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741. SDSS quasar catalog: twelfth data release
ID:
ivo://CDS.VizieR/VII/279
Title:
SDSS quasar catalog: twelfth data release
Short Name:
VII/279
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the Data Release 12 Quasar catalog (DR12Q) from the Baryon Oscillation Spectroscopic Survey (BOSS) of the Sloan Digital Sky SurveyIII. This catalog includes all SDSS-III/BOSS objects that were spectroscopically targeted as quasar candidates during the full survey and that are confirmed as quasars via visual inspection of the spectra, have luminosities M_i_[z=2]< -20.5 (in a {Lambda}CDM cosmology with H_0_=70km/s/Mpc, {Omega}_M_=0.3, and {Omega}_{Lambda}_=0.7), and either display at least one emission line with a full width at half maximum (FWHM) larger than 500km/s or, if not, have interesting/complex absorption features. The catalog also includes previously known quasars (mostly from SDSS-I andII) that were reobserved by BOSS. The catalog contains 297 301 quasars (272 026 are new discoveries since the beginning of SDSS-III) detected over 9376deg^2^ with robust identification and redshift measured by a combination of principal component eigenspectra. The number of quasars with z>2.15 (184 101, of which 167 742 are new discoveries) is about an order of magnitude greater than the number of z>2.15 quasars known prior to BOSS. Redshifts and FWHMs are provided for the strongest emission lines (CIV, CIII], MgII). The catalog identifies 29 580 broad absorption line quasars and lists their characteristics. For each object, the catalog presents five-band (u, g, r, i, z) CCD-based photometry with typical accuracy of 0.03mag together with some information on the optical morphology and the selection criteria. When available, the catalog also provides information on the optical variability of quasars using SDSS and Palomar Transient Factory multi-epoch photometry. The catalog also contains X-ray, ultraviolet, near-infrared, and radio emission properties of the quasars, when available, from other large-area surveys. The calibrated digital spectra, covering the wavelength region 3600-10 500{AA} at a spectral resolution in the range 1300<R<2500, can be retrieved from the SDSS Catalog Archive Server. We also provide a supplemental list of an additional 4841 quasars that have been identified serendipitously outside of the superset defined to derive the main quasar catalog.
742. SDSS quasar catalog with Swift observations
ID:
ivo://CDS.VizieR/J/ApJS/201/10
Title:
SDSS quasar catalog with Swift observations
Short Name:
J/ApJS/201/10
Date:
21 Oct 2021
Publisher:
CDS
Description:
We have compiled a catalog of optically selected quasars with simultaneous observations in UV/optical and X-ray bands by the Swift Gamma-ray Burst Explorer. Objects in this catalog are identified by matching the Swift pointings with the Sloan Digital Sky Survey Data Release 5 quasar catalog. The final catalog contains 843 objects, among which 637 have both Ultraviolet Optical Telescope (UVOT) and X-Ray Telescope (XRT) observations and 354 of which are detected by both instruments. The overall X-ray detection rate is ~60% which rises to ~85% among sources with at least 10ks of XRT exposure time. We construct the time-averaged spectral energy distribution (SED) for each of the 354 quasars using UVOT photometric measurements and XRT spectra. From model fits to these SEDs, we find that the big blue bump contributes about ~0.3 dex to the quasar luminosity. We re-visit the {alpha}_ox_-L_2500_{AA} relation by selecting a clean sample with only Type 1 radio-quiet quasars; the dispersion of this relation is reduced by at least 15% compared with studies that use non-simultaneous UV/optical and X-ray data.
743. SDSS quasars with weak emission lines
ID:
ivo://CDS.VizieR/J/A+A/568/A114
Title:
SDSS quasars with weak emission lines
Short Name:
J/A+A/568/A114
Date:
21 Oct 2021
Publisher:
CDS
Description:
A tiny fraction of the quasar population shows remarkably weak emission lines. Several hypotheses have been developed, but the weak line quasar (WLQ) phenomenon still remains puzzling. The aim of this study was to create a sizeable sample of WLQs and WLQ-like objects and to evaluate various properties of this sample. We performed a search for WLQs in the spectroscopic data from the Sloan Digital Sky Survey Data Release 7 based on Kohonen self-organising maps for nearly 10^5^ quasar spectra. The final sample consists of 365 quasars in the redshift range z=0.6-4.2 (z{bar}=1.50+/-0.45) and includes in particular a subsample of 46 WLQs with equivalent widths W_MgII_<11{AA} and W_CIV_<4.8{AA} We compared the luminosities, black hole masses, Eddington ratios, accretion rates, variability, spectral slopes, and radio properties of the WLQs with those of control samples of ordinary quasars. Particular attention was paid to selection effects.
