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81. BOSS narrow CIV absorption lines. II. zem>2.4
ID:
ivo://CDS.VizieR/J/ApJS/215/12
Title:
BOSS narrow CIV absorption lines. II. zem>2.4
Short Name:
J/ApJS/215/12
Date:
21 Oct 2021
Publisher:
CDS
Description:
As the second work in a series of papers aiming to detect absorption systems in the quasar spectra of the Baryon Oscillation Spectroscopic Survey, we continue the analysis of Paper I (Chen+, 2014, J/ApJS/210/7; 2014ApJS..212...17C) by expanding the quasar sample to those quasars with z_em_>2.4. This yields a sample of 21963 appropriate quasars to search for narrow CIV{lambda}{lambda}1548,1551 absorptions with W_r_>=0.2{AA} for both lines. There are 9708 quasars with at least one appropriate absorption system imprinted on their spectra. From these spectra, we detect 13919 narrow C IV absorption systems whose absorption redshifts cover a range of z_abs_=1.8784-4.3704. In this paper and Paper I, we have selected 37241 appropriate quasars with median S/N>=4 and 1.54<~z_em_<~5.16 to visually analyze narrow CIV{lambda}{lambda}1548,1551 absorption doublets one by one. A total of 15999 quasars are found to have at least one appropriate absorption system imprinted on their spectra. From these 15999 quasar spectra, we have detected 23336 appropriate CIV{lambda}{lambda}1548,1551 absorption systems with W_r_>=0.2{AA} whose absorption redshifts cover a range of z_abs_=1.4544-4.3704. The largest values of W_r_ are 3.19{AA} for the {lambda}1548 absorption line and 2.93{AA} for the {lambda}1551 absorption line, respectively. We find that only a few absorbers show large values of W_r_. About 1.1% of the total absorbers have W_r_{lambda}1548>=2.0{AA}.
82. BOSS narrow CIV absorption lines. I. zem<=2.4
ID:
ivo://CDS.VizieR/J/ApJS/210/7
Title:
BOSS narrow CIV absorption lines. I. zem<=2.4
Short Name:
J/ApJS/210/7
Date:
21 Oct 2021
Publisher:
CDS
Description:
We have assembled absorption systems by visually identifying CIV {lambda}{lambda}1548, 1551 absorption doublets in the quasar spectra of the Baryon Oscillation Spectroscopic Survey (BOSS) one by one. This paper is the first of the series of work. In this paper, we focus on quasars with relatively low redshifts and high signal-to-noise ratio spectra, and hence we limit our analysis to quasars with z_em_<=2.4 and to doublets with W_r_{lambda}1548>=0.2{AA}. Out of the more than 87000 quasars in Data Release 9, we limit our search to 10121 quasars that have the appropriate redshifts and spectra with high enough signal-to-noise ratios to identify narrow CIV absorption lines. Among them, 5442 quasars are detected to have at least one CIV {lambda}{lambda}1548, 1551 absorption doublet. We obtain a catalog containing 8368 CIV {lambda}{lambda}1548, 1551 absorption systems, whose redshifts are within z_abs_=1.4544-2.2805. In this catalog, about 33.7% absorbers have 0.2{AA}<=W_r_{lambda}1548<0.5{AA}, about 45.9% absorbers have 0.5{AA}<=W_r_{lambda}1548<1.0{AA}, about 19.2% absorbers have 1.0{AA}<=W_r_{lambda}1548<2.0{AA}, and about 1.2% absorbers have W_r_{lambda}1548>=2.0{AA}.
83. BOSS: quasar luminosity function
ID:
ivo://CDS.VizieR/J/ApJ/773/14
Title:
BOSS: quasar luminosity function
Short Name:
J/ApJ/773/14
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a new measurement of the optical quasar luminosity function (QLF), using data from the Sloan Digital Sky Survey-III: Baryon Oscillation Spectroscopic Survey (SDSS-III: BOSS). From the SDSS-III Data Release Nine, a uniform sample of 22301 i<~21.8 quasars are selected over an area of 2236deg^2^, with confirmed spectroscopic redshifts between 2.2<z<3.5, filling in a key part of the luminosity-redshift plane for optical quasar studies. The completeness of the survey is derived through simulated quasar photometry, and this completeness estimate is checked using a sample of quasars selected by their photometric variability within the BOSS footprint. We investigate the level of systematics associated with our quasar sample using the simulations, in the process generating color-redshift relations and a new quasar K-correction. We probe the faint end of the QLF to M_i_(z=2.2){approx}-24.5 and see a clear break in the QLF at all redshifts up to z=3.5. A log-linear relation (in log{Phi}*-M*) for a luminosity evolution and density evolution model is found to adequately describe our data within the range 2.2<z<3.5; across this interval the break luminosity increases by a factor of ~2.6 while {Phi}* declines by a factor of ~8. At z<~2.2 our data are reasonably well fit by a pure luminosity evolution model, and only a weak signature of "AGN downsizing" is seen, in line with recent studies of the hard X-ray luminosity function. We compare our measured QLF to a number of theoretical models and find that models making a variety of assumptions about quasar triggering and halo occupation can fit our data over a wide range of redshifts and luminosities.
