- ID:
- ivo://CDS.VizieR/J/ApJ/805/96
- Title:
- SDSS-RM project: velocity dispersions of QSOs
- Short Name:
- J/ApJ/805/96
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present host stellar velocity dispersion measurements for a sample of 88 broad-line quasars at 0.1<z<1 (46 at z>0.6) from the Sloan Digital Sky Survey Reverberation Mapping (SDSS-RM) project. High signal-to-noise ratio coadded spectra (average S/N~30 per 69km/s pixel) from SDSS-RM allowed for the decomposition of the host and quasar spectra and for measurements of the host stellar velocity dispersions and black hole (BH) masses using the single-epoch (SE) virial method. The large sample size and dynamic range in luminosity (L_5100_=10^43.2-44.7^erg/s) lead to the first clear detection of a correlation between SE virial BH mass and host stellar velocity dispersion far beyond the local universe. However, the observed correlation is significantly flatter than the local relation, suggesting that there are selection biases in high-z luminosity-threshold quasar samples for such studies. Our uniform sample and analysis enable an investigation of the redshift evolution of the M_{dot}_-{sigma}_*_ relation relatively free of caveats by comparing different samples/analyses at disjoint redshifts. We do not observe evolution of the M_{dot}_-{sigma}_*_ relation in our sample up to z~1, but there is an indication that the relation flattens toward higher redshifts. Coupled with the increasing threshold luminosity with redshift in our sample, this again suggests that certain selection biases are at work, and simple simulations demonstrate that a constant M_{dot}_-{sigma}_*_ relation is favored to z~1. Our results highlight the scientific potential of deep coadded spectroscopy from quasar monitoring programs, and offer a new path to probe the co-evolution of BHs and galaxies at earlier times.
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Search Results
- ID:
- ivo://CDS.VizieR/J/ApJ/811/91
- Title:
- SDSS-RM project: z<1 QSO host galaxies
- Short Name:
- J/ApJ/811/91
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Quasar host galaxies are key for understanding the relation between galaxies and the supermassive black holes (SMBHs) at their centers. We present a study of 191 broad-line quasars and their host galaxies at z<1 using high signal-to-noise ratio (S/N) spectra produced by the Sloan Digital Sky Survey Reverberation Mapping project. Clear detection of stellar absorption lines allows a reliable decomposition of the observed spectra into nuclear and host components, using spectral models of quasar and stellar radiations as well as emission lines from the interstellar medium. We estimate age, mass M*, and velocity dispersion {sigma}* of the host stars, the star formation rate (SFR), quasar luminosity, and SMBH mass M_{dot}_ for each object. The quasars are preferentially hosted by massive galaxies with M*~10^11^M_{sun}_ characterized by stellar ages around 1 billion yr, which coincides with the transition phase of normal galaxies from the blue cloud to the red sequence. The host galaxies have relatively low SFRs and fall below the main sequence of star-forming galaxies at similar redshifts. These facts suggest that the hosts have experienced an episode of major star formation sometime in the past 1 billion yr, which was subsequently quenched or suppressed. The derived M_{dot}_-{sigma}* and M_{dot}_-M* relations agree with our past measurements and are consistent with no evolution from the local universe. The present analysis demonstrates that reliable measurements of stellar properties of quasar host galaxies are possible with high-S/N fiber spectra, which will be acquired in large numbers with future powerful instruments such as the Subaru Prime Focus Spectrograph.
- ID:
- ivo://CDS.VizieR/J/ApJS/166/470
- Title:
- SDSS-Spitzer type I QSOs IR photometry
- Short Name:
- J/ApJS/166/470
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an analysis of the mid-infrared (MIR) and optical properties of type 1 (broad-line) quasars detected by the Spitzer Space Telescope. The MIR color-redshift relation is characterized to z~3, with predictions to z=7. We demonstrate how combining MIR and optical colors can yield even more efficient selection of active galactic nuclei (AGNs) than MIR or optical colors alone. Composite spectral energy distributions (SEDs) are constructed for 259 quasars with both Sloan Digital Sky Survey and Spitzer photometry, supplemented by near-IR, GALEX, VLA, and ROSAT data, where available.
