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651. Quasar-galaxy associations
ID:
ivo://CDS.VizieR/J/AZh/78/675
Title:
Quasar-galaxy associations
Short Name:
J/AZh/78/675
Date:
21 Oct 2021
Publisher:
CDS
Description:
A new catalog of 8382 close quasar-galaxy pairs is presented. The catalog was composed using published catalogued quasars and active galactic nuclei containing 11358 objects, as well as the LEDA catalog of galaxies, which contains on the order of 100000 objects.
652. Quasars and Active Galactic Nuclei (11th Ed.)
ID:
ivo://CDS.VizieR/VII/235
Title:
Quasars and Active Galactic Nuclei (11th Ed.)
Short Name:
VII/235
Date:
21 Oct 2021
Publisher:
CDS
Description:
This catalogue is an update of the previous versions. The recent release of the final release of the 2dF quasar catalogue and of the first part of the SLOAN catalogue, almost doubling the number of known QSOs, led us to prepare an updated version of our Catalogue of quasars and active nuclei, which now contains 48921 quasars, 876 BL Lac objects and 15069 active galaxies (including 11777 Seyfert 1). Like the tenth edition, it includes position and redshift as well as photometry (U, B, V) and 6 and 11 cm flux densities when available. The present edition this catalogue contains the quasars with measured redshift known prior to August 1st, 2003.
653. Quasars and Active Galactic Nuclei (7th Ed.)
ID:
ivo://CDS.VizieR/VII/188
Title:
Quasars and Active Galactic Nuclei (7th Ed.)
Short Name:
VII/188
Date:
21 Oct 2021
Publisher:
CDS
Description:
This catalogue is an update of the the previous versions. It contains 8609 (+172) quasars (defined as brighter than absolute B magnitude -23), 2833 (+978) AGNs (defined as fainter than absolute B magnitude -23), 220 (+49) BL Lac objects from 1662 (+176) references.
654. Quasars and Active Galactic Nuclei (12th Ed.)
ID:
ivo://CDS.VizieR/VII/248
Title:
Quasars and Active Galactic Nuclei (12th Ed.)
Short Name:
VII/248
Date:
21 Oct 2021
Publisher:
CDS
Description:
This catalogue is an update of the previous versions; as in the previous editions no information about absorption lines of X-ray properties are given, but absolute magnitudes are given, assuming Ho=50km/s/Mpc and q_0_=0. In this edition the 20cm radio flux is listed when available, in place of the 11cm flux. The present edition of this catalogue contains the quasars with measured redshift known prior to January 1st, 2006. It contains 85221 quasars, 1122 BL Lac objects and 21737 active galaxies (including 9628 Seyfert 1s), almost doubling the number listed in the 11th edition. Lists of known lensed quasars (table2.dat) and double quasars (table3.dat) are also given here.
655. Quasars and Active Galactic Nuclei (13th Ed.)
ID:
ivo://CDS.VizieR/VII/258
Title:
Quasars and Active Galactic Nuclei (13th Ed.)
Short Name:
VII/258
Date:
21 Oct 2021
Publisher:
CDS
Description:
This catalogue is a compilation of all known AGNs presented in a compact and convenient form. It is an update of the previous versions; and as in the previous editions no information about absorption lines of X-ray properties are given, but absolute magnitudes are given, assuming Ho=71km/s/Mpc and q_0_=0 (notice the change of cosmology: Ho was assumed to be 50km/s/Mpc in the previous editions). When available, the 20cm and 6cm radio flux are given. The present edition of this catalogue contains the quasars with measured redshift known prior to July 1st, 2009. It contains 133336 quasars, 1374 BL Lac objects and 34231 active galaxies (including 15627 Seyfert 1's), almost doubling the number listed in the 12th edition. Lists of known lensed quasars (table2.dat) and double quasars (table3.dat) are also given here.
656. Quasars and Active Galactic Nuclei (9th Ed.)
ID:
ivo://CDS.VizieR/VII/215
Title:
Quasars and Active Galactic Nuclei (9th Ed.)
Short Name:
VII/215
Date:
21 Oct 2021
Publisher:
CDS
Description:
This catalogue is an update of the previous versions. It contains 13214 (+1856) quasars (defined as brighter than absolute B magnitude -23), 4428 (+1094) AGNs (defined as fainter than absolute B magnitude -23) and 462 (+105) BL Lac objects from 2054 (+191) references.
657. Quasars and Active Galactic Nuclei (10th Ed.)
ID:
ivo://CDS.VizieR/VII/224
Title:
Quasars and Active Galactic Nuclei (10th Ed.)
