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1. Absorption features in SDSS. I. MgII abs. doublets
ID:
ivo://CDS.VizieR/J/ApJS/235/11
Title:
Absorption features in SDSS. I. MgII abs. doublets
Short Name:
J/ApJS/235/11
Date:
21 Oct 2021
Publisher:
CDS
Description:
Using the SDSS spectra of quasars included in the DR7Q or DR12Q catalogs, we search for MgII{lambda}{lambda}2796,2803 narrow absorption doublets in the spectra data around MgII{lambda}2798 emission lines. We obtain 17316 MgII doublets, within the redshift range of 0.3299<=z_abs_<=2.5663. We find that a velocity offset of {upsilon}_r_<6000km/s is a safe boundary to constrain the vast majority of associated Mg ii systems, although we find some doublets at {upsilon}_r_>6000km/s. If associated Mg ii absorbers are defined by {upsilon}_r_<6000km/s, ~33.3% of the absorbers are supposed to be contaminants of intervening systems. Removing the 33.3% contaminants, ~4.5% of the quasars present at least one associated MgII system with W_r_^{lambda}2796^>=0.2{AA}. The fraction of associated MgII systems with high-velocity outflows correlates with the average luminosities of their central quasars, indicating a relationship between outflows and the quasar feedback power. The {upsilon}_r_ distribution of the outflow MgII absorbers is peaked at 1023km/s, which is smaller than the corresponding value of the outflow CIV absorbers. The redshift number density evolution of absorbers (dn/dz) limited by {upsilon}_r_{>}-3000km/s differs from that of absorbers constrained by {upsilon}_r_>2000km/s. Absorbers limited by {upsilon}_r_>2000km/s and higher values exhibit profiles similar to dn/dz. In addition, the dn/dz is smaller when absorbers are constrained with larger {upsilon}_r_. The distributions of equivalent widths, and the ratio of W_r_^{lambda}2796^/W_r_^{lambda}2803^, are the same for associated and intervening systems, and independent of quasar luminosity.
2. Absorption in multiphase circumgalactic medium
ID:
ivo://CDS.VizieR/J/MNRAS/445/2061
Title:
Absorption in multiphase circumgalactic medium
Short Name:
J/MNRAS/445/2061
Date:
21 Oct 2021
Publisher:
CDS
Description:
This paper presents an absorption-line study of the multiphase circumgalactic medium (CGM) based on observations of Ly{alpha}, CII, CIV, SiII, SiIII, and SiIV absorption transitions in the vicinities of 195 galaxies at redshift z<0.176. The galaxy sample is established based on a cross-comparison between public galaxy and quasi-stellar object (QSO) survey data and is characterized by a median redshift of <z>=0.041, a median projected distance of <d>=362kpc to the sightline of the background QSO, and a median stellar mass of log(M_star_/M_{sun}_)=9.7+/-1.1. Comparing the absorber features identified in the QSO spectra with known galaxy properties has led to strong constraints for the CGM absorption properties at z<~0.176. First, abundant hydrogen gas is observed out to d~500kpc, well beyond the dark matter halo radius R_h_ of individual galaxies, with a mean covering fraction of ~60 percent. In contrast, no heavy elements are detected at d>~0.7R_h_ from either low-mass dwarfs or high-mass galaxies. The lack of detected heavy elements in low- and high-ionization states suggests that either there exists a chemical enrichment edge at d~0.7R_h_ or gaseous clumps giving rise to the observed absorption lines cannot survive at these large distances. Considering all galaxies at d>R_h_ leads to a strict upper limit for the covering fraction of heavy elements of ~3% (at a 95% confidence level) over d=(1-9)R_h_. At d<R_h_, differential covering fraction between low- and high-ionization gas is observed, suggesting that the CGM becomes progressively more ionized from d<0.3R_h_ to larger distances. Comparing CGM absorption observations at low and high redshifts shows that at a fixed fraction of R_h_ the CGM exhibits stronger mean absorption at z=2.2 than at z~0, and that the distinction is most pronounced in low-ionization species traced by CII and SiII absorption lines. We discuss possible pseudo-evolution of the CGM as a result of misrepresentation of halo radius, and present a brief discussion on the implications of these findings.