- ID:
- ivo://CDS.VizieR/J/AJ/134/973
- Title:
- SDSS Stripe 82 star catalogs
- Short Name:
- J/AJ/134/973
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We describe a standard star catalog constructed using multiple SDSS photometric observations (at least four per band, with a median of 10) in the ugriz system. The catalog includes 1.01 million nonvariable unresolved objects from the equatorial stripe 82 (|{delta}_J2000.0_|<1.266{deg}) in the right ascension range 20^h^34^m^-4^h^00^m^ and with the corresponding r-band (approximately Johnson V-band) magnitudes in the range 14-22. The distributions of measurements for individual sources demonstrate that the photometric pipeline correctly estimates random photometric errors, which are below 0.01mag for stars brighter than 19.5, 20.5, 20.5, 20, and 18.5 in ugriz, respectively (about twice as good as for individual SDSS runs). Several independent tests of the internal consistency suggest that the spatial variation of photometric zero points is not larger than ~0.01mag (rms). In addition to being the largest available data set with optical photometry internally consistent at the ~1% level, this catalog provides a practical definition of the SDSS photometric system. Using this catalog, we show that photometric zero points for SDSS observing runs can be calibrated within a nominal uncertainty of 2% even for data obtained through 1mag thick clouds, and we demonstrate the existence of He and H white dwarf sequences using photometric data alone. Based on the properties of this catalog, we conclude that upcoming large-scale optical surveys such as the Large Synoptic Survey Telescope will be capable of delivering robust 1% photometry for billions of sources.
- ID:
- ivo://CDS.VizieR/J/AJ/122/503
- Title:
- SDSS u*g*r*i*z* photometry and redshift of QSOs
- Short Name:
- J/AJ/122/503
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present data for over 100 high-redshift quasars found in ~700deg^2^ by the Sloan Digital Sky Survey (SDSS), using automated selection algorithms applied to SDSS imaging data and with spectroscopic confirmation obtained during routine spectroscopic observations by the Sloan 2.5 m telescope. The SDSS spectra cover the wavelength range 3900-9200{AA}E at a spectral resolution of 1800 and have been obtained for 116 quasars with redshifts greater than 3.94; 92 of these objects were previously uncatalogued, significantly increasing the current list of published z>4 quasars. The paper also reports observations of seven additional new z>4 quasars; all were selected from the SDSS imaging survey and spectroscopically confirmed with observations by the Apache Point Observatory's 3.5 m telescope or the Hobby-Eberly Telescope.
- ID:
- ivo://CDS.VizieR/J/ApJS/253/20
- Title:
- SEAMBHs XII. Reberberation mapping for 15 PG QSOs
- Short Name:
- J/ApJS/253/20
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this work, we present the first results of the long-term high-cadence spectroscopic monitoring of 15 PG quasars with relatively strong FeII emission, as a part of a broader reverberation mapping campaign performed using the Calar Alto Observatory's 2.2m telescope. The V-band, 5100{AA} continuum, and H{beta} broad emission line light curves are measured for a set of quasars for periods ranging from dozens to more than a hundred epochs between 2017 May and 2020 July. Accurate time lags between the variations of the H{beta} broad-line fluxes and the optical continuum strength are obtained for all 15 quasars, ranging from 17.0_-3.2_^+2.5^ to 95.9_-23.9_^+7.1^ days in the rest frame. The virial masses of the central supermassive black holes are derived for all 15 quasars, ranging between 0.50_-0.19_^+0.18^ and 19.17_-2.73_^+2.98^ in units of 10^7^M_{sun}_. For 11 of the objects in our sample, this is the first reverberation analysis to be published. Of the rest, two objects have been the subject of previous reverberation studies, but we determine time lags for these that are only half as long as those found in the earlier investigations, which had only been able to sample much more sparsely. The remaining two objects have previously been monitored with high sampling rates. Our results here are consistent with the earlier findings, in the sense that the time lag and the line width vary inversely, consistent with virialization.
