos and the influence of the cosmological environment of the simulated galaxies: {1} galaxy halos

  1. UNSHIFTED METASTABLE He I* MINI-BROAD ABSORPTION LINE SYSTEM IN THE NARROW-LINE TYPE 1 QUASAR SDSS J080248.18+551328.9

    SciTech Connect

    Ji, Tuo; Zhou, Hongyan; Jiang, Peng; Wang, Tinggui; Wang, Huiyuan; Liu, Wenjuan; Yang, Chenwei; Ge, Jian; Hamann, Fred; Komossa, S.; Yuan, Weimin; Zuther, Jens; Lu, Honglin; Zuo, Wenwen

    2015-02-10

    We report the identification of an unusual absorption-line system in the quasar SDSS J080248.18+551328.9 and present a detailed study of the system, incorporating follow-up optical and near-IR spectroscopy. A few tens of absorption lines are detected, including He I*, Fe II*, and Ni II*, which arise from metastable or excited levels, as well as resonant lines in Mg I, Mg II, Fe II, Mn II, and Ca II. All of the isolated absorption lines show the same profile of width Δv ∼ 1500 km s{sup –1} centered at a common redshift as that of the quasar emission lines, such as [O II], [S II], and hydrogen Paschen and Balmer series. With narrow Balmer lines, strong optical Fe II multiplets, and weak [O III] doublets, its emission-line spectrum is typical for that of a narrow-line Seyfert 1 galaxy (NLS1). We have derived reliable measurements of the gas-phase column densities of the absorbing ions/levels. Photoionization modeling indicates that the absorber has a density of n {sub H} ∼ (1.0-2.5) × 10{sup 5} cm{sup –3} and a column density of N {sub H} ∼ (1.0-3.2) × 10{sup 21} cm{sup –2} and is located at R ∼100-250 pc from the central supermassive black hole. The location of the absorber, the symmetric profile of the absorption lines, and the coincidence of the absorption- and emission-line centroid jointly suggest that the absorption gas originates from the host galaxy and is plausibly accelerated by stellar processes, such as stellar winds and/or supernova explosions. The implications for the detection of such a peculiar absorption-line system in an NLS1 are discussed in the context of coevolution between supermassive black hole growth and host galaxy buildup.

  2. Line-Parameter Measurements and Stringent Tests of Line-Shape Models Based on Cavity-Enhanced Absorption Spectroscopy

    NASA Astrophysics Data System (ADS)

    Bielska, Katarzyna; Fleisher, Adam J.; Hodges, Joseph T.; Lin, Hong; Long, David A.; Reed, Zachary D.; Sironneau, Vincent; Truong, Gar-Wing; Wójtewicz, Szymon

    2014-06-01

    Laser methods that are based on cavity-enhanced absorption spectroscopy (CEAS) are well-suited for measuring molecular line parameters under conditions of low optical density, and as such they are complementary to broadband Fourier-transform spectroscopy (FTS) techniques. Attributes of CEAS include relatively low detection limits, accurate and precise detuning axes and high fidelity measurements of line shape. In many cases these performance criteria are superior to those obtained using direct laser absorption spectroscopy and FTS-based systems. In this presentation we will survey several examples of frequency-stabilized cavity ring-down spectroscopy (FS-CRDS)1 measurements obtained with laser spectrometers developed at the National Institute of Standards and Technology (NIST) in Gaithersburg Maryland. These experiments, which are motivated by atmospheric monitoring and remote-sensing applications that require high-precision and accuracy, involve nearinfrared transitions of carbon dioxide, water, oxygen and methane. We discuss spectra with signal-to-noise ratios exceeding 106, frequency axes with absolute uncertainties in the 10 kHz to 100 kHz range and linked to a Cs clock, line parameters with relative uncertainties at the 0.2 % level and isotopic ratios measured with a precision of 0.03 %. We also present FS-CRDS measurements of CO2 line intensities which are measured at atmospheric concentration levels and linked to gravimetric standards for CO2 in air, and we quantify pressure-dependent deviations between various theoretical line profiles and measured line shapes. Finally we also present recent efforts to increase data throughput and spectral coverage in CEAS experiments. We describe three new high-bandwidth CEAS techniques including frequency-agile, rapid scanning spectroscopy (FARS)2, which enables continuous-wave measurements of cavity mode linewidth and acquisition of ringdown decays with no dead time during laser frequency tuning, heterodyne

  3. Made-to-measure galaxy modelling utilising absorption line strength data

    NASA Astrophysics Data System (ADS)

    Long, R. J.

    2016-12-01

    We enhance the Syer & Tremaine made-to-measure (M2M) particle method of stellar dynamical modelling to model simultaneously both kinematic data and absorption line strength data, thus creating a ‘chemo-M2M’ modelling scheme. We apply the enhanced method to four galaxies (NGC 1248, NGC 3838, NGC 4452, NGC 4551) observed using the SAURON integral-field spectrograph as part of the ATLAS3D programme. We are able to reproduce successfully the 2D line strength data achieving mean χ2 per bin values of ≈ 1 with > 95% of particles having converged weights. Because M2M uses a 3D particle system, we are also able to examine the underlying 3D line strength distributions. The extent to which these distributions are plausible representations of real galaxies requires further consideration. Overall, we consider the modelling exercise to be a promising first step in developing a ‘chemo-M2M’ modelling system and in understanding some of the issues to be addressed. While the made-to-measure techniques developed have been applied to absorption line strength data, they are in fact general and may be of value in modelling other aspects of galaxies.

  4. Conduction noise absorption by ITO thin films attached to microstrip line utilizing Ohmic loss

    SciTech Connect

    Kim, Sun-Hong; Kim, Sung-Soo

    2010-07-15

    For the aim of wide-band noise absorbers with a special design for low frequency performance, this study proposes conductive indium-tin oxide (ITO) thin films as the absorbent materials in microstrip line. ITO thin films were deposited on the polyimide film substrates by rf magnetron cosputtering of In{sub 2}O{sub 3} and Sn targets. The deposited ITO films show a typical value of electrical resistivity ({approx}10{sup -4} {Omega} m) and sheet resistance can be controlled in the range of 20-230 {Omega} by variation in film thickness. Microstrip line with characteristic impedance of 50 {Omega} was used for determining their noise absorbing properties. It is found that there is an optimum sheet resistance of ITO films for the maximum power absorption. Reflection parameter (S{sub 11}) is increased with decrease in sheet resistance due to impedance mismatch. On the while, transmission parameter (S{sub 21}) is decreased with decrease in sheet resistance due to larger Ohmic loss of the ITO films. Experimental results and computational prediction show that the optimum sheet resistance is about 100 {Omega}. For this film, greater power absorption is predicted in the lower frequency region than ferrite thin films of high magnetic loss, which indicates that Ohmic loss is the predominant loss parameter for power absorption in the low frequency range.

  5. Atlas of Absorption Lines from 0 to 17900 Cm (sup)-1

    NASA Technical Reports Server (NTRS)

    Park, J. H.; Rothman, L. S.; Rinsland, C. P.; Pickett, H. M.; Richardson, D. J.; Namkung, J. S.

    1987-01-01

    Plots of logarithm (base 10) of absorption line strength versus wavenumber from 0 to 17900/cm(sup)-1 are shown for the 28 atmospheric gases (H2O, CO2, O3, N2O, CO, CH4, O2, NO, SO2, NO2, NH3, HNO3, OH, HF, HCl, HBr, HI, ClO, OCS, H2CO, HOCl, N2, HCN, CH3Cl, H2O2, C2H2, C2H6, PH3), which appear in the 1986 Air Force Geophysics Laboratory high-resolution transmission molecular absorption data base (HITRAN) compilation, and for O(P-3), O-18 isotopic ozone, and HO2 from the 1984 JPL compilation in the 0- to 200/cm(sup)-1 region, and infrared solar CO lines at 4500 K. Also shown are plots of logarithm (base 10) of approximate infrared absorption cross sections of 11 heavy molecules versus wavenumber. The cross-section data cover 700 to 1800/cm(sup)-1 and are included as a separate data file in the 1986 HITRAN database.

  6. THE SURPRISING ABSENCE OF ABSORPTION IN THE FAR-ULTRAVIOLET SPECTRUM OF Mrk 231

    SciTech Connect

    Veilleux, S.; Trippe, M.; Krug, H.; Hamann, F.; Rupke, D. S. N.; Tripp, T. M.; Netzer, H.; Lutz, D.; Genzel, R.; Sturm, E.; Tacconi, L.; Sembach, K. R.; Teng, S. H.; Maiolino, R. E-mail: veilleux@astro.umd.edu

    2013-02-10

    Mrk 231, the nearest (z = 0.0422) quasar, hosts both a galactic-scale wind and a nuclear-scale iron low-ionization broad absorption line (FeLoBAL) outflow. We recently obtained a far-ultraviolet (FUV) spectrum of this object covering {approx}1150-1470 A with the Cosmic Origins Spectrograph on board the Hubble Space Telescope. This spectrum is highly peculiar, highlighted by the presence of faint ({approx}<2% of predictions based on H{alpha}), broad ({approx}>10,000 km s{sup -1} at the base), and highly blueshifted (centroid at {approx} -3500 km s{sup -1}) Ly{alpha} emission. The FUV continuum emission is slightly declining at shorter wavelengths (consistent with F {sub {lambda}}{proportional_to}{lambda}{sup 1.7}) and does not show the presence of any obvious photospheric or wind stellar features. Surprisingly, the FUV spectrum also does not show any unambiguous broad absorption features. It thus appears to be dominated by the AGN, rather than hot stars, and virtually unfiltered by the dusty FeLoBAL screen. The observed Ly{alpha} emission is best explained if it is produced in the outflowing BAL cloud system, while the Balmer lines arise primarily from the standard broad emission line region seen through the dusty (A{sub V} {approx} 7 mag) broad absorption line region. Two possible geometric models are discussed in the context of these new results.

  7. The Surprising Absence of Absorption in the Far-ultraviolet Spectrum of Mrk 231

    NASA Technical Reports Server (NTRS)

    Veilleux, S.; Trippe, M.; Hamann, F.; Rupke, D. S. N.; Tripp, T. M.; Netzer, H.; Lutz, D.; Sembach, K. R.; Krug, H.; Teng, Stacy H.; Genzel, R.; Maiolino, R.; Sturm, E.; Tacconi, L.

    2013-01-01

    Mrk 231, the nearest (z = 0.0422) quasar, hosts both a galactic-scale wind and a nuclear-scale iron low-ionization broad absorption line (FeLoBAL) outflow. We recently obtained a far-ultraviolet (FUV) spectrum of this object covering approx. 1150-1470A with the Cosmic Origins Spectrograph on board the Hubble Space Telescope. This spectrum is highly peculiar, highlighted by the presence of faint (< or approx.2% of predictions based on H(alpha)), broad (> or approx.10,000 km/s at the base), and highly blueshifted (centroid at approx. 3500 km/s) Ly(aplpha) emission. The FUV continuum emission is slightly declining at shorter wavelengths (consistent with F(sub lambda) Alpha Lambda(sup 1.7)) and does not show the presence of any obvious photospheric or wind stellar features. Surprisingly, the FUV spectrum also does not show any unambiguous broad absorption features. It thus appears to be dominated by the AGN, rather than hot stars, and virtually unfiltered by the dusty FeLoBAL screen. The observed Ly(alpha) emission is best explained if it is produced in the outflowing BAL cloud system, while the Balmer lines arise primarily from the standard broad emission line region seen through the dusty (Av approx. 7 mag) broad absorption line region. Two possible geometric models are discussed in the context of these new results.

  8. Low redshift Lyman alpha absorption lines and the dark matter halos of disk galaxies

    NASA Technical Reports Server (NTRS)

    Maloney, Philip

    1993-01-01

    Recent observations using the Hubble Space Telescope of the z = 0.156 QSO 3C 273 have discovered a surprisingly large number of Ly-alpha absorption lines. In particular, Morris et al. found 9 certain and 7 possible Ly-alpha lines with equivalent widths above 25 mA. This is much larger (by a factor of 5-10) than the number expected from extrapolation of the high-redshift behavior of the Ly-alpha forest. Within the context of pressure-confined models for the Ly-alpha clouds, this behavior can be understood if the ionizing background declines sharply between z is approximately 2 and z is approximately 0. However, this requires that the ionizing photon flux drop as rapidly as the QSO volume emissivity; moreover, the absorbers must have a space density n(sub O) is approximately 2.6(N/10)h/((D/100 kpc)(sup 2)) Mpc(sup -3) where D is the present-day diameter of the absorbers. It is somewhat surprising that such necessarily fragile objects could have survived in such numbers to the present day. It is shown that it is plausible that the atomic hydrogen extents of spiral and irregular galaxies are large enough to produce the observed number of Ly-alpha absorption lines toward 3C 273, and that the neutral column densities and doppler b-values expected under these conditions fall in the range found by Morris et al. (1991).

  9. Quasar Absorption Lines from Radiative Shocks: Implications for Multiphase Outflows and Feedback

    NASA Astrophysics Data System (ADS)

    Faucher-Giguère, C.-A.

    2012-08-01

    Photoionization modeling of certain low-ionization broad absorption lines in quasars implies very compact (ΔR ˜0.01 pc), galaxy-scale (R˜ kpc) absorbers blueshifted by several 1000 km s-1. While these are likely signatures of quasar outflows, the lifetimes of such compact absorbers are too short for them to be direct ejecta from a nuclear wind. Instead, I argue that the absorbing clouds must be transient and created in situ. Following arguments detailed by Faucher-Giguère, Quataert, & Murray (2011), I show that a model in which the cool absorbers form in radiative shocks arising when a quasar blast wave impacts an interstellar cloud along the line of sight successfully explains the key observed properties. Using this radiative shock model, the outflow kinetic luminosities for three luminous quasars are estimated to be Ėk ≍ 2-5% LAGN (with corresponding momentum fluxes Ṗ ≍2-15 LAGN/c), consistent with feedback models of the M-σ relation. These energetics are similar to those recently inferred of molecular outflows in local ultra-luminous infrared galaxies and in post-starburt winds, suggesting that active galactic nuclei (AGN) are capable of driving such outflows. Radiative shocks probably affect the multiphase structure of outflows in a range of other systems, potentially including narrower and higher-ionization quasar absorption lines, and compact intergalactic absorbers ejected by star formation and/or AGN activity.

  10. When galaxies collide: understanding the broad absorption-line radio galaxy 4C +72.26

    NASA Astrophysics Data System (ADS)

    Smith, D. J. B.; Simpson, C.; Swinbank, A. M.; Rawlings, S.; Jarvis, M. J.

    2010-05-01

    We present a range of new observations of the `broad absorption-line radio galaxy' 4C +72.26 (z ~ 3.5), including sensitive rest-frame ultraviolet integral field spectroscopy using the Gemini/GMOS-N instrument and Subaru/CISCO K-band imaging and spectroscopy. We show that 4C +72.26 is a system of two vigorously star-forming galaxies superimposed along the line of sight separated by ~1300 +/- 200 km s-1 in velocity, with each demonstrating spectroscopically resolved absorption lines. The most active star-forming galaxy also hosts the accreting supermassive black hole which powers the extended radio source. We conclude that the star formation is unlikely to have been induced by a shock caused by the passage of the radio jet, and instead propose that a collision is a more probable trigger for the star formation. Despite the massive starburst, the ultraviolet-mid-infrared spectral energy distribution suggests that the pre-existing stellar population comprises ~1012Msolar of stellar mass, with the current burst only contributing a further ~2 per cent, suggesting that 4C +72.26 has already assembled most of its final stellar mass.

  11. Heterodyne detection of the 752.033-GHz H2O rotational absorption line

    NASA Astrophysics Data System (ADS)

    Dionne, G. F.; Fitzgerald, J. F.; Chang, T. S.; Litvak, M. M.; Fetterman, H. R.

    1980-08-01

    A tunable high resolution two stage heterodyne radiometer was developed for the purpose of investigating the intensity and lineshape of the 752.033 GHz rotational transition of water vapor. Single-sideband system noise temperatures of approximately 45,000 K were obtained using a sensitive GaAs Schottky diode as the first stage mixer. First local oscillator power was supplied by a CO2 laser pumped formic acid laser (761.61 GHz), generating an X-band IF signal with theoretical line center at 9.5744 GHz. Second local oscillator power was provided by means of a 3 GHz waveguide cavity filter with only 9 dB insertion loss. In absorption measurements of the H2O taken from a laboratory simulation of a high altitude rocket plume, the center frequency of the 752 GHz line was determined to within 1 MHz of the reported value. A rotational temperature 75 K, a linewidth 5 MHz and a Doppler shift 3 MHz were measured with the line-of-sight intersecting the simulated-plume axis at a distance downstream of 30 nozzle diameters. These absorption data were obtained against continuum background radiation sources at temperatures of 1175 and 300 K.

  12. Heterodyne detection of the 752.033-GHz H2O rotational absorption line

    NASA Technical Reports Server (NTRS)

    Dionne, G. F.; Fitzgerald, J. F.; Chang, T. S.; Litvak, M. M.; Fetterman, H. R.

    1980-01-01

    A tunable high resolution two stage heterodyne radiometer was developed for the purpose of investigating the intensity and lineshape of the 752.033 GHz rotational transition of water vapor. Single-sideband system noise temperatures of approximately 45,000 K were obtained using a sensitive GaAs Schottky diode as the first stage mixer. First local oscillator power was supplied by a CO2 laser pumped formic acid laser (761.61 GHz), generating an X-band IF signal with theoretical line center at 9.5744 GHz. Second local oscillator power was provided by means of a 3 GHz waveguide cavity filter with only 9 dB insertion loss. In absorption measurements of the H2O taken from a laboratory simulation of a high altitude rocket plume, the center frequency of the 752 GHz line was determined to within 1 MHz of the reported value. A rotational temperature 75 K, a linewidth 5 MHz and a Doppler shift 3 MHz were measured with the line-of-sight intersecting the simulated-plume axis at a distance downstream of 30 nozzle diameters. These absorption data were obtained against continuum background radiation sources at temperatures of 1175 and 300 K.

  13. Instabilities in line-driven stellar winds. III - Wave propagation in the case of pure line absorption

    NASA Technical Reports Server (NTRS)

    Owocki, S. P.; Rybicki, G. B.

    1986-01-01

    The spatial and temporal evolution of small-amplitude velocity perturbations is examined in the idealized case of a stellar wind that is driven by pure line absorption of the star's continuum radiation. It is established that the instability in the supersonic region is of the advective type relative to the star, but of the absolute type relative to the wind itself. It is also shown that the inward propagation of information in such a wind is limited to the sound speed, in contrast to the theory of Abbott, which predicts inward propagation faster than sound. This apparent contradiction is resolved through an extensive discussion of the analytically soluble case of zero sound speed.

  14. Quasar Absorption Lines: The Evolution of Galactic Gas Over Cosmic Time

    NASA Astrophysics Data System (ADS)

    Charlton, J.

    1996-12-01

    A view of the formation and evolution of galaxies and structure over the whole history of the Universe requires observations both of stars and of gas. From the stars in galaxies, now observed in deep images back in time to less than a billion years past the Big Bang, we can study the evolution of galaxy morphology and of star formation rates. Direct observation of gas in the Universe at all epochs is also possible, using absorption spectra of quasars as a probe of intervening material. This absorption arises not only from the gas in developed galaxies and in their environments, but also from the clumps of gas that will eventually combine to form galaxies, and from the gas spread through the Universe that is gradually flowing into the galaxies. This study of gas through quasar absorption lines has opened the possibility of observing directly the formation of galaxies through the assembly of their gas over time. Furthermore, with high resolution spectroscopy, the substructures observed in absorption profiles provide information about the internal workings of galaxies. This talk will present an overview of progress toward a comprehensive picture of the formation and evolution of galaxies through quasar absorption line studies. The absorption profiles that are observed due to the passage of the quasar light through a given structure are a convolution of several properties of the gas, including its spatial and kinematic distribution, its chemical composition, and its state of ionization. Illustrative models will be utilized to show how these various factors affect the appearance of synthetic spectra. Beginning with the philosophy ``what you see is what you get'', the kinematic spectral signatures of higher redshift absorbers will be modeled by familiar components of nearby galaxies: a rotating disk, an isothermal halo, and gas in radial inflow. A combination of these basic models goes a long way toward producing a variety of complex absorption profiles which are in fact

  15. Improved and Quality-assessed Emission and Absorption Line Measurements in Sloan Digital Sky Survey Galaxies

    NASA Astrophysics Data System (ADS)

    Oh, Kyuseok; Sarzi, Marc; Schawinski, Kevin; Yi, Sukyoung K.

    2011-08-01

    We present a new database of absorption and emission-line measurements based on the entire spectral atlas from the Sloan Digital Sky Survey (SDSS) 7th data release of galaxies within a redshift of 0.2. Our work makes use of the publicly available penalized pixel-fitting (pPXF) and gas and absorption line fitting (gandalf) IDL codes, aiming to improve the existing measurements for stellar kinematics, the strength of various absorption-line features, and the flux and width of the emissions from different species of ionized gas. Our fit to the stellar continuum uses both standard stellar population models and empirical templates obtained by combining a large number of stellar spectra in order to fit a subsample of high-quality SDSS spectra for quiescent galaxies. Furthermore, our fit to the nebular spectrum includes an exhaustive list of both recombination and forbidden lines. Foreground Galactic extinction is implicitly treated in our models, whereas reddening in the SDSS galaxies is included in the form of a simple dust screen component affecting the entire spectrum that is accompanied by a second reddening component affecting only the ionized gas emission. In order to check for systematic departures from the rather standard set of assumptions that enters our models, we provide a quality assessment for our fit to the SDSS spectra in our sample, for both the stellar continuum and the nebular emissions and across different wavelength regions. This quality assessment also allows the identification of objects with either problematic data or peculiar features. We hope to foster the discovery potential of our database; therefore, our spectral fit is available to the community. For example, based on the quality assessment around the Hα and [N II] λ6584 lines, approximately 1% of the SDSS spectra classified as "galaxies" by the SDSS pipeline do in fact require additional broad lines to be matched, even though they do not show a strong continuum from an active nucleus, as

  16. IMPROVED AND QUALITY-ASSESSED EMISSION AND ABSORPTION LINE MEASUREMENTS IN SLOAN DIGITAL SKY SURVEY GALAXIES

    SciTech Connect

    Oh, Kyuseok; Yi, Sukyoung K.; Sarzi, Marc; Schawinski, Kevin

    2011-08-01

    We present a new database of absorption and emission-line measurements based on the entire spectral atlas from the Sloan Digital Sky Survey (SDSS) 7th data release of galaxies within a redshift of 0.2. Our work makes use of the publicly available penalized pixel-fitting (pPXF) and gas and absorption line fitting (gandalf) IDL codes, aiming to improve the existing measurements for stellar kinematics, the strength of various absorption-line features, and the flux and width of the emissions from different species of ionized gas. Our fit to the stellar continuum uses both standard stellar population models and empirical templates obtained by combining a large number of stellar spectra in order to fit a subsample of high-quality SDSS spectra for quiescent galaxies. Furthermore, our fit to the nebular spectrum includes an exhaustive list of both recombination and forbidden lines. Foreground Galactic extinction is implicitly treated in our models, whereas reddening in the SDSS galaxies is included in the form of a simple dust screen component affecting the entire spectrum that is accompanied by a second reddening component affecting only the ionized gas emission. In order to check for systematic departures from the rather standard set of assumptions that enters our models, we provide a quality assessment for our fit to the SDSS spectra in our sample, for both the stellar continuum and the nebular emissions and across different wavelength regions. This quality assessment also allows the identification of objects with either problematic data or peculiar features. We hope to foster the discovery potential of our database; therefore, our spectral fit is available to the community. For example, based on the quality assessment around the H{alpha} and [N II] {lambda}6584 lines, approximately 1% of the SDSS spectra classified as 'galaxies' by the SDSS pipeline do in fact require additional broad lines to be matched, even though they do not show a strong continuum from an active

  17. THE SLOAN DIGITAL SKY SURVEY REVERBERATION MAPPING PROJECT: RAPID C iv BROAD ABSORPTION LINE VARIABILITY

    SciTech Connect

    Grier, C. J.; Brandt, W. N.; Trump, J. R.; Schneider, D. P.; Hall, P. B.; Shen, Yue; Vivek, M.; Dawson, K. S.; Ak, N. Filiz; Chen, Yuguang; Denney, K. D.; Kochanek, C. S.; Peterson, B. M.; Green, Paul J.; Jiang, Linhua; McGreer, Ian D.; Pâris, I.; Tao, Charling; Bizyaev, Dmitry; and others

    2015-06-10

    We report the discovery of rapid variations of a high-velocity C iv broad absorption line trough in the quasar SDSS J141007.74+541203.3. This object was intensively observed in 2014 as a part of the Sloan Digital Sky Survey Reverberation Mapping Project, during which 32 epochs of spectroscopy were obtained with the Baryon Oscillation Spectroscopic Survey spectrograph. We observe significant (>4σ) variability in the equivalent width (EW) of the broad (∼4000 km s{sup −1} wide) C iv trough on rest-frame timescales as short as 1.20 days (∼29 hr), the shortest broad absorption line variability timescale yet reported. The EW varied by ∼10% on these short timescales, and by about a factor of two over the duration of the campaign. We evaluate several potential causes of the variability, concluding that the most likely cause is a rapid response to changes in the incident ionizing continuum. If the outflow is at a radius where the recombination rate is higher than the ionization rate, the timescale of variability places a lower limit on the density of the absorbing gas of n{sub e} ≳ 3.9 × 10{sup 5} cm{sup −3}. The broad absorption line variability characteristics of this quasar are consistent with those observed in previous studies of quasars, indicating that such short-term variability may in fact be common and thus can be used to learn about outflow characteristics and contributions to quasar/host-galaxy feedback scenarios.

  18. A Survey for Intervening CIV Absorption-Line Systems Using SDSS Quasar Spectra

    NASA Astrophysics Data System (ADS)

    Monier, Eric M.; Nestor, D. B.; Daino, M. M.; Quider, A. M.; Rao, S. M.; Turnshek, D. A.

    2006-06-01

    Intervening CIV absorption-line systems are readily found in Sloan Digital Sky Survey (SDSS) quasar spectra at redshifts z > 1.5. Given the large number of absorbers, high statistical accuracy is possible in comparison to what was possible in the past. Here we present preliminary results on the incidence and evolution of the CIV systems as a function of CIV rest equivalent width. The absorber incidence is proportional to the product of gas cross-section and co-moving number density of absorbers, while the rest equivalent width is related to their kinematic spread. We discuss the interpretation of our results.

  19. New aspects of absorption line formation in intervening turbulent clouds - II. Monte Carlo simulation of interstellar H+D Lyalpha absorption profiles

    NASA Astrophysics Data System (ADS)

    Levshakov, Sergei A.; Kegel, Wilhelm H.; Mazets, Igor E.

    1997-07-01

    Stochastic velocity fields with finite correlation lengths affect the formation of interstellar (intergalactic) absorption lines in a way not accounted for in the standard analysis procedure in which Voigt profiles are fitted to the observed line profiles. We investigate these effects, accounting in particular for the fact that interstellar absorption spectra reflect only one realization of the velocity field, since (i) actually only one line of sight is observed and (ii) the velocity structure of the cloud has to be considered to be `frozen' over the exposure time. This paper presents results of Monte Carlo calculations. In this technique an ensemble of line profiles is computed, each one of which corresponds to one realization of the random velocity field. The most important results are the following. (1) The individual line profiles may deviate substantially from each other and from the ensemble average. (2) Correlated velocity fields may cause complex multicomponent absorption features which in a traditional analysis would be attributed to several clouds, i.e. to density and/or kinetic temperature inhomogeneities. (3) Each line of sight has its own curve-of-growth. (4) Applying the standard analysis to such line profiles may produce misleading results concerning the physical parameters of the cloud. (5) In particular, the apparent scatter of the D/H ratio revealed in the ISM on the basis of the Copernicus, IUE, and HST observations may be caused by an inadequate analysis. Finally, we discuss under which conditions cloud characteristics may be derived from absorption lines without relying on a particular physical model.

  20. Water-vapor absorption line measurements in the 940-nm band by using a Raman-shifted dye laser

    NASA Technical Reports Server (NTRS)

    Chu, Zhiping; Wilkerson, Thomas D.; Singh, Upendra N.

    1993-01-01

    We report water-vapor absorption line measurements that are made by using the first Stokes radiation (930-982 nm) with HWHM 0.015/cm generated by a narrow-linewidth, tunable dye laser. Forty-five absorption line strengths are measured with an uncertainty of 6 percent and among them are fourteen strong lines that are compared with previous measurements for the assessment of spectral purity of the light source. Thirty air-broadened linewidths are measured with 8 percent uncertainty at ambient atmospheric pressure with an average of 0.101/cm. The lines are selected for the purpose of temperature-sensitive or temperature-insensitive lidar measurements. Results for these line strengths and linewidths are corrected for broadband radiation and finite laser linewidth broadening effects and compared with the high-resolution transmission molecular absorption.

  1. Absorption-line spectrum of GC 1556 + 335 - ejected or intervening material

    SciTech Connect

    Morris, S.L.; Weymann, R.J.; Foltz, C.B.; Turnshek, D.A.; Shectman, S.

    1986-11-01

    Two rich C IV absorption complexes in the radio-loud QSO GC 1556 + 335 are described. Column densities for seven of the redshift systems in these complexes are measured, and limits on the distances between the QSO and absorbing clouds are derived using ionization parameters estimated from matching photoionization models to the observations and a density estimated from an upper limit to the C II(asterisk) column density in the z = 1.65367 redshift system. These limits show that GC 1556 + 335 is not a typical member of the BALQSO class. Two alternative models are discussed in which the absorption complexes are caused by material either entrained into a radio jet from the QSO or contained in two clusters of galaxies along the line of sight. It is suggested that the emission associated with the complexes may be detectable, and that a study of the velocity field and geometry of such emission might be decisive in determining the mechanism responsible for the absorption. 40 references.

  2. THE JHU-SDSS METAL ABSORPTION LINE CATALOG: REDSHIFT EVOLUTION AND PROPERTIES OF Mg II ABSORBERS

    SciTech Connect

    Zhu Guangtun; Menard, Brice

    2013-06-20

    We present a generic and fully automatic method aimed at detecting absorption lines in the spectra of astronomical objects. The algorithm estimates the source continuum flux using a dimensionality reduction technique and nonnegative matrix factorization, and then detects and identifies metal absorption lines. We apply it to a sample of {approx}10{sup 5} quasar spectra from the Sloan Digital Sky Survey and compile a sample of {approx}40,000 Mg II- and Fe II-absorber systems, spanning the redshift range 0.4 < z < 2.3. The corresponding catalog is publicly available. We study the statistical properties of these absorber systems and find that the rest equivalent width distribution of strong Mg II absorbers follows an exponential distribution at all redshifts, confirming previous studies. Combining our results with recent near-infrared observations of Mg II absorbers, we introduce a new parameterization that fully describes the incidence rate of these systems up to z {approx} 5. We find the redshift evolution of strong Mg II absorbers to be remarkably similar to the cosmic star formation history over 0.4 < z < 5.5 (the entire redshift range covered by observations), suggesting a physical link between these two quantities.

  3. Line formation in Be star circumstellar disks Shear broadening, shell absorption, stellar obscuration and rotational parameter

    NASA Astrophysics Data System (ADS)

    Hummel, W.; Vrancken, M.

    2000-07-01

    We improve the theory of Horne & Marsh on shear broadening in accretion disks of CVs and adapt it to Be star circumstellar disks. Stellar obscuration and shell absorption are taken into account in detail. It is shown that shell absorption is already present in those emission lines where the central depression does not drop below the stellar continuum. The model profiles are fitted to observed symmetric Hα net emission lines with low equivalent width. The derived disk radii range from Rd = 5.3 R_* to Rd = 18 R_* and the surface emissivity varies as ~ R-m with 1.6 < m < 3.5. The comparison between model profiles of rotational parameter j>(1)/(2) with the optically thick Hα profile of HR 5440 rules out the range of j>(1)/(2). This can be understood by the lack of velocity shear in the outer disk regions. We conclude that Keplerian rotation (j=(1)/(2)) is a valid approximation. Based on observations collected at the German-Spanish Astronomical Center (DSAZ), Calar Alto, operated by the Max-Plank-Institut für Astronomie Heidelberg jointly with the Spanish National Commission for Astronomy. Based on observations collected at the Observatoire de Haute-Provence (OHP), CNRS, France.

  4. High-resolution absorption spectroscopy of the OH 2Π3/2 ground state line

    NASA Astrophysics Data System (ADS)

    Wiesemeyer, H.; Güsten, R.; Heyminck, S.; Jacobs, K.; Menten, K. M.; Neufeld, D. A.; Requena-Torres, M. A.; Stutzki, J.

    2012-06-01

    The chemical composition of the interstellar medium is determined by gas phase chemistry, assisted by grain surface reactions, and by shock chemistry. The aim of this study is to measure the abundance of the hydroxyl radical (OH) in diffuse spiral arm clouds as a contribution to our understanding of the underlying network of chemical reactions. Owing to their high critical density, the ground states of light hydrides provide a tool to directly estimate column densities by means of absorption spectroscopy against bright background sources. We observed onboard the SOFIA observatory the 2Π3/2, J = 5/2 ← 3/2 2.5 THz line of ground-state OH in the diffuse clouds of the Carina-Sagittarius spiral arm. OH column densities in the spiral arm clouds along the sightlines to W49N, W51 and G34.26+0.15 were found to be of the order of 1014 cm-2, which corresponds to a fractional abundance of 10-7 to 10-8, which is comparable to that of H2O. The absorption spectra of both species have similar velocity components, and the ratio of the derived H2O to OH column densities ranges from 0.3 to 1.0. In W49N we also detected the corresponding line of 18OH.

  5. Absorption-Line Probes of Gas and Dust in Galactic Superwinds

    NASA Astrophysics Data System (ADS)

    Heckman, Timothy M.; Lehnert, Matthew D.; Strickland, David K.; Armus, Lee

    2000-08-01

    We have obtained moderate resolution (R=few thousand) spectra of the Na I λλ5890, 5896 (Na D) absorption line in a sample of 32 far-IR-bright starburst galaxies. In 18 cases, the Na D line in the nucleus is produced primarily by interstellar gas, while cool stars contribute significantly in the others. In 12 of the 18 ``interstellar-dominated'' cases the Na D line is blueshifted by over 100 km s-1 relative to the galaxy systemic velocity (the ``outflow sources''), while no case shows a net redshift of more than 100 km s-1. The absorption-line profiles in these outflow sources span the range from near the galaxy systemic velocity to a maximum blueshift of ~400-600 km s-1. The outflow sources are galaxies systematically viewed more nearly face-on than the others. We therefore argue that the absorbing material consists of ambient interstellar material that has been entrained and accelerated along the minor axis of the galaxy by a hot starburst-driven superwind. The Na D lines are optically thick, but indirect arguments imply total hydrogen column densities of NH~few×1021 cm-2. This implies that the superwind is expelling matter at a rate comparable to the star formation rate. This outflowing material is evidently very dusty: we find a strong correlation between the depth of the Na D profile and the line-of-sight reddening. Typical implied values are E(B-V)=0.3-1 over regions several-to-10 kpc in size. We briefly consider some of the potential implications of these observations. The estimated terminal velocities of superwinds inferred from the present data and extant X-ray data are typically 400-800 km-1, are independent of the galaxy rotation speed, and are comparable to (substantially exceed) the escape velocities for L* (dwarf) galaxies. The resulting selective loss of metals from shallower potential wells can establish the mass-metallicity relation in spheroids, produce the observed metallicity in the intracluster medium, and enrich a general IGM to of order 10

  6. Probing the interstellar medium in Puppis-Vela through optical absorption line spectroscopy

    NASA Astrophysics Data System (ADS)

    Cha, Alexandra Nicole Stuehler

    2000-06-01

    The interstellar medium (ISM) toward Puppis-Vela (l = 245° to 275°, b = -15° to +5°) has been studied using high resolution, R ~ 75,000-90,000, high signal-to-noise, S/N ~ 100, optical Na I and Ca II absorption spectra along several hundred lines of sight. The distance of the Vela supernova remnant was found to be at d ~ 250 pc, a factor of two less than the canonical value. Lines of sight passing through the Vela supernova remnant were seen to have optical spectra that varied over epochs of a few years, including those toward HD 72089, HD 72127, HD 72997, HD 73658, HD 74455, HD 75309, and HD 75821. The variability of the first three lines of sight had been previously documented, but variability in the spectra toward the latter four stars had not been observed. An analysis of the Local ISM (d < 200 pc) toward Puppis-Vela is presented, and using both Na I absorption features and accurate distances to the stars, courtesy of Hipparcos trigonometric parallax data, spatially compact, homogeneous velocity components were mapped. In the Local ISM, the Puppis-Vela region abuts the apparent extension of the Local Bubble (or Cavity) known as the β CMa tunnel, and the compiled Na I lines of sight suggest that within 200 pc, the extent of the tunnel is confined to a region smaller than was previously thought. The technique of identifying and mapping individual velocity components in three dimensions was extended to the Puppis-Vela ISM out to d ~ 1 kpc, and a total of 7 velocity components were identified. Gas with velocities higher than that expected in the ambient ISM combined with higher than normal reddening was detected toward two regions, (l ~ 254°, b ~ -1°) and (l ~ 251°, b ~ -7°), suggesting the presence of previously unidentified structures. Nearby, gas associated with the IRAS Vela Shell was detected in Na I at distances >~ 300 pc. The Na I velocity components from IRAS Vela Shell sight lines were fit with a model of a spherically expanding filled sphere with

  7. Multi-Sightline Observation of Narrow Absorption Lines in Lensed Quasar SDSS J1029+2623

    NASA Astrophysics Data System (ADS)

    Misawa, Toru; Saez, Cristian; Charlton, Jane C.; Eracleous, Michael; Chartas, George; Bauer, Franz E.; Inada, Naohisa; Uchiyama, Hisakazu

    2016-07-01

    We exploit the widely separated images of the lensed quasar SDSS J1029+2623 ({z}{em} = 2.197, θ = 22.″5) to observe its outflowing wind through two different sightlines. We present an analysis of three observations, including two with the Subaru telescope in 2010 February and 2014 April, separated by four years, and one with the Very Large Telescope, separated from the second Subaru observation by ˜2 months. We detect 66 narrow absorption lines (NALs), of which 24 are classified as intrinsic NALs that are physically associated with the quasar based on partial coverage analysis. The velocities of intrinsic NALs appear to cluster around values of {v}{ej} ˜ 59,000, 43,000, and 29,000 km s-1, which is reminiscent of filamentary structures obtained by numerical simulations. There are no common intrinsic NALs at the same redshift along the two sightlines, implying that the transverse size of the NAL absorbers should be smaller than the sightline distance between two lensed images. In addition to the NALs with large ejection velocities of {v}{ej} > 1000 km s-1, we also detect broader proximity absorption lines (PALs) at {z}{abs} ˜ {z}{em}. The PALs are likely to arise in outflowing gas at a distance of r ≤ 620 pc from the central black hole with an electron density of n e ≥8.7 × 103 cm-3. These limits are based on the assumption that the variability of the lines is due to recombination. We discuss the implications of these results on the three-dimensional structure of the outflow.

  8. Search for correlated UV and x ray absorption of NGC 3516

    NASA Technical Reports Server (NTRS)

    Martin, Christopher; Halpern, Jules P.; Kolman, Michiel

    1991-01-01

    NGC 3516, a low-luminosity Seyfert galaxy, is one of a small fraction of Seyfert galaxies that exhibit broad absorption in a resonance line. In order to determine whether the UV and x ray absorption in NGC 3516 are related, 5 IUE observations were obtained, quasi-simultaneously with 4 Ginga observations. The results are presented and discussed. The following subject areas are covered: short-term UV variability; emission lines; galactic absorption lines; the C IV, N V, and Si IV absorption features; lower limit on the carbon column density; estimate of the distance from the absorber to the continuum source; variability in the continuum and absorption; a comparison with BAL QSO's; and the x ray-UV connection.

  9. Cavity ring-down spectroscopy of Doppler-broadened absorption line with sub-MHz absolute frequency accuracy.

    PubMed

    Cheng, C-F; Sun, Y R; Pan, H; Lu, Y; Li, X-F; Wang, J; Liu, A-W; Hu, S-M

    2012-04-23

    A continuous-wave cavity ring-down spectrometer has been built for precise determination of absolute frequencies of Doppler-broadened absorption lines. Using a thermo-stabilized Fabry-Pérot interferometer and Rb frequency references at the 780 nm and 795 nm, 0.1 - 0.6 MHz absolute frequency accuracy has been achieved in the 775-800 nm region. A water absorption line at 12579 cm(-1) is studied to test the performance of the spectrometer. The line position at zero-pressure limit is determined with an uncertainty of 0.3 MHz (relative accuracy of 0.8 × 10(-9)).

  10. Inter-Stellar Medium Absorption Lines As Outflow Tracers - A Comparison Between AGNs And SFGs

    NASA Astrophysics Data System (ADS)

    Talia, Margherita; Cimatti, A.; Brusa, M.

    2016-10-01

    To reproduce the properties of galaxies in the local Universe, as well as the scaling relations between host galaxies and black holes properties, many galaxy formation models invoke the presence of fast and energetic winds extending over galaxy scales. These massive gas outflows can be powered either by star-formation (SF) or AGN activity, though the relative dominance and efficiency of the different mechanisms is not yet fully understoodIn the last decade much effort has been put in the search for observational evidence of such phenomena, especially at the peak of both SF and AGN activity through cosmic time (1absorption lines in the UV regime, as well as broad, blue-shifted profiles in optical emission lines have been observed in galaxies at all redshifts and are usually interpreted as evidence of fast material moving towards our line of sight. More recently, especially thanks to new facilities like ALMA, outflows are being observed also in neutral and molecular gasIn order to study the differences and possible synergy between the two main driving outflow mechanisms (AGN or SF activity) and to understand the role that outflows might play in SF quenching and galaxy evolution, we collected a large sample of AGNs and SFGs at z>1.7 from large optical spectroscopic surveys (zCOSMOS, VUDS, ESO public surveys), complemented with HST imaging, X-ray (Chandra) and IR data. The richness of available data for our sample allowed us to map a large portion of the physical parameters space. We concentrated our analysis on the ISM absorption lines in the rest-frame UV wavelength range. Through stacking tecniques we studied the relation between such lines and AGN and SFG properties. I will present our results (Talia et al

  11. The velocity distribution of interstellar gas observed in strong UV absorption lines

    NASA Technical Reports Server (NTRS)

    Cowie, L. L.; York, D. G.

    1978-01-01

    Observations of three strong interstellar UV absorption lines of N I (1199 A), N II (1083 A), and Si III (1206 A) in 47 stars of widely varying distance and a variety of spectral types are analyzed to obtain a velocity distribution function for the interstellar gas. A technique based on the maximum and minimum velocities observed along a line of sight is adopted because of heavy line blending, and results are discussed for both power-law and exponential distribution functions. The expected distribution of radiative-phase supernova remnants (SNRs) in the interstellar medium is calculated as a function of SNR birthrate and of the interstellar density in which they evolve. The results are combined with observed distance estimates, and it is shown that an interstellar density in excess of 0.1 per cu cm would be required to keep the SNRs sufficiently confined so that their cross sections are consistent with the observed number of components. The alternative possibility is considered that SNRs do not enter the radiative phase before escaping from the Galaxy or colliding with neighboring remnants.

  12. Gamma-Gamma Absorption in the Broad Line Region Radiation Fields of Gamma-Ray Blazars

    NASA Astrophysics Data System (ADS)

    Böttcher, Markus; Els, Paul

    2016-04-01

    The expected level of γγ absorption in the Broad Line Region (BLR) radiation field of γ-ray loud Flat Spectrum Radio Quasars (FSRQs) is evaluated as a function of the location of the γ-ray emission region. This is done self-consistently with parameters inferred from the shape of the spectral energy distribution (SED) in a single-zone leptonic EC-BLR model scenario. We take into account all geometrical effects both in the calculation of the γγ opacity and the normalization of the BLR radiation energy density. As specific examples, we study the FSRQs 3C279 and PKS 1510-089, keeping the BLR radiation energy density at the location of the emission region fixed at the values inferred from the SED. We confirm previous findings that the optical depth due to γγ absorption in the BLR radiation field exceeds unity for both 3C279 and PKS 1510-089 for locations of the γ-ray emission region inside the inner boundary of the BLR. It decreases monotonically, with distance from the central engine and drops below unity for locations within the BLR. For locations outside the BLR, the BLR radiation energy density required for the production of GeV γ-rays rapidly increases beyond observational constraints, thus making the EC-BLR mechanism implausible. Therefore, in order to avoid significant γγ absorption by the BLR radiation field, the γ-ray emission region must therefore be located near the outer boundary of the BLR.

  13. Determination of molecular line parameters for acrolein (C(3)H(4)O) using infrared tunable diode laser absorption spectroscopy.

    PubMed

    Harward, Charles N; Thweatt, W David; Baren, Randall E; Parrish, Milton E

    2006-04-01

    Acrolein (C(3)H(4)O) molecular line parameters, including infrared (IR) absorption positions, strengths, and nitrogen broadened half-widths, must be determined since they are not included in the high resolution transmission (HITRAN) molecular absorption database of spectral lines. These parameters are required for developing a quantitative analytical method for measuring acrolein in a single puff of cigarette smoke using tunable diode laser absorption spectroscopy (TDLAS). The task is complex since acrolein has many highly overlapping infrared absorption lines in the room temperature spectrum and the cigarette smoke matrix contains thousands of compounds. This work describes the procedure for estimating the molecular line parameters for these overlapping absorption lines in the wavenumber range (958.7-958.9 cm(-1)) using quantitative reference spectra taken with the infrared lead-salt TDLAS instrument at different pressures and concentrations. The nitrogen broadened half-width for acrolein is 0.0937 cm(-1)atm(-1) and to our knowledge, is the first time it has been reported in the literature.

  14. A new perspective on the interstellar cloud surrounding the Sun from UV absorption line results

    NASA Astrophysics Data System (ADS)

    Gry, Cecile; Jenkins, Edward B.

    2015-01-01

    We offer a new, more inclusive, picture of the local interstellar medium, where it is composed of a single, monolithic cloud that surrounds the Sun in all directions. Our study of velocities based on Mg II and Fe II ultraviolet absorption lines indicates that the cloud has an average motion consistent with the velocity vector of gas impacting the heliosphere and does not behave like a rigid body: gas within the cloud is being differentially decelerated in the direction of motion, and the cloud is expanding in directions perpendicular to this flow, much like the squashing of a balloon. The outer boundary of the cloud is in average 10 pc away from us but is highly irregular, being only a few parsecs away in some directions, with possibly a few extensions up to 20 pc. Average H I volume densities vary between 0.03 and 0.1 cm3 over different sight lines. Metals appear to be significantly depleted onto grains, and there is a steady increase in this effect from the rear of the cloud to the apex of motion. There is no evidence that changes in the ionizing radiation influence the apparent abundances. Additional, secondary velocity components are detected in 60% of the sight lines. Almost all of them appear to be interior to the volume holding the gas that we identify with the main cloud. Half of the sight lines exhibit a secondary component moving at about - 7.2 km/s with respect to the main component, which may be the signature of an implosive shock propagating toward the cloud's interior.

  15. Metal-line absorption at Z(sub abs) approximately Z(sub em) from associated galaxies

    NASA Technical Reports Server (NTRS)

    Ellingson, E.; Yee, H. K. C.; Bechtold, Jill; Dobrzycki, Adam

    1994-01-01

    For a preliminary study of whether C IV absorption at Z(sub abs) approximately Z(sub em) is related to associated galaxy companions, we have collected data from a sample of 10 quasars with 0.15 less than z less than 0.65 for which high-resolution optical and UV spectroscopy is available from the literature, and for which we have deep optical images and limited spectroscopy. We also present new optical spectra for two of our samples. Four of these quasars have associated C IV absorption systems. In thes four fields, there are eight galaxies with M(sub r) less than -19.0 mag within 35 kpc of the quasar (projected distance, assuming they are at the quasar redshift), which may be candidates for the associated C IV absorption. This observed density of galaxies near quasars with associated C IV absorption is significantly greater than that for a control sample of quasars chosen from the literature. This result suggests that galaxies near the quasar line of sight may be linked with associated C IV absorption. None of these quasars show associated Mg II absorption, despite the presence of galaxies very near the line of sight, suggesting a Mg II 'proximity effect,' where ionizing flux from the quasar destroys the Mg(+) from at least the outer parts of the galaxies. Three quasars are located in rich galaxy clusters, but none of these quasars are found to have associated C IV absorption. This suggests that galaxies in rich clusters associated with quasars are less likely to be metal-line absorbers. It is plausible that the extended galaxy halos which may be responsible for the absorptions are stripped from galaxies in these dense environments. While it seems that at Z approximately 0.6 rich clusters do not cause them, associated C IV absorption systems at higher redshift may be explained by associated clusters if there has been evolution in the properties of galaxy halos in dense environments.