Short Name:
VII/224
Date:
21 Oct 2021
Publisher:
CDS
Description:
This catalogue is an update of the previous versions. The recent publication of the first release of the 2dF quasar survey (Croom et al., 2001MNRAS.322L..29C, see Cat. <VII/223>) containing nearly 10,000 new QSOs, almost doubled the number of known such objects: there are now 23760 (+10546) quasars (defined as brighter than absolute B magnitude -23), 5751 (+1323) AGNs (defined as fainter than absolute B magnitude -23) of which 2765 are Seyfert 1, and 608 (+146) BL Lac objects from 2173 (+119) references. Like the ninth edition, it includes position and redshift as well as photometry (U, B, V) and 6 and 11 cm flux densities when available. The present edition this catalogue contains the quasars with measured redshift known prior to May 1st, 2001.
658. Quasars and Active Galactic Nuclei (8th Ed.)
ID:
ivo://CDS.VizieR/VII/207
Title:
Quasars and Active Galactic Nuclei (8th Ed.)
Short Name:
VII/207
Date:
21 Oct 2021
Publisher:
CDS
Description:
This catalogue is an update of the previous versions. It contains 11358 (+2759) quasars (defined as brighter than absolute B magnitude -23), 3334 (+501) AGNs (defined as fainter than absolute B magnitude -23) and 357 (+137) BL Lac objects from 1863 (+201) references.
659. Quasars as standard candles. III.
ID:
ivo://CDS.VizieR/J/A+A/642/A150
Title:
Quasars as standard candles. III.
Short Name:
J/A+A/642/A150
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a new catalogue of ~2400 optically selected quasars with spectroscopic redshifts and X-ray observations from either Chandra or XMM-Newton. The sample can be used to investigate the non-linear relation between the UV and X-ray luminosity of quasars, and to build a Hubble diagram up to redshift z~7.5. We selected sources that are neither reddened by dust in the optical/UV nor obscured by gas in the X-rays, and whose X-ray fluxes are free from flux-limit related biases. After checking for any possible systematics, we confirm, in agreement with our previous works, that (i) the X-ray to UV relation provides distance estimates matching those from supernovae up to z~1.5, and (ii) its slope shows no redshift evolution up to z~5. We provide a full description of the methodology for testing cosmological models, further supporting a trend whereby the Hubble diagram of quasars is well reproduced by the standard flat LambdaCDM model up to z~1.5-2, but strong deviations emerge at higher redshifts. Since we have minimized all non-negligible systematic effects, and proven the stability of the Lx-Lo relation at high redshifts, we conclude that an evolution of the expansion rate of the Universe should be considered as a possible explanation for the observed deviation, rather than some systematic (redshift-dependent) effect associated with high-redshift quasars.
660. Quasars properties and reverberation mapping
ID:
ivo://CDS.VizieR/J/ApJ/801/45
Title:
Quasars properties and reverberation mapping
Short Name:
J/ApJ/801/45
Date:
21 Oct 2021
Publisher:
CDS
Description:
We explore the practical feasibility of active galactic nucleus (AGN) broadband reverberation mapping and present first results. We lay out and apply a rigorous approach for the stochastic reverberation mapping of unevenly sampled multi-broadband flux measurements, assuming that the broad-line region (BLR) line flux is contributing up to 15% in some bands, and is directly constrained by one spectroscopical epoch. The approach describes variations of the observed flux as the continuum, modeled as a stochastic Gaussian process, and emission line contribution, modeled as a scaled, smoothed, and delayed version of the continuum. This approach can be used not only to interpolate in time between measurements, but also to determine confidence limits on continuum-line emission delays. This approach is applied to Sloan Digital Sky Survey observations in Stripe 82 (S82), providing flux measurements that are precise to 2% at ~60 epochs over ~10 yr. The strong annual variations in the epoch sampling prove a serious limitation in practice. In addition, suitable redshift ranges must be identified where strong, broad emission lines contribute to one filter, but not to another. By generating and evaluating problem-specific mock data, we verify that S82-like data can constrain {tau}_delay_ for a simple transfer function model. In application to real data, we estimate {tau}_delay_ for 323 AGNs with 0.225<z<0.846, combining information for different objects through the ensemble-scaling relationships for BLR size and black hole mass. Our analysis tentatively indicates a 1.7 times larger BLR size of H{alpha} and Mg II compared to Kaspi et al. (2000ApJ...533..631K; 2007ApJ...659..997K) and Vestergaard (2002ApJ...571..733V; 2006ApJ...641..689V), but the seasonal data sampling casts doubt on the robustness of the inference.