84. Bright blazars variability brightness temp.
ID:
ivo://CDS.VizieR/J/ApJ/866/137
Title:
Bright blazars variability brightness temp.
Short Name:
J/ApJ/866/137
Date:
21 Oct 2021
Publisher:
CDS
Description:
Relativistic effects dominate the emission of blazar jets complicating our understanding of their intrinsic properties. Although many methods have been proposed to account for them, the variability Doppler factor method has been shown to describe the blazar populations best. We use a Bayesian hierarchical code called Magnetron to model the light curves of 973 sources observed by the Owens Valley Radio Observatory's 40-m telescope as a series of flares with an exponential rise and decay, and estimate their variability brightness temperature. Our analysis allows us to place the most stringent constraints on the equipartition brightness temperature i.e., the maximum achieved intrinsic brightness temperature in beamed sources which we found to be <T_{eq}>=2.78x10^11^K+/-26%. Using our findings we estimated the variability Doppler factor for the largest sample of blazars increasing the number of available estimates in the literature by almost an order of magnitude. Our results clearly show that {gamma}-ray loud sources have faster and higher amplitude flares than {gamma}-ray quiet sources. As a consequence they show higher variability brightness temperatures and thus are more relativistically beamed, with all of the above suggesting a strong connection between the radio flaring properties of the jet and {gamma}-ray emission.
85. Bright extragalactic radio sources at 2.7 GHz
ID:
ivo://CDS.VizieR/J/MNRAS/216/173
Title:
Bright extragalactic radio sources at 2.7 GHz
Short Name:
J/MNRAS/216/173
Date:
21 Oct 2021
Publisher:
CDS
Description:
The brightest extragalactic radio sources at 2.7 GHz are catalogued. The complete sample comprises 233 sources found in the major centimeter wavelength surveys carried out at ANRAO/Parkes, NNRAO/Greenbank, and MPIfR/Bonn: the sample covers 9.81 sr and has limits S(27) = 2.0 Jy and |b| > 10{deg}. A critical reanalysis of the data shows that 227 (97 percent) have optical identifications and 171 (73 percent) have measured redshifts. The implications of the catalogue statistics for the luminosity functions of different radio-source populations are considered.
86. Bright QSOs in Southern Hemisphere (QUBRICS)
ID:
ivo://CDS.VizieR/J/ApJ/887/268
Title:
Bright QSOs in Southern Hemisphere (QUBRICS)
Short Name:
J/ApJ/887/268
Date:
21 Oct 2021
Publisher:
CDS
Description:
The study of absorptions along the lines of sight to bright high-z QSOs is an invaluable cosmological tool that provides a wealth of information on the inter-/circum-galactic medium, dark matter, primordial elements, reionization, fundamental constants, and general relativity. Unfortunately, the number of bright (i<~18) QSOs at z>~2 in the southern hemisphere is much lower than that in the north, due to the lack of wide multiwavelength surveys at decl. {delta}<0{deg}, hampering the effectiveness of observations from southern observatories. In this work we present a new method based on Canonical Correlation Analysis to identify such objects, taking advantage of a number of available databases: Skymapper, Gaia DR2, WISE, and 2MASS. Our QSO candidate sample lists 1476 sources with i<18 over 12400deg^2^ in the southern hemisphere. With a preliminary campaign we observed spectroscopically 69 of them, confirming 54 new bright QSOs at z>2.5, corresponding to a success rate of our method of ~80%. Furthermore, we estimate a completeness of ~90% of our sample at completion of our observation campaign. The new QSOs confirmed by this first and the forthcoming campaigns (QUBRICS survey) will be the targets of subsequent studies using higher resolution spectrographs, like ESPRESSO, UVES, and (in the long term) ELT/HIRES.