  16. The Bal Basera Project: The Body as Home

    ERIC Educational Resources Information Center

    Lynch, Carissa Hope

    2011-01-01

    The author travelled to Jaipur, India, in June 2009 to run a project with a group of 12 young runaways at the Bal Basera Centre, a transitional shelter for boys under the age of 18. The Centre sits within the Jaipur Municipal Police force compound, just a few yards away from the City Railway Station. Bal Basera, or "transit home" in…

  17. A novel control system for automatically locking a diode laser frequency to a selected gas absorption line

    NASA Astrophysics Data System (ADS)

    Dong, Lei; Yin, Wangbao; Ma, Weiguang; Jia, Suotang

    2007-05-01

    A novel control system has been developed for avoiding manual operation during traditional frequency locking. The control system uses a computer with a commercial data acquisition card. This accomplishes the whole operation of frequency locking, including generating ramp, searching locking point, engaging a proportional-integral-differential (PID) regulator at the proper time and outputting PID compensation signal. Moreover, a new method has also been employed to make the novel control system accurately identify the locking points of all absorption lines within the scanning range, so that the laser frequency can be automatically firmly brought onto any selected absorption line centre without any adjusting time. The operation of the system, the ability to identify absorption lines and the performance of the frequency locking were discussed in detail. Successful tests were made with two different lasers: external cavity diode lasers and distributed feedback diode lasers.

  18. High-resolution IUE observations of interstellar absorption lines in the Vela supernova remnant

    NASA Technical Reports Server (NTRS)

    Jenkins, E. B.; Wallerstein, G.; Silk, J.

    1984-01-01

    Ultraviolet spectra of 45 stars in the vicinity of the Vela supernova remnant were recorded by the short-wavelength echelle spectrograph aboard the International Ultraviolet Explorer (IUE). Over one-third of the stars show interstellar absorption lines at large radial velocities (greater than 60 km/s). The mapping of these high-velocity components in the sky suggests the motions are chaotic, rather than from a coherent expansion of the remnant material. In accord with earlier conclusions from Copernicus data, the gas at high velocity exhibits higher than normal ionization and shows substantially less depletion of nonvolatile elements than normal interstellar material at low velocities. Relatively strong lines from neutral carbon in the two excited fine-structure states indicate that the neutral clouds within the remnant have had their pressures enhanced by the passage of the blast wave from the supernova. Also, the remnant seems to show a significant enhancement in the abundances of low-velocity Si IV, C IV, and N V over those found in the general interstellar medium.

  19. Magnetic Turbulence and Line Broadening in Simulations of Lyman-Alpha Absorption

    NASA Astrophysics Data System (ADS)

    Gurvich, Alex; Burkhart, Blakesley K.; Bird, Simeon

    2016-01-01

    We use the Illustris cosmological AREPO simulations to study the effects of gas turbulence and magnetic fields on measurements from the Lyman-Alpha forest. We generate simulated Lyman-Alpha spectra and plot the distributions of Column Density (CDD) and Doppler Width (b) both by adhering to the canonical method of fitting Voigt profiles to absorption lines and by directly measuring the column density and equivalent widths from snapshot data .We investigate the effects of additional unresolved gas turbulence in Illustris by adding an additional broadening term to the line profiles to mimic turbulent broadening. When we do this, we find a measurable effect in the CDD and an offset in the mean of the b distribution corresponding to the additional turbulence. We also compare different MHD runs in AREPO we find that the CDD can measurably differentiate between magnetic seed field at redshifts as low as z=0.1, but we do not find that the b distribution is affected at a detectable level. Our work suggests that the effects of turbulence and magnetic fields from z=2-0.1 can potentially be measured with these diagnostics. This work was supported in part by the NSF REU and DoD ASSURE programs under NSF grant no. 1262851 and by the Smithsonian Institution.

  20. A far wing line shape theory and its application to the foreign-broadened water continuum absorption. III

    NASA Technical Reports Server (NTRS)

    Ma, Q.; Tipping, R. H.

    1992-01-01

    The far wing line shape theory developed previously and applied to the calculation of the continuum absorption of pure water vapor is extended to foreign-broadened continua. Explicit results are presented for H2O-N2 and H2O-CO2 in the frequency range from 0 to 10,000/cm. For H2O-N2 the positive and negative resonant frequency average line shape functions and absorption coefficients are computed for a number of temperatures between 296 and 430 K for comparison with available laboratory data. In general the agreement is very good.

  1. No Evidence for Variability of Intervening Absorption Lines toward GRB 060206: Implications for the MgII Incidence Problem

    NASA Astrophysics Data System (ADS)

    Aoki, Kentaro; Totani, Tomonori; Hattori, Takashi; Ohta, Kouji; Kawabata, Koji S.; Kobayashi, Naoto; Iye, Masanori; Nomoto, Ken'ichi; Kawai, Nobuyuki

    2009-02-01

    We examined the variability of absorption line strength of intervening systems along the line of sight to GRB 060206 at z = 4.05, utilizing low-resolution optical spectra obtained by the Subaru telescope from six to ten hours after the burst. Strong variabilities of FeII and MgII lines at z = 1.48 during t = 5--8hr have been reported for this GRB, and those have been used to support the idea of clumpy MgII cloudlets, which was originally proposed to explain the anomalously high incidence of MgII absorbers in the GRB spectra compared to quasars. However, our spectra with a higher signal-to-noise ratio do not show any evidence for variability in t = 6--10hr. There is a clear discrepancy between our data and those of Hao et al. (2007, ApJ, 659, L99) in the overlapping time interval. Furthermore, the line strengths in our data are in agreement with those observed at t ˜ 2hr by Thöne et al. (2008, A&A, 489, 37). We also detected FeII and MgII absorption lines for a system at z = 2.26; these lines do not show evidence for variability either. Therefore, we conclude that there is no strong evidence for the variability in the intervening absorption lines toward GRB 060206, offering poor support for the MgII cloudlet hypothesis by the GRB 060206 data.

  2. A Variable Energy, Redshifted, Iron Absorption Line in a recoiling Black Hole

    NASA Astrophysics Data System (ADS)

    Civano, Francesca

    The aim of this proposal is to maximize the scientific return of a medium deep (123 ksec) XMM-Newton observation, awarded during the AO10 call for proposal, to obtain a high quality X-ray spectrum of CID-42, a very peculiar source discovered in the COSMOS survey. CID-42 is exceptional in many respects showing a redshifted, variable energy absorption line plus an emission line at ~ 6 keV forming an inverted P-Cygni profile. These features were never observed before in the X-rays. The peculiar nature of CID-42 extends well beyond the X-ray spectrum. First, two optical sources in a common envelope are clearly seen in the HST data. They are separated by about 2.45 kpc. Thanks to the unrivaled Chandra HRC resolution it was possible to unambiguously associate the X-ray emission to only one of the two optical sources. Second, a high velocity (1100 km/s) offset, between the broad and narrow component of the H-beta line is measured in the VLT/Magellan/Keck optical spectra. The velocity offset observed is unlikely to be due to a ongoing merger because too high. Third, the above mentioned inverted P-Cygni profile in the hard X-ray spectrum would be naturally explained by an high velocity (v~0.02-0.14c) gas infall in the innermost region of the accreting Black Hole. All together the observed properties support the interpretation of a Black Hole kicked from the center of the galaxy by asymmetric emission of gravitational waves produced during a major merger. The Black Hole is caught while still active, at ~10^6 yrs after the kick and at a substantial distance from the center of the galaxy. The theoretical expectations suggest that they are extremely rare and just 1 or 2 gravitational wave recoiling Black Holes are expected in a survey like COSMOS. CID- 42 thus represents a ``Rosetta stone'' for the study of SMBH mergers that are believed to occur during galaxy-galaxy mergers, and their fate after the merging. The detailed study of the hard X-ray XMM-Newton spectrum, in the

  3. Absorption and emission line shapes in the O2 atmospheric bands - Theoretical model and limb viewing simulations

    NASA Technical Reports Server (NTRS)

    Abreu, Vincent J.; Bucholtz, A.; Hays, P. B.; Ortland, D.; Skinner, W. R.

    1989-01-01

    A multiple scattering radiative transfer model has been developed to carry out a line-by-line calculation of the absorption and emission limb measurements that will be made by the High Resolution Doppler Imager to be flown on the Upper Atmosphere Research Satellite. The multiple scattering model uses the doubling and adding methods to solve the radiative transfer equation, modified to take into account a spherical inhomogeneous atmosphere. Representative absorption and emission line shapes in the O2 1Sigma(+)g - 3Sigma(-)g atmospheric bands (A,B, and gamma) and their variation with altitude are presented. The effects of solar zenith angle, aerosol loading, surface albedo, and cloud height on the line shapes are also discussed.

  4. First detection of ionized helium absorption lines in infrared K band spectra of O-type stars

    NASA Technical Reports Server (NTRS)

    Conti, Peter S.; Block, David L.; Geballe, T. R.; Hanson, Margaret M.

    1993-01-01

    We have obtained high SNR, moderate-resolution K band spectra of two early O-type main sequence stars, HD 46150 O5 V, and HD 46223 O4 V, in the Rosette Nebula. We report the detection, for the first time, of the 2.189 micron He II line in O-type stars. Also detected is the 2.1661 micron Br-gamma line in absorption. The 2.058 micron He I line appears to be present in absorption in both stars, although its appearance at our resolution is complicated by atmospheric features. These three lines can form the basis for a spectral classification system for hot stars in the K band that may be used at infrared wavelengths to elucidate the nature of those luminous stars in otherwise obscured H II and giant H II regions.

  5. Probing the Circumgalactic Medium of Submillimeter Galaxies with QSO Absorption Line Spectroscopy

    NASA Astrophysics Data System (ADS)

    Fu, Hai; Hennawi, Joseph F.; Prochaska, Jason X.; Stockton, Alan N.; Mutel, Robert Lucien; Casey, Caitlin; Cooray, Asantha R.; Keres, Dusan

    2017-01-01

    We present first results from an ongoing survey to characterize the circumgalactic medium (CGM) of the massive high-redshift galaxieds detected as submillimeter galaxies (SMGs). By cross-matching far-infrared-selected galaxies from Herschel with spectroscopically confirmed quasars, we constructed a sample of 163 SMG-QSO pairs with separations less than 36". We observed 62 SMG-QSO pairs with the Very Large Array (VLA) and the Atacama Large Millimeter Array (ALMA). These observations obtained sub-arcsecond positions of 31 SMGs and identified seven previously-thought SMG-QSO pairs as submillimeter-luminous QSOs. We are currently conducting a redshift survey of the VLA/ALMA-confirmed SMGs and acquiring high S/N UV-optical specrtoscopy of the background QSOs. For the small sample of three VLA-confirmed SMG-QSO pairs that we have the complete data set, absorption line spectra of the background QSOs allow us to analyze the CGM of SMGs for the first time, providing insight into the fuel-supply ultimately powering their tremendous starbursts. Our observations reveal strong HI Ly-alpha absorption (rest-frame equivalent widths about 2-3 A) around all three SMGs; however, none exhibit compelling evidence for strong neutral absorbers (NHI > 1017.2 cm-2) or metal absorption, allowing us to place an 1-sigma upper limit on the covering factor of optically thick HI gas around SMGs of fC < 36.9%. This is significantly lower than the covering factor around the co-eval population of luminous QSOs. Theoretical models predict that the structure of the CGM is entirely determined by dark matter halo mass. Given that that SMGs are believed to inhabit massive dark matter halos comparable to those hosting quasars, this difference in covering factor is unexpected. Therefore, our results tentatively indicate that SMGs may not have substantial cool gas reservoirs in their halos and that they may inhabit much less massive halos than previously thought.

  6. Dependence of the Broad Absorption Line Quasar Fraction on Radio Luminosity

    NASA Astrophysics Data System (ADS)

    Shankar, Francesco; Dai, Xinyu; Sivakoff, Gregory R.

    2008-11-01

    We find that the fraction of classical broad absorption line quasars (BALQSOs) among the FIRST radio sources in the Sloan Data Release 3, is 20.5+ 7.3-5.9% at the faintest radio powers detected (L1.4 GHz ~ 1032 erg s-1), and rapidly drops to lesssim8% at L1.4 GHz ~ 3 × 1033 erg s-1. Similarly, adopting the broader absorption index (AI) definition of Trump et al., we find the fraction of radio BALQSOs to be 44+ 8.1-7.8%, reducing to 23.1+ 7.3-6.1% at high luminosities. While the high fraction at low radio power is consistent with the recent near-IR estimates by Dai et al., the lower fraction at high radio powers is intriguing and confirms previous claims based on smaller samples. The trend is independent of the redshift range, the optical and radio flux selection limits, or the exact definition of a radio match. We also find that at fixed optical magnitude, the highest bins of radio luminosity are preferentially populated by non-BALQSOs, consistent with the overall trend. We do find, however, that those quasars identified as AI-BALQSOs but not under the classical definition do not show a significant drop in their fraction as a function of radio power, further supporting independent claims that these sources, characterized by lower equivalent width, may represent an independent class from the classical BALQSOs. We find the balnicity index, a measure of the absorption trough in BALQSOs, and the mean maximum wind velocity to be roughly constant at all radio powers. We discuss several plausible physical models which may explain the observed fast drop in the fraction of the classical BALQSOs with increasing radio power, although none is entirely satisfactory. A strictly evolutionary model for the BALQSO and radio emission phases requires a strong fine-tuning to work, while a simple geometric model, although still not capable of explaining polar BALQSOs and the paucity of FRII BALQSOs, is statistically successful in matching the data if part of the apparent radio

  7. Unveiling the X-ray/UV properties of disk winds in active galactic nuclei using broad and mini-broad absorption line quasars

    NASA Astrophysics Data System (ADS)

    Giustini, M.

    2016-05-01

    We present the results of the uniform analysis of 46 XMM-Newton observations of six BAL and seven mini-BAL QSOs belonging to the Palomar-Green Quasar catalogue. Moderate-quality X-ray spectroscopy was performed with the EPIC-pn, and allowed to characterise the general source spectral shape to be complex, significantly deviating from a power law emission. A simple power law analysis in different energy bands strongly suggests absorption to be more significant than reflection in shaping the spectra. If allowing for the absorbing gas to be either partially covering the continuum emission source or to be ionised, large column densities of the order of 1022-1024 cm-2 are inferred. When the statistics was high enough, virtually every source was found to vary in spectral shape on various time scales, from years to hours. All in all these observational results are compatible with radiation driven accretion disk winds shaping the spectra of these intriguing cosmic sources.

  8. Evidence for two spatially separated UV continuum emitting regions in the Cloverleaf broad absorption line quasar

    NASA Astrophysics Data System (ADS)

    Sluse, D.; Hutsemékers, D.; Anguita, T.; Braibant, L.; Riaud, P.

    2015-10-01

    Testing the standard Shakura-Sunyaev model of accretion is a challenging task because the central region of quasars where accretion takes place is unresolved with telescopes. The analysis of microlensing in gravitationally lensed quasars is one of the few techniques that can test this model, yielding to the measurement of the size and of temperature profile of the accretion disc. We present spectroscopic observations of the gravitationally lensed broad absorption line quasar H1413+117, which reveal partial microlensing of the continuum emission that appears to originate from two separated regions: a microlensed region, corresponding the compact accretion disc; and a non-microlensed region, more extended and contributing to at least 30% of the total UV-continuum flux. Because this extended continuum is occulted by the broad absorption line clouds, it is not associated with the host galaxy, but rather with light scattered in the neighbourhood of the central engine. We measure the amplitude of microlensing of the compact continuum over the rest-frame wavelength range 1000-7000 Å. Following a Bayesian scheme, we confront our measurements to microlensing simulations of an accretion disc with a temperature varying as T ∝ R-1/ν. We find a most likely source half-light radius of R1/2 = 0.61 × 1016cm (i.e., 0.002 pc) at 0.18 μm, and a most-likely index of ν = 0.4. The standard disc (ν = 4/3) model is not ruled out by our data, and is found within the 95% confidence interval associated with our measurements. We demonstrate that, for H1413+117, the existence of an extended continuum in addition to the disc emission only has a small impact on the inferred disc parameters, and is unlikely to solve the tension between the microlensing source size and standard disc sizes, as previously reported in the literature. Based on observations made with ESO Telescopes at the Paranal Observatory (Chile). ESO program ID: 386.B-0337.Appendices A and B are available in electronic form

  9. On the covering fraction variability in an EUV mini-BAL outflow from PG 1206+459

    NASA Astrophysics Data System (ADS)

    Muzahid, S.; Srianand, R.; Charlton, J.; Eracleous, M.

    2016-04-01

    We report on the first detection of extreme-ultraviolet (EUV) absorption variability in the Ne VIII λλ770, 780 mini-broad absorption line (mini-BAL) in the spectrum of the quasar (QSO) PG 1206+459. The observed equivalent width (EW) of the Ne VIII doublet shows a ˜4σ variation over a time-scale of 2.8 months in the QSO's rest frame. Both members of the Ne VIII doublet exhibit non-black saturation, indicating partial coverage of the continuum source. An increase in the Ne VIII covering fraction from fc = 0.59 ± 0.05 to 0.72 ± 0.03 is observed over the same period. The Ne VIII profiles are too highly saturated to be susceptible to changes in the ionization state of the absorbing gas. In fact, we do not observe any significant variation in the EW and/or column density after correcting the spectra for partial coverage. We, thus, propose transverse motions of the absorbing gas as the cause of the observed variability. Using a simple model of a transiting cloud we estimate a transverse speed of ˜1800 km s-1. For Keplerian motion, this corresponds to a distance between the absorber and the central engine of ˜1.3 pc, which places the absorber just outside the broad-line region. We further estimate a density of ˜5 × 106 cm-3 and a kinetic luminosity of ˜1043-1044 erg s-1. Such large kinetic powers suggest that outflows detected via EUV lines are potentially major contributors to active galactic nuclei feedback.

  10. Isotopic ratios at z = 0.68 from molecular absorption lines toward B 0218+357

    NASA Astrophysics Data System (ADS)

    Wallström, S. H. J.; Muller, S.; Guélin, M.

    2016-11-01

    Isotopic ratios of heavy elements are a key signature of the nucleosynthesis processes in stellar interiors. The contribution of successive generations of stars to the metal enrichment of the Universe is imprinted on the evolution of isotopic ratios over time. We investigate the isotopic ratios of carbon, nitrogen, oxygen, and sulfur through millimeter molecular absorption lines arising in the z = 0.68 absorber toward the blazar B 0218+357. We find that these ratios differ from those observed in the Galactic interstellar medium, but are remarkably close to those in the only other source at intermediate redshift for which isotopic ratios have been measured to date, the z = 0.89 absorber in front of PKS 1830-211. The isotopic ratios in these two absorbers should reflect enrichment mostly from massive stars, and they are indeed close to the values observed toward local starburst galaxies. Our measurements set constraints on nucleosynthesis and chemical evolution models. The reduced spectra are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/595/A96

  11. MOSFIRE ABSORPTION LINE SPECTROSCOPY OF z > 2 QUIESCENT GALAXIES: PROBING A PERIOD OF RAPID SIZE GROWTH

    SciTech Connect

    Belli, Sirio; Ellis, Richard S.; Konidaris, Nick P.; Newman, Andrew B.

    2014-06-20

    Using the MOSFIRE near-infrared multi-slit spectrograph on the Keck 1 Telescope, we have secured high signal-to-noise ratio absorption line spectra for six massive galaxies with redshift 2 < z < 2.5. Five of these galaxies lie on the red sequence and show signatures of passive stellar populations in their rest-frame optical spectra. By fitting broadened spectral templates we have determined stellar velocity dispersions and, with broad-band Hubble Space Telescope and Spitzer photometry and imaging, stellar masses and effective radii. Using this enlarged sample of galaxies, we confirm earlier suggestions that quiescent galaxies at z > 2 have small sizes and large velocity dispersions compared to local galaxies of similar stellar mass. The dynamical masses are in very good agreement with stellar masses (log M {sub *}/M {sub dyn} = –0.02 ± 0.03), although the average stellar-to-dynamical mass ratio is larger than that found at lower redshift (–0.23 ± 0.05). By assuming evolution at fixed velocity dispersion, not only do we confirm a surprisingly rapid rate of size growth but we also consider the necessary evolutionary track on the mass-size plane and find a slope α = dlog R{sub e} /dlog M {sub *} ≳ 2 inconsistent with most numerical simulations of minor mergers. Both results suggest an additional mechanism may be required to explain the size growth of early galaxies.

  12. The intervening and associated O VI absorption-line systems in the ultraviolet spectrum of H1821+643

    NASA Astrophysics Data System (ADS)

    Savage, Blair D.; Tripp, Todd M.; Lu, Limin

    1998-02-01

    GHRS and FOS ultraviolet spectra of the bright QSO H1821+643 reveal the presence of strong O VI 1031.93, 1037.62 A absorption systems at z(abs) = 0.225 and 0.297, the latter being at the redshift of the QSO itself. Ground-based galaxy redshift measurements by us and others reveal two emission-line galaxies near the redshift of the intervening system at z(abs) = 0.225, suggesting the existence of a galaxy group at this redshift. The intervening O VI absorption system is also detected in H I but is not detected in the lines of Si II, Si IV, C IV, or N V. These ionization characteristics can be explained by a low-density, extended diffuse gas distribution that is photoionized by the metagalactic UV background if the gas has a metallicity of 0.1 times solar. Such a photoionized gas may be associated with the extended halo of the luminous intervening spiral galaxy at a projected distance of 100 h kpc, or with an intragroup medium. Alternatively, the absorption may be produced in hot collisionally ionized halo gas or in a hot intragroup medium. The associated system with z(abs) = 0.297 contains narrow and broad O VI absorption. The narrow absorption, which is also detected in H I, C III, C IV, and Si IV, can be modeled as gas photoionized by H1821+643 with roughly solar abundances. This gas is probably situated close to H1821+643. The broad O VI absorption that is centered at the emission redshift of H1821+643 may represent a weak and narrow example of the broad absorption line phenomena.

  13. NARROW Na AND K ABSORPTION LINES TOWARD T TAURI STARS: TRACING THE ATOMIC ENVELOPE OF MOLECULAR CLOUDS

    SciTech Connect

    Pascucci, I.; Simon, M. N.; Edwards, S.; Heyer, M.; Rigliaco, E.; Hillenbrand, L.; Gorti, U.; Hollenbach, D.

    2015-11-20

    We present a detailed analysis of narrow Na i and K i absorption resonance lines toward nearly 40 T Tauri stars in Taurus with the goal of clarifying their origin. The Na i λ5889.95 line is detected toward all but one source, while the weaker K i λ7698.96 line is detected in about two-thirds of the sample. The similarity in their peak centroids and the significant positive correlation between their equivalent widths demonstrate that these transitions trace the same atomic gas. The absorption lines are present toward both disk and diskless young stellar objects, which excludes cold gas within the circumstellar disk as the absorbing material. A comparison of Na i and CO detections and peak centroids demonstrates that the atomic gas and molecular gas are not co-located, the atomic gas being more extended than the molecular gas. The width of the atomic lines corroborates this finding and points to atomic gas about an order of magnitude warmer than the molecular gas. The distribution of Na i radial velocities shows a clear spatial gradient along the length of the Taurus molecular cloud filaments. This suggests that absorption is associated with the Taurus molecular cloud. Assuming that the gradient is due to cloud rotation, the rotation of the atomic gas is consistent with differential galactic rotation, whereas the rotation of the molecular gas, although with the same rotation axis, is retrograde. Our analysis shows that narrow Na i and K i absorption resonance lines are useful tracers of the atomic envelope of molecular clouds. In line with recent findings from giant molecular clouds, our results demonstrate that the velocity fields of the atomic and molecular gas are misaligned. The angular momentum of a molecular cloud is not simply inherited from the rotating Galactic disk from which it formed but may be redistributed by cloud–cloud interactions.

  14. Impact of broadened laser line-shape on retrievals of atmospheric species from lidar sounding absorption spectra.

    PubMed

    Chen, Jeffrey R; Numata, Kenji; Wu, Stewart T

    2015-02-09

    We examine the impact of broadened laser line-shape on retrievals of atmospheric species from lidar-sounding absorption spectra. The laser is assumed to be deterministically modulated into a stable, nearly top-hat frequency comb to suppress the stimulated Brillouin scattering, allowing over 10-fold pulse energy increase without adding measurement noise. Our model remains accurate by incorporating the laser line-shape factor into the effective optical depth. Retrieval errors arising from measurement noise and model bias are analyzed parametrically and numerically to provide deeper insight. The stable laser line-shape broadening minimally degrades the column-averaged retrieval, but can significantly degrade the multiple-layer retrievals.

  15. Highly Ionized Iron Absorption Lines from Outflowing Gases in the X-ray Spectrum of NGC 1365

    NASA Technical Reports Server (NTRS)

    Risaliti, G.; Bianchi, S.; Matt, G.; Baldi, A.; Elvis, M.; Fabbiano, G.; Zezas, A.

    2006-01-01

    We present the discovery of four absorption lines in the X-ray spectrum of the Seyfert galaxy NGC 1365, at energies between 6.7 and 8.3 keV. The lines are detected with high statistical confidence (from >20 sigma for the strongest to -4 sigma for the weakest) in two XMM-Newton observations 60 ks long. We also detect the same lines, with a lower signal-to-noise ratio (but still >2 sigma for each line), in two previous shorter (-10 ks) XMM-Newton observations. The spectral analysis identifies these features as Fe XXV and Fe XXVI Kalpha and Kbeta lines, outflowing with velocities varying between -1000 and -5000 km/s among the observations. These are the highest quality detections of such lines so far. The high equivalent widths [EW (Kalpha) approximately 100 eV] and the Kalpha/Kbeta ratios imply that the lines are due to absorption of the AGN continuum by a highly ionized gas with column density NH-5?1023 cm(exp -2) at a distance of -(50-100)RS from the continuum source.

  16. Formation of a Giant Galactic Gaseous Halo: Metal-Absorption Lines and High-Velocity Clouds

    NASA Astrophysics Data System (ADS)

    Li, Fan

    1992-04-01

    A Galactic gaseous halo formed through the interstellar disk-halo connection is simulated by means of a two-dimensional axisymmetric hydrodynamic code based upon the chimney model of the interstellar medium, a new version of the galactic fountain. Galactic rotation, heating processes by diffuse UV flux, and radiative cooling processes are taken into account. The resulting gaseous halo can be divided into three categories, i.e., wind-type halo, bound-type halo, and cooled-type halo. In this way, we try to reproduce the column densities of C IV, N V, O VI, and Si IV in the observed absorption lines of halo stars. Assuming that the radiatively cooled halo gas condenses into clouds due to thermal instabilities, we can calculate their distribution and ballistic motions in the Galactic gravitational field. These correspond to the high- and intermediate-velocity clouds observed at high Galactic latitudes. We find that a cooled-type halo with a gas temperature between 5 X 10^5 and 10^6 K and a density between 10^-3 and 10^-2 cm^-3 at the disk-halo interface can reproduce the observational facts about our Galaxy. Supposing that the metal-absorption-line systems of QSOs arise from the halos of intervening galaxies formed by similar processes, we calculate features of the Ca II, Mg II, C IV, and Si IV absorption lines in various stages of galactic evolution. We conclude that C IV systems which are greater than 50 kpc in size correspond to the wind-type halo. On the other hand, Mg II and Ca II systems can only be detected in a very restricted region ( Metaxa, SMALL FAINT CLUSTERS IN THE LMC This is a short review of the main results of my Ph.D. thesis concerning some important problems on the dynamical properties of the LMC star clusters. The topic of this thesis was to find and study the dynamical paramters (tidal radius r_t core radius r_c concentration parameters log (r_t/r_c), and total mass M) for a large sample of small LMC clusters and to define their location in the

  17. The Near Infrared Absorption Spectrum of Water by CRDS Between 1.26-1.70 µm:Complete Empirical Line List and Continuum Absorption

    NASA Astrophysics Data System (ADS)

    Mondelain, Didier; Campargue, Alain; Kassi, Samir; Mikhailenko, Semen

    2014-06-01

    Due to the increasing performances of Airborne- and ground-based spectrometers, a more and more accurate characterization of the water vapor absorption is required. This is especially true in the transparency windows, corresponding to low absorption spectral regions widely used for probing the Earth's atmosphere. State-of-the-art experimental developments are required to fulfill the needs in terms of accuracy of the spectroscopic data. For that purpose, we are using high-sensitivity Continuous Wave Cavity Ring Down Spectroscopy (CW-CRDS) allowing reproducing in laboratory conditions comparable to the atmospheric ones in terms of absorption path length (tens of kilometers), temperature and pressure. From extensive analysis of our CRDS spectra, we have constructed an empirical line list for "natural" water vapor at 296 K in the 5850 7920 cm-1 region including 38 318 transitions of four major water isotopologues (H2 16O, H218O, H217O and HD16O) with an intensity cut-off of 1·10-29 cm/molecule. The list is made mostly complete over the whole spectral region by including a large number of unobserved weak lines with positions calculated using experimentally determined energy levels and intensities obtained from variational calculations. In addition, we provide HD18O and HD 17O lists in the same region for transitions with intensities larger than 1·10-29 cm/molecule. The HD18O and HD17O lists (1 972 lines in total) were obtained using empirical energy levels available in the literature and variational intensities. The global list (40 290 transitions) including the contribution of the six major isotopologues has been adopted for the new edition of the GEISA database in the region. The advantages and drawbacks of our list will be discussed in comparison with the list provided for the same region in the 2012 edition of the HITRAN database. Separate experiments were dedicated to the measurement of the water vapor self-continuum crosssections in the 1.6 µm window by CW

  18. INVISIBLE ACTIVE GALACTIC NUCLEI. II. RADIO MORPHOLOGIES AND FIVE NEW H i 21 cm ABSORPTION LINE DETECTORS

    SciTech Connect

    Yan, Ting; Stocke, John T.; Darling, Jeremy; Momjian, Emmanuel; Sharma, Soniya; Kanekar, Nissim

    2016-03-15

    This is the second paper directed toward finding new highly redshifted atomic and molecular absorption lines at radio frequencies. To this end, we selected a sample of 80 candidates for obscured radio-loud active galactic nuclei (AGNs) and presented their basic optical/near-infrared (NIR) properties in Paper I. In this paper, we present both high-resolution radio continuum images for all of these sources and H i 21 cm absorption spectroscopy for a few selected sources in this sample. A-configuration 4.9 and 8.5 GHz Very Large Array continuum observations find that 52 sources are compact or have substantial compact components with size <0.″5 and flux densities >0.1 Jy at 4.9 GHz. The 36 most compact sources were then observed with the Very Long Baseline Array at 1.4 GHz. One definite and 10 candidate Compact Symmetric Objects (CSOs) are newly identified, which is a detection rate of CSOs ∼three times higher than the detection rate previously found in purely flux-limited samples. Based on possessing compact components with high flux densities, 60 of these sources are good candidates for absorption-line searches. Twenty-seven sources were observed for H i 21 cm absorption at their photometric or spectroscopic redshifts with only six detections (five definite and one tentative). However, five of these were from a small subset of six CSOs with pure galaxy optical/NIR spectra (i.e., any AGN emission is obscured) and for which accurate spectroscopic redshifts place the redshifted 21 cm line in a radio frequency intereference (RFI)-free spectral “window” (i.e., the percentage of H i 21 cm absorption-line detections could be as high as ∼90% in this sample). It is likely that the presence of ubiquitous RFI and the absence of accurate spectroscopic redshifts preclude H i detections in similar sources (only 1 detection out of the remaining 22 sources observed, 13 of which have only photometric redshifts); that is, H i absorption may well be present but is masked by

  19. Reconstruction of combustion temperature and gas concentration distributions using line-of-sight tunable diode laser absorption spectroscopy

    NASA Astrophysics Data System (ADS)

    Zhang, Zhirong; Sun, Pengshuai; Pang, Tao; Xia, Hua; Cui, Xiaojuan; Li, Zhe; Han, Luo; Wu, Bian; Wang, Yu; Sigrist, Markus W.; Dong, Fengzhong

    2016-07-01

    Spatial temperature and gas concentration distributions are crucial for combustion studies to characterize the combustion position and to evaluate the combustion regime and the released heat quantity. Optical computer tomography (CT) enables the reconstruction of temperature and gas concentration fields in a flame on the basis of line-of-sight tunable diode laser absorption spectroscopy (LOS-TDLAS). A pair of H2O absorption lines at wavelengths 1395.51 and 1395.69 nm is selected. Temperature and H2O concentration distributions for a flat flame furnace are calculated by superimposing two absorption peaks with a discrete algebraic iterative algorithm and a mathematical fitting algorithm. By comparison, direct absorption spectroscopy measurements agree well with the thermocouple measurements and yield a good correlation. The CT reconstruction data of different air-to-fuel ratio combustion conditions (incomplete combustion and full combustion) and three different types of burners (one, two, and three flat flame furnaces) demonstrate that TDLAS has the potential of short response time and enables real-time temperature and gas concentration distribution measurements for combustion diagnosis.

  20. Searching for narrow absorption and emission lines in XMM-Newton spectra of gamma-ray bursts

    NASA Astrophysics Data System (ADS)

    Campana, S.; Braito, V.; D'Avanzo, P.; Ghirlanda, G.; Melandri, A.; Pescalli, A.; Salafia, O. S.; Salvaterra, R.; Tagliaferri, G.; Vergani, S. D.

    2016-08-01

    We present the results of a spectroscopic search for narrow emission and absorption features in the X-ray spectra of long gamma-ray burst (GRB) afterglows. Using XMM-Newton data, both EPIC and RGS spectra, of six bright (fluence > 10-7 erg cm-2) and relatively nearby (z = 0.54-1.41) GRBs, we performed a blind search for emission or absorption lines that could be related to a high cloud density or metal-rich gas in the environ close to the GRBs. We detected five emission features in four of the six GRBs with an overall statistical significance, assessed through Monte Carlo simulations, of ≲ 3.0σ. Most of the lines are detected around the observed energy of the oxygen edge at ~ 0.5 keV, suggesting that they are not related to the GRB environment but are most likely of Galactic origin. No significant absorption features were detected. A spectral fitting with a free Galactic column density (NH) testing different models for the Galactic absorption confirms this origin because we found an indication of an excess of Galactic NH in these four GRBs with respect to the tabulated values.

  1. Higher-order mode absorption measurement of X-band choke-mode cavities in a radial line structure

    NASA Astrophysics Data System (ADS)

    Zha, Hao; Shi, Jiaru; Wu, Xiaowei; Chen, Huaibi

    2016-04-01

    An experiment is presented to study the higher-order mode (HOM) suppression of X-band choke-mode structures with a vector network analyzer (VNA). Specific radial line disks were built to test the reflection from the corresponding damping load and different choke geometries. The mismatch between the radial lines and the VNA was calibrated through a special multi-short-load calibration method. The measured reflections of different choke geometries showed good agreement with the theoretical calculations and verified the HOM absorption feature of each geometric design.

  2. Laser absorption spectroscopy of water vapor confined in nanoporous alumina: wall collision line broadening and gas diffusion dynamics.

    PubMed

    Svensson, Tomas; Lewander, Märta; Svanberg, Sune

    2010-08-02

    We demonstrate high-resolution tunable diode laser absorption spectroscopy (TDLAS) of water vapor confined in nanoporous alumina. Strong multiple light scattering results in long photon pathlengths (1 m through a 6 mm sample). We report on strong line broadening due to frequent wall collisions (gas-surface interactions). For the water vapor line at 935.685 nm, the HWHM of confined molecules are about 4.3 GHz as compared to 2.9 GHz for free molecules (atmospheric pressure). Gas diffusion is also investigated, and in contrast to molecular oxygen (that moves rapidly in and out of the alumina), the exchange of water vapor is found very slow.

  3. No Evidence for Variability of Intervening Absorption Lines toward GRB 060206: Implications for the Mg II Incidence Problem

    NASA Astrophysics Data System (ADS)

    Aoki, K.; Totani, T.; Hattori, T.; Ohta, K.; Kawabata, K. S.; Kobayashi, N.; Iye, M.; Nomoto, K.; Kawai, N.

    2009-05-01

    We examine variability of absorption line strength of intervening systems along the line of sight to GRB 060206 at z = 4.05, by the low-resolution optical spectra obtained by the Subaru telescope from six to ten hours after the burst. Strong variabilities of Fe II and Mg II lines at z = 1.48 during t = 5-8 hours have been reported for this GRB [8], and this has been used to support the idea of clumpy Mg II cloudlets that was originally proposed to explain the anomalously high incidence of Mg II absorbers in GRB spectra compared with quasars. However, our spectra with higher signal-to-noise ratio do not show any evidence for variability in t = 6-10 hours. There is a clear discrepancy between our data and Hao et al. data in the overlapping time interval. Furthermore, the line strengths in our data are in good agreement with those observed at t~2 hours by Thone et al. [22]. Therefore we conclude that there is no strong evidence for variability of intervening absorption lines toward GRB 060206, significantly weakening the support to the Mg II cloudlet hypothesis by the GRB 060206 data.

  4. Wavelength locking to CO2 absorption line-center for 2-μm pulsed IPDA lidar application

    NASA Astrophysics Data System (ADS)

    Refaat, Tamer F.; Petros, Mulugeta; Antill, Charles W.; Singh, Upendra N.; Yu, Jirong

    2016-05-01

    An airborne 2-m triple-pulse integrated path differential absorption (IPDA) lidar is currently under development at NASA Langley Research Center (LaRC). This IPDA lidar system targets both atmospheric carbon dioxide (CO2) and water vapor (H2O) column measurements. Independent wavelength control of each of the transmitted laser pulses is a key feature for the success of this instrument. The wavelength control unit provides switching, tuning and locking for each pulse in reference to a 2-μm CW laser source locked to CO2 line-center. Targeting the CO2 R30 line center, at 2050.967 nm, a wavelength locking unit has been integrated using semiconductor laser diode. The CO2 center-line locking unit includes a laser diode current driver, temperature controller, center-line locking controller and CO2 absorption cell. This paper presents the CO2 center-line locking unit architecture, characterization procedure and results. Assessment of wavelength jitter on the IPDA measurement error will also be addressed by comparison to the system design.

  5. Recovery of acetylene absorption line profile basing on tunable diode laser spectroscopy with intensity modulation and photoacoustic spectroscopy

    NASA Astrophysics Data System (ADS)

    Li, Li; Thursby, Graham; Stewart, George; Arsad, Norhana; Uttamchandani, Deepak; Culshaw, Brian; Wang, Yiding

    2010-04-01

    A novel and direct absorption line recovery technique based on tunable diode laser spectroscopy with intensity modulation is presented. Photoacoustic spectroscopy is applied for high sensitivity, zero background and efficient acoustic enhancement at a low modulation frequency. A micro-electromechanical systems (MEMS) mirror driven by an electrothermal actuator is used for generating laser intensity modulation (without wavelength modulation) through the external reflection. The MEMS mirror with 10μm thick structure material layer and 100nm thick gold coating is formed as a circular mirror of 2mm diameter attached to an electrothermal actuator and is fabricated on a chip that is wire-bonded and placed on a PCB holder. Low modulation frequency is adopted (since the resonant frequencies of the photoacoustic gas cell and the electrothermal actuator are different) and intrinsic high signal amplitude characteristics in low frequency region achieved from measured frequency responses for the MEMS mirror and the gas cell. Based on the property of photoacoustic spectroscopy and Beer's law that detectable sensitivity is a function of input laser intensity in the case of constant gas concentration and laser path length, a Keopsys erbium doped fibre amplifier (EDFA) with opto-communication C band and high output power up to 1W is chosen to increase the laser power. High modulation depth is achieved through adjusting the MEMS mirror's reflection position and driving voltage. In order to scan through the target gas absorption line, the temperature swept method is adopted for the tunable distributed feed-back (DFB) diode laser working at 1535nm that accesses the near-infrared vibration-rotation spectrum of acetylene. The profile of acetylene P17 absorption line at 1535.39nm is recovered ideally for ~100 parts-per-million (ppm) acetylene balanced by nitrogen. The experimental signal to noise ratio (SNR) of absorption line recovery for 500mW laser power was ~80 and hence the

  6. Absorption lines from magnetically driven winds in X-ray binaries

    NASA Astrophysics Data System (ADS)

    Chakravorty, S.; Petrucci, P.-O.; Ferreira, J.; Henri, G.; Belmont, R.; Clavel, M.; Corbel, S.; Rodriguez, J.; Coriat, M.; Drappeau, S.; Malzac, J.

    2016-05-01

    Context. High resolution X-ray spectra of black hole X-ray binaries (BHBs) show blueshifted absorption lines suggesting the presence of outflowing winds. Furthermore, observations show that the disk winds are equatorial and they occur in the Softer (disk dominated) states of the outburst and are less prominent or absent in the Harder (power-law dominated) states. Aims: We want to test whether the self-similar magneto-hydrodynamic (MHD) accretion-ejection models can explain the observational results for accretion disk winds in BHBs. In our models, the density at the base of the outflow from the accretion disk is not a free parameter. This mass loading is determined by solving the full set of dynamical MHD equations without neglecting any physical term. Thus, the physical properties of the outflow depend on and are controlled by the global structure of the disk. Methods: We studied different MHD solutions characterized by different values of the disk aspect ratio (ɛ) and the ejection efficiency (p). We also generate two kinds of MHD solutions depending on the absence (cold solution) or presence (warm solution) of heating at the disk surface. Such heating could be either from dissipation of energy due to MHD turbulence in the disk or from illumination of the disk surface. Warm solutions can have large (>0.1) values of p, which would imply larger wind mass loading at the base of the outflow. We use each of these MHD solutions to predict the physical parameters (distance, density, velocity, magnetic field, etc.) of an outflow. Motivated by observational results, we have put limits on the ionization parameter (ξ), column density, and timescales. Further constraints were derived for the allowed values of ξ from thermodynamic instability considerations, particularly for the Hard SED. These physical constraints were imposed on each of these outflows to select regions within it, which are consistent with the observed winds. Results: The cold MHD solutions are found to be

  7. The hydration dependence of CaCO3 absorption lines in the Far IR

    NASA Astrophysics Data System (ADS)

    Powell, Johnny; Emery, Logan P

    2014-06-01

    The far infrared (FIR) absorption lines of CaCO3 have been measured at a range of relative humidities (RH) between 33 and 92% RH using a Bruker 66v/S spectrometer. Hydration measurements on CaCO3 have been made in the mid-infrared (MIR) by [Al-Hosney, H.A. and Grassian, V.H., 2005, Phys. Chem. Chem. Phys., 7, 1266], and astrophysically-motivated temperature-dependent FIR measurements of CaCO3 in vacuum have also been reported [Posch, T., et al., 2007, Ap. J., 668, 993]. The custom sample cell constructed for these hydrated-FIR spectra is required because the 66v/S bench is under vacuum (3 mbar) during typical measurements. Briefly, the sample cell consists of two Thalium Bromoiodide (KRS-5) windows, four O-rings, a plastic ring for separating the windows and providing a volume for the saturated atmosphere. CaCO3 was deposited on KRS-5 windows using doubly-distilled water as an intermediary. The KRS-5 window with sample and assembled sample cell were placed in a desiccator with the appropriated saturated salt solution [Washburn, E.W. (Ed.), International Critical Tables of Numerical Data, Physics Chemistry and Technology, Vol. 1, (McGraw-Hill, New York, 1926), p. 67-68] and allowed to hydrate for 23 hours. For spectroscopy the desiccator was quickly opened and the second KRS-5 window placed in the cell to seal the chamber. A spectrum was then taken of the sample at the appropriate RH. The spectra taken characterize the adsorption of water vapor and CaCO3 that might occur in circumstellar environments [Melnick, G.J., et al. 2001, Nature, 412, 160].The MIR and FIR reflectance spectra of calcite (CaCO3) have been thoroughly studied by [Hellwege, K.H., et al., 1970, Z. Physik, 232, 61]. Five Lorentzian curves were fit to our data in the range from 378-222 cm-1/SUP> and each was able to be assigned to a known mode of CaCO3. The data does not support the conclusion of a hydration effect on these modes of CaCO3, but it does suggest a possible broadening of three modes

  8. X-ray Weak Broad-line Qquasars: Absorption or Intrinsic X-ray Weakness

    NASA Technical Reports Server (NTRS)

    Mushotzky, Richard (Technical Monitor); Risaliti, Guida

    2005-01-01

    XMM observations of X-ray weak quasars have been performed during 2003 and 2004. The data for all the observations have become available in 2004 (there has been a delay of several months on the initial schedule, due to high background flares which contaminated the observations: as a consequence, most of them had to be rescheduled). We have reduced and analyzed all the data, and obtained interesting scientific results. Out of the eight sources, 4 are confirmed to be extremely X-ray weak, in agreement with the results of previous Chandra observations. 3 sources are confined to be highly variable both in flux (by factor 20-50) and in spectral properties (dramatic changes in spectral index). For both these groups of objects we are completing a publication: 1) For the X-ray weak sources, a paper is submitted with a complete analysis of the X-ray spectra both from Chandra and XMM-Newton, and a comparison with optical and near-IR photometry obtained from all-sky surveys. Possible models for the unusual spectral energy distribution of these sources are also presented. 2) For the variable sources, a paper is being finalized where the X-ray spectra obtained with XMM-Newton are compared with previous X-ray observations and with observations at other wavelengths. It is shown that these sources are high luminosity and extreme cases of the highly variable class of narrow-line Seyfert Is. In order to further understand the nature of these X-ray weak quasars, we submitted proposals for spectroscopy at optical and infrared telescopes. We obtained time at the TNG 4 meter telescope for near-IR observations and at the Hobby-Eberly Telescope for optical high-resolution spectroscopy. These observations have been performed in early 2004. They will complement the XMM data and will lead to understanding of whether the X-ray weakness of these sources is an intrinsic property or is due to absorption by circum-nuclear material. The infrared spectra of the variable sources have been already

  9. NEW PERSPECTIVE ON GALAXY OUTFLOWS FROM THE FIRST DETECTION OF BOTH INTRINSIC AND TRAVERSE METAL-LINE ABSORPTION

    SciTech Connect

    Kacprzak, Glenn G.; Cooke, Jeff; Martin, Crystal L.; Ho, Stephanie H.; Bouché, Nicolas; LeReun, Audrey; Schroetter, Ilane; Churchill, Christopher W.; Klimek, Elizabeth

    2014-09-01

    We present the first observation of a galaxy (z = 0.2) that exhibits metal-line absorption back-illuminated by the galaxy (down-the-barrel) and transversely by a background quasar at a projected distance of 58 kpc. Both absorption systems, traced by Mg II, are blueshifted relative to the galaxy systemic velocity. The quasar sight line, which resides almost directly along the projected minor axis of the galaxy, probes Mg I and Mg II absorption obtained from the Keck/Low Resolution Imaging Spectrometer as well as Lyα, Si II, and Si III absorption obtained from the Hubble Space Telescope/Cosmic Origins Spectrograph. For the first time, we combine two independent models used to quantify the outflow properties for down-the-barrel and transverse absorption. We find that the modeled down-the-barrel deprojected outflow velocities range between V {sub dtb} = 45-255 km s{sup –1}. The transverse bi-conical outflow model, assuming constant-velocity flows perpendicular to the disk, requires wind velocities V {sub outflow} = 40-80 km s{sup –1} to reproduce the transverse Mg II absorption kinematics, which is consistent with the range of V {sub dtb}. The galaxy has a metallicity, derived from Hα and N II, of [O/H] = –0.21 ± 0.08, whereas the transverse absorption has [X/H] = –1.12 ± 0.02. The galaxy star formation rate is constrained between 4.6-15 M {sub ☉} yr{sup –1} while the estimated outflow rate ranges between 1.6-4.2 M {sub ☉} yr{sup –1} and yields a wind loading factor ranging between 0.1-0.9. The galaxy and gas metallicities, the galaxy-quasar sight-line geometry, and the down-the-barrel and transverse modeled outflow velocities collectively suggest that the transverse gas originates from ongoing outflowing material from the galaxy. The ∼1 dex decrease in metallicity from the base of the outflow to the outer halo suggests metal dilution of the gas by the time it reached 58 kpc.

  10. Determination of vibration-rotation lines intensities from absorption Fourier spectra

    NASA Technical Reports Server (NTRS)

    Mandin, J. Y.

    1979-01-01

    The method presented allows the line intensities to be calculated from either their equivalent widths, heights, or quantities deduced from spectra obtained by Fourier spectrometry. This method has proven its effectiveness in measuring intensities of 60 lines of the molecule H2O with a precision of 10%. However, this method cannot be applied to isolated lines.

  11. X-ray absorption lines suggest matter infalling onto the central black-hole of Mrk 509

    NASA Astrophysics Data System (ADS)

    Dadina, M.; Cappi, M.; Malaguti, G.; Ponti, G.; de Rosa, A.