3. Absorption-line systems in QSO spectra - CoALS
ID:
ivo://CDS.VizieR/J/A+A/412/707
Title:
Absorption-line systems in QSO spectra - CoALS
Short Name:
J/A+A/412/707
Date:
21 Oct 2021
Publisher:
CDS
Description:
Absorption lines and absorption-line systems (ALSs) observed in the spectra of QSOs contain fundamental information on distribution of matter between the observer and the QSO, and on physical processes in the Universe in different epochs of the cosmological evolution. The presented catalog contains a compilation of basic information on absorption-line systems (ALSs) in QSO spectra. The data are taken from publications available to the authors up to January 2002. The catalog includes, in particular, all the data of the catalogs by Junkkarinen et al. (1991ApJS...77..203J) and York et al. (1991MNRAS.250...24Y ). The catalog consists of table1.dat, table2.txt and the list of references in refs.dat file. The present catalog is also available at the site of the Dept. of Theor. Astrophys. of the Ioffe Physical Technical Institute: <www.ioffe.ru/astro/QC>
4. A catalog of post-starburst QSOs from SDSS-DR7Q
ID:
ivo://CDS.VizieR/J/ApJ/857/27
Title:
A catalog of post-starburst QSOs from SDSS-DR7Q
Short Name:
J/ApJ/857/27
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a catalog of nearby (z<=0.5) quasars with significant features of post-starburst stellar populations in their optical spectra: so-called post-starburst quasars, or PSQs. After carefully decomposing spectra from the Sloan Digital Sky Survey (SDSS) Data Release 7 (DR7) Quasar Catalog into quasar and host-galaxy components, we derive a sample of 208 PSQs. Their host-galaxy components have strong H{delta} absorption (EW>=6{AA}) indicating a significant contribution of an intermediate-aged stellar population formed in a burst of star formation within the past 1Gyr, which makes them potentially useful for studying the co-evolution of supermassive black holes and their host galaxies.
5. A catalogue of faint UV-excess objects
ID:
ivo://CDS.VizieR/J/MNRAS/243/1
Title:
A catalogue of faint UV-excess objects
Short Name:
J/MNRAS/243/1
Date:
21 Oct 2021
Publisher:
CDS
Description:
Spectra, positions, magnitudes and colours are presented for 1400 faint (B<~21mag) stellar objects identified in a complete, ultraviolet-excess (UVX) survey. The objects were selected from COSMOS machine measurements of UK Schmidt U and J plates and observed with the Fibre Optic Coupled Aperture Plate (FOCAP) system at the Anglo-Australian Telescope (AAT). In total, 420 QSOs were identified, of which nine belong to the broad absorption line (BAL) class of QSOs. A further 57 galaxies with narrow emission lines were found. Halo subdwarfs from the vast majority (~90 per cent) of the 824 galactic stars identified in this survey; the remaining galactic stars are comprised principally of hot white dwarfs (42 objects) and horizontal branch stars (nine objects). Updated versions of the QSO number-magnitude relation and luminosity function derived from this survey are also presented in this paper.
6. Accretion rate distributions of AGNs
ID:
ivo://CDS.VizieR/J/other/ChA+A/32.351
Title:
Accretion rate distributions of AGNs
Short Name:
J/other/ChA+A/32
Date:
21 Oct 2021
Publisher:
CDS
Description:
The redshift, central black hole mass and accretion rate are important parameters when studying the AGN evolution. The central black hole masses for 172 quasars and Seyfert galaxies are calculated in this paper using the reverberation mapping method. The distributions of central black hole masses, redshifts and the Eddington accretion rates are analyzed, to verify the transition from the quasar to the Seyfert galaxy in the course of evolution.