744. SDSS-RM AGNs CFHT & Bok photometry over 4yrs
ID:
ivo://CDS.VizieR/J/ApJS/250/10
Title:
SDSS-RM AGNs CFHT & Bok photometry over 4yrs
Short Name:
J/ApJS/250/10
Date:
21 Oct 2021
Publisher:
CDS
Description:
The Sloan Digital Sky Survey (SDSS) Reverberation Mapping program monitors 849 active galactic nuclei (AGNs) both spectroscopically and photometrically. The photometric observations used in this work span over 4yr and provide an excellent baseline for variability studies of these objects. We present the photometric light curves from 2014 to 2017 obtained by the Steward Observatory's Bok telescope and the Canada-France-Hawaii telescope with MegaCam. We provide details on the data acquisition and processing of the data from each telescope, the difference imaging photometry used to produce the light curves, and the calculation of a variability index to quantify each AGN's variability. We find that the Welch-Stetson J index provides a useful characterization of AGN variability and can be used to select AGNs for further study.
745. SDSS-ROSAT AGN data
ID:
ivo://CDS.VizieR/J/AJ/130/387
Title:
SDSS-ROSAT AGN data
Short Name:
J/AJ/130/387
Date:
21 Oct 2021
Publisher:
CDS
Description:
Using a sample of 228 optically selected active galactic nuclei (AGNs) in the 0.01-6.3 redshift range with a high fraction of X-ray detections (81%-86%), we study the relation between rest-frame UV and soft X-ray emission and its evolution with cosmic time. The majority of the AGNs in our sample (155 objects) have been selected from the Sloan Digital Sky Survey (SDSS) in an unbiased way, rendering the sample results representative of all SDSS AGNs.
746. SDSS search for binary AGN
ID:
ivo://CDS.VizieR/J/ApJ/716/866
Title:
SDSS search for binary AGN
Short Name:
J/ApJ/716/866
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present active galactic nuclei (AGNs) from the Sloan Digital Sky Survey (SDSS) having double-peaked profiles of [OIII]5007,4959 and other narrow emission lines, motivated by the prospect of finding candidate binary AGNs. These objects were identified by means of a visual examination of 21592 quasars at z<0.7 in SDSS Data Release 7 (DR7). Of the spectra with adequate signal-to-noise, 148 spectra exhibit a double-peaked [OIII] profile. Of these, 86 are Type 1 AGNs and 62 are Type 2 AGNs. Only two give the appearance of possibly being optically resolved double AGNs in the SDSS images, but many show close companions or signs of recent interaction. Radio-detected quasars are three times more likely to exhibit a double-peaked [OIII] profile than quasars with no detected radio flux, suggesting a role for jet interactions in producing the double-peaked profiles. Of the 66 broad-line (Type 1) AGNs that are undetected in the FIRST survey, 0.9% show double-peaked [OIII] profiles.
747. SDSS spectral analysis of IR-bright DOGs
ID:
ivo://CDS.VizieR/J/ApJ/850/140
Title:
SDSS spectral analysis of IR-bright DOGs
Short Name:
J/ApJ/850/140
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the ionized gas properties of infrared (IR)-bright dust-obscured galaxies (DOGs) that show an extreme optical/IR color, (i-[22])_AB_>7.0, selected with the Sloan Digital Sky Survey (SDSS) and Wide-field Infrared Survey Explorer (WISE). For 36 IR-bright DOGs that show [OIII]{lambda}5007 emission in the SDSS spectra, we performed a detailed spectral analysis to investigate their ionized gas properties. In particular, we measured the velocity offset (the velocity with respect to the systemic velocity measured from the stellar absorption lines) and the velocity dispersion of the [OIII] line. We found that the derived velocity offset and dispersion of most IR-bright DOGs are larger than those of Seyfert 2 galaxies (Sy2s) at z<0.3, meaning that the IR-bright DOGs show relatively strong outflows compared to Sy2s. This can be explained by the difference in IR luminosity contributed from active galactic nuclei, L_IR_ (AGN), because we found that (i) L_IR_ (AGN) correlates with the velocity offset and dispersion of [OIII] and (ii) our IR-bright DOG sample has larger L_IR_ (AGN) than Sy2s. Nevertheless, the fact that about 75% IR- bright DOGs have a large (>300km/s) velocity dispersion, which is a larger fraction compared to other AGN populations, suggests that IR-bright DOGs are good laboratories to investigate AGN feedback. The velocity offset and dispersion of [OIII] and [NeIII]{lambda}3869 are larger than those of [OII]{lambda}3727, which indicates that the highly ionized gas tends to show stronger outflows.