    2005-11-01

    Evidence for both red- and blue-shifted absorption lines due to ionized Fe in the X-ray spectrum of the Seyfert 1 galaxy Mrk 509 is reported. These features appear to be transient on time-scales as short as ~20 ks, and have been observed with two different satellites, BeppoSAX and XMM-Newton. The red- and blue-shifted lines are found at E˜5.5 keV and ~8.1-8.3 keV (rest-frame), respectively. The first is seen in one out of six BeppoSAX observations, the latter is seen by both satellites. Under the assumption that the absorption is due to either H- or He-like Iron, the implied velocities for the absorbing matter are v˜0.15-0.2 c, in both outward and inward directions. An alternative explanation in terms of gravitational red-shift for the ~5.5 keV line cannot be ruled out with the current data. We argue, however, that the temporal patterns and sporadic nature of the lines are more easily reconciled with models that predict important radial motions close to the central black hole, such as the "aborted jet" model, the "thundercloud" model, or magneto-hydrodynamical models of jets and accretion-disks.

  12. Temperature dependences of mechanisms responsible for the water-vapor continuum absorption. I. Far wings of allowed lines.

    PubMed

    Ma, Q; Tipping, R H; Leforestier, C

    2008-03-28

    It is well known that the water-vapor continuum plays an important role in the radiative balance in the Earth's atmosphere. This was first discovered by Elsasser almost 70 years ago, and since that time there has been a large body of work, both experimental and theoretical, on this topic. It has been experimentally shown that for ambient atmospheric conditions, the continuum absorption scales quadratically with the H(2)O number density and has a strong, negative temperature dependence (T dependence). Over the years, there have been three different theoretical mechanisms postulated: Far wings of allowed transitions, water dimers, and collision-induced absorption. Despite the improvements in experimental data, at present there is no consensus on which mechanism is primarily responsible for the absorption. The first mechanism proposed was the accumulation of the far-wing absorption of the strong allowed transitions. Later, absorption by water dimers was proposed and this mechanism provides a qualitative explanation for the strong, negative T dependence. Recently, some atmospheric modelers have proposed that collision-induced absorption is one of the major contributors. However, based on improvements in the theoretical calculation of accurate far-wing line shapes, ab initio dimer calculations, and theoretical collision-induced absorptions, it is now generally accepted that the dominant mechanism for the absorption in the infrared (IR) windows is that due to the far wings. Whether this is true for other spectral regions is not presently established. Although all these three mechanisms have a negative T dependence, their T dependences will be characterized by individual features. To analyze the characteristics of the latter will enable one to assess their roles with more certainty. In this paper, we present a detailed study of the T dependence of the far-wing absorption mechanism. We will then compare our theoretical calculations with the most recent and accurate

  13. The Complete Ultraviolet Spectrum of the Archetypal "Wind-dominated" Quasar Mrk 231: Absorption and Emission from a High-speed Dusty Nuclear Outflow

    NASA Astrophysics Data System (ADS)

    Veilleux, S.; Meléndez, M.; Tripp, T. M.; Hamann, F.; Rupke, D. S. N.

    2016-07-01

    New near- and far-ultraviolet (NUV and FUV) Hubble Space Telescope spectra of Mrk 231, the nearest quasar known, are combined with ground-based optical spectra to study the remarkable dichotomy between the FUV and NUV-optical spectral regions in this object. The FUV emission-line features are faint, broad, and highly blueshifted (up to ˜7000 km s-1), with no significant accompanying absorption. In contrast, the profiles of the NUV absorption features resemble those of the optical Na i D, He i, and Ca ii H and K lines, exhibiting broad blueshifted troughs that overlap in velocity space with the FUV emission-line features and indicate a dusty, high-density and patchy broad absorption line (BAL) screen covering ˜90% of the observed continuum source at a distance ≲2-20 pc. The FUV continuum emission does not show the presence of any obvious stellar features and is remarkably flat compared with the steeply declining NUV continuum. The NUV (FUV) features and continuum emission have not varied significantly over the past ˜22 (3) years and are unresolved on scales ˜40 (170) pc. These results favor an active galactic nucleus origin for the NUV-FUV line and continuum emission. The observed FUV line emission is produced in the outflowing BAL cloud system, while the Balmer lines arise primarily from the standard broad line region seen through the dusty BAL screen. Our data are inconsistent with the recently proposed binary black hole model. We argue instead that Mrk 231 is the nearest example of weak-lined “wind-dominated” quasars with high Eddington ratios and geometrically thick (“slim”) accretion disks; these quasars are likely more common in the early universe.

  14. Time-averaging approximation in the interaction picture: absorption line shapes for coupled chromophores with application to liquid water.

    PubMed

    Yang, Mino; Skinner, J L

    2011-10-21

    The time-averaging approximation (TAA), originally developed to calculate vibrational line shapes for coupled chromophores using mixed quantum/classical methods, is reformulated. In the original version of the theory, time averaging was performed for the full one-exciton Hamiltonian, while herein the time averaging is performed on the coupling (off-diagonal) Hamiltonian in the interaction picture. As a result, the influence of the dynamic fluctuations of the transition energies is more accurately described. We compare numerical results of the two versions of the TAA with numerically exact results for the vibrational absorption line shape of the OH stretching modes in neat water. It is shown that the TAA in the interaction picture yields theoretical line shapes that are in better agreement with exact results.

  15. Pulsed Airborne Lidar Measurements of Atmospheric CO2 Column Absorption and Line Shapes from 3-13 km Altitudes

    NASA Technical Reports Server (NTRS)

    Abshire, James; Riris, Haris; Allan, Graham; Weaver, Clark; Mao, Jianping; Sun, Xiaoli; Hasselbrack, William

    2010-01-01

    We have developed a pulsed lidar technique for measuring the tropospheric CO2 concentrations as a candidate for NASA's planned ASCENDS space mission. Our technique uses two pulsed laser transmitters allowing simultaneous measurement of a CO2 absorption line in the 1570 nm band, O2 extinction in the Oxygen A-band and surface height and backscatter. The lidar measures the energy and time of flight of the laser echoes reflected from the atmosphere and surface. The lasers are rapidly and precisely stepped in wavelength across the CO2 line and an O2 line region during the measurement. The direct detection receiver uses a telescope and photon counting detectors, and measures the background light and energies of the laser echoes from the surface along with scattering from any aerosols in the path. The gas extinction and column densities for the CO2 and O2 gases are estimated from the ratio of the on- and off- line signals via the DIAL technique. Time gating is used to isolate the laser echo signals from the surface, and to reject laser photons scattered in the atmosphere. The time of flight of the laser pulses are also used to estimate the height of the scattering surface and to identify cases of mixed cloud and ground scattering. We have developed an airborne lidar to demonstrate the CO2 measurement from the NASA Glenn Lear-25 aircraft. The airborne lidar steps the pulsed laser's wavelength across the selected CO2 line with 20 steps per scan. The line scan rate is 450 Hz, the laser pulse widths are 1 usec, and laser pulse energy is 24 uJ. The time resolved laser backscatter is collected by a 20 cm telescope, detected by a photomultiplier and is recorded by a photon counting system. We made initial airborne measurements on flights during fall 2008. Laser backscatter and absorption measurements were made over a variety of land and water surfaces and through thin clouds. The atmospheric CO2 column measurements using the 1572.33 nm CO2 lines. Two flights were made above the

  16. Selecting Cells for Bioartificial Liver Devices and the Importance of a 3D Culture Environment: A Functional Comparison between the HepaRG and C3A Cell Lines

    PubMed Central

    van Wenum, Martien; Adam, Aziza A.A.; Hakvoort, Theodorus B.M.; Hendriks, Erik J.; Shevchenko, Valery; van Gulik, Thomas M.; Chamuleau, Robert A.F.M.; Hoekstra, Ruurdtje

    2016-01-01

    Recently, the first clinical trials on Bioartificial Livers (BALs) loaded with a proliferative human hepatocyte cell source have started. There are two cell lines that are currently in an advanced state of BAL development; HepaRG and HepG2/C3A. In this study we aimed to compare both cell lines on applicability in BALs and to identify possible strategies for further improvement. We tested both cell lines in monolayer- and BAL cultures on growth characteristics, hepatic differentiation, nitrogen-, carbohydrate-, amino acid- and xenobiotic metabolism. Interestingly, both cell lines adapted the hepatocyte phenotype more closely when cultured in BALs; e.g. monolayer cultures produced lactate, while BAL cultures showed diminished lactate production (C3A) or conversion to elimination (HepaRG), and urea cycle activity increased upon BAL culturing in both cell lines. HepaRG-BALs outperformed C3A-BALs on xenobiotic metabolism, ammonia elimination and lactate elimination, while protein synthesis was comparable. In BAL cultures of both cell lines ammonia elimination correlated positively with glutamine production and glutamate consumption, suggesting ammonia elimination was mainly driven by the balance between glutaminase and glutamine synthetase activity. Both cell lines lacked significant urea cycle activity and both required multiple culture weeks before reaching optimal differentiation in BALs. In conclusion, culturing in BALs enhanced hepatic functionality of both cell lines and from these, the HepaRG cells are the most promising proliferative cell source for BAL application. PMID:27489500

  17. The Fundamental Quadrupole Band of (14)N2: Line Positions from High-Resolution Stratospheric Solar Absorption Spectra

    NASA Technical Reports Server (NTRS)

    Rinsland, C. P.; Zander, R.; Goldman, A.; Murcray, F. J.; Murcray, D. G.; Grunson, M. R.; Farmer, C. B.

    1991-01-01

    The purpose of this note is to report accurate measurements of the positions of O- and S-branch lines of the (1-0) vibration-rotation quadrupole band of molecular nitrogen ((14)N2) and improved Dunham coefficients derived from a simultaneous least-squares analysis of these measurements and selected infrared and far infrared data taken from the literature. The new measurements have been derived from stratospheric solar occultation spectra recorded with Fourier transform spectrometer (FTS) instruments operated at unapodized spectral resolutions of 0.002 and 0.01 /cm. The motivation for the present investigation is the need for improved N2 line parameters for use in IR atmospheric remote sensing investigations. The S branch of the N2 (1-0) quadrupole band is ideal for calibrating the line-of-sight airmasses of atmospheric spectra since the strongest lines are well placed in an atmospheric window, their absorption is relatively insensitive to temperature and is moderately strong (typical line center depths of 10 to 50% in high-resolution ground-based solar spectra and in lower stratospheric solar occultation spectra), and the volume mixing ratio of nitrogen is constant in the atmosphere and well known. However, a recent investigation has'shown the need to improve the accuracies of the N2 fine positions, intensities, air-broadened half-widths, and their temperature dependences to fully exploit this calibration capability (1). The present investigation addresses the problem of improving the accuracy of the N2 line positions.

  18. Attosecond transient absorption of argon atoms in the vacuum ultraviolet region: line energy shifts versus coherent population transfer

    NASA Astrophysics Data System (ADS)

    Cao, Wei; Warrick, Erika R.; Neumark, Daniel M.; Leone, Stephen R.

    2016-01-01

    Using attosecond transient absorption, the dipole response of an argon atom in the vacuum ultraviolet (VUV) region is studied when an external electromagnetic field is present. An isolated attosecond VUV pulse populates Rydberg states lying 15 eV above the argon ground state. A synchronized few-cycle near infrared (NIR) pulse modifies the oscillating dipoles of argon impulsively, leading to alterations in the VUV absorption spectra. As the NIR pulse is delayed with respect to the VUV pulse, multiple features in the absorption profile emerge simultaneously including line broadening, sideband structure, sub-cycle fast modulations, and 5-10 fs slow modulations. These features indicate the coexistence of two general processes of the light-matter interaction: the energy shift of individual atomic levels and coherent population transfer between atomic eigenstates, revealing coherent superpositions. An intuitive formula is derived to treat both effects in a unifying framework, allowing one to identify and quantify the two processes in a single absorption spectrogram.

  19. Ratio of Dust to Metal Abundance in Quasar Absorption Line Systems from 1.9 < z < 3.3

    NASA Astrophysics Data System (ADS)

    Stawinski, Stephanie; Malhotra, Sangeeta

    2017-01-01

    Measuring the ratio of dust to metal abundance in quasar absorption line systems will provide insight to the chemical evolution of galaxies, dust formation, and dust properties in the early universe. Quasar absorption systems allow us to study the abundance of dust from many different redshifts, in this project up to z ~ 3.3 for absorber redshift. The absorption bump at 2175 Å is a broad, but strong, dust feature within the UV-optical wavelength range. This feature, if detected, can be directly related to the optical depth of the dust in the absorbing systems. However, the 2175 Å bump is very broad, having a full-width half-maximum approximately 350 * (1 + z) Å, and therefore hard to distinguish from a single spectrum. To find this bump, it is important to co-add many quasar spectra. In this project, we look at how the abundance of dust compares to that of metals for 105 quasar spectra with strong damped Lyman alpha systems with absorber redshifts ranging from 1.9 < z < 3.3. From these spectra, we created a composite spectrum to analyze the 2175 Å bump and the absorption of heavy elements. We will present the results including the strength of the 2175 Å feature found in our composite spectrum.

  20. Pulsed Airborne Lidar Measurements of Atmospheric CO2 Column Absorption and Line Shapes from 3-13 km Altitudes

    NASA Technical Reports Server (NTRS)

    Abshire, J. B.; Riris, H.; Allan, G. R.; Weaver, C.; Hasselbrack, W.; Sun, X.

    2009-01-01

    We have developed a lidar technique for measuring the tropospheric C02 concentrations as a candidate for NASA's planned ASCENDS mission. Our technique uses two pulsed laser transmitters allowing simultaneous measurement of a C02 absorption line in the 1570 nm band, 02 extinction in the Oxygen A-band and surface height and backscatter. The lidar measures the energy and time of flight of the laser echoes reflected from the atmosphere and surface. The lasers are stepped in wavelength across the C02 line and an 02 line region during the measurement. The receiver uses a telescope and photon counting detectors, and measures the background light and energies of the laser echoes from the surface along with scattering from any aerosols in the path. The gas extinction and column densities for the C02 and 02 gases are estimated from the ratio of the on- and off- line signals via the DIAL technique. Time gating is used to isolate the laser echo signals from the surface, and to reject laser photons scattered in the atmosphere. We have developed an airborne lidar to demonstrate the C02 measurement from the NASA Glenn Lear 25 aircraft. The airborne lidar steps the pulsed laser's wavelength across a selected C02 line with 20 steps per scan. The line scan rate is 450 Hz and laser pulse widths are I usec. The time resolved laser backscatter is collected by a 20 cm telescope, detected by a photomultiplier and is recorded by a photon counting system. We made initial airborne measurements on flights during October and December 2008. Laser backscatter and absorption measurements were made over a variety of land and water surfaces and through thin and broken clouds. Atmospheric C02 column measurements using the 1571.4, 1572.02 and 1572.33 nm C02 lines. Two flights were made above the DOE SGP ARM site at altitudes from 3-8 km. These nights were coordinated with DOE investigators who Hew an in-situ C02 sensor on a Cessna aircraft under the path. The increasing C02 line absorptions with

  1. Pulsed Airborne Lidar measurements of Atmospheric CO2 Column Absorption and Line Shapes from 3-13 km altitudes

    NASA Astrophysics Data System (ADS)

    Abshire, J. B.; Riris, H.; Allan, G. R.; Weaver, C. J.; Hasselbrack, W. E.; Sun, X.

    2009-12-01

    We have developed a lidar technique for measuring the tropospheric CO2 concentrations as a candidate for NASA’s planned ASCENDS mission. Our technique uses two pulsed laser transmitters allowing simultaneous measurement of a CO2 absorption line in the 1570 nm band, O2 extinction in the Oxygen A-band and surface height and backscatter. The lidar measures the energy and time of flight of the laser echoes reflected from the atmosphere and surface. The lasers are stepped in wavelength across the CO2 line and an O2 line region during the measurement. The receiver uses a telescope and photon counting detectors, and measures the background light and energies of the laser echoes from the surface along with scattering from any aerosols in the path. The gas extinction and column densities for the CO2 and O2 gases are estimated from the ratio of the on- and off- line signals via the DIAL technique. Time gating is used to isolate the laser echo signals from the surface, and to reject laser photons scattered in the atmosphere. We have developed an airborne lidar to demonstrate the CO2 measurement from the NASA Glenn Lear-25 aircraft. The airborne lidar steps the pulsed laser’s wavelength across a selected CO2 line with 20 steps per scan. The line scan rate is 450 Hz, laser pulse energy is 25 uJ and laser pulse widths are 1 usec. The time resolved laser backscatter is collected by a 20 cm telescope, detected by a photomultiplier and is recorded by a photon counting system. We made initial airborne measurements on flights during October and December 2008. Laser backscatter and absorption measurements were made over a variety of land and water surfaces and through thin and broken clouds. Atmospheric CO2 column measurements using the 1571.4, 1572.02 and 1572.33 nm CO2 lines. Two flights were made above the DOE SGP ARM site at altitudes from 3-8 km. These flights were coordinated with DOE investigators who flew an in-situ CO2 sensor on a Cessna aircraft under the path. The

  2. Origins of optical absorption and emission lines in AlN

    SciTech Connect

    Yan, Qimin; Janotti, Anderson; Van de Walle, Chris G.; Scheffler, Matthias

    2014-09-15

    To aid the development of AlN-based optoelectronics, it is essential to identify the defects that cause unwanted light absorption and to minimize their impact. Using hybrid functional calculations, we investigate the role of native defects and their complexes with oxygen, a common impurity in AlN. We find that Al vacancies are the source of the absorption peak at 3.4 eV observed in irradiated samples and of the luminescence signals at 2.78 eV. The absorption peak at ∼4.0 eV and higher, and luminescence signals around 3.2 and 3.6 eV observed in AlN samples with high oxygen concentrations are attributed to complexes of Al vacancies and oxygen impurities. We also propose a transition involving Al and N vacancies and oxygen impurities that may be a cause of the absorption band peaked at 2.9 eV.

  3. VizieR Online Data Catalog: QSO B0218+357 molecular absorption lines (Wallstroem+, 2016)

    NASA Astrophysics Data System (ADS)

    Wallstroem, S. H. J.; Muller, S.; Guelin, M.

    2016-08-01

    ASCII files of the absorption spectra presented in Figure 2. The files are named after the molecule or isotopologue. Column 1 is velocity, column 2 is intensity (normalized to 1), Velocities are in a heliocentric frame, with zabs=0.68466 (11 data files).

  4. Detection of High Velocity Absorption Components in the He I Lines of Eta Carinae near the Time of Periastron

    NASA Technical Reports Server (NTRS)

    Richardson, Noel D.; St-Jean, Lucas; Gull, Theodore R.; Madura, Thomas; Hillier, D. John; Teodoro, Mairan; Moffat, Anthony; Corcoran, Michael; Damineli, Augusto

    2014-01-01

    We have obtained a total of 58 high spectral resolution (R90,000) spectra of the massive binary star eta Carinae since 2012 in an effort to continue our orbital and long-term echelle monitoring of this extreme binary (Richardson et al. 2010, AJ, 139, 1534) with the CHIRON spectrograph on the CTIO 1.5 m telescope (Tokovinin et al. 2013, PASP, 125, 1336) in the 45507500A region. We have increased our monitoring efforts and observation frequency as the periastron event of 2014 has approached. We note that there were multiple epochs this year where we observe unusual absorption components in the P Cygni troughs of the He I triplet lines. In particular, we note high velocity absorption components related to the following epochs for the following lines: He I 4713: HJD 2456754- 2456795 (velocity -450 to -560 kms) He I 5876: HJD 2456791- 2456819 (velocity -690 to -800 kms) He I 7065: HJD 2456791- 2456810 (velocity -665 to -730 kms) Figures: Note that red indicates a high-velocity component noted above. He I 4713: http:www.astro.umontreal.carichardson4713.png He I 5876: http:www.astro.umontreal.carichardson5876.png He I 7065: http:www.astro.umontreal.carichardson7065.png These absorptions are likely related to the wind-wind collision region and bow shock, as suggested by the high-velocity absorption observed by Groh et al. (2010, AA, 519, 9) in the He I 10830 Atransition. In these cases, we suspect that we look along an arm of the shock cone and that we will see a fast absorption change from the other collision region shortly after periastron. We suspect that this is related to the multiple-components of the He II 4686 line that was noted by Walter (ATel6334), and is confirmed in our data. Further, high spectral resolution data are highly encouraged,especially for resolving powers greater than 50,000.These observations were obtained with the CTIO 1.5 m telescope, operated by the SMARTS Consortium, and were obtained through both SMARTS and NOAO programs 2012A-0216,2012B-0194

  5. THE COS-HALOS SURVEY: AN EMPIRICAL DESCRIPTION OF METAL-LINE ABSORPTION IN THE LOW-REDSHIFT CIRCUMGALACTIC MEDIUM

    SciTech Connect

    Werk, Jessica K.; Prochaska, J. Xavier; Tripp, Todd M.; O'Meara, John M.; Peeples, Molly S.

    2013-02-15

    We present the equivalent width and column density measurements for low and intermediate ionization states of the circumgalactic medium (CGM) surrounding 44 low-z, L Almost-Equal-To L* galaxies drawn from the COS-Halos survey. These measurements are derived from far-UV transitions observed in HST/COS and Keck/HIRES spectra of background quasars within an impact parameter R < 160 kpc to the targeted galaxies. The data show significant metal-line absorption for 33 of the 44 galaxies, including quiescent systems, revealing the common occurrence of a cool (T Almost-Equal-To 10{sup 4}-10{sup 5} K), metal-enriched CGM. The detection rates and column densities derived for these metal lines decrease with increasing impact parameter, a trend we interpret as a declining metal surface density profile for the CGM. A comparison of the relative column densities of adjacent ionization states indicates that the gas is predominantly ionized. The large surface density in metals demands a large reservoir of metals and gas in the cool CGM (very conservatively, M {sup cool} {sub CGM} > 10{sup 9} M {sub Sun }), which likely traces a distinct density and/or temperature regime from the highly ionized CGM traced by O{sup +5} absorption. The large dispersion in absorption strengths (including non-detections) suggests that the cool CGM traces a wide range of densities or a mix of local ionizing conditions. Lastly, the kinematics inferred from the metal-line profiles are consistent with the cool CGM being bound to the dark matter halos hosting the galaxies; this gas may serve as fuel for future star formation. Future work will leverage this data set to provide estimates on the mass, metallicity, dynamics, and origin of the cool CGM in low-z, L* galaxies.

  6. Digital signal processor-based high-precision on-line Voigt lineshape fitting for direct absorption spectroscopy.

    PubMed

    Xu, Lijun; Liu, Chang; Zheng, Deyan; Cao, Zhang; Cai, Weiwei

    2014-12-01

    To realize on-line high-accuracy measurement in direct absorption spectroscopy (DAS), a system-on-chip, high-precision digital signal processor-based on-line Voigt lineshape fitting implementation is introduced in this paper. Given that the Voigt lineshape is determined by the Gauss full width at half maximum (FWHM) and Lorentz FWHM, a look-up table, which covers a range of combinations of both, is first built to achieve rapid and accurate calculation of Voigt lineshape. With the look-up table and raw absorbance data in hand, Gauss-Newton nonlinear fitting module is implemented to obtain the parameters including both the Gauss and Lorentz FWHMs, which can be used to calculate the integrated absorbance. To realize the proposed method in hardware, a digital signal processor (DSP) is adopted to fit the Voigt lineshape in a real-time DAS measurement system. In experiment, temperature and H2O concentration of a flat flame are recovered from the transitions of 7444.36 cm(-1) and 7185.6 cm(-1) by the DSP-based on-line Voigt lineshape fitting and on-line integral of the raw absorbance, respectively. The results show that the proposed method can not only fit the Voigt lineshape on-line but also improve the measurement accuracy compared with those obtained from the direct integral of the raw absorbance.

  7. The magnetic field of an isolated neutron star from X-ray cyclotron absorption lines.

    PubMed

    Bignami, G F; Caraveo, P A; De Luca, A; Mereghetti, S

    2003-06-12

    Isolated neutron stars are highly magnetized, fast-rotating objects that form as an end point of stellar evolution. They are directly observable in X-ray emission, because of their high surface temperatures. Features in their X-ray spectra could in principle reveal the presence of atmospheres, or be used to estimate the strength of their magnetic fields through the cyclotron process, as is done for X-ray binaries. Almost all isolated neutron star spectra observed so far appear as featureless thermal continua. The only exception is 1E1207.4-5209 (refs 7-9), where two deep absorption features have been detected, but with insufficient definition to permit unambiguous interpretation. Here we report a long X-ray observation of the same object in which the star's spectrum shows three distinct features, regularly spaced at 0.7, 1.4 and 2.1 keV, plus a fourth feature of lower significance, at 2.8 keV. These features vary in phase with the star's rotation. The logical interpretation is that they are features from resonant cyclotron absorption, which allows us to calculate a magnetic field strength of 8 x 10(10) G, assuming the absorption arises from electrons.

  8. Time resolved metal line profile by near-ultraviolet tunable diode laser absorption spectroscopy

    NASA Astrophysics Data System (ADS)

    Vitelaru, C.; de Poucques, L.; Minea, T. M.; Popa, G.

    2011-03-01

    Pulsed systems are extensively used to produce active species such as atoms, radicals, excited states, etc. The tunable diode laser absorption spectroscopy (TD-LAS) is successfully used to quantify the density of absorbing species, but especially for stationary or slow changing systems. The time resolved-direct absorption profile (TR-DAP) measurement method by TD-LAS, with time resolution of μs is proposed here as an extension of the regular use of diode laser absorption spectroscopy. The spectral narrowness of laser diodes, especially in the blue range (˜0.01 pm), combined with the nanosecond fast trigger of the magnetron pulsed plasma and long trace recording on the oscilloscope (period of second scale) permit the detection of the sputtered titanium metal evolution in the afterglow (˜ms). TR-DAP method can follow the time-dependence of the temperature (Doppler profile) and the density (deduced from the absorbance) of any medium and heavy species in a pulsed system.

  9. The Features of the Frequency-Modulation Method When Studying the Shapes of the Spectral Lines of Nonlinear Absorption

    NASA Astrophysics Data System (ADS)

    Golubiatnikov, G. Yu.; Belov, S. P.; Lapinov, A. V.

    2017-01-01

    We briefly consider the method of the frequency (phase) modulation and signal detection at the second harmonic of the modulation frequency for recording and analyzing the spectral-line shapes. The precision sub-Doppler spectrometer in the millimeter- and submillimeter-wave ranges, which operated in the regime of nonlinear saturation of the spectral transitions in a standing wave (the Lamb-dip method), was used during the measurements. The influence of the saturation degree on the value and shape of the recorded frequency-modulated signals in the quadrature channels during the synchronous detection is demonstrated. Variation in the relationships among the signals determined by dispersion and absorption was observed. The necessity of allowance for the influence of the group-velocity dispersion and coherent effects on the shape of the recorded spectral lines is experimentally shown.

  10. FUSE and STIS Observations of Intervening O VI Absorption Line Systems in the Spectrum of PG 0953+415

    NASA Astrophysics Data System (ADS)

    Savage, B. D.; Sembach, K. R.; Tripp, T. M.; Richter, P.; Jenkins, E. B.

    2000-12-01

    We analyze Far Ultraviolet Spectroscopic Explorer (FUSE) and Space Telescope Imaging Spectrograph (STIS) observations of the intergalactic O VI absorption line systems in the direction of the bright QSO PG 0953+415 (z = 0.239). The FUSE observations cover the wavelength range from 905 to 1187 Å with a velocity resolution of 20 km/s. The STIS observations obtained with the E140M echelle spectrograph extend from 1150 to 1730 Å with a resolution of 8 km/s. These are supplemented with STIS G140M and G230M observations from 1145-1201 Å and from 1724-1814 A with a resolution of 30 km/s. We detect a strong O VI system at z = 0.06807 in the lines of H I Ly alpha, beta, and gamma, O VI 1031.93, 1037.62, N V 1238.80, 1242.80, C IV 1548.20, 1550.77, and C III 977.02 Å. We confirm the detection of the z = 0.14232 O VI system studied previously by Tripp and Savage (2000). The new FUSE observations of this system record Ly beta , O VI 1031.93, 1037.62, and C III 977.02 Å. We derive column densities for the absorption lines detected in both O VI systems using curve of growth and profile fitting techniques. We study the physical conditions in each system and attempt to determine the origin(s) of the ionization. Both detected O VI systems occur at redshifts where there are peaks in the number density of intervening galaxies along the line of sight based on a WIYN redshift survey of galaxies in the one degree field centered on PG 0953+415. We discuss the implications of these observations for the baryonic content of O VI absorption line systems. Financial support has been provided by NASA contract NAS-532985 and STSCI Grants GO 06499.02 and GO 08165.02.

  11. An accelerated line-by-line option for MODTRAN combining on-the-fly generation of line center absorption within 0.1 cm-1 bins and pre-computed line tails

    NASA Astrophysics Data System (ADS)

    Berk, Alexander; Conforti, Patrick; Hawes, Fred

    2015-05-01

    A Line-By-Line (LBL) option is being developed for MODTRAN6. The motivation for this development is two-fold. Firstly, when MODTRAN is validated against an independent LBL model, it is difficult to isolate the source of discrepancies. One must verify consistency between pressure, temperature and density profiles, between column density calculations, between continuum and particulate data, between spectral convolution methods, and more. Introducing a LBL option directly within MODTRAN will insure common elements for all calculations other than those used to compute molecular transmittances. The second motivation for the LBL upgrade is that it will enable users to compute high spectral resolution transmittances and radiances for the full range of current MODTRAN applications. In particular, introducing the LBL feature into MODTRAN will enable first-principle calculations of scattered radiances, an option that is often not readily available with LBL models. MODTRAN will compute LBL transmittances within one 0.1 cm-1 spectral bin at a time, marching through the full requested band pass. The LBL algorithm will use the highly accurate, pressure- and temperature-dependent MODTRAN Padé approximant fits of the contribution from line tails to define the absorption from all molecular transitions centered more than 0.05 cm-1 from each 0.1 cm-1 spectral bin. The beauty of this approach is that the on-the-fly computations for each 0.1 cm-1 bin will only require explicit LBL summing of transitions centered within a 0.2 cm-1 spectral region. That is, the contribution from the more distant lines will be pre-computed via the Padé approximants. The status of the LBL effort will be presented. This will include initial thermal and solar radiance calculations, validation calculations, and self-validations of the MODTRAN band model against its own LBL calculations.

  12. HIGHLY IONIZED Fe-K ABSORPTION LINE FROM CYGNUS X-1 IN THE HIGH/SOFT STATE OBSERVED WITH SUZAKU

    SciTech Connect

    Yamada, S.; Yoshikawa, A.; Makishima, K.; Torii, S.; Noda, H.; Mineshige, S.; Ueda, Y.; Kubota, A.; Gandhi, P.; Done, C.

    2013-04-20

    We present observations of a transient He-like Fe K{alpha} absorption line in Suzaku observations of the black hole binary Cygnus X-1 on 2011 October 5 near superior conjunction during the high/soft state, which enable us to map the full evolution from the start to the end of the episodic accretion phenomena or dips for the first time. We model the X-ray spectra during the event and trace their evolution. The absorption line is rather weak in the first half of the observation, but instantly deepens for {approx}10 ks, and weakens thereafter. The overall change in equivalent width is a factor of {approx}3, peaking at an orbital phase of {approx}0.08. This is evidence that the companion stellar wind feeding the black hole is clumpy. By analyzing the line with a Voigt profile, it is found to be consistent with a slightly redshifted Fe XXV transition, or possibly a mixture of several species less ionized than Fe XXV. The data may be explained by a clump located at a distance of {approx}10{sup 10-12} cm with a density of {approx}10{sup (-13)-(-11)} g cm{sup -3}, which accretes onto and/or transits the line of sight to the black hole, causing an instant decrease in the observed degree of ionization and/or an increase in density of the accreting matter. Continued monitoring for individual events with future X-ray calorimeter missions such as ASTRO-H and AXSIO will allow us to map out the accretion environment in detail and how it changes between the various accretion states.

  13. The X-ray spectrum and spectral energy distribution of FIRST J155633.8+351758: a LoBAL quasar with a probable polar outflow

    NASA Astrophysics Data System (ADS)

    Berrington, Robert C.; Brotherton, Michael S.; Gallagher, Sarah C.; Ganguly, Rajib; Shang, Zhaohui; DiPompeo, Michael; Chatterjee, Ritaban; Lacy, Mark; Gregg, Michael D.; Hall, Patrick B.; Laurent-Muehleisen, S. A.

    2013-12-01

    We report the results of a new 60 ks Chandra X-ray Observatory Advanced CCD Imaging Spectrometer S-array (ACIS-S) observation of the reddened, radio-selected, highly polarized `FeLoBAL' quasar FIRST J1556+3517. We investigated a number of models of varied sophistication to fit the 531-photon spectrum. These models ranged from simple power laws to power laws absorbed by hydrogen gas in differing ionization states and degrees of partial covering. Preferred fits indicate that the intrinsic X-ray flux is consistent with that expected for quasars of similarly high luminosity, i.e. an intrinsic, dereddened and unabsorbed optical to X-ray spectral index of -1.7. We cannot tightly constrain the intrinsic X-ray power-law slope, but find indications that it is flat (photon index Γ = 1.7 or flatter at a >99 per cent confidence for a neutral hydrogen absorber model). Absorption is present, with a column density a few times 1023 cm-2, with both partially ionized models and partially covering neutral hydrogen models providing good fits. We present several lines of argument that suggest the fraction of X-ray emissions associated with the radio jet is not large. We combine our Chandra data with observations from the literature to construct the spectral energy distribution of FIRST J1556+3517 from radio to X-ray energies. We make corrections for Doppler beaming for the pole-on radio jet, optical dust reddening and X-ray absorption, in order to recover a probable intrinsic spectrum. The quasar FIRST J1556+3517 seems to be an intrinsically normal radio-quiet quasar with a reddened optical/UV spectrum, a Doppler-boosted but intrinsically weak radio jet and an X-ray absorber not dissimilar from that of other broad absorption line quasars.

  14. VizieR Online Data Catalog: 188 CIV BAL QSOs from SDSS DR7 (He+, 2015)

    NASA Astrophysics Data System (ADS)

    He, Z.-C.; Bian, W.-H.; Ge, X.; Jiang, X.-L.

    2016-07-01

    In the SDSS DR7, it is found that there are 1080 spectra of 480 CIV BAL QSOs with at least two-epoch observations. In order to identify the variable regions in CIV BAL troughs, we select BAL QSOs with SDSS spectral signal-to-noise ratio (S/N) at r band larger than 10, and redshift more than 1.7. It consists of 188 CIV BAL QSOs with 428 SDSS spectra. (2 data files).

  15. Interstellar H I and H2 in the Magellanic Clouds: An Expanded Sample Based on Ultraviolet Absorption-line Data

    NASA Astrophysics Data System (ADS)

    Welty, Daniel E.; Xue, Rui; Wong, Tony

    2012-02-01

    We have determined column densities of H I and/or H2 for sight lines in the Magellanic Clouds from archival Hubble Space Telescope and Far-Ultraviolet Spectroscopic Explorer spectra of H I Lyα and H2 Lyman-band absorption. Together with some similar data from the literature, we now have absorption-based N(H I) and/or N(H2) for 285 Large Magellanic Cloud (LMC) and Small Magellanic Cloud (SMC) sight lines (114 with a detection or limit for both species)—enabling more extensive, direct, and accurate determinations of molecular fractions, gas-to-dust ratios, and elemental depletions in these two nearby, low-metallicity galaxies. For sight lines where the N(H I) estimated from 21 cm emission is significantly higher than the value derived from Lyα absorption (presumably due to emission from gas beyond the target stars), integration of the 21 cm profile only over the velocity range seen in Na I or H2 absorption generally yields much better agreement. Conversely, N(21 cm) can be lower than N(Lyα) by factors of 2-3 in some LMC sight lines—suggestive of small-scale structure within the 21 cm beam(s) and/or some saturation in the emission. The mean gas-to-dust ratios obtained from N(Htot)/E(B - V) are larger than in our Galaxy, by factors of 2.8-2.9 in the LMC and 4.1-5.2 in the SMC—i.e., factors similar to the differences in metallicity. The N(H2)/E(B - V) ratios are more similar in the three galaxies, but with considerable scatter within each galaxy. These data may be used to test models of the atomic-to-molecular transition at low metallicities and predictions of N(H2) based on comparisons of 21 cm emission and the IR emission from dust. ), the MAST archive at STScI (FUSE data), and the University of Bonn (LAB and GASS 21 cm surveys).

  16. Ultraviolet interstellar absorption lines in the LMC: Searching for hidden SNRs

    NASA Technical Reports Server (NTRS)

    Chu, You-Hua; Wakker, Bart; Low, Mordecai-Mark Mac; Garcia-Segura, Guillermo

    1994-01-01

    Strong x-ray emission detected in Large Magellanic Cloud (LMC) superbubbles has been explained as the result of interior supernova remnants (SNRs) hitting the dense superbubble shell. Such SNRs cannot be found using conventional criteria. We thus investigate the possibility of using the interstellar absorption properties in the ultraviolet (UV) as a diagnostic of hidden SNR shocks. The International Ultraviolet Explorer (IUE) archives provide the database for this pilot study. They contain high-dispersion spectra of several stars in x-ray bright superbubbles. To distinguish the effects of SNR shocks from those of local stellar winds and a global hot halo around the LMC, we included control objects in different environments. We find that almost all interstellar absorption properties can be explained by the interstellar environment associated with the objects. Summarizing the two most important results of this study: (1) a large velocity shift between the high-ionization species (C IV and Si IV) and the low-ionization species (S II, Si II, and C II*) is a diagnostic of hidden SNR shocks; however, the absence of a velocity shift does not preclude the existence of SNR shocks; (2) there is no evidence that the LMC is uniformly surrounded by hot gas; hot gas is preferentially found associated with large interstellar structures like superbubbles and supergiant shells, which may extend to large distances from the plane.

  17. The SLUGGS survey: globular cluster stellar population trends from weak absorption lines in stacked spectra

    NASA Astrophysics Data System (ADS)

    Usher, Christopher; Forbes, Duncan A.; Brodie, Jean P.; Romanowsky, Aaron J.; Strader, Jay; Conroy, Charlie; Foster, Caroline; Pastorello, Nicola; Pota, Vincenzo; Arnold, Jacob A.

    2015-01-01

    As part of the SAGES Legacy Unifying Globulars and GalaxieS (SLUGGS) survey, we stack 1137 Keck DEIMOS (Deep Imaging Multi-Object Spectrograph) spectra of globular clusters from 10 galaxies to study their stellar populations in detail. The stacked spectra have median signal-to-noise ratios of ˜90 Å-1. Besides the calcium triplet, we study weaker sodium, magnesium, titanium and iron lines as well as the Hα and higher order Paschen hydrogen lines. In general, the stacked spectra are consistent with old ages and a Milky Way-like initial mass function. However, we see different metal line index strengths at fixed colour and magnitude, and differences in the calcium triplet-colour relation from galaxy to galaxy. We interpret this as strong evidence for variations in the globular cluster colour-metallicity relation between galaxies. Two possible explanations for the colour-metallicity relation variations are that the average ages of globular clusters vary from galaxy to galaxy or that the average abundances of light elements (i.e. He, C, N and O) differ between galaxies. Stacking spectra by magnitude, we see that the colours become redder and metal line indices stronger with brighter magnitudes. These trends are consistent with the previously reported `blue tilts' being mass-metallicity relations.

  18. A Two-Line Absorption Instrument for Scramjet Temperature and Water Vapor Concentration Measurement in HYPULSE

    NASA Technical Reports Server (NTRS)

    Tsai, C. Y.

    1998-01-01

    A three beam water vapor sensor system has been modified to provide for near simultaneous temperature measurement. The system employs a tunable diode laser to scan spectral line of water vapor. The application to measurements in a scramjet combustor environment of a shock tunnel facility is discussed. This report presents and discusses die initial calibration of the measurement system.

  19. Measurement of the ozone absorption cross-section at the 253. 7 nm Mercury line

    SciTech Connect

    Mauersberger, K.; Barnes, J.; Hanson, D.; Morton, J.

    1986-07-01

    The absorption cross-section of ozone at 253.7 nm is frequently used as a standard for the entire UV wavelength range. The presently accepted value is 1.147 x 10/sup -17/ cm/sup 2/, known with an uncertainty of about 2%. The cross-section has been recently measured by simultaneously monitoring the ozone pressure, the impurities in the ozone gas, the gas temperature and the UV beam intensity. The cross-section at room temperature was found to be 1.137 x 10/sup -17/ cm/sup 2/, having an uncertainty of +- .7%. The improved accuracy will aid a number of ozone experiments including the i-italicn-italic s-italici-italict-italicu-italic photometers and Solar Backscatter Ultraviolet instruments.

  20. Detection of carbon monoxide and water absorption lines in an exoplanet atmosphere.

    PubMed

    Konopacky, Quinn M; Barman, Travis S; Macintosh, Bruce A; Marois, Christian

    2013-03-22

    Determining the atmospheric structure and chemical composition of an exoplanet remains a formidable goal. Fortunately, advancements in the study of exoplanets and their atmospheres have come in the form of direct imaging--spatially resolving the planet from its parent star--which enables high-resolution spectroscopy of self-luminous planets in jovian-like orbits. Here, we present a spectrum with numerous, well-resolved molecular lines from both water and carbon monoxide from a massive planet orbiting less than 40 astronomical units from the star HR 8799. These data reveal the planet's chemical composition, atmospheric structure, and surface gravity, confirming that it is indeed a young planet. The spectral lines suggest an atmospheric carbon-to-oxygen ratio that is greater than that of the host star, providing hints about the planet's formation.

  1. Asymptotic expansions of the kernel functions for line formation with continuous absorption

    NASA Technical Reports Server (NTRS)

    Hummer, D. G.

    1991-01-01

    Asymptotic expressions are obtained for the kernel functions M2(tau, alpha, beta) and K2(tau, alpha, beta) appearing in the theory of line formation with complete redistribution over a Voigt profile with damping parameter a, in the presence of a source of continuous opacity parameterized by beta. For a greater than 0, each coefficient in the asymptotic series is expressed as the product of analytic functions of a and eta. For Doppler broadening, only the leading term can be evaluated analytically.

  2. The Hubble Space Telescope quasar absorption line key project. 6: Properties of the metal-rich systems

    NASA Technical Reports Server (NTRS)

    Bergeron, Jacqueline; Petitjean, Patrick; Sargent, W. L. W.; Bahcall, John N.; Boksenberg, Alec; Hartig, George F.; Jannuzi, Buell T.; Kirhakos, Sofia; Savage, Blair D.; Schneider, Donald P.

    1994-01-01

    We present an analysis of the properties of a sample of 18 metal-rich, low-redshift z(sub abs) much less than z(sub em) absorbers seen in low- and medium-resolution spectra obtained for the Quasar Absorption Line Key Project with the Hubble Space Telescope Faint Object Spectrograph (HST/FOS). For most of the C IV and Lyman-limit systems, observations in the optical wavelength range of the expected associated Mg II absorption are available. As at high redshift (z approximately 2), there are two subclasses of absorbers which are characterized by the presence or absence of MG II absorption. However, some low-redshift Mg II and Fe absorptions originate from regions optically thin to UV ionizing photons and thus, at low redshift, the low-ionization systems do not always trace high opacities, as is the case at high redshift. This implies that the mean ionization state of metal-rich, optically thin absorbing clouds falls with decreasing redshift, which is consistent with the hypothesis that the gas is photoionized by the metagalactic UV background radiation field. Two main constraints are derived from the analysis of the Lyman-limit sample, assuming photoionization models are valid. First, a low opacity to ionizing photons (tau(sub LL) approximately less than 1), as observed for several Mg II-Fe II systems at z approximately 0.5, sets limits on the ionization level of hydrogen, thus on the total hydrogen column density and the heavy element abundances, (Z/H) approximately -0.5 to -0.3. Second, the dimensions of individual Mg II clouds are smaller than at high redshift by a factor 3-10. At z approximately greater than 0.6, the O VI absorption doublet is detected in four of the five z(sub abs) much less than z(sub em) systems for which the O VI wavelength range has been observed, whereas the associated N V doublet is detected in only two cases. This suggests that the presence of a high-ionization O VI phase is a general property of z approximately 0.6-1 absorption systems

  3. Beyond the single-atom response in absorption line shapes: probing a dense, laser-dressed helium gas with attosecond pulse trains.

    PubMed

    Liao, Chen-Ting; Sandhu, Arvinder; Camp, Seth; Schafer, Kenneth J; Gaarde, Mette B

    2015-04-10

    We investigate the absorption line shapes of laser-dressed atoms beyond the single-atom response, by using extreme ultraviolet (XUV) attosecond pulse trains to probe an optically thick helium target under the influence of a strong infrared (IR) field. We study the interplay between the IR-induced phase shift of the microscopic time-dependent dipole moment and the resonant-propagation-induced reshaping of the macroscopic XUV pulse. Our experimental and theoretical results show that as the optical depth increases, this interplay leads initially to a broadening of the IR-modified line shape, and subsequently, to the appearance of new, narrow features in the absorption line.

  4. A Census of Intrinsic Narrow Absorption Lines in the Spectra of Quasars at z = 2-4

    NASA Astrophysics Data System (ADS)

    Misawa, Toru; Charlton, Jane C.; Eracleous, Michael; Ganguly, Rajib; Tytler, David; Kirkman, David; Suzuki, Nao; Lubin, Dan

    2007-07-01

    We use Keck HIRES spectra of 37 optically bright quasars at z=2-4 to study narrow absorption lines that are intrinsic to the quasars (intrinsic NALs, produced in gas that is physically associated with the quasar central engine). We identify 150 NAL systems, which contain 124 C IV, 12 N V, and 50 Si IV doublets, of which 18 are associated systems (within 5000 km s-1 of the quasar redshift). We use partial coverage analysis to separate intrinsic NALs from NALs produced in cosmologically intervening structures. We find 39 candidate intrinsic systems (28 reliable determinations and 11 that are possibly intrinsic). We estimate that 10%-17% of C IV systems at blueshifts of 5000-70,000 km s-1 relative to quasars are intrinsic. At least 32% of quasars contain one or more intrinsic C IV NALs. Considering N V and Si IV doublets showing partial coverage as well, at least 50% of quasars host intrinsic NALs. This result constrains the solid angle subtended by the absorbers to the background source(s). We identify two families of intrinsic NAL systems, those with strong N V absorption and those with negligible absorption in N V but with partial coverage in the C IV doublet. We discuss the idea that these two families represent different regions or conditions in accretion disk winds. Of the 26 intrinsic C IV NAL systems, 13 have detectable low-ionization absorption lines at similar velocities, suggesting that these are two-phase structures in the wind rather than absorbers in the host galaxy. We also compare possible models for quasar outflows, including radiatively accelerated disk-driven winds, magnetocentrifugally accelerated winds, and pressure-driven winds, and we discuss ways of distinguishing between these models observationally. The data presented here were 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 the National Aeronautics and Space Administration

  5. Study of the Many Fluorescent Lines and the Absorption Variability in GX 301-2 with XMM-Newton

    NASA Technical Reports Server (NTRS)

    Fuerst, F.; Suchy, S.; Kreykenbohm, I.; Barragan, L.; Wilms, J.; Pottschmidt, K.; Caballero, I.; Kretschmar, P.; Ferrigno, C.; Rothschild, R. E.

    2011-01-01

    We present an in-depth study of the High Mass X-ray Binary (HMXB) GX 301-2 during its pre-periastron flare using data from the XMM-Newton satellite. The energy spectrum shows a power law continuum absorbed by a large equivalent hydrogen column on the order of 10(exp 24)/ sq cm and a prominent Fe K-alpha fluorescent emission line. Besides the Fe K-alpha line, evidence for Fe K-Beta, Ni K-alpha, Ni K-Beta, S K-alpha, Ar K-alpha, Ca K-alpha, and Cr K-alpha fluorescent lines is found. The observed line strengths are consistent with fluorescence in a cold absorber. This is the first time that Cr K-alpha is seen in emission in the X-ray spectrum of a HMXB. In addition to the modulation by the strong pulse period of approx 685 sec the source is highly variable and shows different states of activity. We perform time-resolved as well as pulse-to-pulse resolved spectroscopy to investigate differences between these states of activity. We find that fluorescent line fluxes are strongly variable and generally follow the overall flux. The N-H value is variable by a factor of 2, but not correlated to continuum normalization. We find an interval of low flux in the light curve in which the pulsations cease almost completely, without any indication of an increasing absorption column. We investigate this dip in detail and argue that it is most likely that during the dip the accretion ceased and the afterglow of the fluorescent iron accounted for the main portion of the X-ray flux. A similar dip was found earlier in RXTE data, and we compare our findings to these results.

  6. Intersstellar absorption lines between 2000 and 3000 A in nearby stars observed with BUSS. [Balloon Borne Ultraviolet Spectrophotometer

    NASA Technical Reports Server (NTRS)

    De Boer, K. S.; Lenhart, H.; Van Der Hucht, K. A.; Kamperman, T. M.; Kondo, Y.