87. Bright radio sources at 178 MHz (3CRR)
ID:
ivo://CDS.VizieR/J/MNRAS/204/151
Title:
Bright radio sources at 178 MHz (3CRR)
Short Name:
J/MNRAS/204/151
Date:
21 Oct 2021
Publisher:
CDS
Description:
A revised sample of bright radio sources at 178MHz is defined in order to correct the biases introduced into the 3CR catalog by confusion and partial resolution. The sample is shown to be 96 percent complete to a flux-density limit of 10Jy for sources smaller than 10arcmin. The bias of the 3CR catalog against objects of larger angular size is also reduced. Optical identifications are presented for 96 percent of the sources, 71 percent with galaxies and 25 percent with quasars. The radio-galaxy population is found to show strong space-density evolution for luminosities in excess of approximately 10^26.5^W/Hz/sr at 178MHz (redshifts greater than or approximately equal to 0.2), while the evolutionary properties of galaxies and quasars of the same luminosity and redshift are very similar.
88. Bright southern sub-mm sources
ID:
ivo://CDS.VizieR/J/A+A/376/1123
Title:
Bright southern sub-mm sources
Short Name:
J/A+A/376/1123
Date:
21 Oct 2021
Publisher:
CDS
Description:
Table1 contains the 130 brightest sources of a 230GHz survey of quasars and BL Lacertae objects performed at the SEST. The objects which showed a 230GHz flux density above500 mJy most of the time were selected as pointing sources. Name, coordinates (B1950) and type are given in the table. Due to the variability of many objects the minimum and maximum flux density at 230GHz is given as well. A few values are taken from literature. These data are marked with an asterisk.
89. BRI photometry of 3 QSO fields
ID:
ivo://CDS.VizieR/J/AJ/123/2206
Title:
BRI photometry of 3 QSO fields
Short Name:
J/AJ/123/2206
Date:
21 Oct 2021
Publisher:
CDS
Description:
This paper describes the acquisition and analysis of imaging data for the identification of galaxies associated with z~4 damped Ly{alpha} systems. We present deep BRI images of three fields known to contain four z~4 damped systems. We discuss the reduction and calibration of the data, detail the color criteria used to identify z~4 galaxies, and present a photometric redshift analysis to complement the color selection. We have found no galaxy candidates closer to the QSO than 7" that could be responsible for the damped Ly{alpha} systems. Assuming that at least one of the galaxies is not directly beneath the QSO, we set an upper limit on this damped Ly {alpha} system of L<L^*^_LBG_/4. Finally, we have established a Web site to release these imaging data to the public, at http://kingpin.ucsd.edu/~dlaimg/papers/refern.html . The observations where made with LRIS on the Keck II telescope, on 13 Jan 1999 for PSS 0132+1341 and BR 0951-0450, and 23 Jan 1999 for PSS 1443+2724.
90. Broad Absorption Line Quasars from SDSS
ID:
ivo://CDS.VizieR/J/AJ/125/1711
Title:
Broad Absorption Line Quasars from SDSS
Short Name:
J/AJ/125/1711
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a catalog of 224 broad absorption line quasars (BALQSOs) from the Sloan Digital Sky Survey's Early Data Release Quasar Catalog, (Schneider et al., 2002, Cat. <J/AJ/123/567>) including a relatively complete and homogeneous subsample of 131 BALQSOs. Since the identification of BALQSOs is subject to considerable systematic uncertainties, we attempt to create a complete sample of SDSS BALQSOs by combining the results of two automated selection algorithms and a by-eye classification scheme. One of these automated algorithms finds broad absorption line troughs by comparing with a composite quasar spectrum. We present the details of this algorithm and compare this method with one that uses a power-law fit to the continuum. The BALQSOs in our sample are further classified as high-ionization BALQSOs (HiBALs), low-ionization BALQSOs (LoBALs), and BALQSOs with excited iron absorption features (FeLoBALs); composite spectra of each type are presented. We further present a study of the properties of the BALQSOs in terms of the balnicity distribution, which rises with decreasing balnicity. This distribution of balnicities suggests that the fraction of quasars with intrinsic outflows may be significantly underestimated. The balnicity index defined by Weymann et al. (1991ApJ...373...23W) amounts to a sort of equivalent width: a quasar is declared to be a BAL when its balnicity index is >=0.