7. Accurate positions of 2978 SBS objects
ID:
ivo://CDS.VizieR/J/A+AS/147/169
Title:
Accurate positions of 2978 SBS objects
Short Name:
J/A+AS/147/169
Date:
21 Oct 2021
Publisher:
CDS
Description:
Optical positions of 2978 objects listed in the Second Byurakan Survey (SBS) were obtained using the Digitized Sky Survey (DSS), and are given with an rms un certainty ~1 arcsec in each coordinate.
8. A deep HST H-band imaging survey. II. QUEST QSOs
ID:
ivo://CDS.VizieR/J/ApJ/701/587
Title:
A deep HST H-band imaging survey. II. QUEST QSOs
Short Name:
J/ApJ/701/587
Date:
21 Oct 2021
Publisher:
CDS
Description:
We report the results from a deep Hubble Space Telescope (HST) NICMOS H-band imaging survey of 28 z<0.3 QSOs from the Palomar-Green (PG) sample. This program is part of QUEST (Quasar/ULIRG Evolution Study) and complements a similar set of data on 26 highly nucleated ULIRGs presented in Paper I (Veilleux et al. 2006ApJ...643..707V). Our analysis indicates that the fraction of QSOs with elliptical hosts is higher among QSOs with undetected far-infrared (FIR) emission, small infrared excess (L_IR_/L_B_<10), and luminous hosts. The hosts of FIR-faint QSOs show a tendency to have less pronounced merger-induced morphological anomalies and larger QSO-to-host luminosity ratios on average than the hosts of FIR-bright QSOs, consistent with late-merger evolution from FIR-bright to FIR-faint QSOs.
9. A deep multicolor survey. I.
ID:
ivo://CDS.VizieR/J/ApJS/104/185
Title:
A deep multicolor survey. I.
Short Name:
J/ApJS/104/185
Date:
21 Oct 2021
Publisher:
CDS
Description:
We have used the Kitt Peak National Observatory 4m Mayall telescope to image 0.83 square degrees of sky in six fields at high Galactic latitude in six filters spanning 3000-10000A to magnitude limits ranging from 22.1 to 23.8. We have assembled a catalog of 21375 stellar objects detected in the fields for use primilary in conducting a multicolor search for quasars. This paper describes the data reduction techniques used on the CCD data, the methods used to construct the stellar object catalog, and the simulations performed to understand its completeness and contamination.
10. A deep multicolor survey. II.
ID:
ivo://CDS.VizieR/J/ApJ/462/614
Title:
A deep multicolor survey. II.
Short Name:
J/ApJ/462/614
Date:
21 Oct 2021
Publisher:
CDS
Description:
We have used the Kitt Peak National Observatory 4m Mayall telescope to image 0.83 square degrees of sky in six fields at high galactic latitude in six filters spanning 3000-10000A to magnitude limits ranging from 22.1 to 23.8. As a first use of this database, we have conducted a multicolor survey for quasars. We discuss various methods of selecting outliers in different color-color diagrams and multicolor space that have been used to identify quasars at all redshifts from their colors alone. We discuss the initial results of our program of spectroscopic identification which has so far resulted in the identification of over 40 faint quasars, including one a z>4, a similar number of compact narrow emission-line galaxies, and a number of unusual and potentially interesting stars. We use these spectroscopic results, along with extensive simulations of quasar spectra, to study the efficiency of our candidate selection procedures. Finally, we compare the number counts of our quasars and quasar candidates to the expected numbers based on previous studies of the quasar luminosity function. The agreement of our observations with these expectations is good in most cases. However, we do estimate that our survey contains more quasars with B<21 and z<2.3 than expected from the results published by Koo & Kron in (1988ApJ...325...92K) and more z>3 quasars than expected from the results published by Warren, Hewett & Osmer in (1994ApJ...421..412W), both at the 3 {sigma} level. Additional spectroscopic observations will be required to confirm or refute these excesses.