    1986-01-01

    Spectra obtained between 2000 and 3000 A with the Balloon Borne Ultraviolet Spectrophotometer (BUSS) payload were examined for interstellar absorption lines. In bright stars, with spectral types between O9V and F5V, such lines were measured of Mg I, Mg II, Cr II, Mn II, Fe II and Zn II, with Cr II and Zn II data of especially high quality. Column densities were derived and interstellar abundances were determined for the above species. It was found that metal depletion increases with increasing E(B-V); Fe was most affected and Zn showed a small depletion for E(B-V) greater than 0.3 towards Sco-Oph. The metal column densities, derived for Alpha-And, Kappa-Dra, Alpha-Com, Alpha-Aql, and 29 Cyg were used to infer N(H I). It was shown that the ratio of Mg I to Na I is instrumental in determining the ionization structure along each line of sight. The spectra of Aql stars confirms the presence of large gas densities near Alpha-Oph. Moreover, data indicated that the Rho-Oph N(H I) value needs to be altered to 35 x 10 to the 20th/sq cm, based on observed ion ratios and analysis of the Copernicus L-alpha profile.

  7. Atmospheric Profiling Combining the Features of GPS ro & Mls: Satellite to Satellite Occultations Near Water & Ozone Absorption Lines

    NASA Astrophysics Data System (ADS)

    Kursinski, E. R.; Ward, D.; Otarola, A. C.; McGhee, J.; Reed, H.; Erickson, D.

    2015-12-01

    Assessing climate models & their predictions requires observations that determine the state of the real climate system precisely and unambiguously, independently from models. For this purpose, we have been developing a new orbiting remote sensing system called the Active Temperature, Ozone & Moisture Microwave Spectrometer (ATOMMS) which is a cross between GPS RO and the Microwave Limb Sounder. ATOMMS actively probes water vapor, ozone & other absorption lines at cm & mm wavelengths in a satellite to satellite occultation geometry to simultaneously profile temperature, pressure, water vapor and ozone as well as other important constituents. Individual profiles of water vapor, temperature & pressure heights will extend from near the surface into the mesosphere with ~1%, 0.4K and 10 m precision respectively and still better accuracy, with 100 m vertical resolution. Ozone profiles will extend upward from the upper troposphere. Line of sight wind profiles will extend upwards from the mid-stratosphere. ATOMMS is a doubly differential absorption system which eliminates drift and both sees clouds and sees thru them, to deliver performance in clouds within a factor of 2 of the performance in clear skies. This all-weather sampling combined with insensitivity to surface emissivity avoids sampling biases that limit most existing satellite records. ATOMMS will profile slant liquid water in clouds & rain and as well as turbulence via scintillations ("twinkling of a star"). Using prototype ATOMMS instrumentation that we developed with funding from NSF, several ATOMMS ground field campaigns precisely measured water vapor, cloud amount, rainfall, turbulence and absorption line spectroscopy. ATOMMS's dynamic range was demonstrated as water vapor was derived to 1% precision in optical depths up to 17. We are developing high altitude aircraft to aircraft instrumentation to further demonstrate ATOMMS performance, refine spectroscopy & support future field campaigns. Our vision is a

  8. Limits on variations in fundamental constants from 21-cm and ultraviolet Quasar absorption lines.

    PubMed

    Tzanavaris, P; Webb, J K; Murphy, M T; Flambaum, V V; Curran, S J

    2005-07-22

    Quasar absorption spectra at 21-cm and UV rest wavelengths are used to estimate the time variation of x [triple-bond] alpha(2)g(p)mu, where alpha is the fine structure constant, g(p) the proton g factor, and m(e)/m(p) [triple-bond] mu the electron/proton mass ratio. Over a redshift range 0.24 < or = zeta(abs) < or = 2.04, (Deltax/x)(weighted)(total) = (1.17 +/- 1.01) x 10(-5). A linear fit gives x/x = (-1.43 +/- 1.27) x 10(-15) yr(-1). Two previous results on varying alpha yield the strong limits Deltamu/mu = (2.31 +/- 1.03) x 10(-5) and Deltamu/mu=(1.29 +/- 1.01) x10(-5). Our sample, 8 x larger than any previous, provides the first direct estimate of the intrinsic 21-cm and UV velocity differences 6 km s(-1).

  9. In-Line Capacitance Sensor for Real-Time Water Absorption Measurements

    NASA Technical Reports Server (NTRS)

    Nurge, Mark A.; Perusich, Stephen A.

    2010-01-01

    A capacitance/dielectric sensor was designed, constructed, and used to measure in real time the in-situ water concentration in a desiccant water bed. Measurements were carried out with two experimental setups: (1) passing nitrogen through a humidity generator and allowing the gas stream to become saturated at a measured temperature and pressure, and (2) injecting water via a syringe pump into a nitrogen stream. Both water vapor generating devices were attached to a downstream vertically-mounted water capture bed filled with 19.5 g of Moisture Gone desiccant. The sensor consisted of two electrodes: (1) a 1/8" dia stainless steel rod placed in the middle of the bed and (2) the outer shell of the stainless steel bed concentric with the rod. All phases of the water capture process (background, heating, absorption, desorption, and cooling) were monitored with capacitance. The measured capacitance was found to vary linearly with the water content in the bed at frequencies above 100 kHz indicating dipolar motion dominated the signal; below this frequency, ionic motion caused nonlinearities in the water concentration/capacitance relationship. The desiccant exhibited a dielectric relaxation whose activation energy was lowered upon addition of water indicating either a less hindered rotational motion or crystal reorientation.

  10. X-Ray Weak Broad-Line Quasars: Absorption or Intrinsic X-Ray Weakness

    NASA Technical Reports Server (NTRS)

    Risaliti, Guido; Mushotzky, Richard F. (Technical Monitor)

    2004-01-01

    XMM observations of X-ray weak quasars have been performed during 2003. The data for all but the last observation are now available (there has been a delay of several months on the initial schedule, due to high background flares which contaminated the observations: as a consequence, most of them had to be rescheduled). We have reduced and analyzed these data, and obtained interesting preliminary scientific results. Out of the eight sources, 4 are confirmed to be extrimely X-ray weak, in agreement with the results of previous Chandra observations. 3 sources are confirmed to be highly variable both in flux (by factors 20-50) and in spectral properties (dramatic changes in spectral index). For both these groups of objects, an article is in preparation. Preliminary results have been presented at an international workshop on AGN surveys in December 2003, in Cozumel (Mexico). In order to further understand the nature of these X-ray weak quasars, we submitted proposals for spectroscopy at optical and infrared telescopes. We obtained time at the TNG 4 meter telescope for near-IR observations, and at the Hobby-Eberly Telescope for optical high-resolution spectroscopy. These observations will be performed in early 2004, and will complement the XMM data, in order to understand whether the X-ray weakness of these sources is an intrinsic property or is due to absorption by circumnuclear material.

  11. Excitation ahead of shock fronts in krypton measured by single line laser absorption

    NASA Astrophysics Data System (ADS)

    Boetticher, W.; Kilpin, D.

    1984-12-01

    The absorption of single-mode radiation (from a dye laser tuned to 587.25 and 557.18 nm) by Kr in front of shock waves with Mach numbers 12-21 in a 50-mm-diameter 4.4-m-long free-position driver shock tube at preshock pressures 0.7-2.7 kPa is measured to determine the number densities of the metastable 5s(1 1/2)2 and 5s(1 1/2)1 precursor states (1s5 and 1s4 in Paschen notation, respectively). The measurement technique and calculations follow those of Ernst (1982). The results are presented in tables and graphs and characterized in comparison with previous findings. The time constant of the exponential rise of the precursor is found to be about 8 microsec, and the concentration of 1s5 + 1s4 for Mach 20 is calculated as about 10 ppm, in agreement (to within a factor of 5) with model predictions for Ar and Xe.

  12. Resonator spectrometer for precise broadband investigations of atmospheric absorption in discrete lines and water vapor related continuum in millimeter wave range.

    PubMed

    Tretyakov, M Yu; Krupnov, A F; Koshelev, M A; Makarov, D S; Serov, E A; Parshin, V V

    2009-09-01

    The instrument and methods for measuring spectral parameters of discrete atmospheric lines and water-related continuum absorption in the millimeter wave range are described. The instrument is based on measurements of the Fabry-Pérot resonance response width using fast phase continuous scanning of the frequency-synthesized radiation. The instrument allows measurement of gas absorptions at the cavity eigenfrequencies ranging from 45 to 370 GHz with the highest to date absorption variation sensitivity of 4x10(-9) cm(-1). The use of a module of two rigidly bounded maximum identical resonators differing in length by exactly a factor of two allows accurate separation of the studied gas absorption and spectrometer baseline, in particular, the absorption by water adsorbed on the resonator elements. The module is placed in a chamber with temperature controlled between -30 and +60 degrees C, which permits investigation of temperature dependence of absorption. It is shown that systematic measurement error of discrete atmospheric line parameters does not exceed the statistical one and the achieved accuracy satisfies modern demands for the atmospheric remote sensing data retrieval. Potential systematic error arising from the neglect of the effect of water adsorption on mirror surfaces is discussed. Examples of studies of water and oxygen spectral line parameters as well as continuum absorption in wet nitrogen are given.

  13. A Bayesian Method For Finding Galaxies That Cause Quasar Absorption Lines

    NASA Astrophysics Data System (ADS)

    Shoemaker, Emileigh Suzanne; Laubner, David Andrew; Scott, Jennifer E.

    2016-01-01

    We present a study of candidate absorber-galaxy pairs for 39 low redshift quasar sightlines (0.06 < z < 0.85) using a statistical approach to match absorbers with galaxies near the quasar lines of sight. Of the 75 quasars observed with HST/Cosmic Origins Spectrograph (COS) and archived on the Mikulski Archive for Space Telescopes (MAST), 39 overlap with the footprint of the Sloan Digital Sky Survey (SDSS). We downloaded the COS linelists for these quasar spectra from MAST and queried the SDSS DR12 database for photometric data on all galaxies within 1 Mpc of each of these quasar lines of sight. We calculated photometric redshifts for all the SDSS galaxies using the Bayesian Photometric Redshift code. We used all these absorber and galaxy data as input into an absorber-galaxy matching code which also employs a Bayesian scheme, along with known statistics of the intergalactic medium and circumgalactic media of galaxies, for finding the most probable galaxy match for each absorber. We compare our candidate absorber-galaxy matches to existing studies in the literature and explore trends in the absorber and galaxy properties among the matched and non-matched populations. This method of matching absorbers and galaxies can be used to find targets for follow up spectroscopic studies.

  14. Ca II AND Na I QUASAR ABSORPTION-LINE SYSTEMS IN AN EMISSION-SELECTED SAMPLE OF SDSS DR7 GALAXY/QUASAR PROJECTIONS. I. SAMPLE SELECTION

    SciTech Connect

    Cherinka, B.; Schulte-Ladbeck, R. E.

    2011-10-15

    The aim of this project is to identify low-redshift host galaxies of quasar absorption-line systems by selecting galaxies that are seen in projection onto quasar sightlines. To this end, we use the Seventh Data Release of the Sloan Digital Sky Survey to construct a parent sample of 97,489 galaxy/quasar projections at impact parameters of up to 100 kpc to the foreground galaxy. We then search the quasar spectra for absorption-line systems of Ca II and Na I within {+-}500 km s{sup -1} of the galaxy's velocity. This yields 92 Ca II and 16 Na I absorption systems. We find that most of the Ca II and Na I systems are sightlines through the Galactic disk, through high-velocity cloud complexes in our halo, or Virgo Cluster sightlines. Placing constraints on the absorption line rest equivalent width significance ({>=}3.0{sigma}), the local standard of rest velocity along the sightline ({>=}345 km s{sup -1}), and the ratio of the impact parameter to the galaxy optical radius ({<=}5.0), we identify four absorption-line systems that are associated with low-redshift galaxies at high confidence, consisting of two Ca II systems (one of which also shows Na I) and two Na I systems. These four systems arise in blue, {approx}L*{sub r} galaxies. Tables of the 108 absorption systems are provided to facilitate future follow-up.

  15. Investigation of optical and spectroscopic properties of Sm3+ ions in CaBAl glasses

    NASA Astrophysics Data System (ADS)

    Brito, D. R. N.; Queiroz, M. N.; Barboza, M. J.; Steimacher, A.; Pedrochi, F.

    2017-02-01

    Samples of CaBAl glass with composition of (25-x)CaO-50B2O3-15Al2O3-10CaF2-xSm2O3, with Sm2O3 concentration varying from 0.5 to 7 wt%, were prepared by using melt-quenching method in air atmosphere. The samples were prepared with different concentrations of Sm2O3, aiming to understand how the dopant changes the optical and spectroscopic properties of the glass. The doped CaBAl glasses were studied by means of volumetric density measurements, refractive index, optical absorption, luminescence at room temperature, luminescence as function of the temperature and radiative lifetime. All results were discussed in function of Sm2O3 concentration. The measured volumetric density and polarizability showed an increase with Sm2O3 doping. The refractive index showed a small increase due to RE doping, although within the errors. The absorption bands were attributed to Sm3+ transitions from the ground state 6H5/2 to the various excited states. The luminescence spectra present emission bands assigned to the appropriate electronic f-f transitions of Sm3+ ions; there are four emission bands at 565, 602, 649 and 710 nm. The luminescence quenching was observed up to 2 wt% of Sm2O3. The O/R ratio as function of the Sm2O3 concentration showed changes in the symmetry site with addition of Sm2O3. The CIE 1931 diagram presented a reddish-orange shift color with Sm2O3 doping. The luminescence intensity presents a decrease with temperature increase for all studied samples. The experimental lifetime decreases with the increase of Sm2O3, mainly due to ion-ion interaction.

  16. Optical frequency standard by using a 1560 nm diode laser locked to saturated absorption lines of rubidium vapor

    SciTech Connect

    Masuda, Shin; Seki, Atsushi; Niki, Shoji

    2007-07-20

    A robust, compact, highly accurate rubidium optical frequency standard module was developed to overcome the delicate performance of conventional frequency stabilized lasers. A frequency doubled1560 nm distributed feedback diode laser locked to a rubidium D2 saturated absorption line without using an optical amplifier was demonstrated, and dithering-free optical output was obtained. In addition, the sensitivity of the developed optical frequency standard to magnetic fields was investigated. We confirmed that the influence of the magnetic fields on the optical frequency standard can be almost negligible when using appropriate magnetic-shield films. As a result, the magnetic-field-insensitive optical frequency standard, which can be embedded in optical systems,exhibiting uncertainty less than at least 100 kHz, was successfully realized for the first time to the best of our knowledge.

  17. Detection of copper in water using on-line plasma-excited atomic absorption spectroscopy (AAS).

    PubMed

    Porento, Mika; Sutinen, Veijo; Julku, Timo; Oikari, Risto

    2011-06-01

    A measurement method and apparatus was developed to measure continuously toxic metal compounds in industrial water samples. The method was demonstrated by using copper as a sample metal. Water was injected into the sample line and subsequently into a nitrogen plasma jet, in which the samples comprising the metal compound dissolved in water were decomposed. The transmitted monochromatic light was detected and the absorbance caused by copper atoms was measured. The absorbance and metal concentration were used to calculate sensitivity and detection limits for the studied metal. The sensitivity, limit of detection, and quantification for copper were 0.45 ± 0.02, 0.25 ± 0.01, and 0.85 ± 0.04 ppm, respectively.

  18. A Fourth H I 21 cm Absorption System in the Sight Line of MG J0414+0534: A Record for Intervening Absorbers

    NASA Astrophysics Data System (ADS)

    Tanna, A.; Curran, S. J.; Whiting, M. T.; Webb, J. K.; Bignell, C.

    2013-08-01

    We report the detection of a strong H I 21 cm absorption system at z = 0.5344, as well as a candidate system at z = 0.3389, in the sight line toward the z = 2.64 quasar MG J0414+0534. This, in addition to the absorption at the host redshift and the other two intervening absorbers, takes the total to four (possibly five). The previous maximum number of 21 cm absorbers detected along a single sight line is two and so we suspect that this number of gas-rich absorbers is in some way related to the very red color of the background source. Despite this, no molecular gas (through OH absorption) has yet been detected at any of the 21 cm redshifts, although, from the population of 21 cm absorbers as a whole, there is evidence for a weak correlation between the atomic line strength and the optical-near-infrared color. In either case, the fact that so many gas-rich galaxies (likely to be damped Lyα absorption systems) have been found along a single sight line toward a highly obscured source may have far-reaching implications for the population of faint galaxies not detected in optical surveys, a possibility which could be addressed through future wide-field absorption line surveys with the Square Kilometer Array.

  19. Using ISM abundances in the SMC to Correct for Element Depletions by Dust in QSO Absorption Line Systems

    NASA Astrophysics Data System (ADS)

    Jenkins, Edward

    2014-10-01

    The availability of 10-m class telescopes with high resolution echelle spectrographs has enabled astronomers to measure accurately the gas-phase abundances of various elements in QSO absorption line systems at high redshifts. These systems offer insights on the chemical evolution of galaxies (and their nearby environments) in their early stages of development. However, in order to obtain total abundances the observations need to be corrected for the depletions caused by the formation of dust, and traditionally people have done so by using the depletion patterns seen in our own Galaxy. There is now evidence that indicates that such patterns in low-metallicity systems differ from those of our Galaxy and thus the corrections may be misleading. The aim of our proposed HST observations is to measure the gas-phase abundances toward stars in the Small Magellanic Cloud, which is a low-metallicity dwarf galaxy where there exist good measurements of stellar comparison abundances. We plan to record ISM absorption features from STIS medium-resolution echelle spectra for 14 stars in the SMC that are known to have varying levels of depletion, so that we can derive the gas-phase abundance patterns of the elements Ni, Fe, Cr, Mn, Si, Mg, Ge, Kr, Zn, and perhaps P.

  20. Atmospheric profiling via satellite to satellite occultations near water and ozone absorption lines for weather and climate

    NASA Astrophysics Data System (ADS)

    Kursinski, E. R.; Ward, D.; Otarola, A. C.; McGhee, J.; Stovern, M.; Sammler, K.; Reed, H.; Erickson, D.; McCormick, C.; Griggs, E.

    2016-05-01

    Significantly reducing weather and climate prediction uncertainty requires global observations with substantially higher information content than present observations provide. While GPS occultations have provided a major advance, GPS observations of the atmosphere are limited by wavelengths chosen specifically to minimize interaction with the atmosphere. Significantly more information can be obtained via satellite to satellite occultations made at wavelengths chosen specifically to characterize the atmosphere. Here we describe such a system that will probe cm- and mmwavelength water vapor absorption lines called the Active Temperature, Ozone and Moisture Microwave Spectrometer (ATOMMS). Profiling both the speed and absorption of light enables ATOMMS to profile temperature, pressure and humidity simultaneously, which GPS occultations cannot do, as well as profile clouds and turbulence. We summarize the ATOMMS concept and its theoretical performance. We describe field measurements made with a prototype ATOMMS instrument and several important capabilities demonstrated with those ground based measurements including retrieving temporal variations in path-averaged water vapor to 1%, in clear, cloudy and rainy conditions, up to optical depths of 17, remotely sensing turbulence and determining rain rates. We conclude with a vision of a future ATOMMS low Earth orbiting satellite constellation designed to take advantage of synergies between observational needs for weather and climate, ATOMMS unprecedented orbital remote sensing capabilities and recent cubesat technological innovations that enable a constellation of dozens of very small spacecraft to achieve many critical, but as yet unfulfilled, monitoring and forecasting needs.

  1. Side-line tunable laser transmitter for differential absorption lidar measurements of CO2: design and application to atmospheric measurements.

    PubMed

    Koch, Grady J; Beyon, Jeffrey Y; Gibert, Fabien; Barnes, Bruce W; Ismail, Syed; Petros, Mulugeta; Petzar, Paul J; Yu, Jirong; Modlin, Edward A; Davis, Kenneth J; Singh, Upendra N

    2008-03-01

    A 2 microm wavelength, 90 mJ, 5 Hz pulsed Ho laser is described with wavelength control to precisely tune and lock the wavelength at a desired offset up to 2.9 GHz from the center of a CO(2) absorption line. Once detuned from the line center the laser wavelength is actively locked to keep the wavelength within 1.9 MHz standard deviation about the setpoint. This wavelength control allows optimization of the optical depth for a differential absorption lidar (DIAL) measuring atmospheric CO(2) concentrations. The laser transmitter has been coupled with a coherent heterodyne receiver for measurements of CO(2) concentration using aerosol backscatter; wind and aerosols are also measured with the same lidar and provide useful additional information on atmospheric structure. Range-resolved CO(2) measurements were made with <2.4% standard deviation using 500 m range bins and 6.7 min? (1000 pulse pairs) integration time. Measurement of a horizontal column showed a precision of the CO(2) concentration to <0.7% standard deviation using a 30 min? (4500 pulse pairs) integration time, and comparison with a collocated in situ sensor showed the DIAL to measure the same trend of a diurnal variation and to detect shorter time scale CO(2) perturbations. For vertical column measurements the lidar was setup at the WLEF tall tower site in Wisconsin to provide meteorological profiles and to compare the DIAL measurements with the in situ sensors distributed on the tower up to 396 m height. Assuming the DIAL column measurement extending from 153 m altitude to 1353 m altitude should agree with the tower in situ sensor at 396 m altitude, there was a 7.9 ppm rms difference between the DIAL and the in situ sensor using a 30 min? rolling average on the DIAL measurement.

  2. AN STIS ATLAS OF Ca II TRIPLET ABSORPTION LINE KINEMATICS IN GALACTIC NUCLEI

    SciTech Connect

    Batcheldor, D.; Mandalou, J.; Axon, D.; Valluri, M.; Merritt, D.

    2013-09-15

    The relations observed between supermassive black holes and their host galaxies suggest a fundamental link in the processes that cause these two objects to evolve. A more comprehensive understanding of these relations could be gained by increasing the number of supermassive black hole mass (M{sub .}) measurements. This can be achieved, in part, by continuing to model the stellar dynamics at the centers of galactic bulges using data of the highest possible spatial resolution. Consequently, we present here an atlas of galaxies in the Space Telescope Imaging Spectrograph (STIS) data archive that may have spectra suitable for new M{sub .} estimates. Archived STIS G750M data for all non-barred galactic bulges are co-aligned and combined, where appropriate, and the radial signal-to-noise ratios calculated. The line-of-sight velocity distributions from the Ca II triplet are then determined using a maximum penalized likelihood method. We find 19 out of 42 galaxies may provide useful new M{sub .} estimates since they are found to have data that is comparable in quality with data that has been used in the past to estimate M{sub .}. However, we find no relation between the signal-to-noise ratio in the previously analyzed spectra and the uncertainties of the black hole masses derived from the spectra. We also find that there is a very limited number of appropriately observed stellar templates in the archive from which to estimate the effects of template mismatching.

  3. Diurnal and Interannual Variation in Absorption Lines of Isotopic Carbon Dioxide in Mars Atmosphere

    NASA Astrophysics Data System (ADS)

    Livengood, Timothy A.; Kostiuk, Theodor; Hewagama, Tilak; Kolasinski, John R.; Henning, Wade G.

    2015-11-01

    Groundbased observations of Mars in 2003, 2007, 2012, and 2014 have detected transitions of carbon dioxide containing the stable minor isotopes of oxygen and carbon as well as the primary isotopes, using the ultrahigh resolution spectrometer HIPWAC at the NASA Infrared Telescope Facility. The most well characterized minor isotope is O-18, due to strong lines and observational opportunities. The average estimated O-18/O-16 isotope ratio is roughly consistent with other in situ and remote spectroscopic measurements but demonstrates an additional feature in that the retrieved ratio appears to increase with greater ground surface temperature. These conclusions primarily come from analyzing a subset of the 2007 data. Additional observations have been acquired over a broad range of local time and meridional position to evaluate variability with respect to ground surface temperature. These additional observations include one run of measurements with C-13. These observations can be compared to local in situ measurements by the Curiosity rover to narrow the uncertainty in absolute isotope ratio and extend isotopic measurements to other regions and seasons on Mars. The relative abundance of carbon dioxide heavy isotopes on Mars is central to estimating the primordial atmospheric inventory on Mars. Preferential freeze-distillation of heavy isotopes means that any measurement of the isotope ratio can be only a lower limit on heavy isotope enrichment due to past and current loss to space.

  4. An STIS Atlas of Ca II Triplet Absorption Line Kinematics in Galactic Nuclei

    NASA Astrophysics Data System (ADS)

    Batcheldor, D.; Axon, D.; Valluri, M.; Mandalou, J.; Merritt, D.

    2013-09-01

    The relations observed between supermassive black holes and their host galaxies suggest a fundamental link in the processes that cause these two objects to evolve. A more comprehensive understanding of these relations could be gained by increasing the number of supermassive black hole mass (M •) measurements. This can be achieved, in part, by continuing to model the stellar dynamics at the centers of galactic bulges using data of the highest possible spatial resolution. Consequently, we present here an atlas of galaxies in the Space Telescope Imaging Spectrograph (STIS) data archive that may have spectra suitable for new M • estimates. Archived STIS G750M data for all non-barred galactic bulges are co-aligned and combined, where appropriate, and the radial signal-to-noise ratios calculated. The line-of-sight velocity distributions from the Ca II triplet are then determined using a maximum penalized likelihood method. We find 19 out of 42 galaxies may provide useful new M • estimates since they are found to have data that is comparable in quality with data that has been used in the past to estimate M •. However, we find no relation between the signal-to-noise ratio in the previously analyzed spectra and the uncertainties of the black hole masses derived from the spectra. We also find that there is a very limited number of appropriately observed stellar templates in the archive from which to estimate the effects of template mismatching. 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.

  5. The 13CH4 absorption spectrum in the Icosad range (6600-7692 cm-1) at 80 K and 296 K: Empirical line lists and temperature dependence

    NASA Astrophysics Data System (ADS)

    Campargue, A.; Béguier, S.; Zbiri, Y.; Mondelain, D.; Kassi, S.; Karlovets, E. V.; Nikitin, A. V.; Rey, M.; Starikova, E. N.; Tyuterev, Vl. G.

    2016-08-01

    The 13CH4 absorption spectrum has been recorded at 296 K and 80 K in the Icosad range between 6600 and 7700 cm-1. The achieved noise equivalent absorption of the spectra recorded by differential absorption spectroscopy (DAS) is about αmin ≈ 1.5 × 10-7 cm-1. Two empirical line lists were constructed including 17,792 and 24,139 lines at 80 K and 296 K, respectively. For comparison, the HITRAN database provides only 1040 13CH4 lines in the region determined from methane spectra with natural isotopic abundance. Empirical values of the lower state energy level, Eemp, were systematically derived from the intensity ratios of the lines measured at 80 K and 296 K. Overall 10,792 Eemp values were determined providing accurate temperature dependence for most of the 13CH4 absorption in the region (93% and 82% at 80 K and 296 K, respectively). The quality of the derived empirical values of the lower state rotational quantum number, Jemp, is illustrated by their clear propensity to be close to an integer. A good agreement is achieved between our small Jemp values, with previous accurate determinations obtained by applying the 2T method to jet and 80 K spectra. The line lists at 296 K and 80 K which are provided as Supplementary material will be used for future rovibrational assignments based on accurate variational calculations.

  6. Evidence for ultra-fast outflows in radio-quiet AGNs. I. Detection and statistical incidence of Fe K-shell absorption lines

    NASA Astrophysics Data System (ADS)

    Tombesi, F.; Cappi, M.; Reeves, J. N.; Palumbo, G. G. C.; Yaqoob, T.; Braito, V.; Dadina, M.

    2010-10-01

    Context. Blue-shifted Fe K absorption lines have been detected in recent years between 7 and 10 keV in the X-ray spectra of several radio-quiet AGNs. The derived blue-shifted velocities of the lines can often reach mildly relativistic values, up to 0.2-0.4c. These findings are important because they suggest the presence of a previously unknown massive and highly ionized absorbing material outflowing from their nuclei, possibly connected with accretion disk winds/outflows. Aims: The scope of the present work is to statistically quantify the parameters and incidence of the blue-shifted Fe K absorption lines through a uniform analysis on a large sample of radio-quiet AGNs. This allows us to assess their global detection significance and to overcome any possible publication bias. Methods: We performed a blind search for narrow absorption features at energies greater than 6.4 keV in a sample of 42 radio-quiet AGNs observed with XMM-Newton. A simple uniform model composed by an absorbed power-law plus Gaussian emission and absorption lines provided a good fit for all the data sets. We derived the absorption lines parameters and calculated their detailed detection significance making use of the classical F-test and extensive Monte Carlo simulations. Results: We detect 36 narrow absorption lines on a total of 101 XMM-Newton EPIC pn observations. The number of absorption lines at rest-frame energies higher than 7 keV is 22. Their global probability to be generated by random fluctuations is very low, less than 3 × 10-8, and their detection have been independently confirmed by a spectral analysis of the MOS data, with associated random probability <10-7. We identify the lines as Fe XXV and Fe XXVI K-shell resonant absorption. They are systematically blue-shifted, with a velocity distribution ranging from zero up to ~0.3c, with a peak and mean value at ~0.1c. We detect variability of the lines on both EWs and blue-shifted velocities among different XMM-Newton observations

  7. Unveiling the Intrinsic X-Ray Properties of Broad Absorption Line Quasars with a Relatively Unbiased Sample

    NASA Astrophysics Data System (ADS)

    Morabito, Leah K.; Dai, Xinyu; Leighly, Karen M.; Sivakoff, Gregory R.; Shankar, Francesco

    2014-05-01

    There is growing evidence of a higher intrinsic fraction of broad absorption line quasars (BALQSOs) than that obtained in optical surveys, on which most previous X-ray studies of BALQSOs have focused. Here we present Chandra observations of 18 BALQSOs at z ~ 2, selected from a near-infrared (Two Micron All Sky Survey) sample, where the BALQSO fraction is likely to be close to the intrinsic fraction. We measure photon indices using the stacked spectra of the optically faint (i - Ks >= 2.3 mag) and optically bright (i - Ks < 2.3 mag) samples to be Γ ~= 1.5-2.1. We constrain their intrinsic column density by modeling the X-ray fractional hardness ratio, finding a mean column density of 3.5 × 1022 cm-2 assuming neutral absorption. We incorporate Sloan Digital Sky Survey optical measurements (rest frame UV) to study the broadband spectral index between the X-ray and UV bands, and compare this to a large sample of normal quasars. We estimate that the optically faint BALQSOs are X-ray weaker than the optically bright ones, and the entire sample of BALQSOs are intrinsically X-ray weak when compared to normal active galactic nuclei (AGNs). Correcting for magnification of X-ray emission via gravitational lensing by the central black hole viewed at large inclination angles makes these BALQSOs even more intrinsically X-ray weak. Finally, we estimate AGN kinetic feedback efficiencies of a few percent for an X-ray wind of 0.3c in high-ionization BALQSOs. Combined with energy carried by low-ionization BALQSOs and UV winds, the total kinetic energy in BALQSOs can be sufficient to provide AGN kinetic feedback required to explain the co-evolution between black holes and host galaxies.

  8. PG1416-129: a Close BALQSO with Low Intrinsic X-Ray Absorption

    NASA Astrophysics Data System (ADS)

    Meurs, Evert; de Kool, Marthijn

    1992-12-01

    We present a ROSAT X-ray spectrum of the close BALQSO PG1416-129. The spectrum in the ROSAT energy range is found to be well fitted by a power law spectrum with spectral index alpha = -1.2 (0.15), absorbed by the known galactic N_H. The spectral index we find is typical for QSOs, and much steeper than the very flat spectrum found from GINGA observations at higher energies. The combined GINGA/ROSAT spectra fit onto each other well, but show a very sharp break at 3 keV. We derive an upper limit on the internal absorbing column in the BALQSO of N_H < 10(20) cm(-2) if the absorbing matter is cold, and N_H < 5 times 10(20) cm(-2) if the absorbing matter is sufficiently ionized to produce the broad absorption lines. This is considerably smaller than previously derived upper limits on the internal absorption in BALQSOs, which were ~ 10(22) cm(-2) . In combination with the large equivalent width of the BALs observed in PG1461-129, our result significantly constrains the ionization parameter in the BAL clouds and indicates that these clouds can not be very optically thick in the UV resonance lines of CIV and NV.

  9. Dual Analysis for Mycobacteria and Propionibacteria in Sarcoidosis BAL

    PubMed Central

    Oswald-Richter, Kyra A.; Beachboard, Dia C.; Seeley, Erin H.; Abraham, Susamma; Shepherd, Bryan E.; Jenkins, Cathy A.; Culver, Daniel A.; Caprioli, Richard M.; Drake, Wonder P.

    2012-01-01

    Purpose Sarcoidosis is a non-caseating granulomatous disease for which a role for infectious antigens continues to strengthen. Recent studies have reported molecular evidence of mycobacteria or propionibacteria. We assessed for immune responses against mycobacterial and propionibacterial antigens in sarcoidosis bronchoalveolar lavage (BAL) using flow cytometry, and localized signals consistent with microbial antigens with sarcoidosis specimens, using matrix-assisted laser desorption ionization imaging mass spectrometry (MALDI-IMS). Methods BAL cells from 27 sarcoidosis, 14 PPD- controls, and 9 subjects with nontuberculosis mycobacterial (NTM) infections were analyzed for production of IFN-γ after stimulation with mycobacterial ESAT-6 and Propionibacterium acnes proteins. To complement the immunological data, MALDI-IMS was performed to localize ESAT-6 and Propionibacterium acnes signals within sarcoidosis and control specimens. Results CD4+ immunologic analysis for mycobacteria was positive in 17/27 sarcoidosis subjects, compared to 2/14 PPD-subjects, and 5/9 NTM subjects (p=00.008 and p=00.71 respectively, Fisher's exact test). There was no significant difference for recognition of P. acnes, which occurred only in sarcoidosis subjects that also recognized ESAT-6. Similar results were also observed for the CD8+ immunologic analysis. MALDI-IMS localized signals consistent with ESAT-6 only within sites of granulomatous inflammation, whereas P. acnes signals were distributed throughout the specimen. Conclusions MALDI-IMS localizes signals consistent with ESAT-6 to sarcoidosis granulomas, whereas no specific localization of P. acnes signals is detected. Immune responses against both mycobacterial and P. acnes are present within sarcoidosis BAL, but only mycobacterial signals are distinct from disease controls. These immunologic and molecular investigations support further investigation of the microbial community within sarcoidosis granulomas. PMID:22552860

  10. Effect of buffer gases on broadening of the Iodine-127 resonance absorption line at a 633-nm He-Ne laser wavelength

    SciTech Connect

    Kireev, S.V.; Shnyrev, S.L.; Zaspa, Yu.P.

    1995-04-01

    Collisional broadening coefficients are measured for iodine-127 resonance absorption lines in several rare cases of atmospheric air and CO{sub 2}. The results obtained are used to determine the optimum pressure of a gaseous mixture in a measuring cell for detecting iodine-127 by a helium-neon (633 nm) laser-induced fluorescence technique of monitoring iodine in atmospheric air.

  11. Improved Experimental Line Positions for the (1,1) Band of the b 1Σ+ - X 3Σ- Transition of O2 by Intracavity Laser Absorption Spectroscopy

    NASA Astrophysics Data System (ADS)

    O'Brien, Leah C.; O'Brien, Emily C.; O'Brien, James J.

    2012-06-01

    We report improved experimental line positions for the (1,1) band of the b 1Σ+ - X 3Σ- transition of O2. Results are comparised with previous experimental measurements and predicted values. Additionally, a new method of producing vibrationally hot molecules for use in absorption spectroscopy of stable gas phase molecules is described.

  12. The KMOS GTO Cluster Program: Absorption Line Spectroscopy of Cluster Galaxies at z˜1.5

    NASA Astrophysics Data System (ADS)

    Houghton, R. C. W.; Davies, R. L.; Bender, R.; Beifiori, A.; Chan, J.; Cappellari, M.; Galametz, A.; Lewis, I.; Mendel, J. T.; Prichard, L.; Saglia, R. P.; Sharples, R.; Smith, R.; Stott, J.; Wilman, D.; Wegner, M.

    2016-10-01

    The GTO KMOS cluster program (P.I.s Davies & Bender) is investigating the absorption line spectra of individual cluster galaxies during the peak epoch of star formation at 1.3< z<2. The multiplexed nature of KMOS increases the observing efficiency by more than an order-of-magnitude compared to single integral field units, which is essential for obtaining deep spectra of many faint targets. Furthermore, the NIR capabilities of KMOS produce observations of the well understood rest-frame V-band indices at these redshifts, providing reliable measures of age and composition for the stellar populations. The kinematics coupled with archival HST photometry allow us to construct the fundamental plane and study the evolution in size and mass-to-light when the Universe was less than 5 Gyrs old. The program has already obtained spectra of ˜60 galaxies in three clusters with on-source exposure times of 15-20 hrs per galaxy. We present early results from these data and provide an overview of the project.

  13. Crystal-field analysis and calculation of two-photon absorption line strengths of dicesium sodium hexachlorogadolinate(III).

    PubMed

    Duan, Chang-Kui; Tanner, Peter A

    2010-03-31

    The crystal-field energy level calculation of the 4f(7) ion Gd(3+) in the crystal Cs(2)NaGdCl(6) has fitted 45 levels with standard deviation 12 cm(-1), with the energy parameters being consistent with those from other studies. The resulting eigenvectors have been employed in the calculation of two-photon absorption (TPA) intensities of transitions from the electronic ground state (8)S(7/2) to the crystal-field levels of excited (6)P, (6)I and (6)D multiplet terms. The TPA line strengths are highly polarization dependent and exhibit striking differences for linearly polarized incident radiation compared with circularly polarized radiation. The relative intensities are compared with those available from previous experimental studies and some reassignments have been made. Good agreement of calculated and experimental TPA spectra is found, except for the intensity ratio of the transitions to (6)P(7/2) or (6)P(5/2) compared with that to (6)P(3/2), for linear and circular polarizations, where the calculation overestimates the ratio. Reasons for this disagreement are presented.

  14. Determination of cobalt in biological samples by line-source and high-resolution continuum source graphite furnace atomic absorption spectrometry using solid sampling or alkaline treatment

    NASA Astrophysics Data System (ADS)

    Ribeiro, Anderson Schwingel; Vieira, Mariana Antunes; da Silva, Alessandra Furtado; Borges, Daniel L. Gallindo; Welz, Bernhard; Heitmann, Uwe; Curtius, Adilson José

    2005-06-01

    Two procedures for the determination of Co in biological samples by graphite furnace atomic absorption spectrometry (GF AAS) were compared: solid sampling (SS) and alkaline treatment with tetramethylammonium hydroxide (TMAH) using two different instruments for the investigation: a conventional line-source (LS) atomic absorption spectrometer and a prototype high-resolution continuum source atomic absorption spectrometer. For the direct introduction of the solid samples, certified reference materials (CRM) were ground to a particle size ≤50 μm. Alkaline treatment was carried out by placing about 250 mg of the sample in polypropylene flasks, adding 2 mL of 25% m/v tetramethylammonium hydroxide and de-ionized water. Due to its unique capacity of providing a 3-D spectral plot, a high-resolution continuum source (HR-CS) graphite furnace atomic absorption spectrometry was used as a tool to evaluate potential spectral interferences, including background absorption for both sample introduction procedures, revealing that a continuous background preceded the atomic signal for pyrolysis temperatures lower than 700 °C. Molecular absorption bands with pronounced rotational fine structure appeared for atomization temperatures >1800 °C probably as a consequence of the formation of PO. After optimization had been carried out using high resolution continuum source atomic absorption spectrometry, the optimized conditions were adopted also for line-source atomic absorption spectrometry. Six biological certified reference materials were analyzed, with calibration against aqueous standards, resulting in agreement with the certified values (according to the t-test for a 95% confidence level) and in detection limits as low as 5 ng g -1.

  15. Optical and spectroscopic properties of Eu2O3 doped CaBAl glasses

    NASA Astrophysics Data System (ADS)

    Melo, G. H. A.; Dias, J. D. M.; Lodi, T. A.; Barboza, M. J.; Pedrochi, F.; Steimacher, A.

    2016-04-01

    Eu2O3 doped CaBAL glasses (x Eu2O3) - (25-x) CaO - (50) B2O3 - (15) Al2O3 - (10) CaF2 (x = 0, 5, 1, 2, 3, 4, 5, 10 wt%) were prepared by using conventional melt-quenching and studied by means of density measurements, refractive index, optical absorption, luminescence and radiative lifetime. The results are discussed in terms of Eu2O3 content. The incorporation of Eu2O3 leads to an increase in the electronic polarizability and the refractive index. A linear increase with Eu2O3 content was observed in the optical absorption coefficient at 394 nm. The luminescence spectra present typical Eu3+ emission and do not present quenching up to 10 wt%. The luminescence ratio R/O I(5D0 → 7F2)/I(5D0 → 7F1) presents an increase with Eu2O3 doping; it indicates a reduction in local symmetry around the Eu3+ ions. The CIE 1931 diagram presents a red shift and an increase of color purity with Eu2O3 addition. The luminescence as a function of temperature shows an increase of 25% in the luminescence intensity for the Eu0.5 sample, at 592 nm. The radiative lifetime at 614 nm shows an exponential decay due to the reduction of the interionic distance Eu3+ - Eu3+ and the increase of the ion-ion interaction.

  16. Absorption cross sections for HF laser lines due to traces of CO/sub 2/, N/sub 2/O, and CH/sub 4/ in air

    SciTech Connect

    Agroskin, V.Ya.; Vasil'ev, G.K.; Gur'ev, V.I.; Tatarinova, E.E.

    1986-12-01

    The emission from an HF (DF) laser is spread over a large number of vibrational-rotational lines in the range 2.7-4.2 ..mu..m, which contains absorption bands of virtually all substances of interesting quantitative gas analysis, and in particular, detecting atmospheric pollutants, determining discharges from industrial plants, locating deposits of certain minerals, forecasting volcanic activity, and so on. Pulsed chemical HF (DF) lasers can be based on the chain reaction of fluorine with hydrogen (deuterium), which is promising for these purposes because the number of lines is large by comparison with any other type of laser (about 100 lines). These lasers also have high efficiency in converting the pumping energy to radiation and high beam power with relatively small dimensions and the same laser cell can be used to obtain the emission from carbon dioxide in the range 9.6-10.6 ..mu..m by energy transfer from DF to carbon dioxide. It is necessary to know the absorption characteristics of the substances at the lines of the HF (DF) laser. In this paper, the authors report measured cross sections for carbon dioxide, nitrogen oxide, and carbon hydrogenate, in the form of minor impurities in the air (about 1-10%) for various lines from an HF laser. The authors compare the data with published values, while the available spectroscopic characteristics are used in theoretical calculations of the absorption cross section and compared with the experiment.

  17. Radiometric observations of the 752.033-GHz rotational absorption line of H2O from a laboratory jet. [simulation of rocket plumes

    NASA Technical Reports Server (NTRS)

    Dionne, G. F.; Fitzgerald, J. F.; Chang, T.-S.; Fetterman, H. R.; Litvak, M. M.

    1980-01-01

    With the aid of a high-resolution two-stage heterodyne radiometer, spectral absorption measurements of the 752.033 GHz line of water vapor were carried out, using a blackbody continuum as a background radiation source for investigating the absorptive properties of the H2O content of high altitude rocket plumes. To simulate this physical situation in a laboratory environment, a small steam jet was operated within a large high-vacuum chamber, with the H2O jet plume traversing the radiometer line of sight. The experiments verified that this rotational line is optically thick, with excitation temperatures below 100 K, in the downstream part of the plume, as predicted by theoretical modelling.

  18. Abundances of O, Mg, S, Cr, Mn, Ti, Ni and Zn from absorption lines of neutral gas in the Large Magellanic Cloud in front of R136

    NASA Technical Reports Server (NTRS)

    De Boer, K. S.; Fitzpatrick, E. L.; Savage, B. D.

    1985-01-01

    Weak absorption lines of C I, O I, Mg I, Mg II, Si I, Si II, P I, Cl I, Cr II, Mn II, Fe I, Ni II, Zn II, CO and C2 are detected in neutral gas in front of the 30 Doradus H II region by IUE spectra of R 136. The Large Magellanic Cloud abundances from the absorption lines are a factor of 2 or 3 below those of the Milky Way, in agreement with emission line study results. Neutral gas density and temperature are estimated from the observed excitation and ionization to be about 300/cu cm and 100 K, respectively; this implies a gas pressure of 30,000/cu cm K.

  19. CHANDRA VIEW OF THE WARM-HOT INTERGALACTIC MEDIUM TOWARD 1ES 1553+113: ABSORPTION-LINE DETECTIONS AND IDENTIFICATIONS. I

    SciTech Connect

    Nicastro, F.; Zappacosta, L.; Elvis, M.; Krongold, Y.; Mathur, S.; Gupta, A.; Danforth, C.; Shull, J. M.; Barcons, X.; Borgani, S.; Branchini, E.; Cen, R.; Dave, R.; Kaastra, J.; Paerels, F.; Piro, L.; Takei, Y.

    2013-06-01

    We present the first results from our pilot 500 ks Chandra Low Energy Transmission Grating Large Program observation of the soft X-ray brightest source in the z {approx}> 0.4 sky, the blazar 1ES 1553+113, aimed to secure the first uncontroversial detections of the missing baryons in the X-rays. We identify a total of 11 possible absorption lines, with single-line statistical significances between 2.2{sigma} and 4.1{sigma}. Six of these lines are detected at high single-line statistical significance (3.6 {<=} {sigma} {<=} 4.1), while the remaining five are regarded as marginal detections in association with either other X-ray lines detected at higher significance and/or far-ultraviolet (FUV) signposts. Three of these lines are consistent with metal absorption at z {approx_equal} 0, and we identify them with Galactic O I and C II. The remaining eight lines may be imprinted by intervening absorbers and are all consistent with being high-ionization counterparts of FUV H I and/or O VI intergalactic medium signposts. In particular, five of these eight possible intervening absorption lines (single-line statistical significances of 4.1{sigma}, 4.1{sigma}, 3.9{sigma}, 3.8{sigma}, and 2.7{sigma}), are identified as C V and C VI K{alpha} absorbers belonging to three WHIM systems at z{sub X} = 0.312, z{sub X} = 0.237, and (z{sub X} ) = 0.133, which also produce broad H I (and O VI for the z{sub X} = 0.312 system) absorption in the FUV. For two of these systems (z{sub X} = 0.312 and 0.237), the Chandra X-ray data led the a posteriori discovery of physically consistent broad H I associations in the FUV (for the third system the opposite applies), so confirming the power of the X-ray-FUV synergy for WHIM studies. The true statistical significances of these three X-ray absorption systems, after properly accounting for the number of redshift trials, are 5.8{sigma} (z{sub X} = 0.312; 6.3{sigma} if the low-significance O V and C V K{beta} associations are considered), 3.9{sigma} (z

  20. High Dust Depletion in two Intervening Quasar Absorption Line Systems with the 2175 Å Extinction Bump at z ~ 1.4

    NASA Astrophysics Data System (ADS)

    Jiang, Peng; Ge, Jian; Prochaska, J. Xavier; Wang, Junfeng; Zhou, Hongyan; Wang, Tinggui

    2010-12-01

    We present the column densities of heavy elements and dust depletion studies in two strong Mg II absorption systems at z ~ 1.4 displaying the 2175 Å dust extinction feature. Column densities are measured from low-ionization absorption lines using an Apparent Optical Depth Method on the Keck/ESI spectra. We find that the dust depletion patterns resemble that of cold diffuse clouds in the Milky Way (MW). The values, [Fe/Zn] ≈-1.5 and [Si/Zn]<-0.67, are among the highest dust depletion measured for quasar absorption line systems. In another 2175 Å absorber at z = 1.64 toward the quasar SDSS J160457.50+220300.5, Noterdaeme et al. reported a similar dust depletion measurement ([Fe/Zn] = -1.47 and [Si/Zn] = -1.07) and detected C I and CO absorption lines on its VLT/UVES spectrum. We conclude that heavy dust depletion (i.e., a characteristic of cold dense clouds in MW) is required to produce a pronounced 2175 Å extinction bump. The data presented herein were 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 the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation.

  1. Discovery of two broad absorption line quasars at redshift about 4.75 using the Lijiang 2.4 m telescope

    NASA Astrophysics Data System (ADS)

    Yi, WeiMin; Wu, XueBing; Wang, FeiGe; Yang, JinYi; Yang, Qian; Bai, JinMing

    2015-09-01

    The ultraviolet broad absorption lines have been seen in the spectra of quasars at high redshift, and are generally considered to be caused by outflows with velocities from thousands kilometers per second to one tenth of the speed of light. They provide crucial implications for the cosmological structures and physical evolutions related to the feedback of active galactic nuclei (AGNs). Recently, through a dedicated program of optically spectroscopic identifications of selected quasar candidates at redshift 5 by using the Lijiang 2.4 m telescope, we discovered two luminous broad absorption line quasars (BALQSOs) at redshift about 4.75. One of them may even have the potentially highest absorption Balnicity Index (BI) ever found to date, which is remarkably characterized by its deep, broad absorption lines and sub-relativistic outflows. Further physical properties, including the metal abundances, variabilities, evolutions of the supermassive black holes (SMBH) and accretion disks associated with the feedback process, can be investigated with multi-wavelength follow-up observations in the future.

