- ID:
- ivo://CDS.VizieR/J/ApJS/140/143
- Title:
- HST FOS spectral atlas
- Short Name:
- J/ApJS/140/143
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We analyzed the absorption line spectra of all quasars observed with the high-resolution gratings of the Faint Object Spectrograph on board the Hubble Space Telescope. We examined 788 spectra for 334 quasars and present line lists and identifications of absorption lines in the spectra of 271 of them. Analysis of the statistics of the Ly{alpha} and metal absorption systems are presented in companion papers. The data and several analysis products are available on the authors' Web site, http://lithops.as.arizona.edu/~jill/QuasarSpectra .
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- ID:
- ivo://CDS.VizieR/J/ApJ/524/536
- Title:
- Nearby Ly{alpha} quasar absorbers
- Short Name:
- J/ApJ/524/536
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Spectroscopy of 10 quasars obtained with the Goddard High Resolution Spectrograph (GHRS) of the Hubble Space Telescope (HST) is presented. In the 10 sight lines, we detect 357 absorption lines above a significance level of 3{sigma} and 272 lines above a significance level of 4.5{sigma}. Automated software is used to detect and identify the lines, almost all of which are unresolved at the GHRS G140L resolution of 200km/s. After identifying Galactic lines, intervening metal lines, and higher order Lyman lines, we are left with 139 Ly{alpha} absorbers in the redshift range 0<z<0.22 (lines within 900km/s of geocoronal Ly{alpha} are not selected). These diffuse hydrogen absorbers have column densities that are mostly in the range 10^13^-10^15^cm^-2^ for an assumed Doppler parameter of 30km/s. The number density of lines above a rest equivalent width of 0.24{AA}, dN/dz=38.3{+/-}5.3, agrees well with the measurement from the Quasar Absorption-Line Key Project. There is marginal evidence for cosmic variance in the number of absorbers detected among the 10 sight lines.
- ID:
- ivo://CDS.VizieR/J/ApJS/122/355
- Title:
- Properties of low z QSO absorption systems
- Short Name:
- J/ApJS/122/355
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- (Partial): We examine the clustering properties of low-redshift Ly{alpha} and heavy-element QSO absorption line systems seen in the spectra of 13 QSOs at the Galactic poles. This is the densest sample of ~1 degree separated QSOs observed spectroscopically with the Hubble Space Telescope to date. At the median redshift of the Ly{alpha} sample (z{=~}0.7), the QSO lines of sight are separated on transverse scales from about 15 to 200h^-1^Mpc (q_0_=0.5, H=100h.km/s/Mpc), allowing the three-dimensional clustering of the absorbers to be examined on those scales. The Galactic poles are also regions where relatively deep and wide-field galaxy redshift surveys have taken place, so the distributions of galaxies and Ly{alpha} systems can be compared within the same volume of space. There are 545 total absorption lines detected in the complete sample from 13 QSOs. We identify 307 Ly{alpha} systems, of which 18 contain heavy-element lines. We confirm the relatively slow redshift number density evolution for Ly systems at z{<=}1. There are also five likely C IV doublets in our sample, for which the Ly{alpha} line is not accessible.