- ID:
- ivo://CDS.VizieR/VII/276
- Title:
- Second Byurakan Survey. General Catalogue
- Short Name:
- VII/276
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Second Byurakan Survey (SBS) General Catalogue is presented. The SBS, a continuation of the Markarian survey reaching fainter limiting magnitudes, is the first survey which combines the search of galaxies and QSOs. A total area of 991 square degrees of the Northern sky was covered with the use of three objective prisms in combination with Schott filters. The limited magnitude on the best plates reached B~19.5. The General Catalogue consists of 3563 objects presented in two parts: a Catalogue of galaxies (1863 objects) and one of stellar objects (1700 objects). The Catalogue of SBS AGN consists of 761 objects (155 SyG, 596 QSOs, and 10 BLLac). Multi-wavelength data are presented for 1438 SBS objects identified with X-ray, IRAS and FIRST sources. Spectrophotometric observations obtained over 26 years are available for 3132 objects. Redshifts were measured for ~2100 extragalactic objects. Spectral classification is presented for ~2970 objects. The majority of the data is presented here for the first time. The Catalogue presents new large homogeneous deep representative complete samples of bright QSOs, AGNs, and faint UVX galaxies in the Northern sky. The SBS sample is found to be complete at 70% for galaxies and ~85% for AGN/QSOs with B<=17.5.
- ID:
- ivo://CDS.VizieR/J/ApJS/95/345
- Title:
- Second Caltech-Jodrell Bank VLBI Survey. I.
- Short Name:
- J/ApJS/95/345
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We define the sample for the second Caltech-Jodrell Bank VLBI survey. This is a sample of 193 flat- or gigahertz-peaked-spectrum sources selected at 4850 MHz. This paper presents images of 91 sources with a resolution of ~1 mas, obtained using VLBI observations at 4992 MHz with a global array. The remaining images and the integrated radio spectra will be presented in a forthcoming paper by Henstock et al.
- ID:
- ivo://CDS.VizieR/J/ApJS/100/1
- Title:
- Second Caltech-Jodrell Bank VLBI Survey. II.
- Short Name:
- J/ApJS/100/1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This is the second of two papers presenting the Second Caltech- Jodrell Bank VLBI survey (CJ2). The CJ2 sample consists of 193 flat- and gigahertz-peaked-spectrum sources selected at 4850 MHz. In this paper we present images of the remaining 102 sources with ~1 mas resolution, obtained using VLBI snapshot observations at 4992 MHz with a global array. We also present integrated radio spectra for the entire CJ2 sample.
- ID:
- ivo://CDS.VizieR/J/AJ/151/154
- Title:
- Second epoch VLBA Calibrator Survey (VCS-II)
- Short Name:
- J/AJ/151/154
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Six very successful Very Long Baseline Array (VLBA) calibrator survey campaigns were run between 1994 and 2007 to build up a large list of compact radio sources with positions precise enough for use as very long baseline interferometry (VLBI) phase reference calibrators. We report on the results of a second epoch VLBA Calibrator Survey campaign (VCS-II) in which 2400 VCS sources were re-observed in the X and S bands in order to improve the upcoming third realization of the International Celestial Reference Frame (ICRF3) as well as to improve their usefulness as VLBI phase reference calibrators. In this survey, some 2062 previously detected sources and 324 previously undetected sources were detected and revised positions are presented. Average position uncertainties for the re-observed sources were reduced from 1.14 and 1.98mas to 0.24 and 0.41mas in R.A. and decl., respectively, or by nearly a factor of 5. Minimum detected flux values were approximately 15 and 28mJy in the X and S bands, respectively, and median total fluxes are approximately 230 and 280mJy. The vast majority of these sources are flat-spectrum sources, with ~82% having spectral indices greater than -0.5.