  2. A Candidate for an Intrinsic Dusty Absorber with a Metal-rich Damped Lyα Absorption Line System in the Quasar J170542.91+354340.2

    NASA Astrophysics Data System (ADS)

    Pan, Xiang; Zhou, Hongyan; Ge, Jian; Jiang, Peng; Yang, Bin; Lu, Honglin; Ji, Tuo; Zhang, Shaohua; Shi, Xiheng

    2017-02-01

    We present a detailed analysis of the unusual damped Lyα absorption line system (DLA) toward the quasar SDSS J170542.91+354340.2 at a redshift of 2, previously reported by Noterdaeme et al. as one of the very few CO absorbers known to date at high z. This DLA is exceptional in that: (1) its extinction curve is similar to peculiar Milky Way sightlines penetrating star formation regions; (2) its absorption components are redshifted at a speed of several hundred km s‑1 compared to broad Balmer emission lines; (3) its gas-phase metallicity is super-solar as evaluated from more than 30 absorption lines; (4) detection of residual flux in the DLA trough and variability of {{C}} {{IV}} absorption is possible. Based on these facts, we argue that this dusty DLA is a good candidate for an intrinsic quasar 2175 Å absorber, and can originate from star formation regions of the quasar’s host galaxy. We discuss in detail the gas and dust properties, and the dust depletion. Follow-up observations, such as spectropolarimetry and optical/infrared spectroscopy, will help to confirm the system’s intrinsic nature and to explore how dust grains behave in the extreme environments proximate to quasars.

  3. Absorption-line Spectroscopy of Gravitationally Lensed Galaxies: Further Constraints on the Escape Fraction of Ionizing Photons at High Redshift

    NASA Astrophysics Data System (ADS)

    Leethochawalit, Nicha; Jones, Tucker A.; Ellis, Richard S.; Stark, Daniel P.; Zitrin, Adi

    2016-11-01

    The fraction of ionizing photons escaping from high-redshift star-forming galaxies is a key obstacle in evaluating whether galaxies were the primary agents of cosmic reionization. We previously proposed using the covering fraction of low-ionization gas, measured via deep absorption-line spectroscopy, as a proxy. We now present a significant update, sampling seven gravitationally lensed sources at 4 < z < 5. We show that the absorbing gas in our sources is spatially inhomogeneous, with a median covering fraction of 66%. Correcting for reddening according to a dust-in-cloud model, this implies an estimated absolute escape fraction of ≃19% ± 6%. With possible biases and uncertainties, collectively we find that the average escape fraction could be reduced to no less than 11%, excluding the effect of spatial variations. For one of our lensed sources, we have sufficient signal-to-noise ratio to demonstrate the presence of such spatial variations and scatter in its dependence on the Lyα equivalent width, consistent with recent simulations. If this source is typical, our lower limit to the escape fraction could be reduced by a further factor ≃2. Across our sample, we find a modest anticorrelation between the inferred escape fraction and the local star formation rate, consistent with a time delay between a burst and leaking Lyman continuum photons. Our analysis demonstrates considerable variations in the escape fraction, consistent with being governed by the small-scale behavior of star-forming regions, whose activities fluctuate over short timescales. This supports the suggestion that the escape fraction may increase toward the reionization era when star formation becomes more energetic and burst-like.

  4. 78 FR 44909 - Regional Reliability Standard BAL-002-WECC-2-Contingency Reserve

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-25

    ... Energy Regulatory Commission 18 CFR Part 40 Regional Reliability Standard BAL-002-WECC-2--Contingency...) proposes to approve regional Reliability Standard BAL-002-WECC-2 (Contingency Reserve). The North American Electric Reliability Corporation (NERC) and Western Electricity Coordinating Council (WECC) submitted...

  5. Drug evaluation: BAL-8557--a novel broad-spectrum triazole antifungal.

    PubMed

    Odds, Frank C

    2006-08-01

    Basilea Pharmaceutica is developing BAL-8557, a water-soluble prodrug of the triazole BAL-4815, for the potential treatment of fungal infections. By August 2005, a phase II study in oral candidiasis was underway. In September 2005, phase III trials were planned for invasive Candida and mold infections, including aspergillus and zygomycetes.

  6. INFRARED ABSORPTION LINES TOWARD NGC 7538 IRS 1: ABUNDANCES OF H{sub 2}, H{sub 3}{sup +}, AND CO

    SciTech Connect

    Goto, Miwa; Geballe, T. R.; Usuda, Tomonori E-mail: tgeballe@gemini.edu

    2015-06-10

    We report high-resolution near-infrared absorption spectroscopy of H{sub 2}, H{sub 3}{sup +}, and CO toward the young high mass object NGC 7538 IRS 1. The v = 1–0 H{sub 2} S(0) line and lines in the CO v = 2–0 band were detected; the v = 1–0 H{sub 2} S(1) line and the v = 1–0 H{sub 3}{sup +} lines [R(1, 1){sup l}, R(1, 0), R(1, 1){sup u}] were not detected. The line of sight traverses two clouds, with temperatures 45 and 259 K and with roughly equal column densities of CO. Assuming that H{sub 2} is at the same temperature as CO and that the two species are uniformly mixed, [H{sub 2}]/[CO] = 3600 ± 1200. NGC 7538 is the most distant object from the Galactic center for which [H{sub 2}]/[CO] has been directly measured using infrared absorption spectroscopy.

  7. A SURVEY OF METAL LINES AT HIGH REDSHIFT. II. SDSS ABSORPTION LINE STUDIES-O VI LINE DENSITY, SPACE DENSITY, AND GAS METALLICITY AT z{sub abs} {approx} 3.0

    SciTech Connect

    Frank, S.; Mathur, S.; Pieri, M.; York, D. G.

    2010-09-15

    studies. These results demonstrate that large spectroscopic data sets such as SDSS can play an important role in QSO absorption line studies, in spite of the relatively low resolution.

  8. Spectral anomalies of the light-induced drift effect caused by the velocity dependence of the collision broadening and shift of the absorption line

    NASA Astrophysics Data System (ADS)

    Parkhomenko, A. I.; Shalagin, Anatolii M.

    2013-02-01

    We have theoretically investigated the spectral features of the light-induced drift (LID) effect, arising due to the dependence of the collision broadening γ and shift Δ of the absorption line on the velocity of resonance particles, ν. It is shown that under certain conditions, account of this dependence can radically change the spectral shape of the LID signal, up to the appearance of additional zeros in the dependence of the drift velocity on the radiation frequency.

  9. Spectral anomalies of the light-induced drift effect caused by the velocity dependence of the collision broadening and shift of the absorption line

    SciTech Connect

    Parkhomenko, A I; Shalagin, Anatolii M

    2013-02-28

    We have theoretically investigated the spectral features of the light-induced drift (LID) effect, arising due to the dependence of the collision broadening {gamma} and shift {Delta} of the absorption line on the velocity of resonance particles, {nu}. It is shown that under certain conditions, account of this dependence can radically change the spectral shape of the LID signal, up to the appearance of additional zeros in the dependence of the drift velocity on the radiation frequency. (nonlinear optical phenomena)

  10. Extremely sensitive detection of NO₂ employing off-axis integrated cavity output spectroscopy coupled with multiple-line integrated absorption spectroscopy.

    PubMed

    Rao, Gottipaty N; Karpf, Andreas

    2011-05-01

    We report on the development of a new sensor for NO₂ with ultrahigh sensitivity of detection. This has been accomplished by combining off-axis integrated cavity output spectroscopy (OA-ICOS) (which can provide large path lengths of the order of several kilometers in a small volume cell) with multiple-line integrated absorption spectroscopy (MLIAS) (where we integrate the absorption spectra over a large number of rotational-vibrational transitions of the molecular species to further improve the sensitivity). Employing an external cavity quantum cascade laser operating in the 1601-1670 cm⁻¹ range and a high-finesse optical cavity, the absorption spectra of NO₂ over 100 transitions in the R band have been recorded. From the observed linear relationship between the integrated absorption versus concentration of NO₂ and the standard deviation of the integrated absorption signal, we report an effective sensitivity of detection of approximately 28 ppt (parts in 10¹²) for NO₂ To the best of our knowledge, this is among the most sensitive levels of detection of NO₂ to date.

  11. Microstructure and magnetic properties of mechanically alloyed FeSiBAlNi (Nb) high entropy alloys

    NASA Astrophysics Data System (ADS)

    Wang, Jian; Zheng, Zhou; Xu, Jing; Wang, Yan

    2014-04-01

    In this paper, the effects of milling duration and composition on the microstructure and magnetic properties of equi-atomic FeSiBAlNi and FeSiBAlNiNb high entropy alloys during mechanical alloying have been investigated using X-ray diffraction, differential scanning calorimetry, scanning electron microscopy, transmission electron microscopy and alternating gradient magnetometry. The amorphous high entropy alloys have been successfully fabricated using the mechanical alloying method. The results show that the Nb addition prolongs the milling time for the formation of the fully FeSiBAlNi amorphous phase and decreases the glass forming ability. However, FeSiBAlNiNb amorphous high entropy alloy has the higher thermal stability and heat resisting properties. Moreover, the as-milled FeSiBAlNi(Nb) powders are soft-magnetic materials indicated by their low coercivity. The saturation magnetization of the as-milled FeSiBAlNi(Nb) powders decreases with prolonging of the milling time and shows the lowest value when the amorphous high entropy alloys are formed. It suggests that the as-milled products with solid solution phases show the better soft-magnetic properties than those with fully amorphous phases. The Nb addition does not improve the soft-magnetic properties of the FeSiBAlNi high entropy alloys. Rather, both amorphous high entropy alloys have similar soft-magnetic properties after a long milling time.

  12. Temporal variations in gas temperature in an atomization stage of cadmium and tellurium evaluated by using the two-line method in graphite furnace atomic absorption spectrometry.

    PubMed

    Shimabukuro, Haruki; Ashino, Tetsuya; Wagatsuma, Kazuaki

    2008-09-01

    In order to discuss the atomization process of an analyte element occurring in a graphite furnace for atomic absorption spectrometry, we measured variations in the characteristic temperature with the progress of an atomization stage, by using a two-line method under the assumption of a Boltzmann distribution. For this purpose, iron was chosen as the analyte element. Also, the atomic absorption of two iron atomic lines, Fe I 372.0 nm and Fe I 373.7 nm, was simultaneously monitored as a probe for the temperature determination. This method enables variations in the gas temperature to be directly traced, yielding a temperature distribution closely related to the diffusion behavior of the probe element in the furnace. This temperature variation was very different from the furnace wall temperatures, which were monitored in conventional temperature control for atomic absorption spectrometry. Correlations between the gas temperature and the charring/atomizing temperatures in the heating program of the furnace were investigated. The atomization of cadmium and tellurium was also investigated by a comparison between the gas temperature with the wall temperature of the furnace. The atomic absorption of cadmium or tellurium appeared to be apart from the absorption of iron while the gas temperature was still low. Therefore, the analyte atoms could be atomized through direct contact with the wall of the graphite furnace, which has a much higher temperature compared to the gas atmosphere during atomization. Their atomization would be caused by conductive heating from the furnace wall rather than by radiant heating in the furnace.

  13. The CO2 absorption spectrum in the 2.3 μm transparency window by high sensitivity CRDS: (I) Rovibrational lines

    NASA Astrophysics Data System (ADS)

    Vasilchenko, S.; Konefal, M.; Mondelain, D.; Kassi, S.; Čermák, P.; Tashkun, S. A.; Perevalov, V. I.; Campargue, A.

    2016-11-01

    The absorption of carbon dioxide is very weak near 2.3 μm which makes this transparency window of particular interest for the study of Venus' lower atmosphere. As a consequence of the weakness of the transitions located in this region, previous experimental data are very scarce and spectroscopic databases provide calculated line lists which should be tested and validated by experiment. In this work, we use the Cavity Ring Down Spectroscopy (CRDS) technique for a high sensitivity characterization of the CO2 absorption spectrum in two spectral intervals of the 2.3 μm window: 4248-4257 and 4295-4380 cm-1 which were accessed using a Distributed Feed Back (DFB) diode laser and a Vertical External Cavity Surface Emitting Laser (VECSEL) as light sources, respectively. The achieved sensitivity (noise equivalent absorption, αmin, on the order of 5×10-10 cm-1) allowed detecting numerous new transitions with intensity values down to 5×10-30 cm/molecule. The rovibrational assignments were performed by comparison with available theoretical line lists in particular those obtained at IAO Tomsk using the global effective operator approach. Hot bands of the main isotopologue and 16O12C18O bands were found to be missing in the HITRAN database while they contribute importantly to the absorption in the region. Additional CRDS spectra of a CO2 sample highly enriched in 18O were recorded in order to improve the spectroscopy of this isotopologue. As a result about 700 lines of 16O12C18O, 16O12C17O, 17O12C18O, 12C18O2 and 13C18O2 were newly measured. The status of the different databases (HITRAN, CDSD, variational calculations) in the important 2.3 μm transparency window is discussed. Possible improvements to correct evidenced deficiencies are suggested.

  14. Spectral aspects of the determination of Si in organic and aqueous solutions using high-resolution continuum source or line source flame atomic absorption spectrometry

    NASA Astrophysics Data System (ADS)

    Kowalewska, Zofia; Pilarczyk, Janusz; Gościniak, Łukasz

    2016-06-01

    High-resolution continuum source flame atomic absorption spectrometry (HR-CS FAAS) was applied to reveal and investigate spectral interference in the determination of Si. An intensive structured background was observed in the analysis of both aqueous and xylene solutions containing S compounds. This background was attributed to absorption by the CS molecule formed in the N2O-C2H2 flame. The lines of the CS spectrum at least partially overlap all five of the most sensitive Si lines investigated. The 251.611 nm Si line was demonstrated to be the most advantageous. The intensity of the structured background caused by the CS molecule significantly depends on the chemical form of S in the solution and is the highest for the most-volatile CS2. The presence of O atoms in an initial S molecule can diminish the formation of CS. To overcome this S effect, various modes of baseline fitting and background correction were evaluated, including iterative background correction (IBC) and utilization of correction pixels (WRC). These modes were used either independently or in conjunction with least squares background correction (LSBC). The IBC + LSBC mode can correct the extremely strong interference caused by CS2 at an S concentration of 5% w:w in the investigated solution. However, the efficiency of this mode depends on the similarity of the processed spectra and the correction spectra in terms of intensity and in additional effects, such as a sloping baseline. In the vicinity of the Si line, three lines of V were recorded. These lines are well-separated in the HR-CS FAAS spectrum, but they could be a potential source of overcorrection when using line source flame atomic absorption spectrometry (LS FAAS). The expected signal for the 251.625 nm Fe line was not registered at 200 mg L- 1 Fe concentration in the solution, probably due to the diminished population of Fe atoms in the high-temperature flame used. The observations made using HR-CS FAAS helped to establish a "safe" level

  15. Discovery of a cyclotron absorption line in the spectrum of the binary X-ray pulsar 4U 1538 - 52 observed by Ginga

    NASA Technical Reports Server (NTRS)

    Clark, George W.; Woo, Jonathan W.; Nagase, Fumiaki; Makishima, Kazuo; Sakao, Taro

    1990-01-01

    A cyclotron absorption line near 20 keV has been found in the spectrum of the massive eclipsing binary X-ray pulsar 4U 1538 - 52 in observations with the Ginga observatory. The line is detected throughout the 529 s pulse cycle with a variable equivalent width that has its maximum value during the smaller peak of the two-peak pulse profile. It is found that the profile of the pulse and the phase-dependence of the cyclotron line can be explained qualitatively by a pulsar model based on recent theoretical results on the properties of pencil beams emitted by accretion-heated slabs of magnetized plasma at the magnetic poles of a neutron star. The indicated field at the surface of the neutron star is 1.7 (1 + z) x 10 to the 12th G, where z is the gravitational redshift.

  16. Oscillator strengths of Cr I lines lying between 200 and 541 nm from hook-method and absorption measurements in a furnace

    NASA Technical Reports Server (NTRS)

    Huber, M. C. E.; Sandeman, R. J.

    1977-01-01

    Measurements of 148 oscillator strengths of neutral chromium transitions were made on Cr vapor in a high-temperature furnace by the hook and absorption methods for strong and weak lines, respectively. With the aid of a 5D-z 5F0 multiplet, the product of the oscillator strengths of the lines of this multiplet with the column densities of their respective lower levels could be determined, and by using estimated oscillator strengths for these lines, all data could be put on a common relative scale. This scale was altered so that the results were matched with relative emission intensities. Results are compared with other authors' results. A correction to the hook method constant was also determined.

  17. First laboratory detection of an absorption line of the first overtone electric quadrupolar band of N2 by CRDS near 2.2 μm

    NASA Astrophysics Data System (ADS)

    Čermák, P.; Vasilchenko, S.; Mondelain, D.; Kassi, S.; Campargue, A.

    2017-01-01

    The extremely weak 2-0 O(14) electric quadrupole transition of N2 has been detected by very high sensitivity Cavity Ring Down spectroscopy near 4518 cm-1. It is the first N2 absorption line in the first overtone band reported so far from laboratory experiments. By combining a feedback narrowed Distributed Feedback laser diode with a passive cell tracking technique, a limit of detection of αmin ∼ 1.2 × 10-11 cm-1 was achieved after one day of spectra averaging. The N2 2-0 O(14) line position and line intensity (about 1.5 × 10-30 cm/molecule) agree with calculated values provided in the HITRAN2012 database.

  18. Evaluation of the absorption line blackbody distribution function of CO2 and H2O using the proper orthogonal decomposition and hyperbolic correlations

    NASA Astrophysics Data System (ADS)

    Liu, F.; Chu, H.; Zhou, H.; Smallwood, G. J.

    2013-10-01

    Databases of the absorption line blackbody distribution function (ALBDF) of CO2 and H2O were generated over a wide range of gas and blackbody temperatures and the full range of gas concentration from line-by-line (LBL) calculations using the latest version of HITEMP. Proper orthogonal decomposition (POD) and the hyperbolic correlations (HC) were then used for rapid calculation the ALBDF value at an arbitrary combination of gas and blackbody temperatures and gas concentration. A novel hyperbolic correlation for H2O was proposed to fully account for the self-broadening effect. The accuracy of POD and the HC was evaluated by comparing the ALBDF values and the total gas emissivities from these two approximate methods at several selected conditions against those from LBL calculations. POD is significantly more accurate than HC at essentially no extra computational costs.

  19. Terminal velocity of wind, mass loss, and absorption lines of the central star of the planetary nebula 75 + 35. 1 deg

    SciTech Connect

    Feibelman, W.A.; Bruhweiler, F.C. Catholic Univ. of America, Washington, DC )

    1989-12-01

    The high-galactic latitude planetary nebula 75 + 35.1 deg was observed in the high-dispersion mode of the International Ultraviolet Explorer (IUE) satellite in the wavelength range 1150-1950 A. The N V resonance doublet at 1240 A and O V subordinate line at 1371 A exhibit strong stellar P Cygni profiles with absorption extending to -2150 km/s and -1000 km/s, respectively. Application of the first moment method implies a mass-loss rate of M = (1-3) x 10 to the -8th solar mass/yr. The high ionization of the wind lines and the presence of strong Fe VI and Fe V lines in the stellar photosphere support that this object is quite hot. A Teff of 75,000 + or - 10,000 K was adopted, although Tc = 94,000 K was found previously from low-resolution IUE data. 18 refs.

  20. Terminal velocity of wind, mass loss, and absorption lines of the central star of the planetary nebula 75 + 35.1 deg

    NASA Technical Reports Server (NTRS)

    Feibelman, Walter A.; Bruhweiler, Frederick C.

    1989-01-01

    The high-galactic latitude planetary nebula 75 + 35.1 deg was observed in the high-dispersion mode of the International Ultraviolet Explorer (IUE) satellite in the wavelength range 1150-1950 A. The N V resonance doublet at 1240 A and O V subordinate line at 1371 A exhibit strong stellar P Cygni profiles with absorption extending to -2150 km/s and -1000 km/s, respectively. Application of the first moment method implies a mass-loss rate of M = (1-3) x 10 to the -8th solar mass/yr. The high ionization of the wind lines and the presence of strong Fe VI and Fe V lines in the stellar photosphere support that this object is quite hot. A Teff of 75,000 + or - 10,000 K was adopted, although Tc = 94,000 K was found previously from low-resolution IUE data.

  1. H2O and O2 Absorption-Line Abundances in the Coma of Comet 67P/Churyumov-Gerasimenko Measured by the R-Alice Ultraviolet Spectrograph

    NASA Astrophysics Data System (ADS)

    Keeney, Brian A.; Stern, S. Alan; Schindhelm, Eric; A'Hearn, Michael F.; Bertaux, Jean-Loup; Bieler, Andre; Feaga, Lori M.; Feldman, Paul D.; Parker, Joel Wm; Steffl, Andrew Joseph; Weaver, Harold A.

    2016-10-01

    The Alice far-UV spectrograph, aboard the ESA Rosetta spacecraft, has observed emissions in the wavelength range 800-2000 Å from the coma of Comet 67P/Churyumov-Gerasimenko since before orbital insertion in September 2014. We present novel observations of the cometary coma in absorption against the stellar continuum of UV-bright stars that were targeted or serendipitously observed near the comet's nucleus between April 2015 and February 2016 at heliocentric radii ranging from 1.2 to 2.4 AU. These spectra show clear signatures of absorption from gaseous H2O and O2. The observed H2O column densities agree well with values found by Rosetta's VIRTIS instrument (Bockelée-Morvan et al. 2015, A&A, 583, A6) and can be reasonably described by a simple Haser model. However, the absorption-derived O2/H2O ratio is somewhat larger than the 1-10% range reported by Rosetta's ROSINA mass spectrometer (Bieler et al. 2015, Nature, 526, 678) from September 2014 through March 2015 at heliocentric radii of 2.1-3.2 AU. We explore potential causes for this discrepancy, including systematic biases in the absorption-line measurements and seasonal variations in O2/H2O as the comet approaches perihelion.

  2. New aspects of absorption-line formation in intervening turbulent clouds - III. The inverse problem in the study of H+D profiles

    NASA Astrophysics Data System (ADS)

    Levshakov, Sergei A.; Kegel, Wilhelm H.; Takahara, Fumio

    1999-02-01

    A new method, based on a reverse Monte Carlo technique and aimed at the inverse problem in the analysis of intergalactic (interstellar) H+D absorption profiles, is presented. We consider the process of line formation in media with a stochastic velocity field accounting for correlation effects (mesoturbulence). This approach generalizes the standard microturbulent approximation, which is commonly used to model the formation of absorption spectra in turbulent media. The method allows one to estimate, from an observed spectrum, both the physical parameters of the absorbing gas and an appropriate structure of the distribution of the velocity component parallel to the line of sight. The validity of the computational procedure is demonstrated using a series of synthetic spectra that emulate the up-to-date best quality data. The H+D Lyα, Lyβ and H I Ly-14 lines were fitted simultaneously. The confidence regions calculated for the `NH i-D/H' plane show that the difference between the recovered and adopted values does not exceed the 3σ level.

  3. Mars Ozone Absorption Line Shapes from Infrared Heterodyne Spectra Applied to GCM-Predicted Ozone Profiles and to MEX/SPICAM Column Retrievals

    NASA Technical Reports Server (NTRS)

    Fast, Kelly E.; Kostiuk, T.; Annen, J.; Hewagama, T.; Delgado, J.; Livengood, T. A.; Lefevre, F.

    2008-01-01

    We present the application of infrared heterodyne line shapes of ozone on Mars to those produced by radiative transfer modeling of ozone profiles predicted by general circulation models (GCM), and to contemporaneous column abundances measured by Mars Express SPICAM. Ozone is an important tracer of photochemistry Mars' atmosphere, serving as an observable with which to test predictions of photochemistry-coupled GCMs. Infrared heterodyne spectroscopy at 9.5 microns with spectral resolving power >1,000,000 is the only technique that can directly measure fully-resolved line shapes of Martian ozone features from the surface of the Earth. Measurements were made with Goddard Space Flight Center's Heterodyne instrument for Planetary Wind And Composition (HIPWAC) at the NASA Infrared Telescope Facility (IRTF) on Mauna Kea, Hawaii on February 21-24 2008 UT at Ls=35deg on or near the MEX orbital path. The HIPWAC observations were used to test GCM predictions. For example, a GCM-generated ozone profile for 60degN 112degW was scaled so that a radiative transfer calculation of its absorption line shape matched an observed HIPWAC absorption feature at the same areographic position, local time, and season. The RMS deviation of the model from the data was slightly smaller for the GCM-generated profile than for a line shape produced by a constant-with-height profile, even though the total column abundances were the same, showing potential for testing and constraining GCM ozone-profiles. The resulting ozone column abundance from matching the model to the HIPWAC line shape was 60% higher than that observed by SPICAM at the same areographic position one day earlier and 2.5 hours earlier in local time. This could be due to day-to-day, diurnal, or north polar region variability, or to measurement sensitivity to the ozone column and its distribution, and these possibilities will be explored. This work was supported by NASA's Planetary Astronomy Program.

  4. Broadening of the infrared absorption lines at reduced temperatures. II - Carbon monoxide in an atmosphere of carbon dioxide.

    NASA Technical Reports Server (NTRS)

    Tubbs, L. D.; Williams, D.

    1972-01-01

    The strengths of the rotational lines in the R branch of the CO fundamental have been determined at temperatures of 298, 202, and 132 K by means of a high-resolution spectrograph. The results can be used to determine line strengths at other temperatures by means of the Herman-Wallis relation or by considerations of the populations of the rotational levels in the ground vibrational state. Parameters describing the self-broadening and carbon dioxide broadening of CO lines have been determined at 298 and 202 K. The results are compared with other recent experimental and theoretical studies.

  5. Amplified spontaneous emission measurement of a line-narrowed, tunable, Ti:Al2O3 amplifier using rubidium absorption

    NASA Technical Reports Server (NTRS)

    Barnes, James C.; Barnes, Norman P.; Lockard, George E.; Cross, Patricia L.

    1989-01-01

    Amplified spontaneous emission, ASE, generated by a Ti:Al2O3 laser amplifier has been measured as a function of pump energy, and thus gain, using the atomic absorption of rubidium, Rb, gas at 0.780 micron. By tuning the Ti:Al2O3 laser, the Rb cell could selectively absorb the narrow spectral bandwidth laser radiation while transmitting the wide spectral bandwidth ASE. Transmission of laser amplifier pulses through a Rb absorption cell, measured at various temperatures, thus allows the measurement of the weak ASE in the vicinity of the strong laser pulse. A model for the transmission of Rb as a function of temperature and wavelength has been developed. The measured transmissions are in good agreement with the transmission model predictions.

  6. Lines

    ERIC Educational Resources Information Center

    Mires, Peter B.

    2006-01-01

    National Geography Standards for the middle school years generally stress the teaching of latitude and longitude. There are many creative ways to explain the great grid that encircles our planet, but the author has found that students in his college-level geography courses especially enjoy human-interest stories associated with lines of latitude…

  7. Assessing the link between chlorophyll concentration and absorption line height at 676 nm over a broad range of water types.

    PubMed

    Nardelli, Schuyler C; Twardowski, Michael S

    2016-10-31

    The relationship between absorption at 676 nm normalized to chlorophyll-a, i.e., specific absorption aph*(676), and various optical and environmental properties is examined in extensive data sets from Case I and Case II waters found globally to assess drivers of variability such as pigment packaging. A better understanding of this variability could lead to more accurate estimates of chlorophyll concentrations from in situ optical measurements that may be made autonomously. Values of aph*(676) ranged from 0.00006 to 0.0944 m2/mg Chl a across all sites studied, but converged on median and mean values (n = 563) of 0.0108 and 0.0139 m2/mg Chl a respectively, with no apparent relationship with various optical properties, latitude, coastal or open ocean environment, depth, temperature, salinity, photoadaptation, ecosystem health, or albedo. Relative consistency in aph* across such diverse water types and the full range in chlorophyll concentration suggests a single aph* may be used to estimate chlorophyll concentration from absorption measurements with better accuracy than currently thought.

  8. Investigation of broadening and shift of vapour absorption lines of H{sub 2}{sup 16}O in the frequency range 7184 – 7186 cm{sup -1}

    SciTech Connect

    Nadezhdinskii, A I; Pereslavtseva, A A; Ponurovskii, Ya Ya

    2014-10-31

    We present the results of investigation of water vapour absorption spectra in the 7184 – 7186 cm{sup -1} range that is of particular interest from the viewpoint of possible application of the data obtained for monitoring water vapour in the Earth's stratosphere. The doublet of H{sub 2}{sup 16}O near ν = 7185.596 cm{sup -1} is analysed. The coefficients of broadening and shift of water vapour lines are found in the selected range in mixtures with buffer gases and compared to those obtained by other authors. (laser spectroscopy)

  9. [Determination of Pb and Cd in atomospheric particulates by flame atomic absorption spectrometry coupled with on-line flow injection pretreatment with ultrasonic leaching].

    PubMed

    Gao, Yan; Wang, Dong-hai; Lin, Yu-bin; Li, Jian-yi; Kong, Qing-zhen

    2003-04-01

    In this paper, the method for extracting the metals from the filter membrane of the atomospheric particulates with ultrasonic leaching was reported. The dissolution conditions of kinds and acidity as well as the interference conditions were studied. The method of determination Pb and Cd of the atomospheric particulates by flame atomic absorption spectrometry coupled with on-line flow injection preconcentration was proved to be rapid and accuracy. The recoveries are more than 97%. The relative standard deviation of six samples are less than 2.6%.

  10. Infrared heterodyne spectroscopy of astronomical and laboratory sources at 8.5 micron. [absorption line profiles of nitrogen oxide and black body emission from Moon and Mars

    NASA Technical Reports Server (NTRS)

    Mumma, M.; Kostiuk, T.; Cohen, S.; Buhl, D.; Vonthuna, P. C.

    1974-01-01

    The first infrared heterodyne spectrometer using tuneable semiconductor (PbSe) diode lasers has been constructed and was used near 8.5 micron to measure absorption line profiles of N2O in the laboratory and black body emission from the Moon and from Mars. Spectral information was recorded over a 200 MHz bandwidth using an 8-channel filter bank. The resolution was 25 MHz and the minimum detectable (black body) power was 1 x 10 to the minus 16th power watts for 8 minutes of integration. The results demonstrate the usefulness of heterodyne spectroscopy for the study of remote and local sources in the infrared.

  11. Gemini 3D spectroscopy of BAL+IR+FeII QSOs - II. IRAS 04505-2958, an explosive QSO with hypershells and a new scenario for galaxy formation and galaxy end phase

    NASA Astrophysics Data System (ADS)

    Lípari, S.; Bergmann, M.; Sanchez, S. F.; Garcia-Lorenzo, B.; Terlevich, R.; Mediavilla, E.; Taniguchi, Y.; Zheng, W.; Punsly, B.; Ahumada, A.; Merlo, D.

    2009-09-01

    From a study of broad absorption line (BAL) + infrared (IR) + FeII quasi-stellar objects (QSOs) [using deep Gemini Multi-Object Spectrograph Integral Field Unit (GMOS-IFU) spectroscopy], new results are presented for IRAS 04505-2958. Specifically, we have studied in detail the outflow (OF) process at two large galactic scales: (i) two blobs/shells at radius r ~ 1.1 and 2.2 kpc, and (ii) an external hypergiant shell at r ~ 11 kpc. In addition, the presence of two very extended hypergiant shells at r ~ 60-80 kpc is also discussed. From this GMOS study the following main results were obtained. (i) For the external hypergiant shell, the kinematics GMOS maps of the ionized gas ([OII], [NeIII], [OIII], Hβ) show a small-scale bipolar OF, with similar properties to those observed in the prototype of exploding external supershells: NGC 5514. (ii) Three main knots - of this hypershell S3 - show the presence of a young starburst. (iii) The two internal shells show OF components with typical properties of nuclear shells. (iv) The two blobs and the hypershell are aligned at PA ~ 131° showing bipolar OF shape at ~10-15 kpc scale. In addition, the more external shells (at ~60-80 kpc scale) are aligned at PA ~ 40° also with bipolar OF shape (perpendicular to the more internal OF). (v) A strong blue continuum and multiple emission-line components were detected in all the GMOS fields. The new GMOS data show a good agreement with an extreme + explosive OF scenario for IRAS 04505-2958, in which part of the interstellar medium (ISM) of the host galaxy was ejected (in multiple shells). This extreme OF could also be associated with two main processes in the evolution of QSOs: (i) the formation of companion/satellite galaxies by giant explosions; and (ii) to define the final mass of the host galaxy, and even if the explosive nuclear OF is extremely energetic, this process could disrupt an important fraction of the host galaxy. Finally, the generation of ultra-high-energy cosmic rays

  12. Gravitationally Redshifted Absorption Lines in the Burst Spectra of the Neutron Star in the X-Ray Binary EXO 0748-676

    NASA Technical Reports Server (NTRS)

    Cottoam, J.; Paerels, F.; Mendez, M.; White, Nicholas E. (Technical Monitor)

    2002-01-01

    The most straightforward manner of determining masses and radii of neutron stars is by measuring the gravitational redshift of spectral lines produced in the neutron star photosphere; such a measurement would provide direct constraints on the mass-to-radius ratio of the neutron star, and therefore on the equation of state for neutron star matter. Using data taken with the Reflection Grating Spectrometer on board the XMM-Newton observatory we identify, for the first time, significant absorption lines in the spectra of 28 bursts of the low-mass X-ray binary EXO 0748-676. The most significant features are consistent with the Fe XXVI and XXV n=2-3 and O VIII n=1-2 transitions, with a redshift of z=0.35, identical within small uncertainties for the different transitions. This constitutes the first direct and unambiguous measurement of the gravitational redshift in a neutron star.

  13. An Fe XXIV Absorption Line in the Persistent Spectrum of the Dipping Low-Mass X-Ray Binary 1A 1744-361

    NASA Technical Reports Server (NTRS)

    Gavriil, Fotis P.; Strohmayer, Tod E.; Bhattacharyya, Sudip

    2012-01-01

    We report on Chandra X-ray Observatory (Chandra) High Energy Transmission Grating spectra of the dipping low-mass X-ray binary 1A 1744-361 during its 2008 July outburst. We find that its persistent emission is well modeled by a blackbody (kT approx. 1.0 keV) plus power law (Gamma approx. 1.7) with an absorption edge. In the residuals of the combined spectrum, we find a significant absorption line at 6.961 +/- 0.002 keV, consistent with the Fe xxvi (hydrogen-like Fe) 2-1 transition.We place an upper limit on the velocity of a redshifted flow of nu < 221 km/s. We find an equivalent width for the line of 27+2/-3 eV, from which we determine a column density of (7 +/- 1)×10(exp 17) /sq. cm via a curve-of-growth analysis. Using XSTAR simulations, we place a lower limit on the ionization parameter of >103.6 erg cm/s. We discuss what implications the feature has on the system and its geometry. We also present Rossi X-ray Timing Explorer data accumulated during this latest outburst and, via an updated color-color diagram, clearly show that 1A 1744-361 is an "atoll" source

  14. Direct determination of radionuclides in building materials with self-absorption correction for the 63 and 186 keV γ-energy lines.

    PubMed

    Długosz-Lisiecka, Magdalena; Ziomek, Martyna

    2015-12-01

    The use of 911 keV and 129 keV γ-line intensity ratio has been applied for self-absorption correction of the 63 keV (234)Th ((238)U) and 186 keV((226)Ra and (235)U) lines in typical building materials and soil samples. Proposed procedure allows to determine (238)U from the (234)Th line (63 keV) and (226)Ra after subtraction of (235)U interference in the 186 keV. It is important in the case of low uranium concentration and weak intensity of (235)U 143 keV γ energy line, when activity of this radionuclide can be apprised on the natural constant (238)U/(235)U ratio, only (excluding accidental anthropogenic depleted uranium deposition in the soil samples). Therefore, by this method a direct and fast determination of the (226)Ra and other important radionuclides, without one month waiting period for (226)Ra-(222)Rn daughter equilibrium, is possible. The accuracy of the method has been confirmed (relative relation deviation <10%) for typical buildings materials such as: tales, bricks, concrete blocks and various type of ceramic materials.

  15. Performance of a total absorption clover detector for Qβ measurements of neutron-rich nuclei far from the β-stability line

    NASA Astrophysics Data System (ADS)

    Hayashi, H.; Shibata, M.; Asai, M.; Osa, A.; Sato, T. K.; Koizumi, M.; Kimura, A.; Oshima, M.

    2014-05-01

    To measure β-decay energies (Qβs) of neutron-rich nuclei far from the β-stability line, we have improved upon the previously described total absorption detector, composed of a clover Ge detector (80 mmϕ×90 mmL×4 crystals) and 4π BGO Compton suppressors. This detector can directly determine the Qβ from the end-point of the measured spectrum. Nuclei of interest such as new isotopes have Qβ values over 4 MeV; therefore, high detection efficiencies are needed. This total absorption detector has a through-hole (alongside its vertical axis) at the center of the four Ge crystals, and the radioactive sources can be placed in this hole to measure the total absorption spectrum. The β- and γ-rays are absorbed by the detector with almost 4π geometry while escaping radiations from the Ge detector can be detected by the 4π BGO Compton suppressors. We also developed a practical analytic procedure based on the folding method, in which response functions of γ- and β-rays were considered with an assumed decay scheme. The systematic uncertainty of the deduced Qβs was evaluated to be ±30 keV using 18 fission products whose Qβ values were precisely measured. With the detector and an on-line mass separator, we have determined the Qβ values of 166Eu and 165Gd for the first time, and have proposed more precise Qβ values for 160-165Eu and 163Gd than previously found. Owing to the especially good energy resolution of the detector, the isomeric state in 163Gd was also successfully observed for the first time through end-point analysis and analysis of the observed γ-rays. This result contributes to the determination of reliable Qβ values for 163Gd and 163Eu.

  16. QED Theory of Radiation Emission and Absorption Lines for Atoms and Ions in a Strong Laser Field

    SciTech Connect

    Glushkov, A. V.

    2008-10-22

    The results of numerical calculating the multi-photon resonance shift and width for transition 6S-6F in the atom of Cs (wavelength 1059nm) in a laser pulse of the Gaussian and soliton-like shapes are presented. QED theory of radiation atomic lines is used.

  17. New on-line method for water isotope analysis of speleothem fluid inclusions using laser absorption spectroscopy (WS-CRDS)

    NASA Astrophysics Data System (ADS)

    Affolter, S.; Fleitmann, D.; Leuenberger, M.

    2014-01-01

    A new online method to analyse water isotopes of speleothem fluid inclusions using a wavelength scanned cavity ring down spectroscopy (WS-CRDS) instrument is presented. This novel technique allows us to simultaneously measure hydrogen and oxygen isotopes for a released aliquot of water. To do so, we designed a new simple line that allows the on-line water extraction and isotope analysis of speleothem samples. The specificity of the method lies in the fact that fluid inclusions release is made on a standard water background, which mainly improves the δD reliability. To saturate the line, a peristaltic pump continuously injects standard water into the line that is permanently heated to 140 °C and flushed with dry nitrogen gas. This permits instantaneous and complete vaporisation of the standard water resulting in an artificial water background with well-known δD and δ18O values. The speleothem sample is placed into a copper tube, attached to the line and after system stabilisation is crushed using a simple hydraulic device to liberate speleothem fluid inclusions water. The released water is carried by the nitrogen/standard water gas stream directly to a Picarro L1102-i for isotope determination. To test the accuracy and reproducibility of the line and to measure standard water during speleothem measurements a syringe injection unit was added to the line. Peak evaluation is done similarly as in gas chromatography to obtain δD and δ18O isotopic composition of measured water aliquots. Precision is better than 1.5‰ for δD and 0.4‰ for δ18O for water measurement for an extended range (-210 to 0‰ for δD and -27 to 0‰ for δ18O) primarily dependent on the amount of water released from speleothem fluid inclusions and secondarily on the isotopic composition of the sample. The results show that WS-CRDS technology is suitable for speleothem fluid inclusion measurements and gives results that are comparable to Isotope Ratio Mass Spectrometry (IRMS) technique.

  18. UV Absorption Lines as Metallicity Estimator and the Metal Content of Star-forming Galaxies at z=5

    NASA Astrophysics Data System (ADS)

    Faisst, Andreas; Capak, Peter L.; Davidson, Iary; Kakazu, Yuko; Salvato, Mara; Laigle, Clotilde; Onodera, Masato; Masters, Daniel; COSMOS Team

    2016-01-01

    Probing the metal content of high redshift galaxies is essential to study their formation and evolution in the early universe. However, the spectral features used to measure the metallicity are shifted out of the wavelength range of current spectrographs at high-z and therefore alternative methods must be used.We measure the relation between four prominent UV absorption complexes and metallicity for more than 50 local galaxies and, by using a sample of more than 20 galaxies at z ~ 2 - 3, verify that this relation holds up to z ˜ 3. We then apply this method to a sample of ˜ 220 galaxies at 3.5 < z < 6.0 in COSMOS, for which unique UV spectra from DEIMOS and accurate stellar mass estimates from SPLASH are available. The z ~ 5 galaxies at 9 < log(m/M⊙) < 11 are characterized by 0.3 - 0.4 dex (in units of 12 + log(O/H)) lower metallicities than galaxies at z ˜ 2 but comparable to z ˜ 3 - 3.5 galaxies. In the same stellar mass range, we do not find a significant relation between stellar mass and metallicity (MZ relation), suggesting that the MZ relation at z ~ 5 is very shallow or breaking down. Since we verify a correlation between dust obscuration (measured by β) and UV absorption strength (i.e., metallicity), we argue that the process of dust production and metal enrichment in the first billion years of galaxy formation is more stochastic than at later times. Using a "bathtub" model approach, we find that an exponential build up of stellar mass within a short time of several 100 Myr can explain a shallow MZ relation at z ˜ 5. Furthermore, we find a weak anti-correlation between star-formation rates and UV absorption strength (i.e., metallicity), indicative of these galaxies being fueled by the inflow of pristine (metal-poor) gas. The galaxy sample presented in this work is unique to further test these scenarios using ALMA and the upcoming James Webb Space Telescope.

  19. Functional Characterization Of Peptide Transporters In MDCKII -MDR1 Cell line As A Model For Oral Absorption Studies

    PubMed Central

    Agarwal, Sheetal; Jain, Ritesh; Pal, Dhananjay; K.Mitra, Ashim

    2007-01-01

    MDCKII-MDR1 cell line has been extensively selected as a model to study P-gp-mediated drug efflux. Recently, investigators have employed this cell line for studying influx of peptide prodrug derivatives of parent compounds which are P-gp substrates. Therefore, the objective of this study is to functionally characterize the peptide mediated uptake and transport of [3H] Glycylsarcosine ([3H] Gly-Sar), a model peptide substrate across MDCKII-MDR1 cells. [3H] Gly-Sar uptake from apical (AP) and basolateral (BL) membranes was found to be time dependent and saturable. Michaelis-Menten (Km) constants of [3H] Gly-Sar uptake across the AP and BL directions in MDCKII-MDR1 cell line were found to be 457 ± 37 μM and 464 ± 85 μM respectively. Vmax values in AP and BL directions for the peptide transporters in MDCKII-MDR1 cell line were calculated to be 0.035 ± 0.001 and 0.35 ± 0.034 pmol/min/mg protein respectively. Uptake of [3H] Gly-Sar was significantly inhibited in the presence of aminocephalosporins and ACE-Inhibitors, known substrates for peptide transporters in both the AP and BL directions. Permeability of [3H] Gly-Sar in the BL direction was maximal at pH 4 as compared to pH 5, 6 and 7.4 whereas such permeability in the AP direction was optimal at pH 7.4. Transepithelial transport of [3H] Gly-Sar in the AP-BL direction was significantly lower than from BL-AP direction at all observed pHs. No statistical difference was observed in the transepithelial permeability of [3H] Gly-Sar across both AP and BL directions over 4–10 days of growth period. The present study indicates that peptide transporters are effectively involved in the bidirectional transport of Gly-Sar across MDCKII-MDR1 cell line; the BL peptide transporter can transport Gly-Sar at a greater rate as compared to the AP peptide transporter. Results from these studies suggest the application of MDCKII-MDR1 cell line as a rapid effective tool to study peptide mediated influx of compounds that may be

  20. VizieR Online Data Catalog: BAL QSOs from SDSS DR3 (Trump+, 2006)

    NASA Astrophysics Data System (ADS)

    Trump, J. R.; Hall, P. B.; Reichard, T. A.; Richards, G. T.; Schneider, D. P.; vanden Berk, D. E.; Knapp, G. R.; Anderson, S. F.; Fan, X.; Brinkman, J.; Kleinman, S. J.; Nitta, A.

    2007-11-01

    We present a total of 4784 unique broad absorption line quasars from the Sloan Digital Sky Survey Third Data Release (Cat. ). An automated algorithm was used to match a continuum to each quasar and to identify regions of flux at least 10% below the continuum over a velocity range of at least 1000km/s in the CIV and MgII absorption regions. The model continuum was selected as the best-fit match from a set of template quasar spectra binned in luminosity, emission line width, and redshift, with the power-law spectral index and amount of dust reddening as additional free parameters. We characterize our sample through the traditional balnicity index and a revised absorption index, as well as through parameters such as the width, outflow velocity, fractional depth, and number of troughs. (1 data file).

  1. An Fe XXVI Absorption Line in the Persistent Spectrum of the Dipping Low Mass X-ray Binary 1A 1744-361

    NASA Technical Reports Server (NTRS)

    Gavriil, Fotis P.; Strohmayer, Tod E.; Bhattacharyya, Sudip

    2009-01-01

    We report on Chandra X-ray Observatory (CXO) High-Energy Transmission Grating (HETG) spectra of the dipping Low Mass X-ray Binary (LMXB) 1A 1744-361 during its July 2008 outburst. We find that its persistent emission is well modeled by a blackbody (kT approx. 1.0 keV) plus power-law (Gamma approx. 1.7) with an absorption edge at 7.6 keV. In the residuals of the combined spectrum we find a significant absorption line at 6.961+/-0.002 keV, consistent with the Fe XXVI (hydrogen-like Fe) 2 - 1 transition. We place an upper limit on the velocity of a redshifted flow of v < 221 km/s. We find an equivalent width for the line of 27+2/-3 eV, from which we determine a column density of 7+/-1 x 10(exp 17)/sq cm via a curve-of-growth analysis. Using XSTAR simulations, we place a lower limit on the ionization parameter of > 10(exp 3.6) erg cm/s. The properties of this line are consistent with those observed in other dipping LMXBs. Using Rossi X-ray Timing Explorer (RXTE) data accumulated during this latest outburst we present an updated color-color diagram which clearly shows that IA 1744-361 is an "atoll" source. Finally, using additional dips found in the RXTE and CXO data we provide an updated orbital period estimate of 52+/-5 minutes.

  2. Molecular gas in absorption and emission along the line of sight to W31C G10.62-0.38

    NASA Astrophysics Data System (ADS)

    Liszt, H. S.; Gerin, M.

    2016-01-01

    Context. The sightline to W31C G10.62-0.38 was extensively observed in absorption under the PRISMAS program on Herschel. Aims: We relate absorbing material to the older view of Galactic molecules gained from CO emission. Methods: We used the Arizona Radio Observatory Kitt Peak 12m antenna to observe emission from the J = 1-0 lines of carbon monoxide, HCO+, and HNC, and the J = 2-1 line of CS toward and around the continuum peak used for absorption studies and we compare them with CH, HNC, C+, and other absorption spectra from PRISMAS. We develop a kinematic analysis that allows a continuous description of the spectral properties and relates them to viewing geometry in the Galaxy. Results: As it is for CH, HF, C+, HCO+, and other species observed in absorption, mm-wave emission in CO, HCO+, HNC, and CS is continuous over the full velocity range expected for material between the Sun and W31 4.95 kpc away. CO emission is much stronger than average in the Galactic molecular ring and the mean H2 density derived from CH, 4 cm-3 ≲ 2⟨ n(H2) ⟩ ≲ 10 cm-3 at 4 ≲ R ≲ 6.4 kpc, is similarly elevated. The CO-H2 conversion factor falls in a narrow range XCO= 1-2 × 1020 H2 cm-2 (K-km s-1)-1 if the emitting gas is mostly on the near side of the subcentral point, as we suggest. The brightnesses of HCO+, HNC, and CS are comparable (0.83%, 0.51%, and 1.1%, respectively, relative to CO) and have no variation in galactocentric radius with respect to CO. Comparison of the profile-averaged HCO+ emission brightness and optical depth implies local densities n(H) ≈ 135 ± 25 cm-3 with most of the excitation of HCO+ from electrons. At this level of density, a consistent picture of the H2-bearing gas, which also accounts for the CO emission, has a volume filling factor of 3% and a 5 pc clump or cloud size.