748. SDSS-Spitzer AGN properties
ID:
ivo://CDS.VizieR/J/ApJ/758/1
Title:
SDSS-Spitzer AGN properties
Short Name:
J/ApJ/758/1
Date:
21 Oct 2021
Publisher:
CDS
Description:
We study a combined sample of 264 star-forming, 51 composite, and 73 active galaxies using optical spectra from the Sloan Digital Sky Survey (SDSS) and mid-infrared (mid-IR) spectra from the Spitzer Infrared Spectrograph. We examine optical and mid-IR spectroscopic diagnostics that probe the amount of star formation and relative energetic contributions from star formation and an active galactic nucleus (AGN). Overall we find good agreement between optical and mid-IR diagnostics. Misclassifications of galaxies based on the SDSS spectra are rare despite the presence of dust obscuration. The luminosity of the [Ne II] 12.8{mu}m emission line is well correlated with the star formation rate measured from the SDSS spectra, and this holds for the star-forming, composite, and AGN-dominated systems. AGNs show a clear excess of [Ne III] 15.6{mu}m emission relative to star-forming and composite systems. We find good qualitative agreement between various parameters that probe the relative contributions of the AGN and star formation, including the mid-IR spectral slope, the ratio of the [Ne V] 14.3{mu}m to [Ne II] 12.8{mu}m fluxes, the equivalent widths of the 7.7{mu}m, 11.3{mu}m, and 17{mu}m polycyclic aromatic hydrocarbon (PAH) features, and the optical "D" parameter which measures the distance at which a source lies from the locus of star-forming galaxies in the optical BPT emission-line diagnostic diagram. We also consider the behavior of the three individual PAH features by examining how their flux ratios depend upon the degree of AGN dominance. We find that the PAH 11.3{mu}m feature is significantly suppressed in the most AGN-dominated systems.
749. SDSS/3XMM X-ray-selected LINERs
ID:
ivo://CDS.VizieR/J/MNRAS/455/2551
Title:
SDSS/3XMM X-ray-selected LINERs
Short Name:
J/MNRAS/455/2551
Date:
21 Oct 2021
Publisher:
CDS
Description:
A sample of 576 X-ray-selected LINERs was constructed by combining data from the 3XMM-DR4 and SDSS-DR7 catalogues. The sample was used to investigate the fraction of galaxies hosting a LINER, finding that the fraction is a strong function of both stellar mass and black hole mass (increasing as f_LINER_{prop.to}M*^1.6+/-0.2^ and f_LINER_{propto}M_BH_^0.6+/-0.1^, respectively) and that it rises close to unity at the highest black hole masses and lowest X-ray luminosities. After obtaining radio flux densities from the FIRST survey, the sample was also used to investigate the Fundamental Plane of black hole activity - a scale-invariant relationship between black hole mass, X-ray luminosity and radio luminosity that is believed to hold across at least nine orders of magnitude of mass. There are key advantages in using only LINERs for the derivation as these are the counterparts of the 'low-hard' X-ray binaries for which the relationship is tightest. The Fundamental Plane was found to be log(L_R_/(erg/s)) = 0.65(+/-0.07)log(L_X_/(10^42^erg/s)) + 0.69(+/-0.10)log(M_BH_/10^8^M_{sun}_) + 38.35(+/-0.10). The scatter around the plane was 0.73+/-0.03dex, too large to suggest that the Fundamental Plane can be used as a tool to estimate black hole mass from the observables of X-ray and radio luminosity. The black hole mass scaling is sensitive to the slope of the mass - velocity dispersion relation and, in order to achieve consistency with X-ray binaries, the analysis favours a steep gradient for this relationship, as found in recent research.
750. SEAMBHs. II. Continuum and Hbeta LCs
ID:
ivo://CDS.VizieR/J/ApJ/793/108
Title:
SEAMBHs. II. Continuum and Hbeta LCs
Short Name:
J/ApJ/793/108
Date:
21 Oct 2021
Publisher:
CDS
Description:
This is the second in a series of papers reporting on a large reverberation mapping (RM) campaign to measure black hole (BH) mass in high accretion rate active galactic nuclei (AGNs). The goal is to identify super-Eddington accreting massive black holes (SEAMBHs) and to use their unique properties to construct a new method for measuring cosmological distances. Based on theoretical models, the saturated bolometric luminosity of such sources is proportional to the BH mass, which can be used to obtain their distance. Here we report on five new RM measurements and show that in four of the cases, we can measure the BH mass and three of these sources are SEAMBHs. Together with the three sources from our earlier work, we now have six new sources of this type. We use a novel method based on a minimal radiation efficiency to identify nine additional SEAMBHs from earlier RM-based mass measurements. We use a Bayesian analysis to determine the parameters of the new distance expression and the method uncertainties from the observed properties of the objects in the sample. The ratio of the newly measured distances to the standard cosmological ones has a mean scatter of 0.14 dex, indicating that SEAMBHs can be use as cosmological distance probes. With their high luminosity, long period of activity, and large numbers at high redshifts, SEAMBHs have a potential to extend the cosmic distance ladder beyond the range now explored by Type Ia supernovae.