  3. NONLINEAR COLOR-METALLICITY RELATIONS OF GLOBULAR CLUSTERS. V. NONLINEAR ABSORPTION-LINE INDEX VERSUS METALLICITY RELATIONS AND BIMODAL INDEX DISTRIBUTIONS OF M31 GLOBULAR CLUSTERS

    SciTech Connect

    Kim, Sooyoung; Yoon, Suk-Jin; Chung, Chul; Lee, Young-Wook; Caldwell, Nelson; Schiavon, Ricardo P.; Kang, Yongbeom; Rey, Soo-Chang

    2013-05-10

    Recent spectroscopy on the globular cluster (GC) system of M31 with unprecedented precision witnessed a clear bimodality in absorption-line index distributions of old GCs. Such division of extragalactic GCs, so far asserted mainly by photometric color bimodality, has been viewed as the presence of merely two distinct metallicity subgroups within individual galaxies and forms a critical backbone of various galaxy formation theories. Given that spectroscopy is a more detailed probe into stellar population than photometry, the discovery of index bimodality may point to the very existence of dual GC populations. However, here we show that the observed spectroscopic dichotomy of M31 GCs emerges due to the nonlinear nature of metallicity-to-index conversion and thus one does not necessarily have to invoke two separate GC subsystems. We take this as a close analogy to the recent view that metallicity-color nonlinearity is primarily responsible for observed GC color bimodality. We also demonstrate that the metallicity-sensitive magnesium line displays non-negligible metallicity-index nonlinearity and Balmer lines show rather strong nonlinearity. This gives rise to bimodal index distributions, which are routinely interpreted as bimodal metallicity distributions, not considering metallicity-index nonlinearity. Our findings give a new insight into the constitution of M31's GC system, which could change much of the current thought on the formation of GC systems and their host galaxies.

  4. Circulation of the Venus upper mesosphere/lower thermosphere: Doppler wind measurements from 2001-2009 inferior conjunction, sub-millimeter CO absorption line observations

    NASA Astrophysics Data System (ADS)

    Clancy, R. Todd; Sandor, Brad J.; Moriarty-Schieven, Gerald

    2012-02-01

    Sub-millimeter 12CO (346 GHz) and 13CO (330 GHz) line absorptions, formed within the mesospheric to lower thermospheric altitude (70-120 km) region of the Venus atmosphere, have been mapped across the nightside disk of Venus during 2001-2009 inferior conjunctions, employing the James Clerk Maxwell Telescope (JCMT). Radiative transfer analysis of these thermal line absorptions supports temperature and CO mixing profile retrievals, as described in a companion paper ( Clancy et al., 2012). Here, we consider the analysis of the sharp line absorption cores of these CO spectra in terms of accurate Doppler wind profile measurements at 95-115 km altitudes versus local time (˜8 pm-4 am) and latitude (˜60N-60S). These Doppler wind measurements support determinations of the nightside zonal and subsolar-to-antisolar (SSAS) circulation components over a variety of timescales. The average behavior fitted from 21 retrieved maps of 12CO Doppler winds (obtained over hourly, daily, weekly, and interannual intervals) indicates stronger average zonal (85 m/s retrograde) versus SSAS (65 m/s) circulation at the 1 μbar pressure (108-110 km altitude) level. However, the absolute and relative magnitudes of these circulation components exhibit extreme variability over daily to weekly timescales. Furthermore, the individual Doppler wind measurements within each nightside mapping observation generally show significant deviations (20-50 m/s, averaged over 5000 km horizontal scales) from the simple zonal/SSAS solution, with distinct local time and latitudinal characters that are also time variable. These large scale residual circulations contribute 30-70% of the observed nightside Doppler winds at any given time, and may be most responsible for global variations in nightside lower thermospheric trace composition and temperatures, as coincidentally retrieved CO abundance and temperature distributions do not correlate with solution retrograde zonal and SSAS winds (see companion paper, Clancy

  5. Pressure Sounding of the Middle Atmosphere from ATMOS Solar Occultation Measurements of Atmospheric CO(sub 2) Absorption Lines

    NASA Technical Reports Server (NTRS)

    Abrams, M.; Gunson, M.; Lowes, L.; Rinsland, C.; Zander, R.

    1994-01-01

    A method for retrieving the atmospheric pressure corresponding to the tangent point of an infrared spectrum recorded in the solar occultation mode is described and applied to measurements made by the Atmospheric Trace Molecule Spectroscopy (ATMOS) Fourier transform spectrometer. Tangent pressure values are inferred from measurements of isolated CO(sub 2) lines with temperature-insensitive intensities. Tangent pressures are determined with a spectroscopic precision of 1-3%, corresponding to a tangent point height precision, depending on the scale height, of 70-210 meters.

  6. Upper limits on the 21 cm power spectrum at z = 5.9 from quasar absorption line spectroscopy

    NASA Astrophysics Data System (ADS)

    Pober, Jonathan C.; Greig, Bradley; Mesinger, Andrei

    2016-11-01

    We present upper limits on the 21 cm power spectrum at z = 5.9 calculated from the model-independent limit on the neutral fraction of the intergalactic medium of x_{H I} < 0.06 + 0.05 (1σ ) derived from dark pixel statistics of quasar absorption spectra. Using 21CMMC, a Markov chain Monte Carlo Epoch of Reionization analysis code, we explore the probability distribution of 21 cm power spectra consistent with this constraint on the neutral fraction. We present 99 per cent confidence upper limits of Δ2(k) < 10-20 mK2 over a range of k from 0.5 to 2.0 h Mpc-1, with the exact limit dependent on the sampled k mode. This limit can be used as a null test for 21 cm experiments: a detection of power at z = 5.9 in excess of this value is highly suggestive of residual foreground contamination or other systematic errors affecting the analysis.

  7. Automated on-line preconcentration of trace aqueous mercury with gold trap focusing for cold vapor atomic absorption spectrometry.

    PubMed

    Puanngam, Mahitti; Dasgupta, Purnendu K; Unob, Fuangfa

    2012-09-15

    A fully automated system for the determination of trace mercury in water by cold vapor atomic absorption spectrometry (CVAAS) is reported. The system uses preconcentration on a novel sorbent followed by liberation of the mercury and focusing by a gold trap. Mercury ions were extracted from water samples by passage through a solid phase sorbent column containing 2-(3-(2-aminoethylthio)propylthio)ethanamine modified silica gel. The captured mercury is released by thiourea and then elemental Hg is liberated by sodium borohydride. The vapor phase Hg is recaptured on a gold-plated tungsten filament. This is liberated as a sharp pulse (half-width<2 s) by directly electrically heating the tungsten filament in a dry argon stream. The mercury is measured by CVAAS; no moisture removal is needed. The effects of chloride and selected interfering ions were studied. The sample loading flow rate and argon flow rates for solution purging and filament sweeping were optimized. An overall 50-fold improvement in the limit of detection was observed relative to direct measurement by CVAAS. With a relatively modest multi-user instrument we attained a limit of detection of 35 ng L(-1) with 12% RSD at 0.20 μg L(-1) Hg level. The method was successfully applied to accurately determine sub-μg L(-1) level Hg in standard reference water samples.

  8. Rest-UV Absorption Lines as Metallicity Estimator: The Metal Content of Star-forming Galaxies at z ~ 5

    NASA Astrophysics Data System (ADS)

    Faisst, A. L.; Capak, P. L.; Davidzon, I.; Salvato, M.; Laigle, C.; Ilbert, O.; Onodera, M.; Hasinger, G.; Kakazu, Y.; Masters, D.; McCracken, H. J.; Mobasher, B.; Sanders, D.; Silverman, J. D.; Yan, L.; Scoville, N. Z.

    2016-05-01

    We measure a relation between the depth of four prominent rest-UV absorption complexes and metallicity for local galaxies and verify it up to z˜ 3. We then apply this relation to a sample of 224 galaxies at 3.5\\lt z\\lt 6.0 (< z> =4.8) in the Cosmic Evolution Survey (COSMOS), for which unique UV spectra from the Deep Imaging Multi-object Spectrograph (DEIMOS) and accurate stellar masses from the Spitzer Large Area Survey with Hyper-Suprime-Cam (SPLASH) are available. The average galaxy population at z˜ 5 and {log}(M/{M}⊙ )\\gt 9 is characterized by 0.3-0.4 dex (in units of 12+{log}({{O/H}})) lower metallicities than at z ˜ 2, but comparable to z˜ 3.5. We find galaxies with weak or no Lyα emission to have metallicities comparable to z ˜ 2 galaxies and therefore may represent an evolved subpopulation of z˜ 5 galaxies. We find a correlation between metallicity and dust in good agreement with local galaxies and an inverse trend between metallicity and star-formation rate consistent with observations at z ˜ 2. The relation between stellar mass and metallicity (MZ relation) is similar to z˜ 3.5, but there are indications of it being slightly shallower, in particular for the young, Lyα-emitting galaxies. We show that, within a “bathtub” approach, a shallower MZ relation is expected in the case of a fast (exponential) build-up of stellar mass with an e-folding time of 100-200 Myr. Because of this fast evolution, the process of dust production and metal enrichment as a function of mass could be more stochastic in the first billion years of galaxy formation compared to later times.

  9. CHARACTERIZING THE CIRCUMGALACTIC MEDIUM OF NEARBY GALAXIES WITH HST/COS AND HST/STIS ABSORPTION-LINE SPECTROSCOPY

    SciTech Connect

    Stocke, John T.; Keeney, Brian A.; Danforth, Charles W.; Shull, J. Michael; Froning, Cynthia S.; Green, James C.; Penton, Steven V.; Savage, Blair D.

    2013-02-15

    The circumgalactic medium (CGM) of late-type galaxies is characterized using UV spectroscopy of 11 targeted QSO/galaxy pairs at z {<=} 0.02 with the Hubble Space Telescope Cosmic Origins Spectrograph (COS) and {approx}60 serendipitous absorber/galaxy pairs at z {<=} 0.2 with the Space Telescope Imaging Spectrograph. CGM warm cloud properties are derived, including volume filling factors of 3%-5%, cloud sizes of 0.1-30 kpc, masses of 10-10{sup 8} M {sub Sun }, and metallicities of {approx}0.1-1 Z {sub Sun }. Almost all warm CGM clouds within 0.5 R {sub vir} are metal-bearing and many have velocities consistent with being bound, 'galactic fountain' clouds. For galaxies with L {approx}> 0.1 L*, the total mass in these warm CGM clouds approaches 10{sup 10} M {sub Sun }, {approx}10%-15% of the total baryons in massive spirals and comparable to the baryons in their parent galaxy disks. This leaves {approx}> 50% of massive spiral-galaxy baryons 'missing'. Dwarfs (<0.1 L*) have smaller area covering factors and warm CGM masses ({<=}5% baryon fraction), suggesting that many of their warm clouds escape. Constant warm cloud internal pressures as a function of impact parameter (P/k {approx} 10 cm{sup -3} K) support the inference that previous COS detections of broad, shallow O VI and Ly{alpha} absorptions are of an extensive ({approx}400-600 kpc), hot (T Almost-Equal-To 10{sup 6} K), intra-cloud gas which is very massive ({>=}10{sup 11} M {sub Sun }). While the warm CGM clouds cannot account for all the 'missing baryons' in spirals, the hot intra-group gas can, and could account for {approx}20% of the cosmic baryon census at z {approx} 0 if this hot gas is ubiquitous among spiral groups.

  10. A new limit on the variation of the fine-structure constant using absorption line multiplets in the early universe

    NASA Astrophysics Data System (ADS)

    Thong, Le Duc

    2015-08-01

    One of the key questions of modern physics concerns the possibility that physical constants vary over space and time during the history of the universe. The Standard Model of physics is built on these constants, but it does not provide any explanation for their values, nor requires their constancy over space and time. Here we set a new limit on possible spatial and temporal variations of the fine-structure constant , by comparing transitions line multiplets in an ensemble of Fe II 1608, 2344, 2374, 2383, 2587 and 2600 observed in the early universe with those measured in the laboratory. Based on the optical spectra observations of QSO HE 0515-4414, we deduced a constraint of at redshift z = 1.15. This is at present the tightest limit on at early cosmological epochs compared to the published results in the literature.

  11. A Comparison of the Circumgalactic Medium of Present-Day Dwarf and Milky Way Galaxies using Absorption Line Analysis through Hydrodynamic Cosmological Simulations

    NASA Astrophysics Data System (ADS)

    Vander Vliet, Jacob R.; Churchill, C. W.; Trujillo-Gomez, S.; Klimek, E. S.; Klypin, A. A.

    2014-01-01

    Dwarf galaxies are predicted to have a unique halo structure. They experience the same feedback as more massive galaxies but lack the strong gravitational potential. The structure and composition of gas around dwarfs should be different than for gas around massive galaxies. These differences would show up in quasar absorption spectra. We test this idea by examining mock quasar spectra of the circumgalactic medium of two simulated dwarf galaxies to determine the extent of their metal halos at redshift zero. The galaxies are from a cosmological zoom-in simulation using Eulerian Gasdynamics plus N-body Adaptive Refinement Tree (ART) code. Both galaxies have the same initial conditions but are simulated with different physical conditions. One uses only supernova feedback while the other adds in radiative pressure and an increase in star formation efficiency to recreate the correct stellar properties. We measure the absorption lines of several ions including MgII, CIV, OVI, SiIV, and Ly beta and compare the covering fraction, equivalent width distribution and the velocity distribution for both simulations. These are then compared to more massive halos to explore how the galaxy's mass affects their CGM structure.

  12. The dust, nebular emission, and dependence on QSO radio properties of the associated Mg II absorption line systems

    SciTech Connect

    Khare, Pushpa; Daniel, Vanden Berk; Rahmani, Hadi; York, Donald G.

    2014-10-10

    We studied dust reddening and [O II] emission in 1730 Mg II associated absorption systems (AAS; relative velocity with respect to QSOs, ≤3000 km s{sup –1}; in units of velocity of light, β, ≤0.01) with 0.4 ≤z {sub abs} ≤ 2 in the Sloan Digital Sky Survey DR7, focusing on their dependence on the radio and other QSO properties. We used control samples, several with matching radio properties, to show that (1) AAS in radio-detected (RD) QSOs cause 2.6 ± 0.2 times higher dust extinction than those in radio-undetected (RUD) ones, which in turn cause 2.9 ± 0.7 times the dust extinction in the intervening systems; (2) AAS in core-dominated QSOs cause 2.0 ± 0.1 times higher dust extinction than those in lobe-dominated QSOs; (3) the occurrence of AAS is 2.1 ± 0.2 times more likely in RD QSOs than in RUD QSOs and 1.8 ± 0.1 time more likely in QSOs having black holes with masses larger than 1.23 × 10{sup 9} M {sub ☉} than in those with lower-mass black holes; and (4) there is excess flux in [O II]λ3727 emission in the composite spectra of the AAS samples compared with those of the control samples, which is at the emission redshift. The presence of AAS enhances the O II emission from the active galactic nucleus and/or the host galaxy. This excess is similar for both RD and RUD samples and is 2.5 ± 0.4 times higher in lobe-dominated samples than in core-dominated samples. The excess depends on the black hole mass and Eddington ratio. All these point to the intrinsic nature of the AAS except for the systems with z {sub abs} > z {sub em}, which could be infalling galaxies.

  13. A Stringent Limit on Variation of the Fine-Structure Constant Using Absorption Line Multiplets in the Early Universe

    NASA Astrophysics Data System (ADS)

    Le, T. D.

    2016-06-01

    One of the key questions of modern physics concerns the possibility that physical constants have varied throughout the history of the Universe. The standard model of physics is built on these constants, but it does not provide any explanation for their values, nor does it require their constancy over space and time. Here, we set a new limit on possible spatial and temporal variations of the fine-structure constant α = e 2/4πɛ0 ħc by comparing transitions and line multiplets in an ensemble of Fe II λ 1608, λ 2344, λ 2374, λ 2383, λ 2587, and λ 2600 observed in the early Universe with those measured in the laboratory. Based on the optical spectrum observations of QSO HE 0515-4414, we deduce a constraint of Δα/α = (-0.157± 0.300)×10-6 at redshift z = 1.15. At present, this represents the tightest limit on Δα/α in early cosmological epochs compared to the published results in the literature.

  14. Pressure sounding of the middle atmosphere from ATMOS solar occultation measurements of atmospheric CO(2) absorption lines.

    PubMed

    Abrams, M C; Gunson, M R; Lowes, L L; Rinsland, C P; Zander, R

    1996-06-01

    A method for retrieving the atmospheric pressure corresponding to the tangent point of an infrared spectrum recorded in the solar occultation mode is described and applied to measurements made by the Atmospheric Trace Molecule Spectroscopy (ATMOS) Fourier-transform spectrometer. Tangent pressure values are inferred from measurements of isolated CO(2) lines with temperature-insensitive strengths by measuring the slant-column CO(2) amount and by adjusting the viewing geometry until the calculated column matches the observed column. Tangent pressures are determined with a spectroscopic precision of l%-3%, corresponding to a tangent-point height precision of 70-210 m. The total uncertainty is limited primarily by the quality of the spectra and ranges between 4% and 6% (280-420 m) for spectra with signal-to-noise ratios of 300:1 and between 4% and 10% for spectra with signal-to-noise ratios of 100:1. The retrieval of atmospheric pressure increases the accuracy of the retrieved-gas concentrations by minimizing the effect of systematic errors introduced by climatological pressure data, ephemeris parameters, and the uncertainties in instrumental pointing.

  15. Automatic On-line Solid-phase Extraction-Electrothermal Atomic Absorption Spectrometry Exploiting Sequential Injection Analysis for Trace Vanadium, Cadmium and Lead Determination in Human Urine Samples.

    PubMed

    Giakisikli, Georgia; Ayala Quezada, Alejandro; Tanaka, Junpei; Anthemidis, Aristidis N; Murakami, Hiroya; Teshima, Norio; Sakai, Tadao

    2015-01-01

    A fully automated sequential injection column preconcentration method for the on-line determination of trace vanadium, cadmium and lead in urine samples was successfully developed, utilizing electrothermal atomic absorption spectrometry (ETAAS). Polyamino-polycarboxylic acid chelating resin (Nobias chelate PA-1) packed into a handmade minicolumn was used as a sorbent material. Effective on-line retention of chelate complexes of analytes was achieved at pH 6.0, while the highest elution effectiveness was observed with 1.0 mol L(-1) HNO3 in the reverse phase. Several analytical parameters, like the sample acidity, concentration and volume of the eluent as well as the loading/elution flow rates, have been studied, regarding the efficiency of the method, providing appropriate conditions for the analysis of real samples. For a 4.5 mL sample volume, the sampling frequency was 27 h(-1). The detection limits were found to be 3.0, 0.06 and 2.0 ng L(-1) for V(V), Cd(II) and Pb(II), respectively, with the relative standard deviations ranging between 1.9 - 3.7%. The accuracy of the proposed method was evaluated by analyzing a certified reference material (Seronorm(TM) trace elements urine) and spiked urine samples.

  16. STAR CLUSTERS IN M31. IV. A COMPARATIVE ANALYSIS OF ABSORPTION LINE INDICES IN OLD M31 AND MILKY WAY CLUSTERS

    SciTech Connect

    Schiavon, Ricardo P.; Caldwell, Nelson; Morrison, Heather; Harding, Paul; Courteau, Stephane; MacArthur, Lauren A.

    2012-01-15

    We present absorption line indices measured in the integrated spectra of globular clusters both from the Galaxy and from M31. Our samples include 41 Galactic globular clusters, and more than 300 clusters in M31. The conversion of instrumental equivalent widths into the Lick system is described, and zero-point uncertainties are provided. Comparison of line indices of old M31 clusters and Galactic globular clusters suggests an absence of important differences in chemical composition between the two cluster systems. In particular, CN indices in the spectra of M31 and Galactic clusters are essentially consistent with each other, in disagreement with several previous works. We reanalyze some of the previous data, and conclude that reported CN differences between M31 and Galactic clusters were mostly due to data calibration uncertainties. Our data support the conclusion that the chemical compositions of Milky Way and M31 globular clusters are not substantially different, and that there is no need to resort to enhanced nitrogen abundances to account for the optical spectra of M31 globular clusters.

  17. On-line sequential injection dispersive liquid-liquid microextraction system for flame atomic absorption spectrometric determination of copper and lead in water samples.

    PubMed

    Anthemidis, Aristidis N; Ioannou, Kallirroy-Ioanna G

    2009-06-30

    A simple, sensitive and powerful on-line sequential injection (SI) dispersive liquid-liquid microextraction (DLLME) system was developed as an alternative approach for on-line metal preconcentration and separation, using extraction solvent at microlitre volume. The potentials of this novel schema, coupled to flame atomic absorption spectrometry (FAAS), were demonstrated for trace copper and lead determination in water samples. The stream of methanol (disperser solvent) containing 2.0% (v/v) xylene (extraction solvent) and 0.3% (m/v) ammonium diethyldithiophosphate (chelating agent) was merged on-line with the stream of sample (aqueous phase), resulting a cloudy mixture, which was consisted of fine droplets of the extraction solvent dispersed entirely into the aqueous phase. By this continuous process, metal chelating complexes were formed and extracted into the fine droplets of the extraction solvent. The hydrophobic droplets of organic phase were retained into a microcolumn packed with PTFE-turnings. A portion of 300 microL isobutylmethylketone was used for quantitative elution of the analytes, which transported directly to the nebulizer of FAAS. All the critical parameters of the system such as type of extraction solvent, flow-rate of disperser and sample, extraction time as well as the chemical parameters were studied. Under the optimum conditions the enhancement factor for copper and lead was 560 and 265, respectively. For copper, the detection limit and the precision (R.S.D.) were 0.04 microg L(-1) and 2.1% at 2.0 microg L(-1) Cu(II), respectively, while for lead were 0.54 microg L(-1) and 1.9% at 30.0 microg L(-1) Pb(II), respectively. The developed method was evaluated by analyzing certified reference material and applied successfully to the analysis of environmental water samples.

  18. On the possibilities of high-resolution continuum source graphite furnace atomic absorption spectrometry for the simultaneous or sequential monitoring of multiple atomic lines

    NASA Astrophysics Data System (ADS)

    Resano, M.; Rello, L.; Flórez, M.; Belarra, M. A.

    2011-05-01

    This paper explores the potential of commercially available high-resolution continuum source graphite furnace atomic absorption spectrometry instrumentation for the simultaneous or sequential monitoring of various atomic lines, in an attempt to highlight the analytical advantages that can be derived from this strategy. In particular, it is demonstrated how i) the monitoring of multiplets may allow for the simple expansion of the linear range, as shown for the measurement of Ni using the triplet located in the vicinity of 234.6 nm; ii) the use of a suitable internal standard may permit improving the precision and help in correcting for matrix-effects, as proved for the monitoring of Ni in different biological samples; iii) direct and multi-element analysis of solid samples may be feasible on some occasions, either by monitoring various atomic lines that are sufficiently close (truly simultaneous monitoring, as demonstrated in the determination of Co, Fe and Ni in NIST 1566a Oyster tissue) or, alternatively, by opting for a selective and sequential atomization of the elements of interest during every single replicate. Determination of Cd and Ni in BCR 679 White cabbage is attempted using both approaches, which permits confirming that both methods can offer very similar and satisfactory results. However, it is important to stress that the second approach provides more flexibility, since analysis is no longer limited to those elements that show very close atomic lines (closer than 0.3 nm in the ultraviolet region) with a sensitivity ratio similar to the concentration ratio of the analytes in the samples investigated.

  19. BAL31-NGS approach for identification of telomeres de novo in large genomes.

    PubMed

    Peška, Vratislav; Sitová, Zdeňka; Fajkus, Petr; Fajkus, Jiří

    2017-02-01

    This article describes a novel method to identify as yet undiscovered telomere sequences, which combines next generation sequencing (NGS) with BAL31 digestion of high molecular weight DNA. The method was applied to two groups of plants: i) dicots, genus Cestrum, and ii) monocots, Allium species (e.g. A. ursinum and A. cepa). Both groups consist of species with large genomes (tens of Gb) and a low number of chromosomes (2n=14-16), full of repeat elements. Both genera lack typical telomeric repeats and multiple studies have attempted to characterize alternative telomeric sequences. However, despite interesting hypotheses and suggestions of alternative candidate telomeres (retrotransposons, rDNA, satellite repeats) these studies have not resolved the question. In a novel approach based on the two most general features of eukaryotic telomeres, their repetitive character and sensitivity to BAL31 nuclease digestion, we have taken advantage of the capacity and current affordability of NGS in combination with the robustness of classical BAL31 nuclease digestion of chromosomal termini. While representative samples of most repeat elements were ensured by low-coverage (less than 5%) genomic shot-gun NGS, candidate telomeres were identified as under-represented sequences in BAL31-treated samples.

  20. Quantitation of toxic arsenic species and arsenobetaine in Pacific oysters using an off-line process with hydride generation-atomic absorption spectroscopy.

    PubMed

    Hsiung, Tung-Ming; Huang, Chia-Wei

    2006-04-05

    An off-line process-based speciation technique was devised here to quantitatively determine toxic inorganic arsenic (iAs), methylarsonic acid (MA), dimethylarsinic acid (DMA), and the dominant, albeit virtually nontoxic, arsenobetaine (AB) in Pacific oysters (Crassostrea gigas). Oysters were extracted with fresh methanol-water (8+2), and this was replicated three times. They were then evaporated to near dryness and subsequently redissolved in pure water; defatting was then performed with a C18 cartridge. The trace hydride active arsenic species, that is, iAs, MA, and DMA, in the defatted solutions were determined with a sensitive hydride generation-packed coldfinger trap-atomic absorption spectrometric (HG-PCFT-AAS) coupled system. The arsenicals that were desorbed from the cation-exchange resin (Dowex 50W-X8) in the washings of 4 M NH3 were categorized on the basis of AB + DMA. The total quantity of arsenic in the recovered AB + DMA was determined with a commercial hydride generation-atomic absorption spectrometric (HG-AAS) system, and finally, AB was calculated from (AB + DMA) - DMA. The average concentrations of iAs, MA, DMA, AB, and total arsenic (TAs) in the oysters collected from six aquacultural sites along the west coast of Taiwan were, respectively, 0.15, 0.06, 0.64, 6.93, and 13.74 mg kg(-1) of dry weight. AB was the major species, whereas iAs (arsenite + arsenate) were the most toxic species, although the iAs made up only approximately 1% of the TAs in the oysters. The lifetime target cancer risk, as determined by the concentration of iAs on a fresh weight basis in the oysters, was well below the ordinary health protection criteria (10(-6)).

  1. Evidence for Ultra-Fast Outflows in Radio-Quiet AGNs. 2; Detailed Photoionization Modeling of Fe K-Shell Absorption Lines

    NASA Technical Reports Server (NTRS)

    Tombesi, Francesco; Clapp, M.; Reeves, J. N.; Palumbo, G. G. C.; Braito, V.; Dadina, M.

    2011-01-01

    X-ray absorption line spectroscopy has recently shown evidence for previously unknown Ultra-fast Outflows (UFOs) in radio-quiet AGNs. In the previous paper of this series we defined UFOs as those absorbers with an outflow velocity higher than 10,000km/s and assessed the statistical significance of the associated blue shifted FeK absorption lines in a large sample of 42 local radio-quiet AGNs observed with XMM-Newton. In the present paper we report a detailed curve of growth analysis and directly model the FeK absorbers with the Xstar photo-ionization code. We confirm that the frequency of sources in the radio-quiet sample showing UFOs is >35%. The outflow velocity distribution spans from \\sim10,000km/s (\\sim0.03c) up to \\siml00,000kmis (\\sim0.3c), with a peak and mean value of\\sim42,000km/s (\\sim0.14c). The ionization parameter is very high and in the range log\\xi 3-6 erg s/cm, with a mean value of log\\xi 4.2 erg s/cm. The associated column densities are also large, in the range N_H\\siml0(exp 22)-10(exp 24)/sq cm, with a mean value of N_H\\siml0(exp23)/sq cm. We discuss and estimate how selection effects, such as those related to the limited instrumental sensitivity at energies above 7keV, may hamper the detection of even higher velocities and higher ionization absorbers. We argue that, overall, these results point to the presence of extremely ionized and possibly almost Compton thick outflowing material in the innermost regions of AGNs. This also suggests that UFOs may potentially play a significant role in the expected cosmological feedback from AGNs and their study can provide important clues on the connection between accretion disks, winds and jets.

  2. Evidence for Ultra-fast Outflows in Radio-quiet Active Galactic Nuclei. II. Detailed Photoionization Modeling of Fe K-shell Absorption Lines

    NASA Astrophysics Data System (ADS)

    Tombesi, F.; Cappi, M.; Reeves, J. N.; Palumbo, G. G. C.; Braito, V.; Dadina, M.

    2011-11-01

    X-ray absorption line spectroscopy has recently shown evidence for previously unknown Ultra-fast Outflows (UFOs) in radio-quiet active galactic nuclei (AGNs). These have been detected essentially through blueshifted Fe XXV/XXVI K-shell transitions. In the previous paper of this series we defined UFOs as those highly ionized absorbers with an outflow velocity higher than 10,000 km s-1 and assessed the statistical significance of the associated blueshifted absorption lines in a large sample of 42 local radio-quiet AGNs observed with XMM-Newton. The present paper is an extension of that work. First, we report a detailed curve of growth analysis of the main Fe XXV/XXVI transitions in photoionized plasmas. Then, we estimate an average spectral energy distribution for the sample sources and directly model the Fe K absorbers in the XMM-Newton spectra with the detailed Xstar photoionization code. We confirm that the frequency of sources in the radio-quiet sample showing UFOs is >35% and that the majority of the Fe K absorbers are indeed associated with UFOs. The outflow velocity distribution spans from ~10,000 km s-1 (~0.03c) up to ~100,000 km s-1 (~0.3c), with a peak and mean value of ~42,000 km s-1 (~0.14c). The ionization parameter is very high and in the range log ξ ~ 3-6 erg s-1 cm, with a mean value of log ξ ~ 4.2 erg s-1 cm. The associated column densities are also large, in the range N H ~ 1022-1024 cm-2, with a mean value of N H ~ 1023 cm-2. We discuss and estimate how selection effects, such as those related to the limited instrumental sensitivity at energies above 7 keV, may hamper the detection of even higher velocities and higher ionization absorbers. We argue that, overall, these results point to the presence of extremely ionized and possibly almost Compton-thick outflowing material in the innermost regions of AGNs. This also suggests that UFOs may potentially play a significant role in the expected cosmological feedback from AGNs and their study can

  3. Atmospheric absorption cell characterization

    NASA Astrophysics Data System (ADS)

    1982-06-01

    The measurement capability of the Avionics Laboratory IR Facility was used to evaluate an absorption cell that will be used to simulate atmospheric absorption over horizontal paths of 1 - 10 km in length. Band models were used to characterize the transmittance of carbon dioxide (CO2), nitrogen (N2), and nitrous oxide (N2O) in the cell. The measured transmittance was compared to the calculated values. Nitrous oxide is important in the 4 - 4.5 micron range in shaping the weak line absorption of carbon dioxide. The absorption cell is adequate for simulating atmospheric absorption over these paths.

  4. Tunable diode laser absorption spectroscopy-based tomography system for on-line monitoring of two-dimensional distributions of temperature and H2O mole fraction

    NASA Astrophysics Data System (ADS)

    Xu, Lijun; Liu, Chang; Jing, Wenyang; Cao, Zhang; Xue, Xin; Lin, Yuzhen

    2016-01-01

    To monitor two-dimensional (2D) distributions of temperature and H2O mole fraction, an on-line tomography system based on tunable diode laser absorption spectroscopy (TDLAS) was developed. To the best of the authors' knowledge, this is the first report on a multi-view TDLAS-based system for simultaneous tomographic visualization of temperature and H2O mole fraction in real time. The system consists of two distributed feedback (DFB) laser diodes, a tomographic sensor, electronic circuits, and a computer. The central frequencies of the two DFB laser diodes are at 7444.36 cm-1 (1343.3 nm) and 7185.6 cm-1 (1391.67 nm), respectively. The tomographic sensor is used to generate fan-beam illumination from five views and to produce 60 ray measurements. The electronic circuits not only provide stable temperature and precise current controlling signals for the laser diodes but also can accurately sample the transmitted laser intensities and extract integrated absorbances in real time. Finally, the integrated absorbances are transferred to the computer, in which the 2D distributions of temperature and H2O mole fraction are reconstructed by using a modified Landweber algorithm. In the experiments, the TDLAS-based tomography system was validated by using asymmetric premixed flames with fixed and time-varying equivalent ratios, respectively. The results demonstrate that the system is able to reconstruct the profiles of the 2D distributions of temperature and H2O mole fraction of the flame and effectively capture the dynamics of the combustion process, which exhibits good potential for flame monitoring and on-line combustion diagnosis.

  5. Redox speciation analysis of dissolved iron in estuarine and coastal waters with on-line solid phase extraction and graphite furnace atomic absorption spectrometry detection.

    PubMed

    Chen, Yaojin; Feng, Sichao; Huang, Yongming; Yuan, Dongxing

    2015-05-01

    An automatic on-line solid phase extraction (SPE) system employing the flow injection (FI) technique directly coupled to a graphite furnace atomic absorption spectrometer (GFAAS) was established for speciation and determination of dissolved iron in estuarine and coastal waters. Fe(II) was mixed with ferrozine solution in a sample stream to form the Fe(II)-ferrozine complex which was extracted onto a C18 SPE cartridge, eluted with eluent and detected with GFAAS. In a parallel flow channel, Fe(III) was reduced to Fe(II) with ascorbic acid and then detected in the same way as Fe(II). The home-made interface between FI-SPE and GFAAS efficiently realized the sample introduction to the furnace in a semi-automated way. Parameters of the FI-SPE system and graphite furnace program were optimized based on a univariate experimental design and an orthogonal array design. The salinity effect on the method sensitivity was investigated. The proposed method provided a detection limit of 1.38 nmol L(-1) for Fe(II) and 1.87 nmol L(-1) for Fe(II+III). With variation of the sample loading volume, a broadened determination range of 2.5-200 nmol L(-1) iron could be obtained. The proposed method was successfully applied to analyze iron species in samples collected from the Jiulongjiang Estuary, Fujian, China. With the 2-cartridge FI-SPE system developed, on-line simultaneous determination of Fe species with GFAAS was achieved for the first time.

  6. NuSTAR reveals an intrinsically X-ray weak broad absorption line quasar in the ultraluminous infrared galaxy Markarian 231

    SciTech Connect

    Teng, Stacy H.; Rigby, J. R.; Brandt, W. N.; Luo, B.; Harrison, F. A.; Grefenstette, B. W.; Madsen, K. K.; Alexander, D. M.; Gandhi, P.; Bauer, F. E.; Boggs, S. E.; Craig, W. W.; Christensen, F. E.; Comastri, A.; Fabian, A. C.; Farrah, D.; Fiore, F.; Hailey, C. J.; Hickox, R. C.; Ptak, A. F.; and others

    2014-04-10

    We present high-energy (3-30 keV) NuSTAR observations of the nearest quasar, the ultraluminous infrared galaxy (ULIRG) Markarian 231 (Mrk 231), supplemented with new and simultaneous low-energy (0.5-8 keV) data from Chandra. The source was detected, though at much fainter levels than previously reported, likely due to contamination in the large apertures of previous non-focusing hard X-ray telescopes. The full band (0.5-30 keV) X-ray spectrum suggests the active galactic nucleus (AGN) in Mrk 231 is absorbed by a patchy and Compton-thin (N{sub H}∼1.2{sub −0.3}{sup +0.3}×10{sup 23} cm{sup –2}) column. The intrinsic X-ray luminosity (L {sub 0.5–30} {sub keV} ∼ 1.0 × 10{sup 43} erg s{sup –1}) is extremely weak relative to the bolometric luminosity where the 2-10 keV to bolometric luminosity ratio is ∼0.03% compared to the typical values of 2%-15%. Additionally, Mrk 231 has a low X-ray-to-optical power law slope (α{sub OX} ∼ –1.7). It is a local example of a low-ionization broad absorption line quasar that is intrinsically X-ray weak. The weak ionizing continuum may explain the lack of mid-infrared [O IV], [Ne V], and [Ne VI] fine-structure emission lines which are present in sources with otherwise similar AGN properties. We argue that the intrinsic X-ray weakness may be a result of the super-Eddington accretion occurring in the nucleus of this ULIRG, and may also be naturally related to the powerful wind event seen in Mrk 231, a merger remnant escaping from its dusty cocoon.

  7. Bismuth Dimercaptopropanol (BisBAL) Inhibits the Expression of Extracellular Polysaccharides and Proteins by Brevundimonas diminuta: Implications for Membrane Microfiltration

    SciTech Connect

    Badireddy, Appala R.; Chellam, Shankararaman; Yanina, Svetlana; Gassman, Paul L.; Rosso, Kevin M.

    2008-02-15

    A 2:1 molar ratio preparation of bismuth with a lipophilic dithiol (3-dimercapto-1-propanol, BAL)significantly reduced extracellular polymeric substances (EPS) expression by Brevundimonas diminuta in suspended cultures at levels just below the minimum inhibitory concentration (MIC). Total polysaccharides and proteins secreted by B. diminuta decreased by approximately 95% over a 5-day period when exposed to the bismuth-BAL chelate (BisBAL) at near MIC (12 μM). Fourier-transform infrared spectroscopy (FTIR) suggested that a possible mechanism of biofilm disruption by BisBAL is the inhibition of carbohydrate Oacetylation. FTIR also revealed extensive homology between EPS samples with and without BisBAL treatment, with proteins, polysaccharides, and peptides varying predominantly only in the amount expressed. EPS secretion decreased following BisBAL treatment as verified by atomic force microscopy and scanning electron microscopy. Without BisBAL treatment, a slime-like EPS matrix secreted by B. diminuta resulted in biofouling and inefficient hydrodynamic backwashing of microfiltration membranes.

  8. Far Ultraviolet Spectroscopic Explorer and Space Telescope Imaging Spectrograph Observations of Intervening O VI Absorption Line Systems in the Spectrum of PG 0953+415

    NASA Astrophysics Data System (ADS)

    Savage, B. D.; Sembach, K. R.; Tripp, T. M.; Richter, P.

    2002-01-01

    We present Far Ultraviolet Spectroscopic Explorer (FUSE) and Space Telescope Imaging Spectrograph (STIS) observations of the intergalactic medium toward the bright QSO PG 0953+415 (zem=0.239). The FUSE spectra extend from 905 to 1187 Å and have a resolution of 25 km s-1, while the STIS spectra cover 1150-1730 Å and have a resolution of 7 km s-1. Additional STIS observations at 30 km s-1 are obtained in selected wavelength ranges. An O VI system at z=0.06807 is detected in H I Lyα, Lyβ, Lyγ, O VI λλ1031.93, 1037.62, N V λλ1238.82, 1242.80, C IV λλ1548.20, 1550.77, and C III λ977.02. The observed column densities can be modeled as a low-density intervening gas with a metallicity of 0.4+0.6-0.2 times solar in photoionization equilibrium with the ionizing extragalactic background radiation. The best fit is achieved with an ionization parameter, logU=-1.35, which implies nH~10-5 cm-3 and a path length of ~80 kpc through the absorbing gas. H I Lyα absorption at z=0.14232 spans a velocity range of 410 km s-1 with the strongest components near 0 and 80 km s-1 in the z=0.14232 rest frame. In this system, O VI λλ1031.93, 1037.62 absorption is strong near 0 km s-1 and not detected at 80 km s-1. C III λ977.02 absorption is marginally detected at 80 km s-1 but is not detected at 0 km s-1. The observations place constraints on the properties of the z=0.14232 system but do not discriminate between collisional ionization in hot gas versus photoionization in a very low density medium with an ionization parameter logU>-0.74. The z=0.06807 and 0.14232 O VI systems occur at redshifts where there are peaks in the number density of intervening galaxies along the line of sight determined from WIYN redshift measurements of galaxies in the ~1° field centered on PG 0953+415. We combine our observations of PG 0953+415 with those for other QSOs to update the estimate of the low-redshift number density of intervening O VI systems. Over a total unobscured redshift path of Δz=0

  9. On-line preconcentration/determination of zinc from water, biological and food samples using synthesized chelating resin and flame atomic absorption spectrometry.

    PubMed

    Yılmaz, Sibel; Tokalıoğlu, Serife; Sahan, Serkan; Ulgen, Ahmet; Sahan, Ahmet; Soykan, Cengiz

    2013-04-01

    An on-line flow injection pre-concentration-flame atomic absorption spectrometry method was developed to determine trace zinc in water (tap, dam, and well water), biological (hair and nail), and liver samples. As a solid phase extractant, a synthesized new chelating resin, poly(2-thiozylmethacrylamide-co-divinylbenzene-co-2-acrylamido-2-methyl-1-propane sulfonic acid) was used. The resin was characterized by Fourier transform infrared spectroscopy, elemental analysis, and surface area by nitrogen sorption. A pre-concentration factor of 40-fold for a sample volume of 12.6 mL was obtained by using the time-based technique. The detection limit for the pre-concentration method was found to be 2.2 μg L(-1). The precision (as RSD,%) for 10 replicate determinations at the 0.04 μg mL(-1) Zn concentration was 1.2%. The calibration graph using the pre-concentration system for zinc was linear with a correlation coefficient of 0.998 in the concentration range from 0.005 to 0.05 μg mL(-1). The applicability and accuracy of the developed method were estimated by the analysis spiked water, biological, liver samples (83-105%), and also certified reference material TMDA-70 (fortified lake water) and SPS-WW1 Batch 111-Wastewater. The results were in agreement with the certified values.

  10. Thermal structure and CO distribution for the Venus mesosphere/lower thermosphere: 2001-2009 inferior conjunction sub-millimeter CO absorption line observations

    NASA Astrophysics Data System (ADS)

    Clancy, R. Todd; Sandor, Brad J.; Moriarty-Schieven, Gerald

    2012-02-01

    Sub-millimeter 12CO (346 GHz) and 13CO (330 GHz) line absorptions, formed in the mesosphere and lower thermosphere of Venus (70-120 km), have been mapped across the nightside Venus disk during 2001-2009 inferior conjunctions, employing the James Clerk Maxwell Telescope (JCMT). Radiative transfer analysis of these thermal line absorptions supports temperature and CO mixing profile retrievals, as well as Doppler wind fields (described in the companion paper, Clancy et al., 2012). Temporal sampling over the hourly, daily, weekly and interannual timescales was obtained over 2001-2009. On timescales inferred as several weeks, we observe changes between very distinctive CO and temperature nightside distributions. Retrieved nightside CO, temperature distributions for January 2006 and August 2007 observations display strong local time, latitudinal gradients consistent with early morning (2-3 am), low-to-mid latitude (0-40NS) peaks of 100-200% in CO and 20-30 K in temperature. The temperature increases are most pronounced above 100 km altitudes, whereas CO variations extend from 105 km (top altitude of retrieval) down to below 80 km in the mesosphere. In contrast, the 2004 and 2009 periods of observation display modest temperature (5-10 K) and CO (30-60%) increases, that are centered on antisolar (midnight) local times and equatorial latitudes. Doppler wind derived global (zonal and should be SSAS) circulations from the same data do not exhibit variations correlated with these CO, temperature short-term variations. However, large-scale residual wind fields not fit by the zonal, SSAS circulations are observed in concert with the strong temperature, CO gradients observed in 2006 and 2007 (Clancy et al., 2010). These short term variations in nightside CO, temperature distributions may also be related to observed nightside variations in O 2 airglow (Hueso, H., Sánchez-Lavega, A., Piccioni, G., Drossart, P., Gérard, J.C., Khatuntsev, I., Zasova, L., Migliorini, A. [2008]. J

  11. Compressed shell conditions extracted from spectroscopic analysis of Ti K-shell absorption spectra with evaluation of line self-emission

    SciTech Connect

    Johns, H. M.; Mancini, R. C.; Hakel, P.; Nagayama, T.; Smalyuk, V. A.; Regan, S. P.; Delettrez, J.

    2014-08-15

    Ti-doped tracer layers embedded in the shell at varying distances from the fuel-shell interface serve as a spectroscopic diagnostic for direct-drive experiments conducted at OMEGA. Detailed modeling of Ti K-shell absorption spectra produced in the tracer layer considers n = 1–2 transitions in F- through Li-like Ti ions in the 4400–4800 eV range, both including and excluding line self-emission. Testing the model on synthetic spectra generated from 1-D LILAC hydrodynamic simulations reveals that the model including self-emission best reproduces the simulation, while the model excluding self-emission overestimates electron temperature T{sub e} and density N{sub e} to a higher degree for layers closer to the core. The prediction of the simulation that the magnitude of T{sub e} and duration of Ti absorption will be strongly tied to the distance of the layer from the core is consistent with the idea that regions of the shell close to the core are more significantly heated by thermal transport out of the hot dense core, but more distant regions are less affected by it. The simulation predicts more time variation in the observed T{sub e}, N{sub e} conditions in the compressed shell than is observed in the experiment, analysis of which reveals conditions remain in the range T{sub e} = 400–600 eV and N{sub e} = 3.0–10.0 × 10{sup 24} cm{sup −3} for all but the most distant Ti-doped layer, with error bars ∼5% T{sub e} value and ∼10% N{sub e} on average. The T{sub e}, N{sub e} conditions of the simulation lead to a greater degree of ionization for zones close to the core than occurs experimentally, and less ionization for zones far from the core.

  12. BAL: A library for the brute-force analysis of dynamical systems

    NASA Astrophysics Data System (ADS)

    Linaro, Daniele; Storace, Marco

    2016-04-01

    This paper describes the functionality and usage of BAL, a C/C++ library with a Python front-end for the brute-force analysis of continuous-time dynamical systems described by ordinary differential equations (ODEs). BAL provides an easy-to-use wrapper for the efficient numerical integration of ODEs and, by detecting intersections of the trajectory with appropriate Poincaré sections, allows to classify the asymptotic trajectory of a dynamical system for bifurcation analysis. Some examples of application are discussed, concerning two-dimensional bifurcation diagrams, Lyapunov exponents and finite-time Lyapunov exponents, basins of attraction, simulation of switching ODE systems, and integration with AUTO, a software package for continuation analysis.

  13. Factors influencing the thermally-induced strength degradation of B/Al composites

    NASA Technical Reports Server (NTRS)

    Dicarlo, J. A.

    1982-01-01

    Literature data related to the thermally-induced strength degradation of B/Al composites were examined in the light of fracture theories based on reaction-controlled fiber weakening. Under the assumption of a parabolic time-dependent growth for the interfacial reaction product, a Griffith-type fracture model was found to yield simple equations whose predictions were in good agreement with data for boron fiber average strength and for B/Al axial fracture strain. The only variables in these equations were the time and temperature of the thermal exposure and an empirical factor related to fiber surface smoothness prior to composite consolidation. Such variables as fiber diameter and aluminum alloy composition were found to have little influence. The basic and practical implications of the fracture model equations are discussed.

  14. Lahar Hazards at Casita and San Cristóbal Volcanoes, Nicaragua

    USGS Publications Warehouse

    Vallance, J.W.; Schilling, S.P.; Devoli, G.; Reid, M.E.; Howell, M.M.; Brien, D.L.

    2004-01-01

    Casita and San Cristóbal volcanoes are part of a volcano complex situated at the eastern end of the Cordillera de los Maribios. Other centers of volcanism in the complex include El Chonco, Cerro Moyotepe, and La Pelona. At 1745 m, San Cristóbal is the highest and only historically active volcano of the complex. The volcano’s crater is 500 to 600 m across and elongate east to west; its western rim is more than 100 m higher than its eastern rim. The conical volcano is both steep and symmetrical. El Chonco, which lies west of San Cristóbal, is crudely conical but has been deeply dissected by streams. Cerro Moyotepe to the northeast of San Cristóbal is even more deeply incised by erosion than El Chonco, and its crater is breached by erosion. Casita volcano, about 5 km east of San Cristóbal volcano, comprises a broad ridge like form, elongate along an eastwest axis, that is deeply dissected. Nested along the ridge are two craters. The younger one, La Ollada crater, truncates an older smaller crater to the east near Casita’s summit (1430 m). La Ollada crater is about 1 km across and 100 m deep. Numerous small fumarole fields occur near the summit of Casita and on nearby slopes outside of the craters. Casita volcano overlaps the 3-km-wide crater of La Pelona to the east. Stream erosion has deeply incised the slopes of La Pelona, and it is likely the oldest center of the Casita-San Cristóbal volcano complex. In late October and early November 1998, torrential rains of Hurricane Mitch caused numerous slope failures in Central America. The most catastrophic occurred at Casita volcano, on October 30, 1998. At Casita, five days of heavy rain triggered a 1.6-million-cubic-meter rock and debris avalanche that generated an 2- to 4- million-cubic-meter debris flow that swept down the steep slopes of the volcano. The debris flow spread out across the volcano’s apron, destroyed two towns, and killed more than 2500 people. In prehistoric time, Casita erupted explosively

  15. Increased levels of interleukin-8 in BAL fluid from smokers susceptible to pulmonary emphysema

    PubMed Central

    Tanino, M; Betsuyaku, T; Takeyabu, K; Tanino, Y; Yamaguchi, E; Miyamoto, K; Nishimura, M

    2002-01-01

    Background: It has previously been shown that smokers with computed tomographic (CT) evidence of subclinical emphysema have signs of neutrophil activation, despite having no appreciable increase in the number of neutrophils in their bronchoalveolar lavage (BAL) fluid. Methods: The levels of the following chemoattractants in BAL fluid from 61 community based older volunteers classified into four groups according to current smoking status and the presence or absence of emphysema were determined: interleukin 8 (IL-8), epithelial neutrophil activating protein 78 (ENA-78) and leukotriene B4 (LTB4) which are primarily chemotactic for neutrophils; monocyte chemoattractant protein 1 (MCP-1) and macrophage inflammatory protein-1α (MIP-1α) which are predominantly chemotactic for mononuclear leucocytes. Results: Of the five chemoattractants studied, only the level of IL-8 in BAL fluid clearly distinguished between subjects with and without emphysema among current smokers (median values 34.7 and 12.2 pg/ml, respectively, p<0.01). In addition, the levels of IL-8 and neutrophil elastase-α1 protease inhibitor complex in BAL fluid were significantly correlated (r=0.65, p<0.01). There was no difference in either the release of IL-8 from cultured alveolar macrophages at 24 hours or the expression of IL-8 messenger RNA of alveolar macrophages in the two groups of current smokers with and without emphysema. Conclusion: An accelerated response of IL-8 to chronic smoking is a factor that characterises those smokers who are susceptible to pulmonary emphysema, although the cellular source of IL-8 remains to be determined. PMID:11978916

  16. A Deep Search For Faint Galaxies Associated With Very Low-redshift C IV Absorbers. II. Program Design, Absorption-line Measurements, and Absorber Statistics

    NASA Astrophysics Data System (ADS)

    Burchett, Joseph N.; Tripp, Todd M.; Prochaska, J. Xavier; Werk, Jessica K.; Tumlinson, Jason; O'Meara, John M.; Bordoloi, Rongmon; Katz, Neal; Willmer, C. N. A.

    2015-12-01

    To investigate the evolution of metal-enriched gas over recent cosmic epochs as well as to characterize the diffuse, ionized, metal-enriched circumgalactic medium, we have conducted a blind survey for C iv absorption systems in 89 QSO sightlines observed with the Hubble Space Telescope Cosmic Origins Spectrograph. We have identified 42 absorbers at z < 0.16, comprising the largest uniform blind sample size to date in this redshift range. Our measurements indicate an increasing C iv absorber number density per comoving path length (d{N}/{dX}= 7.5 ± 1.1) and modestly increasing mass density relative to the critical density of the universe (ΩC iv = 10.0 ± 1.5 × 10-8) from z ˜ 1.5 to the present epoch, consistent with predictions from cosmological hydrodynamical simulations. Furthermore, the data support a functional form for the column density distribution function that deviates from a single power law, also consistent with independent theoretical predictions. As the data also probe heavy element ions in addition to C iv at the same redshifts, we identify, measure, and search for correlations between column densities of these species where components appear to be aligned in velocity. Among these ion-ion correlations, we find evidence for tight correlations between C ii and Si ii, C ii and Si iii, and C iv and Si iv, suggesting that these pairs of species arise in similar ionization conditions. However, the evidence for correlations decreases as the difference in ionization potential increases. Finally, when controlling for observational bias, we find only marginal evidence for a correlation (86.8% likelihood) between the Doppler line width b(C iv) and column density N(C iv).

  17. On-line filtration system for determining total chromium and chromium in the soluble fraction of industrial effluents by flow injection flame atomic absorption spectrometry.

    PubMed

    López-García, I; Merino Meroño, B; Campillo, N; Hernández-Córdoba, M

    2002-05-01

    Two manifolds were assessed for the purpose of determining both the total chromium content and that present as a soluble form in industrial effluents by flow injection flame atomic absorption spectrometry (FI-FAAS). To determine the chromium content in the soluble fraction the samples were used without additional treatment, a 0.45 microm filter being included in the FI system. To determine the total chromium content, the samples were acidified with nitric acid 20% (v/v) and heated for 30 s in a microwave oven (temperatures of about 70 degrees C were reached). The problem posed by the very different concentration range in which total and soluble chromium are present was overcome by using programmed flow rate methodology and by only partially emptying the sample loop. A personal computer controlled both the rotation speed of a peristaltic pump and the volume of sample injected into the system, thus obtaining the dispersion degree required. Using the manifold proposed, the chromium content in the soluble fraction can be determined in the 0.5-20 microg mL(-1) range using a 10 microg mL(-1) single standard for calibration. To determine the total chromium content, a calibration line in the 20-200 microg mL(-1) range was obtained using a single 50 microg mL(-1) chromium standard solution. The reliability of the semi-automatic devices was verified by comparing the results obtained with those found by treating the samples and using both FAAS in a conventional way and a spectrophotometric method using diphenylcarbazide at the 95% confidence level (ANOVA test). The proposed procedures showed a RSD lower than +/-3%.

  18. Modification of a Common BAL Technique to Enhance Sample Diagnostic Value

    PubMed Central

    Singletary, Morgan L; Phillippi-Falkenstein, Kathrine M; Scanlon, Elizabeth; Bohm, Rudolf P; Veazey, Ronald S; Gill, Amy F

    2008-01-01

    Bronchoalveolar lavage (BAL) by means of bronchoscopy is a diagnostic tool frequently used for clinical and research purposes in nonhuman primates. Although many institutions use this procedure, the technique is not standardized. One technical aspect that can vary is the method by which fluid is recovered. The purpose of this study was to evaluate differences between 2 different BAL aspiration techniques. Bronchoscopy and BAL fluid collection were performed on 20 rhesus macaques (Macaca mulatta). Data collected for comparison included heart rate, oxygen saturation levels, rectal temperature, volume of fluid collected, total cell count, cell viability, differential cell count, and flow cytometry. Results showed no significant differences in the heart rate, oxygen saturation, or body temperature between the 2 groups. Likewise, differential cell counts and cell viability studies of the retrieved fluid did not differ between methods. Compared with the conventional technique, the modified aspiration technique led to an 8.3% increase in overall fluid yield and a higher concentration of cells recovered. These differences are statistically significant and likely will be clinically relevant in the context of diagnosis. PMID:18947171

  19. The novel microtubule-destabilizing drug BAL27862 binds to the colchicine site of tubulin with distinct effects on microtubule organization.

    PubMed

    Prota, Andrea E; Danel, Franck; Bachmann, Felix; Bargsten, Katja; Buey, Rubén M; Pohlmann, Jens; Reinelt, Stefan; Lane, Heidi; Steinmetz, Michel O

    2014-04-17

    Microtubule-targeting agents are widely used for the treatment of cancer and as tool compounds to study the microtubule cytoskeleton. BAL27862 is a novel microtubule-destabilizing drug that is currently undergoing phase I clinical evaluation as the prodrug BAL101553. The drug is a potent inhibitor of tumor cell growth and shows a promising activity profile in a panel of human cancer models resistant to clinically relevant microtubule-targeting agents. Here, we evaluated the molecular mechanism of the tubulin-BAL27862 interaction using a combination of cell biology, biochemistry and structural biology methods. Tubulin-binding assays revealed that BAL27862 potently inhibited tubulin assembly at 37 °C with an IC50 of 1.4 μM and bound to unassembled tubulin with a stoichiometry of 1 mol/mol tubulin and a dissociation constant of 244±30 nM. BAL27862 bound to tubulin independently of vinblastine, without the formation of tubulin oligomers. The kinetics of BAL27862 binding to tubulin were distinct from those of colchicine, with evidence of competition between BAL27862 and colchicine for binding. Determination of the tubulin-BAL27862 structure by X-ray crystallography demonstrated that BAL27862 binds to the same site as colchicine at the intradimer interface. Comparison of crystal structures of tubulin-BAL27862 and tubulin-colchicine complexes shows that the binding mode of BAL27862 to tubulin is similar to that of colchicine. However, comparative analyses of the effects of BAL27862 and colchicine on the microtubule mitotic spindle and in tubulin protease-protection experiments suggest different outcomes of tubulin binding. Taken together, our data define BAL27862 as a potent, colchicine site-binding, microtubule-destabilizing agent with distinct effects on microtubule organization.

  20. The FAST BAL Monitoring Campaign: Multi-epoch Constraints on Quasar Outflows

    NASA Astrophysics Data System (ADS)

    Arraki, Kenza S.; Haggard, D.; Anderson, S.; Green, P.; Aldcroft, T.

    2012-01-01

    Kinetic energy carried by AGN winds and jets may rival radiation as the dominant feedback mechanism regulating galaxy-SMBH co-evolution. Though outflows likely accompany all luminous accretion disks, broad absorption line quasars (BALQSOs) provide the most dramatic astrophysical examples; their massive outflows display P-Cygni profiles that span velocities up to 0.3c and are visible in the spectra of 15-40% of optically-selected quasars. Spectroscopic variability studies of BALQSOs probe the structure, stability, location, and dynamics of the emitting and absorbing gas near the SMBH and can provide insight into connections between AGN feedback and host galaxy formation and evolution. We report on a multi-year spectroscopic campaign that monitors seventeen BALQSOs (identified originally in the SDSS) using the Fred Lawrence Whipple Observatory's 1.5m telescope's FAST spectrograph. These targets have Chandra X-ray data and have been repeatedly observed with FAST, in regular cadences from one day to two years -- a 6 year cadence is planned for spring 2012. We identify variability in the broad absorption line region, assess its significance, magnitude, and frequency and discuss the constraints these investigations can place on QSO outflows

  1. On-line UV-photooxidation with peroxodisulfate for automated flow injection and for high-performance liquid chromatography coupled to hydride generation atomic absorption spectrometry

    NASA Astrophysics Data System (ADS)

    Tsalev, Dimiter L.; Sperling, Michael; Welz, Bernhard

    2000-04-01

    An automated on-line UV photooxidation with peroxodisulfate of some environmentally relevant organoarsenic and organotin compounds in a system built from commercially available modules has been studied and optimised with a view to both species-independent quantification of the total arsenic or tin in samples containing different organic species by flow injection hydride generation atomic absorption spectrometry (FI-HGAAS) and speciation analysis by coupled high-performance liquid chromatography (HPLC) with HGAAS detection. For organoarsenicals, the reaction with alkaline peroxodisulfate in a 10-15-m knotted reactor for >1.5 min insures >90% transformation of inorganic As(III) and six organoarsenic species to arsenate: monomethylarsonate, dimethylarsinate, arsenobetaine, arsenocholine, trimethylarsine oxide and tetramethylarsonium. For organotins, the UV photooxidation with acidic peroxodisulfate at 95-100°C provides recoveries of >80% for the inorganic tin, dimethyltin, trimethyltin, triethyltin, tripropyltin, triphenyltin, monobutyltin, dibutyltin and tributyltin but only approximately 15% for tetrabutyltin. The best characteristic masses in integrated absorbance ( Aint) and peak-height ( Ap) measurements, respectively, are 30 pg and 480 pg for arsenic(V) and 22 pg and 410 pg for tin(IV), employing 100-μl injections. The RSDs are 5.5% and 8.5% at 5 ng As(V) levels and 4.3% and 6.4% at 10 ng Sn(IV) levels in Aint and Ap modes, respectively. The limits of detection (LOD, 3σ) for As are 7 μg l -1 and 4 μg l -1 in FI-UV-HGAAS and HPLC-UV-HGAAS, respectively. The LODs for i-Sn(IV) are 2 μg l -1 in FI-UV-HGAAS, with both Aint and Ap measurements. The sample throughput rates are 20 and 12 samples per hour with 10-m and 15-m knotted reactors (i.d. 0.5 mm), respectively. Urine certified reference materials containing 0.052-0.48 μg ml -1 As have been analysed for their total arsenic content.

  2. Direct determination of Hg in polymers by solid sampling-graphite furnace atomic absorption spectrometry. A comparison of the performance of line source and continuum source instrumentation

    NASA Astrophysics Data System (ADS)

    Resano, M.; Briceño, J.; Belarra, M. A.

    2009-06-01

    This work explores the potential of solid sampling-graphite furnace atomic absorption spectrometry (SS-GFAAS) for the fast and direct determination of Hg in polymers. Eight certified reference materials with different composition (polyethylene-PE-, polystyrene-PS-, poly vinyl chloride-PVC- and acrylonitrile butadiene styrene-ABS-) were selected for the study, covering a wide Hg content range (from 20 to 1100 μg g - 1 ). The difficulties found in achieving a selective atomization of the analyte from these samples were partially mitigated by the maintenance of the Ar flow during the atomization step, leading to an improved signal-to-background ratio. Even then, when a line source (LS) GFAAS instrument was employed for analysis, it was only possible to develop truly accurate procedures relying on the use of aqueous standards for calibration for PE and PVC samples, and different atomization conditions (1200 °C and 1300 °C, respectively) were needed for the two types of samples. The use of high-resolution continuum source (HR-CS) GFAAS instrumentation permitted to improve this situation significantly thanks to its higher potential for the correction of high and fast changing background. With such an instrument, satisfactory results could be obtained for all the samples under study using the same atomization conditions (1200 °C) and aqueous standard solutions for calibration. Additionally, the HR-CS GFAAS technique presented a lower limit of detection (0.6 μg g - 1 for CS and 2.2 μg g - 1 for LS), a broader linear range (10 to 320 Hg ng for CS, and 20 to 200 ng for LS), and a somewhat improved sensitivity (approximately 0.0030 s ng - 1 for CS using the three central pixels for quantification, and approximately 0.0025 s ng - 1 for LS). Overall, the use of HR-CS GFAAS permits obtaining significant advantages for the determination of this complex analyte in plastics, such as straightforward calibration with aqueous standards, a high sample throughput (15 min per

  3. SPECTRO-POLARIMETRIC SIMULATIONS OF THE SOLAR LIMB: ABSORPTION-EMISSION Fe I 6301.5 Å AND 6302.5 Å LINE PROFILES AND TORSIONAL FLOWS IN THE INTERGRANULAR MAGNETIC FLUX CONCENTRATIONS

    SciTech Connect

    Shelyag, S.

    2015-03-01

    Using radiative magnetohydrodynamic simulations of the magnetized solar photosphere and detailed spectro-polarimetric diagnostics with the Fe I 6301.5 Å and 6302.5 Å photospheric lines in the local thermodynamic equilibrium approximation, we model active solar granulation as if it was observed at the solar limb. We analyze general properties of the radiation across the solar limb, such as the continuum and the line core limb darkening and the granulation contrast. We demonstrate the presence of profiles with both emission and absorption features at the simulated solar limb, and pure emission profiles above the limb. These profiles are associated with the regions of strong linear polarization of the emergent radiation, indicating the influence of the intergranular magnetic fields on the line formation. We analyze physical origins of the emission wings in the Stokes profiles at the limb, and demonstrate that these features are produced by localized heating and torsional motions in the intergranular magnetic flux concentrations.

  4. Water absorption lines, 931-961 nm - Selected intensities, N2-collision-broadening coefficients, self-broadening coefficients, and pressure shifts in air

    NASA Technical Reports Server (NTRS)

    Giver, L. P.; Gentry, B.; Schwemmer, G.; Wilkerson, T. D.

    1982-01-01

    Intensities were measured for 97 lines of H2O vapor between 932 and 961 nm. The lines were selected for their potential usefulness for remote laser measurements of H2O vapor in the earth's atmosphere. The spectra were obtained with several different H2O vapor abundances and N2 broadening gas pressures; the spectral resolution was 0.046/cm FWHM. Measured H2O line intensities range from 7 x 10 to the -25th to 7 x 10 to the -22nd/cm per (molecules/sq cm). H2O self-broadening coefficients were measured for 13 of these strongest lines; the mean value was 0.5/cm per atm. N2-collision-broadening coefficients were measured for 73 lines, and the average was 0.11 cm per atm HWHM. Pressure shifts in air were determined for a sample of six lines between 948 and 950 nm; these lines shift to lower frequency by an amount comparable to 0.1 of the collision-broadened widths measured in air or N2. The measured intensities of many lines of 300-000 band are much larger than expected from prior computations, in some cases by over an order of magnitude. Coriolis interactions with the stronger 201-000 band appear to be the primary cause of the enhancement of these line intensities.

  5. Assay to evaluate BAL Fluid regulation of Fibroblast α-SMA Expression

    PubMed Central

    Larson-Casey, Jennifer L.; Carter, A. Brent

    2016-01-01

    Because transforming growth factor-β (TGF-β1) induces differentiation of fibroblasts to myofibroblasts, we developed a protocol to evaluate alveolar macrophage-derived TGF-β1 regulation of lung fibroblast differentiation (Larson-Casey et al., 2016). The protocol allows evaluating the ability of mouse bronchoalveolar lavage (BAL) fluid to alter fibroblast differentiation. Fibroblast differentiation was measured by the expression of α-smooth muscle actin (α-SMA). Background Alveolar macrophages play an integral role in pulmonary fibrosis development by increasing the expression of TGF-β1 (He et al., 2011). Our prior data demonstrate that alveolar macrophages are a critical source of TGF-β1 as mice harboring a conditional deletion of TGF-β1 in macrophages were protected from pulmonary fibrosis (Larson-Casey et al., 2016). The expression of α-SMA is a defining feature of myofibroblasts, and TGF-β1 is a well-characterized pro-fibrotic mediator that induces transformation of fibroblasts to myofibroblasts both in vitro (Desmoulière et al., 1993) and in vivo (Sime et al., 1997). Prior studies exposed fibroblasts to recombinant TGF-β1 to show its effect on differentiation and function (Horowitz et al., 2007). Here we have developed a protocol for determining the ability of mouse BAL fluid to alter the differentiation of human lung fibroblasts to myofibroblasts, the cells that produce extracellular matrix proteins. PMID:28239621

  6. Spectral, electron microscopic and chemical investigations of gamma-induced purple color zonings in amethyst crystals from the Dursunbey-Balıkesir region of Turkey

    NASA Astrophysics Data System (ADS)

    Hatipoğlu, Murat; Kibar, Rana; Çetin, Ahmet; Can, Nurdoğan; Helvacı, Cahit; Derin, H.

    2011-07-01

    Amethyst crystals on matrix specimens from the Dursunbey-Balıkesir region in Turkey have five representative purple color zonings: dark purple, light purple, lilac, orchid, and violet. The purple color zonings have been analyzed with optical absorption spectra in the visible wavelength region, chemical full trace element analyses (inductively coupled plasma-atomic emission spectroscopy and inductively coupled plasma-mass spectroscopy), and scanning electron microscopic images with high magnification. It can be proposed that the production of the purple color in amethyst crystals is due to three dominant absorption bands centered at 375, 530, and 675 nm, respectively. In addition, the purple color zonings are also due to four minor absorption bands centered at 435, 480, 620, and 760 nm. X-ray diffraction graphics of the investigated amethyst crystals indicate that these crystals are composed of a nearly pure alpha-quartz phase and do not include any moganite silica phase and/or other mineral implications. Trace element analyses of the amethyst crystals show five representative purple color zonings, suggesting that the absorption bands can be mainly attributed to extrinsic defects (chemical impurities). However, another important factor that influences all structural defects in amethyst is likely to be the gamma irradiation that exists during amethyst crystallization and its inclusion in host materials. This gamma irradiation originates from the large underlying intrusive granitoid body in the region of amethyst formation. Irradiation modifies the valence values of the impurity elements in the amethyst crystals. It is observed that the violet-colored amethyst crystals have the most stable and the least reversible coloration when exposed to strong light sources. This situation can be related to the higher impurity content of Fe (2.50 ppm), Co (3.1 ppm), Ni (38 ppm), Cu (17.9 ppm), Zn (10 ppm), Zr (3.9 ppm), and Mo (21.8 ppm).

  7. Calculated Hanle transmission and absorption spectra of the {sup 87}Rb D{sub 1} line with residual magnetic field for arbitrarily polarized light

    SciTech Connect

    Noh, Heung-Ryoul; Moon, Han Seb

    2010-09-15

    This paper reports a theoretical study on the transmission spectra of an arbitrarily polarized laser beam through a rubidium cell with or without a buffer gas in Hanle-type coherent population trapping (CPT). This study examined how laser polarization, transverse magnetic field, and collisions with buffer gas affects the spectrum. The transmission spectrum due to CPT and the absorption spectrum due to the level crossing absorption (LCA) were calculated according to the laser polarization. The results show that the LCA is strongly dependent on the transverse magnetic field and interaction time of the atoms with a laser light via collisions with the buffer gas. In addition, the spectral shape of the calculated Hanle spectrum is closely related to the direction between the (stray) transverse magnetic field and polarization of the laser.

  8. On-line spectrophotometric method for monitoring weak residual absorption of CaMoO{sub 4} single crystals near the intrinsic luminescence peak

    SciTech Connect

    Buzanov, O. A.; Kanevskii, V. M.; Kornoukhov, V. N.; Nabatov, B. V.; Nabatov, V. V.; Fedorov, V. A.

    2013-11-15

    The optical and spectral characteristics of isotopically enriched Czochralski-grown {sup 40}Ca{sup 100}MoO{sub 4} single crystals have been investigated. This material is promising for detecting double neutrinoless {beta} decay. The possibility and the technique of spectrophotometric monitoring of weak residual absorption near the intrinsic luminescence peak of this scintillation material, which is designed for developing new-generation detectors of elementary particles, are considered.

  9. On-line spectrophotometric method for monitoring weak residual absorption of CaMoO4 single crystals near the intrinsic luminescence peak

    NASA Astrophysics Data System (ADS)

    Buzanov, O. A.; Kanevskii, V. M.; Kornoukhov, V. N.; Nabatov, B. V.; Nabatov, V. V.; Fedorov, V. A.

    2013-11-01

    The optical and spectral characteristics of isotopically enriched Czochralski-grown 40Ca100MoO4 single crystals have been investigated. This material is promising for detecting double neutrinoless β decay. The possibility and the technique of spectrophotometric monitoring of weak residual absorption near the intrinsic luminescence peak of this scintillation material, which is designed for developing new-generation detectors of elementary particles, are considered.

  10. Enhancement of conduction noise absorption by hybrid absorbers composed of indium-tin-oxide thin film and magnetic composite sheet on a microstrip line

    SciTech Connect

    Kim, Sun-Hong; Kim, Sung-Soo

    2014-05-05

    In order to develop wide-band noise absorbers with a focused design for low frequency performance, this study investigates hybrid absorbers that are composed of conductive indium-tin-oxide (ITO) thin film and magnetic composite sheets. The ITO films prepared via reactive sputtering exhibit a typical value of electrical resistivity of ≃10{sup −4} Ω m. Rubber composites with flaky Fe-Si-Al particles are used as the magnetic sheet with a high permeability and high permittivity. For the ITO film with a low surface resistance and covered by the magnetic sheet, approximately 90% power absorption can be obtained at 1 GHz, which is significantly higher than that of the original magnetic sheet or ITO film. The high power absorption of the hybrid absorber is attributed to the enhanced ohmic loss of the ITO film through increased electric field strength bounded by the upper magnetic composite sheet. However, for the reverse layering sequence of the ITO film, the electric field experienced by ITO film is very weak due to the electromagnetic shielding by the under layer of magnetic sheet, which does not result in enhanced power absorption.

  11. VizieR Online Data Catalog: SDSS/BOSS/TDSS CIV BAL quasars (Grier+, 2016)

    NASA Astrophysics Data System (ADS)

    Grier, C. J.; Brandt, W. N.; Hall, P. B.; Trump, J. R.; Filiz, Ak N.; Anderson, S. F.; Green, P. J.; Schneider, D. P.; Sun, M.; Vivek, M.; Beatty, T. G.; Brownstein, J. R.; Roman-Lopes, A.

    2016-08-01

    We began with the 2005 targets from the BAL catalog of Gibson et al. (2009, J/ApJ/692/758), which were observed by SDSS and targeted for additional observations with Baryon Oscillation Spectroscopic Survey (BOSS; Eisenstein et al. 2011AJ....142...72E; Dawson et al. 2013AJ....145...10D) and Time Domain Spectroscopic Survey (TDSS; Morganson et al. 2015ApJ...806..244M). We then searched for BOSS and TDSS observations of these targets as of 2015 June 30, identifying 172 targets that were observed by all three surveys. We restricted the redshift range of our sample to 1.5

  12. Solid-phase synthesis of lidocaine and procainamide analogues using backbone amide linker (BAL) anchoring.

    PubMed

    Shannon, Simon K; Peacock, Mandy J; Kates, Steven A; Barany, George

    2003-01-01

    New solid-phase strategies have been developed for the synthesis of lidocaine (1) and procainamide (2) analogues, using backbone amide linker (BAL) anchoring. Both sets were prepared starting from a common resin-bound intermediate, followed by four general steps: (i) attachment of a primary aliphatic or aromatic amine to the solid support via reductive amination (as monitored by a novel test involving reaction of 2,4-dinitrophenylhydrazine with residual aldehyde groups); (ii) acylation of the resultant secondary amine; (iii) displacement of halide with an amine; and (iv) trifluoroacetic acid-mediated release from the support. A manual parallel strategy was followed to provide 60 novel compounds, of which two dozen have not been previously described. In most cases, initial crude purities were >80%, and overall isolated yields were in the 40-88% range.

  13. Soliton absorption spectroscopy

    PubMed Central

    Kalashnikov, V. L.; Sorokin, E.

    2010-01-01

    We analyze optical soliton propagation in the presence of weak absorption lines with much narrower linewidths as compared to the soliton spectrum width using the novel perturbation analysis technique based on an integral representation in the spectral domain. The stable soliton acquires spectral modulation that follows the associated index of refraction of the absorber. The model can be applied to ordinary soliton propagation and to an absorber inside a passively modelocked laser. In the latter case, a comparison with water vapor absorption in a femtosecond Cr:ZnSe laser yields a very good agreement with experiment. Compared to the conventional absorption measurement in a cell of the same length, the signal is increased by an order of magnitude. The obtained analytical expressions allow further improving of the sensitivity and spectroscopic accuracy making the soliton absorption spectroscopy a promising novel measurement technique. PMID:21151755

  14. Vesicle formation and follicular root sheath separation in mice homozygous for deleterious alleles at the balding (bal) locus.

    PubMed

    Montagutelli, X; Lalouette, A; Boulouis, H J; Guénet, J L; Sundberg, J P

    1997-09-01

    The balding (bal) mutation of the mouse is an autosomal recessive mutation that causes alopecia and immunologic anomalies. A new allele was identified by allelism testing after using an interspecific backcross to localize the mutation to the centromeric end of mouse chromosome 18. We investigated the skin and hair histologic lesions of two alleles (bal(J) and bal(Pas)) at this locus and analyzed the expression of several keratinocyte markers and the production of autoantibodies by immunofluorescence on frozen skin sections. The lesions observed included separation of the inner and outer root sheath in anagen follicles resulting in the hair fiber being very easily plucked from the follicle. Vesicles on the ventral tongue, mucocutaneous junction of the eyelid, foot pads, and rarely in skin were also evident. Separation occurred between the basal and suprabasilar cells forming an empty cleft, resembling that observed in human pemphigus vulgaris. Immunofluorescence studies did not reveal the presence of tissue-bound or circulating autoantibodies. Expression of keratinocyte markers in hair follicles was normal. Keratin 6-positive cells were found on either side of the follicular separation suggesting a molecular defect in adhesion molecules between the inner layer of the outer root sheath cells to layers on either sides. This hypothesis has been confirmed by another group who demonstrated that the bal(J) mutation is due to the insertion of a thymidine in the desmoglein 3 gene, resulting in a premature stop codon.

  15. Fluorescein-labeled dextran concentration is increased in BAL fluid after ANTU-induced edema in rats.

    PubMed

    Guery, B P; Nelson, S; Viget, N; Fialdes, P; Summer, W R; Dobard, E; Beaucaire, G; Mason, C M

    1998-09-01

    Several methodologies have been developed to assess alveolocapillary membrane permeability in acute lung injury. The purpose of this study was to determine the reliability of FITC-dextran compared with radioactive tracers to assess lung permeability alterations. After intraperitoneal administration of alpha-naphthylthiourea (ANTU, 50 mg/kg) or DMSO-ANTU vehicle, the animals were euthanized and their lungs were studied in an isolated-lung preparation. FITC-dextran or radiolabeled tracers were added to the perfusate. At 2 h the bronchoalveolar lavage (BAL) fluid from the ANTU group showed a significantly greater amount of fluorescence in the supernatant after centrifugation of BAL fluid compared with the DMSO group. Consistent results were observed with the radioactive tracers: there was an increase in extravascular albumin space and extravascular lung water compared with the control group. No cleavage of the FITC from the dextran molecule was evident by chromatography comparing samples recovered from the BAL fluid to the pure FITC-dextran molecule. In conclusion, measurement of FITC-dextran in the supernatant of BAL fluid after intravascular administration is a reliable method of assessing lung permeability changes in vivo and ex vivo.

  16. Infrared absorption by pure CO2 near 3340 cm-1: Measurements and analysis of collisional coefficients and line-mixing effects at subatmospheric pressures

    NASA Astrophysics Data System (ADS)

    Daneshvar, L.; Földes, T.; Buldyreva, J.; Vander Auwera, J.

    2014-12-01

    High resolution Fourier transform spectra of the 21102-00001 band of 12C16O2 near 3340 cm-1 have been recorded and analyzed to extract isolated-line intensities and collisional parameters, and first-order line-mixing coefficients. Voigt, hard-collision Rautian and Sobel'man, and quadratic-speed-dependent Voigt profiles have been used. The line-mixing coefficients measured for the three branches have also been evaluated using an Energy-Corrected Sudden approach employing a symmetric metric in the Liouville space. These coefficients compare very favorably with the experimental results and estimations with an algorithm available in the literature. Results of straightforward ECS-modeling of complete band shapes have been compared to the recorded spectra and future improvements of this model required at subatmospheric pressures have been outlined.

  17. Determination of Cd, Co, Cu, Mn, Ni, Pb, and Zn by Inductively Coupled Plasma Mass Spectroscopy or Flame Atomic Absorption Spectrometry after On-line Preconcentration and Solvent Extraction by Flow Injection System

    PubMed

    Bortoli; Gerotto; Marchiori; Mariconti; Palonta; Troncon

    1996-11-01

    The concentrations of Cd, Co, Cu, Mn, Ni, Pb, and Zn in natural and sea waters are too low to be directly determined with by flame atomic absorption spectrometry (FAAS) or graphite furnace atomic absorption spectrometry (GFAAS). Specific sample preparations are requested that make possible the determination of these analytes by preconcentration or extraction. These techniques are affected by severe problems of sample contamination. In this work Cd, Co, Cu, Mn, Ni, Pb, and Zn were determined by inductively coupled plasma mass spectroscopy (ICP-MS) or by atomic absorption spectrometry, in fresh and seawater samples, after on-line preconcentration and following solvent elution with a flow injection system. Bonded silica with octadecyl functional group C18, packed in a microcolumn of 100-μl capacity, was used to collect diethyldithiocarbamate complexes of the heavy metals in aqueous solutions. The metals are complexed with a chelating agent, adsorbed on the C18 column, and eluted with methanol directly in the flow injection system. The methanolic stream can be addressed to FAAS for direct determination of Cu, Ni, and Zn, or collected in a vial for successive analysis by GFAAS. The eluted samples can be also dried in a vacuum container and restored to a little volume with concentrated HNO3 and Milli-Q water for analysis by ICP-MS or GFAAS.

  18. Petrogenesis of the post-collisional Oligo-Miocene Volcanism in NW Anatolia (Turkey): Balıkesir Volcanites

    NASA Astrophysics Data System (ADS)

    Ünal, Alp; Altunkaynak, Şafak; Benowitz, Jeff A.

    2016-04-01

    In this study, we present whole-rock chemical and Sr-Nd-Pb-O isotopic compositions as well as 40Ar/39Ar ages of Balıkesir volcanites to evaluate the nature, genesis and timing of the post-collisional Oligo-Miocene magmatism in NW Anatolia. Three main volcano-stratigraphic groups distinguished in the Balıkesir volcanites on the basis of field observations and petrographical investigations; 1) andesitic lavas and related pyroclastic units representing the lower part of the volcanic sequence; 2) Trachyandesite- basaltic trachyandesite lavas and 3) dacitic lavas and associated pyroclastic units corresponding to the upper part of the volcanic sequence. Both andesitic and dacitic pyroclastic units are represented with ash fall, ash block flow and flow breccia units. Geochemically, Balıkesir volcanites are ranging in composition from basaltic trachy-andesite to dacite. They are sub-alkaline in character and show enrichment in large ion lithophile elements (LILE) and light rare earth elements (LREE) relative to the high field strength elements (HFSE). Balıkesir volcanites display depletion in P, Ta, Nb and Ti. All these trace element characteristics and inter-element ratios suggest that magma forming the Balıkesir volcanites show similar patterns to those of subduction-related arc magmas and/or post collisional lavas. They have high initial 87Sr/86Sr ratios (0.707109-0.708620), low 143Nd/144Nd (0.512322- 0.512493). 206Pb/204Pb and 207Pb/204Pb values vary from 18.703 to 18.867 and 15.681 to 15.714, respectively and ɛNd values range between -5.61 and -2.27. 18O isotopic ratios range between 8.3 and 11.8. All these isotopic characteristics and major-trace element compositions of Balıkesir volcanites suggest that the lavas are co-genetic and originated from a hybrid magma derived from enriched mantle (EM II) source. 40Ar/39Ar dating yielded isochron ages of 22.9±0.2 - 21.0±0.2 which is consistent with other volcanic and plutonic associations of western Anatolia (eg

  19. More Constraints on the Physical Conditions of the Kinematically Complex, Multiphase Absorption Line System at z=0.93 toward PG1206+459

    NASA Astrophysics Data System (ADS)

    Rosenwasser, Ben; Muzahid, Sowgat; Norris, Jackson; Charlton, Jane C.

    2015-01-01

    We present the results of photo- and collisional ionization modeling of the strong MgII absorption system at redshift z~0.93 towards the quasar PG1206+459. This system has been extensively studied over the last two decades (Churchill & Charlton 1999; Ding et al. 2003; Tripp et al. 2011) using a combination of spectra from Keck/HIRES, HST/FOS, HST/STIS, and HST/COS. Here we present newconstraints using the most complete spectral coverage including more recent observations of OVI and the Lyman series from HST/COS. Numerous absorption components are seen over a large velocity spread (~1500km/s), and multiple ionization phases are required to account for the detected transitions, which include MgI, MgII, FeII, SiII, SiIII, SiIV, CII, CIII, CIV, SIII, SIV, SV, SVI, NIII, NIV, NV, OIII, OIV, OV, OVI, and NeVIII. Considering the new constraints, we revisit the question of the physical nature of the structures that produce this absorber.

  20. Interstellar Gas-phase Element Depletions in the Small Magellanic Cloud: A Guide to Correcting for Dust in QSO Absorption Line Systems

    NASA Astrophysics Data System (ADS)

    Jenkins, Edward B.; Wallerstein, George

    2017-04-01

    We present data on the gas-phase abundances for 9 different elements in the interstellar medium of the Small Magellanic Cloud (SMC), based on the strengths of ultraviolet absorption features over relevant velocities in the spectra of 18 stars within the SMC. From this information and the total abundances defined by the element fractions in young stars in the SMC, we construct a general interpretation on how these elements condense into solid form onto dust grains. As a group, the elements Si, S, Cr, Fe, Ni, and Zn exhibit depletion sequences similar to those in the local part of our Galaxy defined by Jenkins. The elements Mg and Ti deplete less rapidly in the SMC than in the Milky Way, and Mn depletes more rapidly. We speculate that these differences might be explained by the different chemical affinities to different existing grain substrates. For instance, there is evidence that the mass fractions of polycyclic aromatic hydrocarbons in the SMC are significantly lower than those in the Milky Way. We propose that the depletion sequences that we observed for the SMC may provide a better model for interpreting the element abundances in low-metallicity Damped Lyman Alpha (DLA) and sub-DLA absorption systems that are recorded in the spectra of distant quasars and gamma-ray burst afterglows. Based on observations with the NASA/ESA Hubble Space Telescope and additional data obtained from the Data Archive at the Space Telescope Science Institute, which is operated by the Associations of Universities for Research in Astronomy, Incorporated, under NASA contract NAS5-26555. These observations are associated with program nr. 13778.

  1. Measurement of atmospheric monoaromatic hydrocarbons using differential optical absorption spectroscopy: Comparison with on-line gas chromatography measurements in urban air

    NASA Astrophysics Data System (ADS)

    Lee, Chulkyu; Choi, Yeo Jin; Jung, Jin Sang; Lee, Jeong Soon; Kim, Ki Hyun; Kim, Young Joon

    A Long Path DOAS system (GIST LP-DOAS) developed by GIST has been used to simultaneously measure atmospheric monoaromatic hydrocarbons (MAHC) and other trace compounds. The validity of GIST LP-DOAS in measuring atmospheric MAHC was tested over 740 m beam paths at an urban site in Seoul, Korea, during two field campaigns held in February 2003. In order to remove the effects of interfering compounds (such as oxygen, ozone, and sulfur dioxide), two oxygen optical density spectra at two path lengths and the reference spectra of sulfur dioxide and ozone were incorporated in the fitting procedure for the determination of MAHC. The mean concentrations of MAHC measured with LP-DOAS system during the measurement period were 0.77 (benzene), 3.68 (toluene), 0.41 ( p-xylene), and 0.54 ppbv ( m-xylene), respectively. The results of our LP-DOAS measurements were compared with those obtained by a collocated on-line Gas Chromatography (on-line GC) system. The concept of a percent difference (PD) and linear regression methods were employed to explain the bias structure between LP-DOAS and on-line GC. The results of this comparative analysis indicated that both systems exhibited strong compatibility with relatively good correlation. According to our correlation analysis between PD values and meteorological parameters, the compatibility between the two systems increased under the conditions of improved visibility and meteorological homogeneity (wind speed >1.3 ms -1). Based on our study, it is concluded that the LP-DOAS system can be used to provide reliable information on both mixing ratios and temporal distribution characteristics of MAHC in urban air.

  2. NuSTAR observations of the supergiant X-ray pulsar IGR J18027-2016: accretion from the stellar wind and possible cyclotron absorption line

    NASA Astrophysics Data System (ADS)

    Lutovinov, Alexander A.; Tsygankov, Sergey S.; Postnov, Konstantin A.; Krivonos, Roman A.; Molkov, Sergey V.; Tomsick, John A.

    2017-04-01

    We report on the first focused hard X-ray view of the absorbed supergiant system IGR J18027-2016 performed with the Nuclear Spectroscopic Telescope Array observatory. The pulsations are clearly detected with a period of Pspin = 139.866(1) s and a pulse fraction of about 50-60 per cent at energies from 3 to 80 keV. The source demonstrates an approximately constant X-ray luminosity on a time-scale of more than dozen years with an average spin-down rate of dot{P}≃ 6× 10^{-10} s s-1. This behaviour of the pulsar can be explained in terms of the wind accretion model in the settling regime. The detailed spectral analysis at energies above 10 keV was performed for the first time and revealed a possible cyclotron absorption feature at energy ∼23 keV. This energy corresponds to the magnetic field B ≃ 3 × 1012 G at the surface of the neutron star, which is typical for X-ray pulsars.

  3. Preliminary optical design of a varied line-space spectrograph for the multi-channel detection of near-edge X-ray absorption fine structure (NEXAFS) spectra in the 280-550 eV energy range

    SciTech Connect

    Wheeler, B.S.; McKinney, W.R.; Hussain, Z.; Padmore, H.

    1996-07-01

    The optical design of a varied line-space spectrograph for the multi-channel recording of NEXAFS spectra in a single {open_quotes}snapshot{close_quotes} is proposed. The spectrograph is to be used with a bending magnet source on beamline 7.3.2 at the Advanced Light Source (ALS). Approximately 20 volts of spectra are simultaneously imaged across a small square of material sample at each respective K absorption edge of carbon, nitrogen, and oxygen. Photoelectrons emitted from the material sample will be collected by an electron imaging microscope, the view field of which determines the sampling size. The sample also forms the exit slit of the optical system. This dispersive method of NEXAFS data acquisition is three to four orders of magnitude faster than the conventional method of taking data point-to-point using scanning of the grating. The proposed design is presented along with the design method and supporting SHADOW raytrace analysis.

  4. An adaptive optics package designed for astronomical use with a laser guide star tuned to an absorption line of atomic sodium

    SciTech Connect

    Salmon, J.T.; Avicola, K.; Brase, J.M.

    1994-04-11

    We present the design and implementation of a very compact adaptive optic system that senses the return light from a sodium guide-star and controls a deformable mirror and a pointing mirror to compensate atmospheric perturbations in the wavefront. The deformable mirror has 19 electrostrictive actuators and triangular subapertures. The wavefront sensor is a Hartmann sensor with lenslets on triangular centers. The high-bandwidth steering mirror assembly incorporates an analog controller that samples the tilt with an avalanche photodiode quad cell. An {line_integral}/25 imaging leg focuses the light into a science camera that can either obtain long-exposure images or speckle data. In laboratory tests overall Strehl ratios were improved by a factor of 3 when a mylar sheet was used as an aberrator. The crossover frequency at unity gain is 30 Hz.

  5. Trace level determination of cadmium in wine by on-line preconcentration in a 5-Br-PADAP functionalized wool-packed microcolumn coupled to flame atomic absorption spectrometry.

    PubMed

    Monasterio, Romina P; Wuilloud, Rodolfo G

    2009-10-15

    An on-line retention and preconcentration system based on a sheep wool-packed microcolumn combined with flame atomic absorption spectrometry is proposed for trace level determination of Cd in wine. A chelating reagent 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol was immobilized onto the wool before retention of the analyte. Several factors influencing the preconcentration efficiency of Cd and his subsequent determination, such as pH, eluent type, sample and eluent flow rates, interfering effects, were studied. A preconcentration factor of 39 was obtained with only 20 mL of sample. The relative standard deviation for five determinations of 1 microg L(-1) Cd was 3.4%. The calibration graph was linear with a correlation coefficient of 0.998 at levels near the detection limit and up to at least 25 microg L(-1). The limit of detection was 37 ng L(-1). The accuracy of the proposed methodology was tested by comparison of the results with those obtained by electrothermal atomic absorption spectrometry analysis along with a recovery study. Finally, the method was employed for evaluating Cd levels in different wines including, blank, rose, and red.

  6. Site specificity of psoralen-DNA interstrand cross-linking determined by nuclease Bal31 digestion

    SciTech Connect

    Zhen, W.; Buchardt, O.; Nielsen, H.; Nielsen, P.E.

    1986-10-21

    A novel method for determination of psoralen photo-cross-linking sites in double-stranded DNA is described, which is based on a pronounced inhibition of Bal31 exonuclease activity by psoralen-DNA interstrand cross-links. The results using a 51 base pair fragment of plasmid pUC19 and a 346 base pair fragment of pBR322 show that 5'-TA sequences are preferred cross-linking sites compared to 3'-TA sequences. They also indicate that sequences flanking the 5'-TA site influence the cross-linking efficiency at the site. The DNA photo-cross-linking by 4,5',8-trimethylpsoralen and 8-methoxypsoralen was analyzed, and these two psoralens showed identical site specificity. The 5'-TA preference is rationalized on the basis of the local DNA structure in terms of ..pi..-..pi.. electronic interaction between the thymines and the intercalated psoralens, as well as on the base tilt angles of the DNA.

  7. Heterogeneity in Lipid Composition of the Outer Membrane and Cytoplasmic Membrane of Pseudomonas BAL-31

    PubMed Central

    Diedrich, D. L.; Cota-Robles, E. H.

    1974-01-01

    The outer membranes and cytoplasmic membranes of the marine bacterium Pseudomonas BAL-31 were separated by washing the cells three times in 0.5 M NaCl and twice in 0.5 M sucrose. Electron microscopy during the removal of membranes revealed that the outer membranes fragmented in a regular manner to give rise to fairly uniform vesicles measuring approximately 140 nm in diameter. Isolated outer membranes had a buoyant density in sucrose of 1.230 g per cm3, whereas the cytoplasmic membranes had a density of 1.194 g per cm3. The removal of the outer membrane during the application of this procedure was monitored by measuring the release of 2-keto-3-deoxyoctulosonic acid and phospholipid. The cells lost 85.5% of their 2-keto-3-deoxyoctulosonic acid and 47.3% of their phospholipid during this treatment. Complete recovery of outer membrane material could be achieved. The removal of 25.5% of the 2-keto-3-deoxyoctulosonic acid and 0.9% of the phospholipid rendered the cells sensitive to lysis with Triton X-100. The phospholipid composition of the outer membrane was calculated to be 78.9% phosphatidylethanolamine and 16.1% phosphatidylglycerol. The phospholipid composition of the cytoplasmic membrane proved to be 71.5% phosphatidylethanolamine and 23.5% phosphatidylglycerol. The fatty acid composition was also found to be quantitatively heterogeneous between the two membranes. Images PMID:4852262

  8. Magnetic properties of Nd-Ga-Fe{sub bal}-Nb-B alloy

    SciTech Connect

    Kim, Hyunkyu; Sung Kim, Chul; Yong An, Sung; Ryong Choi, Kang; Choi, Moonhee

    2014-05-07

    Here, we have synthesized Nd-Ga-Fe{sub bal}-Nb-B alloy by strip casting method. The crystalline and magnetic properties of sample were investigated with x-ray diffractometer (XRD), vibrating sample magnetometer (VSM), and Mössbauer spectrometer. The XRD pattern was analyzed with the Rietveld refinement method, indicating a tetragonal structure and the space group of P4{sub 2}/mnm. The temperature dependence of zero-field cooled (ZFC) magnetization curve was measured under applied field at temperature ranging from 4.2 to 740 K. From the ZFC curve, Curie temperature and spin reorientation temperature are determined to be 615 K and 130 K, respectively. Also, Mössbauer spectra were measured at various temperatures ranging from 4.2 to 620 K. Each spectrum was fitted with 6-sextets for Fe site (8j{sub 1}, 8j{sub 2}, 16k{sub 1}, 16k{sub 2}, 4c, and 4e), and magnetic hyperfine field, Isomer shift, electric quadrupole shift, and area ratio values were obtained from the fit. We observed the change in slope of magnetic hyperfine field and electric quadrupole shift at 130 K while the Curie temperature was determined to be 615 K from the measurement of zero velocity counter, agreeing with the values obtained from VSM measurements.

  9. Studies of cavity enhanced absorption spectroscopy for weak absorption gas measurements

    NASA Astrophysics Data System (ADS)

    Li, Liucheng; Duo, Liping; Gong, Deyu; Ma, Yanhua; Zhang, Zhiguo; Wang, Yuanhu; Zhou, Dongjian; Jin, Yuqi

    2017-01-01

    In order to determine the concentrations of trace amount metastable species in chemical lasers, an off-axis cavity enhanced absorption spectrometer for the detection of weak absorption gases has been built with a noise equivalent absorption sensitivity of 1.6x10-8 cm-1. The absorption spectrum of trace amount gaseous ammonia and water vapor was obtained with a spectral resolution of about 78 MHz. A multiple-line absorption spectroscopic method to determine the temperature of gaseous ammonia has been developed by use of multiple lines of ammonia molecule absorption spectrum.

  10. Absorption of CO laser radiation by NO

    NASA Technical Reports Server (NTRS)

    Hanson, R. K.; Monat, J. P.; Kruger, C. H.

    1976-01-01

    The paper describes absorption calculations and measurements at selected infrared CO laser wavelengths which are nearly coincident with absorption lines in the fundamental vibration-rotation band of NO near 5.3 microns. Initial work was directed towards establishing the optimal CO laser-NO absorption line coincidence for high temperature applications. Measurements of the absorption coefficient at this optimal laser wavelength were carried out, first using a room-temperature absorption cell for high-temperature calculations and then using a shock tube, for the temperature range 630-4000 K, to validate the high temperature calculations.

  11. A study of ultraviolet absorption lines through the complete Galactic halo by the analysis of HST faint object spectrograph spectra of active Galactic nuclei, 1

    NASA Technical Reports Server (NTRS)

    Burks, Geoffrey S.; Bartko, Frank; Shull, J. Michael; Stocke, John T.; Sachs, Elise R.; Burbidge, E. Margaret; Cohen, Ross D.; Junkkarinen, Vesa T.; Harms, Richard J.; Massa, Derck

    1994-01-01

    The ultraviolet (1150 - 2850 A) spectra of a number of active galactic nuclei (AGNs) observed with the Hubble Space Telescope (HST) Faint Object Spectrograph (FOS) have been used to study the properties of the Galactic halo. The objects that served as probes are 3C 273, PKS 0454-220, Pg 1211+143, CSO 251, Ton 951, and PG 1351+640. The equivalent widths of certain interstellar ions have been measured, with special attention paid to the C IV/C II and Si IV/Si II ratios. These ratios have been intercompared, and the highest values are found in the direction of 3C 273, where C IV/C II = 1.2 and Si IV/Si II greater than 1. These high ratios may be due to a nearby supernova remnant, rather than to ionized gas higher up in the Galactic halo. Our data give some support to the notion that QSO metal-line systems may arise from intervening galaxies which contain high supernova rates, galactic fountains, and turbulent mixing layers.

  12. Relationship between airway reactivity induced by methacholine or ultrasonically nebulized distilled cold water and BAL fluid cellular constituents in patients with sulfur mustard gas-induced asthma.

    PubMed

    Emad, Ali; Emad, Yasaman

    2007-01-01

    The objective of this article was to evaluate the relationship between the bronchial reactivity to methacholine and distilled cold water and inflammatory bronchial alveolar lavage (BAL) cells in mustard gas-induced asthma. This was a randomized, crossover clinical study set in a university hospital. The patients were 17 veterans with mustard gas-induced asthma and 17 normal veterans as a control group. Inhalation challenges with ultrasonically nebulized distilled water and methacholine and BAL via bronchoscopy and were performed in all patients and subjects. All patients did sustain a 20% fall in FEV(1) after methacholine, whereas two of them did not with distilled cold water. The patients were sensitive to distilled cold water with a median PD20 of 8.44 +/- 6.55 mL and sensitive to methacholine with the median PC20 of 4.88 +/- 4.22 mg/mL. Significant correlation was found between PC20 of methacholine and PD20 of distilled cold water (r = -0.74, p = 0.005). The proportion of BAL macrophages was significantly lower in patients with asthma than in the control group (p = 0.001). The proportions of lymphocytes and neutrophils were similar in the two groups. The percentage of eosinophils was higher in BAL fluid from the asthmatics compared with that in BAL fluid from the control group (p < 0.001). The percentage of the BAL eosinophils significantly correlated with both PC20 of methacholine (r = - 0.58, p = 0.01) and PD20 of distilled cold water (r = -0.81, p = 0.002). No relationship between PC20 of methacholine or PD20 of distilled cold water was found for other inflammatory BAL cells. This study showed that in patients with mustard gas-induced asthma, the degree of airway responsiveness to both methacholine and distilled water was associated with the percentage of BAL eosinophils.

  13. First theoretical global line lists of ethylene (12C2H4) spectra for the temperature range 50-700 K in the far-infrared for quantification of absorption and emission in planetary atmospheres

    NASA Astrophysics Data System (ADS)

    Rey, M.; Delahaye, T.; Nikitin, A. V.; Tyuterev, Vl. G.

    2016-10-01

    We present the construction of complete and comprehensive ethylene line lists for the temperatures 50-700 K based on accurate ab initio potential and dipole moment surfaces and extensive first-principle calculations. Three lists spanning the [0-6400] cm-1 infrared region were built at T = 80, 160, and 296 K, and two lists in the range [0-5200] cm-1 were built at 500 and 700 K. For each of these five temperatures, we considered possible convergence problems to ensure reliable opacity calculations. Our final list at 700 K was computed up to J = 71 and contains almost 60 million lines for intensities I > 5 × 10-27 cm/molecule. Comparisons with experimental spectra carried out in this study showed that for the most active infrared bands, the accuracy of band centers in our theoretical lists is better on average than 0.3 cm-1, and the integrated absorbance errors in the intervals relevant for spectral analyses are about 1-3%. These lists can be applied to simulations of absorption and emission spectra, radiative and non-LTE processes, and opacity calculations for planetary and astrophysical applications. The lists are freely accessible through the TheoReTS information system at http://theorets.univ-reims.fr and http://theorets.tsu.ru

  14. PERITONEAL ABSORPTION

    PubMed Central

    Hahn, P. F.; Miller, L. L.; Robscheit-Robbins, F. S.; Bale, W. F.; Whipple, G. H.

    1944-01-01

    The absorption of red cells from the normal peritoneum of the dog can be demonstrated by means of red cells labeled with radio-iron incorporated in the hemoglobin of these red cells. Absorption in normal dogs runs from 20 to 100 per cent of the amount given within 24 hours. Dogs rendered anemic by bleeding absorb red cells a little less rapidly—ranging from 5 to 80 per cent of the injected red cells. Doubly depleted dogs (anemic and hypoproteinemic) absorb even less in the three experiments recorded. This peritoneal absorption varies widely in different dogs and even in the same dog at different times. We do not know the factors responsible for these variations but there is no question about active peritoneal absorption. The intact red cells pass readily from the peritoneal cavity into lymph spaces in diaphragm and other areas of the peritoneum. The red cells move along the lymphatics and through the lymph glands with little or no phagocytosis and eventually into the large veins through the thoracic ducts. PMID:19871404

  15. Nutrient absorption.

    PubMed

    Rubin, Deborah C

    2004-03-01

    Our understanding of nutrient absorption continues to grow, from the development of unique animal models and from studies in which cutting-edge molecular and cellular biologic approaches have been used to analyze the structure and function of relevant molecules. Studies of the molecular genetics of inherited disorders have also provided many new insights into these processes. A major advance in lipid absorption has been the cloning and characterization of several intestinal acyl CoA:monoacylglycerol acyltransferases; these may provide new targets for antiobesity drug therapy. Studies of intestinal cholesterol absorption and reverse cholesterol transport have encouraged the development of novel potential treatments for hyperlipidemia. Observations in genetically modified mice and in humans with mutations in glucose transporter 2 suggest the importance of a separate microsomal membrane transport pathway for glucose transport. The study of iron metabolism has advanced greatly with the identification of the hemochromatosis gene and the continued examination of the genetic regulation of iron absorptive pathways. Several human thiamine transporters have been identified, and their specific roles in different tissues are being explored.

  16. The HI absorption "Zoo"

    NASA Astrophysics Data System (ADS)

    Geréb, K.; Maccagni, F. M.; Morganti, R.; Oosterloo, T. A.

    2015-03-01

    We present an analysis of the H I 21 cm absorption in a sample of 101 flux-selected radio AGN (S1.4 GHz> 50 mJy) observed with the Westerbork Synthesis Radio Telescope (WSRT). We detect H I absorption in 32 objects (30% of the sample). In a previous paper, we performed a spectral stacking analysis on the radio sources, while here we characterize the absorption spectra of the individual detections using the recently presented busy function. The H I absorption spectra show a broad variety of widths, shapes, and kinematical properties. The full width half maximum (FWHM) of the busy function fits of the detected H I lines lies in the range 32 km s-1absorption (FW20) lies in the range 63 km s-1lines (FWHM< 100 km s-1), intermediate widths (100 km s-1 200 km s-1). We study the kinematical and radio source properties of each group, with the goal of identifying different morphological structures of H I. Narrow lines mostly lie at the systemic velocity and are likely produced by regularly rotating H I disks or gas clouds. More H I disks can be present among galaxies with lines of intermediate widths; however, the H I in these sources is more unsettled. We study the asymmetry parameter and blueshift/redshift distribution of the lines as a function of their width. We find a trend for which narrow profiles are also symmetric, while broad lines are the most asymmetric. Among the broadest lines, more lines appear blueshifted than redshifted, similarly to what was found by previous studies. Interestingly, symmetric broad lines are absent from the sample. We argue that if a profile is broad, it is also asymmetric and shifted relative to the systemic velocity because it is tracing unsettled H I gas. In particular, besides three of the broadest (up to FW20 = 825 km s-1

  17. Urinary Concentrations and Antibacterial Activity of BAL30072, a Novel Siderophore Monosulfactam, against Uropathogens after Intravenous Administration in Healthy Subjects

    PubMed Central

    Straubinger, Marion; Blenk, Holger; Wagenlehner, Florian M. E.

    2016-01-01

    This annex study to a phase 1 study aimed to correlate urinary concentrations and bactericidal titers (UBTs) of BAL30072, a novel siderophore monosulfactam, in healthy subjects in order to evaluate which dosage of BAL30072 should be investigated in a clinical study on complicated urinary tract infection (UTI). Three cohorts of a total of 19 healthy male subjects were included in the add-on study and received the following BAL30072 dosages. The 1st cohort received 1 g once a day (q.d.) intravenously (i.v.) (1 h) on day 1 and 1 g thrice daily (t.i.d.) on day 2, the 2nd cohort received 2 g q.d. i.v. (1 h) on day 1 and 2 g t.i.d. on day 2, and the 3rd cohort received 1 g q.d. i.v. (4-h infusion) on day 8. Urine was collected up to 24 h after drug administration. UBTs were determined for seven Escherichia coli isolates (three wild type [WT], CTX-M-15, TEM-3, TEM-5, NDM-1), two Klebsiella pneumoniae isolates (WT, KPC), one Proteus mirabilis isolate (WT), and two Pseudomonas aeruginosa isolates (WT, VIM-1 plus AmpC). Urine drug concentrations were measured by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The median urinary excretions of BAL30072 ranged between 38% and 46% (3 cohorts). The median UBTs after i.v. administration of 1 or 2 g q.d. and after 1 or 2 g t.i.d. showed positive UBTs for 24 h after the lowest dosage (1 g q.d.) for 5 of 7 of the Enterobacteriaceae strains and after the higher dosage of 2 g administered i.v. t.i.d. for all strains tested. After i.v. infusion of 1 g over 4 h, positive UBTs were demonstrated for three E. coli strains for up to 12 h, for the K. pneumoniae (KPC) strain for up to 8 h, and for the P. aeruginosa (VIM-1 plus AmpC) strain for up to only 4 h. The minimal bactericidal concentrations (MBCs) of the E. coli (NDM-1) strain and the K. pneumoniae (WT) strain correlated well between broth and urine but did not correlate well for the two P. aeruginosa strains. BAL30072 exhibits positive UBTs for 24 h even after a dosage of 1

  18. LINE ABSORPTION OSCILLATOR STRENGTHS FOR THE c'{sub 4}{sup 1}{Sigma}{sup +}{sub u}(3)-X{sup 1}{Sigma}{sup +}{sub g}(0-5) BANDS IN N{sub 2}

    SciTech Connect

    Lavin, C.; Velasco, A. M.

    2011-09-20

    Theoretical absorption oscillator strengths and emission branching ratios for rotational lines of the c'{sub 4}{sup 1}{Sigma}{sup +}{sub u}(3)-X{sup 1}{Sigma}{sup +}{sub g}(0-5) bands of molecular nitrogen are reported. The calculations have been performed with the molecular quantum defect orbital method, which has proved to be reliable in previous studies of rovibronic transitions in diatomic molecules. The strong interaction between c'{sub 4}{sup 1}{Sigma}{sup +}{sub u}(3) and b' {sup 1}{Sigma}{sup +}{sub u}(10) states has been analyzed through an interaction matrix that includes rotational terms. Owing to the perturbation, the c'{sub 4}{sup 1}{Sigma}{sup +}{sub u}(3)-X{sup 1}{Sigma}{sup +}{sub g}(0), c'{sub 4}{sup 1}{Sigma}{sup +}{sub u}(3)-X{sup 1}{Sigma}{sup +}{sub g}(1), and c'{sub 4}{sup 1}{Sigma}{sup +}{sub u}(3)-X{sup 1}{Sigma}{sup +}{sub g}(5) bands are not weak, in contrast to what would be expected on the basis of the Franck-Condon principle. Moreover, the intensity distribution of the rotational lines within each of the vibronic bands deviates from considerations based on Hoenl-London factors. In this work, we provide data that may be useful to interpret spectra from atmospheres of the Earth, Titan, and Triton, in which transitions from the c'{sub 4}{sup 1}{Sigma}{sup +}{sub u}(3) level have been detected.

  19. Tunable diode laser absorption spectroscopy-based tomography system for on-line monitoring of two-dimensional distributions of temperature and H{sub 2}O mole fraction

    SciTech Connect

    Xu, Lijun Liu, Chang; Jing, Wenyang; Cao, Zhang; Xue, Xin; Lin, Yuzhen

    2016-01-15

    To monitor two-dimensional (2D) distributions of temperature and H{sub 2}O mole fraction, an on-line tomography system based on tunable diode laser absorption spectroscopy (TDLAS) was developed. To the best of the authors’ knowledge, this is the first report on a multi-view TDLAS-based system for simultaneous tomographic visualization of temperature and H{sub 2}O mole fraction in real time. The system consists of two distributed feedback (DFB) laser diodes, a tomographic sensor, electronic circuits, and a computer. The central frequencies of the two DFB laser diodes are at 7444.36 cm{sup −1} (1343.3 nm) and 7185.6 cm{sup −1} (1391.67 nm), respectively. The tomographic sensor is used to generate fan-beam illumination from five views and to produce 60 ray measurements. The electronic circuits not only provide stable temperature and precise current controlling signals for the laser diodes but also can accurately sample the transmitted laser intensities and extract integrated absorbances in real time. Finally, the integrated absorbances are transferred to the computer, in which the 2D distributions of temperature and H{sub 2}O mole fraction are reconstructed by using a modified Landweber algorithm. In the experiments, the TDLAS-based tomography system was validated by using asymmetric premixed flames with fixed and time-varying equivalent ratios, respectively. The results demonstrate that the system is able to reconstruct the profiles of the 2D distributions of temperature and H{sub 2}O mole fraction of the flame and effectively capture the dynamics of the combustion process, which exhibits good potential for flame monitoring and on-line combustion diagnosis.

  20. Assessment of Wound Healing Activity of the Aqueous Extracts of Colutea cilicica Boiss. & Bal. Fruits and Leaves

    PubMed Central

    Peşin Süntar, Ipek; Koca, Ufuk; Küpeli Akkol, Esra; Yılmazer, Demet; Alper, Murat

    2011-01-01

    The fruiting branches of Colutea cilicica Boiss. & Bal., along with leaves and fruits, have been used to heal inflammatory wounds at traditional medicine in various parts of Turkey. In order to evaluate the wound healing activity of the plant, aqueous extracts were prepared from the flowering parts and fruits of Colutea cilicica Boiss. & Bal. by using 40°C distilled water. Incision wound healing models by using tensiometer on rats and excision wound healing models on mice were employed to assess the activity. Significant wound healing activity was observed when ointment formulation of the aqueous extract at 1% concentration was applied on the mentioned models. The fruit extract treated the groups of animals, showing a 78.1% contraction in wounds, which was close to the contraction value of the reference drug Madecassol (100%). On the other hand, the same extract used on the incision wound model demonstrated a significant increase (42%) in wound tensile strength, compared to the flowering aerial parts. Histopathological examination also supported the results shown in both the incision and excision wound models. The wound healing effect was evaluated and compared with the reference ointment Madecassol. Moreover, zinc and vitamin C levels in the fruit (9480 ± 0 mcg g−1; 389 mg g−1) and flowering aerial part (6609 ± 1 mcg g−1; 404 mg g−1) extracts, which might have contributed to the wound healing process, were determined. The experimental data confirmed the traditional usage of C. cilicica Boiss. & Bal. PMID:19946024

  1. Utility of Urinary Biomarkers in Predicting Loss of Residual Renal Function: The balANZ Trial

    PubMed Central

    Cho, Yeoungjee; Johnson, David W.; Vesey, David A.; Hawley, Carmel M.; Clarke, Margaret; Topley, Nicholas

    2015-01-01

    ♦ Background: The ability of urinary biomarkers to predict residual renal function (RRF) decline in peritoneal dialysis (PD) patients has not been defined. The present study aimed to explore the utility of established biomarkers from kidney injury models for predicting loss of RRF in incident PD patients, and to evaluate the impact on RRF of using neutral-pH PD solution low in glucose degradation products. ♦ Methods: The study included 50 randomly selected participants from the balANZ trial who had completed 24 months of follow-up. A change in glomerular filtration rate (GFR) was used as the primary clinical outcome measure. In a mixed-effects general linear model, baseline measurements of 18 novel urinary biomarkers and albumin were used to predict GFR change. The model was further used to evaluate the impact of biocompatible PD solution on RRF, adjusted for each biomarker. ♦ Results: Baseline albuminuria was not a useful predictor of change in RRF in PD patients (p = 0.84). Only clusterin was a significant predictor of GFR decline in the whole population (p = 0.04, adjusted for baseline GFR and albuminuria). However, the relationship was no longer apparent when albuminuria was removed from the model (p = 0.31). When the effect of the administered PD solutions was examined using a model adjusted for PD solution type, baseline albuminuria, and GFR, higher baseline urinary concentrations of trefoil factor 3 (TFF3, p = 0.02), kidney injury molecule 1 (KIM-1, p = 0.04), and interferon γ-induced protein 10 (IP-10, p = 0.03) were associated with more rapid decline of RRF in patients receiving conventional PD solution compared with biocompatible PD solution. ♦ Conclusions: Higher urinary levels of kidney injury biomarkers (TFF3, KIM-1, IP-10) at baseline predicted significantly slower RRF decline in patients receiving biocompatible PD solutions. Findings from the present investigation should help to guide future studies to validate the utility of urinary

  2. On-line speciation and determination of Cr(III) and Cr(VI) in drinking and waste water samples by reversed-phase high performance liquid chromatography coupled with atomic absorption spectrometry.

    PubMed

    Sarica, Deniz Yurtsever; Türker, A Rehber; Erol, Esra

    2006-07-01

    A simple, rapid, and selective on-line method for the speciation and determination of Cr(III) and Cr(VI) in aqueous solutions by ion-pairing HPLC coupled with flame atomic absorption spectrometry (FAAS) is described. The composition of the mobile phase has been optimized for better separation. The effects of column temperature, volume of injection loop, fuel flow rate of FAAS, and nebulizer suction rate of FAAS have also been investigated. Separation is accomplished in almost 2.5 min on a 25 cm length C18 column at 40 degrees C. The selectivity of the method has been established by investigating the effect of interfering elements on chromium determination. The detection limit (3sigma) achieved by the method was calculated as 3.7 ng/mL for Cr(III) and 2.0 ng/mL for Cr(VI). The proposed method has been validated by analyzing certified reference material (BCR 544) and successfully applied to the analysis of drinking water and wastewater samples with a relative error below 6%.

  3. On-line separation and preconcentration of lead(II) by solid-phase extraction using activated carbon loaded with xylenol orange and its determination by flame atomic absorption spectrometry.

    PubMed

    Ensafi, Ali A; Shiraz, A Zendegi

    2008-02-11

    Activated carbon loaded with xylenol orange in a mini-column was used for the highly selective separation and preconcentration of Pb(II) ions. An on-line system for enrichment and the determination of Pb(II) was carried out on flame atomic absorption spectrometry. The conditions of preconcentration and quantitative recovery of Pb(II) from diluted solution, such as pH of aqueous phase, amount of the sorbent, volume of the solutions and flow variables were studied as well as effect of potential interfering ions. Under the optimum conditions, Pb(II) in an aqueous sample was concentrated about 200-fold and the detection limit was 0.4 ng mL(-1) Pb(II). The adsorption capacity of the solid phase was 0.20mg of lead per one gram of the modified activated carbon. The modified activated carbon is stable for several treatments of sample solutions without the need for using any chemical reagent. The recovery of lead(II) from river water, waste water, tap water, and in the following reference materials: SRM 2711 Montana soil and GBW-07605 tea were obtained in the range of 97-104% by the proposed method.

  4. Preparation and characterization of magnetic nanoparticles for the on-line determination of gold, palladium, and platinum in mine samples based on flow injection micro-column preconcentration coupled with graphite furnace atomic absorption spectrometry.

    PubMed

    Ye, Juanjuan; Liu, Shuxia; Tian, Miaomiao; Li, Wanjun; Hu, Bin; Zhou, Weihong; Jia, Qiong

    2014-01-01

    A simple and highly selective procedure for on-line determination of trace levels of Au, Pd, and Pt in mine samples has been developed using flow injection-column adsorption preconcentration coupled with graphite furnace atomic absorption spectrophotometry (FI-column-GFAAS). The precious metals were adsorbed on the as-synthesized magnetic nanoparticles functionalized with 4'-aminobenzo-15-crown-5-ether packed into a micro-column and then eluted with 2% thiourea + 0.1 mol L(-1) HCl solution prior to the determination by GFAAS. The properties of the magnetic adsorbents were investigated by scanning electron microscope (SEM), X-ray diffraction (XRD), and vibrating sample magnetometer (VSM). Various experimental parameters affecting the preconcentration of Au, Pd, and Pt were investigated and optimized. Under the optimal experimental conditions, the detection limits of the developed technique were 0.16 ng mL(-1) for Au, 0.28 ng mL(-1) for Pd, and 1.01 ng mL(-1) for Pt, with enrichment factors of 24.3, 13.9, and 17.8, respectively. Precisions, evaluated as repeatability of results, were 1.1%, 3.9%, and 4.4% respectively for Au, Pd, and Pt. The developed method was validated by the analysis of Au, Pd, and Pt in certified reference materials and mine samples with satisfactory results.

  5. The Stellar Initial Mass Function in Early-type Galaxies from Absorption Line Spectroscopy. IV. A Super-Salpeter IMF in the Center of NGC 1407 from Non-parametric Models

    NASA Astrophysics Data System (ADS)

    Conroy, Charlie; van Dokkum, Pieter G.; Villaume, Alexa

    2017-03-01

    It is now well-established that the stellar initial mass function (IMF) can be determined from the absorption line spectra of old stellar systems, and this has been used to measure the IMF and its variation across the early-type galaxy population. Previous work focused on measuring the slope of the IMF over one or more stellar mass intervals, implicitly assuming that this is a good description of the IMF and that the IMF has a universal low-mass cutoff. In this work we consider more flexible IMFs, including two-component power laws with a variable low-mass cutoff and a general non-parametric model. We demonstrate with mock spectra that the detailed shape of the IMF can be accurately recovered as long as the data quality is high (S/N ≳ 300 Å‑1) and cover a wide wavelength range (0.4–1.0 μm). We apply these flexible IMF models to a high S/N spectrum of the center of the massive elliptical galaxy NGC 1407. Fitting the spectrum with non-parametric IMFs, we find that the IMF in the center shows a continuous rise extending toward the hydrogen-burning limit, with a behavior that is well-approximated by a power law with an index of ‑2.7. These results provide strong evidence for the existence of extreme (super-Salpeter) IMFs in the cores of massive galaxies.

  6. The short- and long-term frequency stabilization of an injection-locked Nd:YAG laser in reference to a Fabry-Perot cavity and an iodine saturated absorption line

    NASA Astrophysics Data System (ADS)

    Musha, Mitsuru; Kanaya, Takeshi; Nakagawa, Ken'ichi; Ueda, Ken-ichi

    2000-09-01

    We have developed a wideband frequency-stabilized injection-locked Nd:YAG laser as a light source for the laser interferometric gravitational wave detector, in which short-term frequency stability of the laser improves the sensitivity of the interferometer and the long-term frequency stability aims for the stable long-time operation of the interferometer. The frequency of a 2-W injection-locked laser is locked to both a rigid Fabry-Perot cavity with ULE spacer and saturated absorption line of 127I2 simultaneously with two nested servo loops, and the long-term as well as short-term frequency stability are obtained. The drift of the resonant frequency of the rigid Fabry-Perot cavity is measured and the stability of the Fabry-Perot cavity is estimated to be 20× f-1 [Hz/√Hz]. The predicted frequency stabilities of the present dual-reference-locked laser are numerically simulated. Our wideband frequency-stabilized laser is also available for the high-resolution spectroscopy.

  7. Synthesis and application of a new functionalized resin for use in an on-line, solid phase extraction system for the determination of trace elements in waters and reference cereal materials by flame atomic absorption spectrometry.

    PubMed

    Karadaş, Cennet; Turhan, Onur; Kara, Derya

    2013-11-15

    The synthesis and characterization of the resin Amberlite XAD-4 functionalized with 2,6-pyridinedicarboxaldehyde and its application in an on-line system for the preconcentration of cadmium, cobalt, copper, lead and manganese prior to determination using flame atomic absorption spectrometry (FAAS) is proposed. Metal ions retained on the modified resin were eluted using 1.0 mol L(-1) HNO3 solution and aspirated directly to the nebulizer-burner system of a FAAS instrument using a flow injection system. Detection limits (3σ) were determined to be 0.13 μg L(-1) for Cd, 0.29 μg L(-1) for Cu, 0.23 μg L(-1) for Mn, 0.58 μg L(-1) for Co and 2.19 μg L(-1) for Pb using a 10 mL of water sample loading volume. The limits of detection would be 100 times higher with units of μg kg(-1) for the solid samples in which their dilution ratios as (volume/weight) were 100. Enrichment factors ranged from 23.6 to 28.9 (for Co and Mn, respectively). The proposed method was successfully applied to determination of the analytes in natural water samples and certified reference materials.

  8. MiR-185/AKT and miR-29a/Collagen 1a pathways are activated in IPF BAL cells

    PubMed Central

    Tsitoura, Eliza; Wells, Athol U.; Karagiannis, Kostantinos; Lasithiotaki, Ismini; Vasarmidi, Eirini; Bibaki, Eleni; Koutoulaki, Chara; Sato, Hiroe; Spandidos, Demetrios A.; Siafakas, Nikolaos M.; Sourvinos, George; Antoniou, Katerina M.

    2016-01-01

    MicroRNA signatures of BAL cells and alveolar macrophages are currently lacking in IPF. Here we sought to investigate the expression of fibrosis-related microRNAs in the cellular component of the BAL in IPF. We thus focused on microRNAs previously associated with fibrosis (miR-29a, miR-29b, miR-29c, let-7d, and miR-21) and rapid IPF progression (miR-185, miR-210, miR-302c-3p miR-376c and miR-423-5p). Among the tested microRNAs miR-29a and miR-185 were found significantly downregulated in IPF while miR-302c-3p and miR-376c were not expressed by BAL cells. Importantly, the downregulation of miR-29a inversely correlated with the significantly increased levels of COL1A1 mRNA in IPF BAL cells. Collagen 1 a was found mainly overexpressed in alveolar macrophages and not other cell types of the BAL by immunofluorescence. In view of the downregulation of miR-185, we tested the response of THP-1 macrophages to profibrotic cytokine TGFb and observed the downregulation of miR-185. Conversely, proinflammatory stimulation lead to miR-185 upregulation. Upon examination of the mRNA levels of known miR-185 targets AKT1, DNMT1 and HMGA2, no significant correlations were observed in the BAL cells. However, increased levels of total AKT and AKTser473 phosphorylation were observed in the IPF BAL cells. Furthermore, miR-185 inhibition in THP-1 macrophages resulted in significant increase of AKTser473 phosphorylation. Our study highlights the importance of BAL microRNA signatures in IPF and identifies significant differences in miR-185/AKT and miR-29a/collagen axes in the BAL cells of IPF patients. PMID:27769060

  9. Iron-rich low-cost superalloys. [Cr(15)-Mn(15)-Mo(2)-C(1. 5)-Si(1. 0)-Nb(1. 0)-Fe(bal. ) and Cr(20)-Mn(10)-C(3. 4)-Fe(bal. )

    SciTech Connect

    Wayne, S.F.

    1985-01-01

    An iron-rich low-cost superalloy has been developed in conjunction with United Technologies Research Center under the NASA program, Conservation of Strategic Aerospace Materials. The alloy, when processed by conventional chill casting, has physical and mechanical properties that compare favorably with existing nickel - and cobalt-based superalloys while containing significantly lower amounts of strategic elements. The composition of the alloy is Cr(15)-Mn(15)-Mo(2)-C(1.5)-Si(1.0)-Nb(1.0)-Fe(bal.), and it can be produced with chromite ore deposits located within the United States. Studies were also made on the properties of Cr(20)-Mn(10)-C(3.4)-Fe(bal.), a eutectic alloy processed by chill casting and directional solidification (D.S.) which produced an aligned microstructure consisting of M/sub 7/C/sub 3/ fibers in an ..gamma..-Fe matrix. This good alignment vanishes when molybdenum or aluminum is added in higher concentrations. Thermal expansion of the M/sub 7/C/sub 3/ (M = Fe, Cr, Mn) carbide lattice was measured up to 800/sup 0/C and found to be highly anisotropic, with the a-axis being the predominant mode of expansion. Repetitive impact-sliding wear experiments performed with the Fe-rich eutectic alloy showed that the directionally solidified microstructure greatly improved the alloy's wear resistance as compared to the chill-cast microstructure and conventional nickel-base superalloys.

  10. Chitosan oligomers as potential and safe absorption enhancers for improving the pulmonary absorption of interferon-alpha in rats.

    PubMed

    Yamada, Keigo; Odomi, Masaaki; Okada, Naoki; Fujita, Takuya; Yamamoto, Akira

    2005-11-01

    Effects of chitosan oligomers on pulmonary absorption of interferon-alpha (IFN) were examined by means of an in vivo pulmonary absorption experiment. Chitosan oligomers used in this study were chitosan dimer, tetramer, hexamer, and water-soluble (WS) chitosan. A significant increase in serum IFN concentrations was observed after intratracheal administration of IFN with these oligomers. Of these chitosan oligomers, 0.5% w/v chitosan hexamer appeared to be more effective in enhancing the pulmonary absorption of IFN than other oligomers at the same concentration, and the AUC value of IFN with chitosan hexamer increased 2.6-fold as compared with the control. On the other hand, chitosan polymers, which have relatively high molecular weights (22-96 kDa), were not effective in enhancing the pulmonary absorption of IFN due to their low solubility in water. Additionally, the effect of different concentrations (0.1%-1% w/v) of chitosan hexamer on the pulmonary absorption of IFN was studied. Of these different concentrations of chitosan hexamers, the highest AUC value of IFN was obtained in the presence of 0.5% w/v chitosan hexamer. Furthermore, chitosan oligomers did not cause any membrane damage to the rat pulmonary tissues, as determined by leakage of protein and lactate dehydrogenase (LDH) in bronchoalveolar lavage (BAL) fluid. Therefore, these findings indicated that the use of chitosan oligomers would be a promising approach for improving of the pulmonary absorption of biologically active peptides including IFN.

  11. ABSORPTION ANALYZER

    DOEpatents

    Brooksbank, W.A. Jr.; Leddicotte, G.W.; Strain, J.E.; Hendon, H.H. Jr.

    1961-11-14

    A means was developed for continuously computing and indicating the isotopic assay of a process solution and for automatically controlling the process output of isotope separation equipment to provide a continuous output of the desired isotopic ratio. A counter tube is surrounded with a sample to be analyzed so that the tube is exactly in the center of the sample. A source of fast neutrons is provided and is spaced from the sample. The neutrons from the source are thermalized by causing them to pass through a neutron moderator, and the neutrons are allowed to diffuse radially through the sample to actuate the counter. A reference counter in a known sample of pure solvent is also actuated by the thermal neutrons from the neutron source. The number of neutrons which actuate the detectors is a function of a concentration of the elements in solution and their neutron absorption cross sections. The pulses produced by the detectors responsive to each neu tron passing therethrough are amplified and counted. The respective times required to accumulate a selected number of counts are measured by associated timing devices. The concentration of a particular element in solution may be determined by utilizing the following relation: T2/Ti = BCR, where B is a constant proportional to the absorption cross sections, T2 is the time of count collection for the unknown solution, Ti is the time of count collection for the pure solvent, R is the isotopic ratlo, and C is the molar concentration of the element to be determined. Knowing the slope constant B for any element and when the chemical concentration is known, the isotopic concentration may be readily determined, and conversely when the isotopic ratio is known, the chemical concentrations may be determined. (AEC)

  12. HIV-1 gp120Bal down-regulates phosphorylated NMDA receptor subunit 1 in cortical neurons via activation of glutamate and chemokine receptors

    PubMed Central

    Ru, Wenjuan; Tang, Shao-Jun

    2015-01-01

    HIV-1 envelope glycoprotein gp120 (gp120) is a major virulence protein implicated in the pathogenesis of HIV-associated neurocognitive disorders (HAND). Although gp120 has been suggested to cause synaptic and neuronal injuries by disrupting NMDA receptor (NMDAR) function, the underlying mechanism is unclear. Here, we show that gp120Bal down-regulates the phosphorylation of the NMDAR subunit 1 NR1 (at Ser896 and Ser897), which is essential for NMDAR function. This effect of gp120Bal is blocked by specific antagonists of both NMDA and AMPA receptors, indicating a critical role of synaptic activation. Furthermore, AMD3100 and maraviroc, antagonists of CCR5 and CXCR4 chemokine receptors, respectively, inhibit the effect of gp120Bal on NR1, suggesting that CXCR4 and CCR5 activation are involved. These findings may provide mechanistic insights into the synaptopathogenesis caused by HIV-1 infection. PMID:26582091

  13. β-Amyloid1-42, HIV-1Ba-L (Clade B) Infection and Drugs of Abuse Induced Degeneration in Human Neuronal Cells and Protective Effects of Ashwagandha (Withania somnifera) and Its Constituent Withanolide A

    PubMed Central

    Kurapati, Kesava Rao Venkata; Samikkannu, Thangavel; Atluri, Venkata Subba Rao; Kaftanovskaya, Elena; Yndart, Adriana; Nair, Madhavan P. N.

    2014-01-01

    Alzheimer's disease (AD) is characterized by progressive dysfunction of memory and higher cognitive functions with abnormal accumulation of extracellular amyloid plaques and intracellular neurofibrillary tangles throughout cortical and limbic brain regions. Withania somnifera (WS) also known as ‘ashwagandha’ (ASH) is used widely in Ayurvedic medicine as a nerve tonic and memory enhancer. However, there is paucity of data on potential neuroprotective effects of ASH against β-Amyloid (1–42) (Aβ) induced neuropathogenesis. In the present study, we have tested the neuroprotective effects of Methanol: Chloroform (3:1) extract of ASH and its constituent Withanolide A (WA) against Aβ induced toxicity, HIV-1Ba-L (clade B) infection and the effects of drugs of abuse using a human neuronal SK-N-MC cell line. Aβ when tested individually, induced cytotoxic effects in SK-N-MC cells as shown by increased trypan blue stained cells. However, when ASH was added to Aβ treated cells the toxic effects were neutralized. This observation was supported by cellular localization of Aβ, MTT formazan exocytosis, and the levels of acetylcholinesterase activity, confirming the chemopreventive or protective effects of ASH against Aβ induced toxicity. Further, the levels of MAP2 were significantly increased in cells infected with HIV-1Ba-L (clade B) as well as in cells treated with Cocaine (COC) and Methamphetamine (METH) compared with control cells. In ASH treated cells the MAP2 levels were significantly less compared to controls. Similar results were observed in combination experiments. Also, WA, a purified constituent of ASH, showed same pattern using MTT assay as a parameter. These results suggests that neuroprotective properties of ASH observed in the present study may provide some explanation for the ethnopharmacological uses of ASH in traditional medicine for cognitive and other HIV associated neurodegenerative disorders and further ASH could be a potential novel drug to

  14. β-Amyloid1-42, HIV-1Ba-L (clade B) infection and drugs of abuse induced degeneration in human neuronal cells and protective effects of ashwagandha (Withania somnifera) and its constituent Withanolide A.

    PubMed

    Kurapati, Kesava Rao Venkata; Samikkannu, Thangavel; Atluri, Venkata Subba Rao; Kaftanovskaya, Elena; Yndart, Adriana; Nair, Madhavan P N

    2014-01-01

    Alzheimer's disease (AD) is characterized by progressive dysfunction of memory and higher cognitive functions with abnormal accumulation of extracellular amyloid plaques and intracellular neurofibrillary tangles throughout cortical and limbic brain regions. Withania somnifera (WS) also known as 'ashwagandha' (ASH) is used widely in Ayurvedic medicine as a nerve tonic and memory enhancer. However, there is paucity of data on potential neuroprotective effects of ASH against β-Amyloid (1-42) (Aβ) induced neuropathogenesis. In the present study, we have tested the neuroprotective effects of Methanol: Chloroform (3:1) extract of ASH and its constituent Withanolide A (WA) against Aβ induced toxicity, HIV-1(Ba-L) (clade B) infection and the effects of drugs of abuse using a human neuronal SK-N-MC cell line. Aβ when tested individually, induced cytotoxic effects in SK-N-MC cells as shown by increased trypan blue stained cells. However, when ASH was added to Aβ treated cells the toxic effects were neutralized. This observation was supported by cellular localization of Aβ, MTT formazan exocytosis, and the levels of acetylcholinesterase activity, confirming the chemopreventive or protective effects of ASH against Aβ induced toxicity. Further, the levels of MAP2 were significantly increased in cells infected with HIV-1(Ba-L) (clade B) as well as in cells treated with Cocaine (COC) and Methamphetamine (METH) compared with control cells. In ASH treated cells the MAP2 levels were significantly less compared to controls. Similar results were observed in combination experiments. Also, WA, a purified constituent of ASH, showed same pattern using MTT assay as a parameter. These results suggests that neuroprotective properties of ASH observed in the present study may provide some explanation for the ethnopharmacological uses of ASH in traditional medicine for cognitive and other HIV associated neurodegenerative disorders and further ASH could be a potential novel drug to reduce

  15. Involvement of Fe Uptake Systems and AmpC β-Lactamase in Susceptibility to the Siderophore Monosulfactam BAL30072 in Pseudomonas aeruginosa

    PubMed Central

    van Delden, Christian; Page, Malcolm G. P.

    2013-01-01

    BAL30072 is a monosulfactam conjugated with an iron-chelating dihydroxypyridone moiety. It is active against Gram-negative bacteria, including multidrug-resistant Pseudomonas aeruginosa. We selected mutants with decreased susceptibilities to BAL30072 in P. aeruginosa PAO1 under a variety of conditions. Under iron-deficient conditions, mutants with overexpression of AmpC β-lactamase predominated. These mutants were cross-resistant to aztreonam and ceftazidime. Similar mutants were obtained after selection at >16× the MIC in iron-sufficient conditions. At 4× to 8× the MIC, mutants with elevated MIC for BAL30072 but unchanged MICs for aztreonam or ciprofloxacin were selected. The expression of ampC and the major efflux pump genes were also unchanged. These BAL30072-specific mutants were characterized by transcriptome analysis, which revealed upregulation of the Fe-dicitrate operon, FecIRA. Whole-genome sequencing showed that this resulted from a single nucleotide change in the Fur-box of the fecI promoter. Overexpression of either the FecI ECF sigma factor or the FecA receptor increased BAL30072 MICs 8- to 16-fold. A fecI mutant and a fecA mutant of PAO1 were hypersusceptible to BAL30072 (MICs < 0.06 μg/ml). The most downregulated gene belonged to the pyochelin synthesis operon, although mutants in pyochelin receptor or synthesis genes had unchanged MICs. The piuC gene, coding for a Fe(II)-dependent dioxygenase located next to the piuA iron receptor gene, was also downregulated. The MICs of BAL30072 for piuC and piuA transposon mutants were increased 8- and 16-fold, respectively. We conclude that the upregulation of the Fe-dicitrate system impacts the expression of other TonB-dependent iron transporters and that PiuA and PiuC contribute to the susceptibility of P. aeruginosa PAO1 to BAL30072. PMID:23422914

  16. Volatile contents of mafic-to-intermediate magmas at San Cristóbal volcano in Nicaragua

    NASA Astrophysics Data System (ADS)

    Robidoux, P.; Aiuppa, A.; Rotolo, S. G.; Rizzo, A. L.; Hauri, E. H.; Frezzotti, M. L.

    2017-02-01

    San Cristóbal volcano in northwest Nicaragua is one of the most active basaltic-andesitic stratovolcanoes of the Central American Volcanic Arc (CAVA). Here we provide novel constraints on the volcano's magmatic plumbing system, by presenting the first direct measurements of major volatile contents in mafic-to-intermediate glass inclusions from Holocene and historic-present volcanic activity. Olivine-hosted (forsterite [Fo] < 80; Fo< 80) glass inclusions from Holocene tephra layers contain moderate amounts of H2O (0.1-3.3 wt%) and S and Cl up to 2500 μg/g, and define the mafic (basaltic) endmember component. Historic-present scoriae and tephra layers exhibit more-evolved olivines (Fo69-72) that contain distinctly lower volatile contents (0.1-2.2 wt% H2O, 760-1675 μg/g S, and 1021-1970 μg/g Cl), and represent a more-evolved basaltic-andesitic magma. All glass inclusions are relatively poor in CO2, with contents reaching 527 μg/g (as measured by nanoscale secondary ion mass spectrometry), suggesting pre- to postentrapment CO2 loss to a magmatic vapor. We use results of Raman spectroscopy obtained in a population of small (< 50 μm) inclusions with CO2-bearing shrinkage bubbles (3-12 μm) to correct for postentrapment CO2 loss to bubbles, and to estimate the original minimum CO2 content in San Cristóbal parental melts at 1889 μg/g, which is consistent with the less-CO2-degassed melt inclusions (MI) (> 1500 μg/g) found in Nicaragua at Cerro Negro, Nejapa, and Granada. Models of H2O and CO2 solubilities constrain the degassing pathway of magmas up to 425 MPa ( 16 km depth), which includes a deep CO2 degassing step (only partially preserved in the MI record), followed by coupled degassing of H2O and S plus crystal fractionation at magma volatile saturation pressures from ∼ 195 to < 10 MPa. The variation in volatile contents from San Cristóbal MI is interpreted to reflect (1) Holocene eruptive cycles characterized by the rapid emplacement of basaltic magma

  17. Reflective-tube absorption meter

    NASA Astrophysics Data System (ADS)

    Zaneveld, J. Ronald V.; Bartz, Robert; Kitchen, James C.

    1990-09-01

    The design and calibration of a proposed in situ spectral absorption meter is evaluated using a laboratory prototype. The design includes a silver coated (second-surface) glass tube, a tungsten light source (stabilized by means of optical feedback), a monochromator, and a solid state detector. The device measures the absorption coefficient plus a portion of the volume scattering function. Theoretical analyses and laboratory experiments which explore the magnitude and variation of the errors due to scattering and internal reflections are described. Similar analyses are performed on the Cary 1 18 Spectrophotometer to allow cross calibration. Algorithms to yield the abscrption coefficient and the zenith-sun diffuse attenuation coefficient are presented and evaluated. Simultaneous measurement of the beam attenuation or backscattering coefficient allows use of algoriThms with much narrower error bands. The various methods of obtaining absorption and diffuse attenuation values are compared. Procedures for using reverse osmosis filtration to produce a clean water calibration standard are described. An absorption spectrum for pure water is obtained. Development of the absorption meter is proceeding along two lines: 1) a two-wavelength side-by-side LED is being fabricated to allow an in situ chlorophyll a absorption meter to be constructed, and 2) scientific projects using a shipboard or laboratory flow.-through pumping system are being planned.

  18. Fluorine speciation analysis using reverse phase liquid chromatography coupled off-line to continuum source molecular absorption spectrometry (CS-MAS): identification and quantification of novel fluorinated organic compounds in environmental and biological samples.

    PubMed

    Qin, Zhiwei; McNee, David; Gleisner, Heike; Raab, Andrea; Kyeremeh, Kwaku; Jaspars, Marcel; Krupp, Eva; Deng, Hai; Feldmann, Jörg

    2012-07-17

    Driven by increasing demand for the monitoring of industrial perfluorinated compounds (PFCs), the identification of novel fluorine containing compounds (FOCs) and the tracking of organofluorine drugs and their degradation products, there is a clear need for sensitive, fluorine-specific detection of unknown FOCs. Here we report the first ever direct fluorine-specific (speciation) method; capable of individually detecting untargeted FOCs in environmental and biological samples through the application of continuum source molecular absorption spectrometry (CS-MAS) using a commercial CS-AAS. Two model FOCs (2,4,6, trifluorobenzoic acid (TFBA) and 5-fluoroindol-5-carboxylic acid (FICA)) were used, achieving fluorine-specific detection across a range of 0.1 to 300 ng/mL fluorine, corresponding to a limit of detection of 4 pg F and 5.26 nM for both compounds. Both TFBA and FICA showed a similar response to CS-MAS detection, potentially enabling the quantification of fluorine content in novel FOCs without having molecular standards available. This paper also reports the use of reverse-phase high performance liquid chromatography (RP-HPLC) coupled off-line with CS-MAS for the identification of single organofluorines in a mixture of FOCs via fraction collection. The linear range of both FOCs was determined to be from 1 to 500 ng/mL. The limits of detection of those species were just above 1 ng/mL (100 pg) and can therefore compete with targeted analytical methods such as ESI-MS. Finally, as a proof of principle the analysis of a fluoride-containing groundwater sample from Ghana demonstrated that this method can be used in the detection of novel FOCs, with identification achieved through parallel ESI-MS. Coupled HPLC-CS-MAS/ESI-MS is the first analytical methodology capable of selectively detecting and identifying novel FOCs, making possible the quantification of all fluorine containing compounds in one sample. This is the necessary analytical requirement to perform

  19. A search for intervening HI absorption

    NASA Astrophysics Data System (ADS)

    Reeves, Sarah N.; Sadler, Elaine M.; Allison, James R.; Koribalski, Baerbel S.; Curran, Stephen J.

    2013-03-01

    HI absorption-line studies provide a unique probe of the gas distribution and kinematics in galaxies well beyond the local universe (z ≳ 0.3). HI absorption-line surveys with next-generation radio telescopes will provide the first large-scale studies of HI in a redshift regime which is poorly understood. However, we currently lack the understanding to infer galaxy properties from absorption-line observations alone. To address this issue, we are conducting a search for intervening HI absorption in a sample of 20 nearby galaxies. Our aim is to investigate how the detection rate varies with distance from the galaxy. We target sight-lines to bright continuum sources, which intercept known gas-rich galaxies, selected from the HIPASS Bright Galaxy Catalogue (Koribalski et al. 2004). In our pilot sample, six galaxies with impact parameters < 20 kpc, we do not detect any absorption lines - although all are detected in 21cm emission. This indicates that an absorption non-detection cannot simply be interpreted as an absence of neutral gas - see Fig. 1. Our detection rate is low compared to previous surveys e.g. Gupta et al. (2010). This is, at least partially, due to the high resolution of the observations reducing the flux of the background source, which will also be an issue in future surveys, such as ASKAP-FLASH.

  20. Geometrical interpretation of optical absorption

    SciTech Connect

    Monzon, J. J.; Barriuso, A. G.; Sanchez-Soto, L. L.; Montesinos-Amilibia, J. M.

    2011-08-15

    We reinterpret the transfer matrix for an absorbing system in very simple geometrical terms. In appropriate variables, the system appears as performing a Lorentz transformation in a (1 + 3)-dimensional space. Using homogeneous coordinates, we map that action on the unit sphere, which is at the realm of the Klein model of hyperbolic geometry. The effects of absorption appear then as a loxodromic transformation, that is, a rhumb line crossing all the meridians at the same angle.

  1. Anomalous atmospheric absorption spectra due to water dimer

    NASA Astrophysics Data System (ADS)

    Cai, Peipei; Zhang, Hansheng; Shen, Shanxiong; Cheng, I.-Shan

    1986-11-01

    The anomalous atmospheric absorption spectra in the window wavelength region of 8-14 microns have been suggested due to the water dimer. Based on laboratory measurements, water continuum CO2 laser absorption spectra and a resonance absorption line due to the weak local wave vapor pure rotational transition have been reported. The equilibrium concentration of water dimers in the atmosphere, the electronic binding energy and the theoretical calculations for absorption attenuation have been obtained in agreement with published data.

  2. Aflatoxin levels in chronic hepatitis B patients with cirrhosis or hepatocellular carcinoma in Balıkesir, Turkey.

    PubMed

    Aydın, M; Aydın, S; Bacanlı, M; Başaran, N

    2015-11-01

    Aflatoxins, the secondary metabolites produced by species of naturally occurring Aspergilli, are commonly found in food such as cereals, dried fruits and juice, wine, beer and spices. They are hepatotoxic and are well known human carcinogens based on evidence from human studies. Aflatoxins are an environmental risk factor for the development of hepatocellular carcinoma (HCC). Chronic hepatitis B-infected patients are at increased risk of cirrhosis, hepatic failure and liver cancer. This study was designed to determine the serum aflatoxin B1 (AFB1 ), aflatoxin B2 (AFB2 ), aflatoxin G1 (AFG1 ) and aflatoxin G2 (AFG2 ) concentrations using high-pressure liquid chromatography (HPLC) in hepatitis B-infected patients with or without cirrhosis and liver cancer, alongside healthy controls in Balıkesir, Turkey. The mean AFB1 and total AF levels in patients without liver cancer and cirrhosis were significantly higher than healthy controls. The mean AFB1 and total AF levels in patients with chronic hepatitis B and HCC were significantly higher than infected patients with or without cirrhosis. These results suggest that patients with chronic hepatitis B who are exposed to AFs are at increased risk for developing HCC, which might be prevented by reducing consumption of contaminated foods.

  3. Bond ionicities in CuBC2 cha