- 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.
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Search Results
- 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/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.
- ID:
- ivo://CDS.VizieR/J/ApJS/206/4
- Title:
- SED and bolometric corrections for luminous QSOs
- Short Name:
- J/ApJS/206/4
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We explore the mid-infrared (mid-IR) through ultraviolet (UV) spectral energy distributions (SEDs) of 119652 luminous broad-lined quasars with 0.064<z<5.46 using mid-IR data from Spitzer and WISE, near-infrared data from the Two Micron All Sky Survey and UKIDSS, optical data from the Sloan Digital Sky Survey, and UV data from the Galaxy Evolution Explorer. The mean SED requires a bolometric correction (relative to 2500{AA}) of BC_2500{AA}_=2.75+/-0.40 using the integrated light from 1um-2keV, and we further explore the range of bolometric corrections exhibited by individual objects. In addition, we investigate the dependence of the mean SED on various parameters, particularly the UV luminosity for quasars with 0.5<~z<~3 and the properties of the UV emission lines for quasars with z>~1.6; the latter is a possible indicator of the strength of the accretion disk wind, which is expected to be SED-dependent.
- ID:
- ivo://CDS.VizieR/J/ApJ/716/30
- Title:
- SED of Fermi bright blazars
- Short Name:
- J/ApJ/716/30
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have conducted a detailed investigation of the broadband spectral properties of the {gamma}-ray selected blazars of the Fermi LAT Bright AGN Sample (LBAS, Cat. J/ApJ/700/597). By combining our accurately estimated Fermi {gamma}-ray spectra with Swift, radio, infra-red, optical, and other hard X-ray/{gamma}-ray data, collected within 3 months of the LBAS data taking period, we were able to assemble high-quality and quasi-simultaneous spectral energy distributions (SED) for 48 LBAS blazars. We have used these SED to characterize the peak intensity of both the low- and the high-energy components. The results have been used to derive empirical relationships that estimate the position of the two peaks from the broadband colors (i.e., the radio to optical, {alpha}_ro_, and optical to X-ray, {alpha}_ox_, spectral slopes) and from the {gamma}-ray spectral index. While more than 50% of known radio bright high energy peaked (HBL) BL Lacs are detected in the LBAS sample, only less than 13% of known bright broad-lined flat spectrum radio quasars (FSRQs) and LBL BL Lacs are included. This suggests that the latter sources, as a class, may be much fainter {gamma}-ray emitters than LBAS blazars, and could in fact radiate close to the expectations of simple synchrotron self-Compton (SSC) models. We categorized all our sources according to a new physical classification scheme based on the generally accepted paradigm for Active Galactic Nuclei and on the results of this SED study.
- ID:
- ivo://CDS.VizieR/J/ApJ/663/81
- Title:
- SED of hard X-ray selected AGN in XMDS
- Short Name:
- J/ApJ/663/81
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the SEDs of a hard X-ray selected sample containing 136 sources with F(2-10)keV>10^-14^erg/cm^2^/s; 132 are AGNs. The sources are detected in a 1deg^2^ area of the XMM-Newton Medium Deep Survey where optical data from the VVDS and CFHTLS and infrared data from the SWIRE survey are available. Based on a SED fitting technique we derive photometric redshifts with {sigma}(1+z)=0.11 and 6% of outliers and identify AGN signatures in 83% of the objects. This fraction is higher than derived when a spectroscopic classification is available. The remaining 17% of AGNs show star-forming galaxy SEDs (SF class).
- ID:
- ivo://CDS.VizieR/J/ApJ/666/806
- Title:
- SED of Spitzer quasars (QUEST)
- Short Name:
- J/ApJ/666/806
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This is the second paper studying the QSOs in the Spitzer QUEST sample. Previously we presented new PAH measurements and argued that most of the observed far-infrared (FIR) radiation is due to star-forming activity. Here we present spectral energy distributions (SEDs) by supplementing our data with optical, NIR, and FIR observations. We define two subgroups, of "weak FIR" and "strong FIR" QSOs, and a third group of FIR nondetections. Assuming a starburst origin for the FIR, we obtain "intrinsic" active galactic nucleus (AGN) SEDs by subtracting a starburst template from the mean SEDs. The resulting SEDs are remarkably similar for all groups.
- ID:
- ivo://CDS.VizieR/J/ApJ/709/1407
- Title:
- SED of the Fermi blazars
- Short Name:
- J/ApJ/709/1407
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We complied the optical, X-ray, and {gamma}-ray data for 54 Fermi blazars and studied the relationship between the broadband spectral index {alpha}_ox_ and {alpha}_x{gamma}_, as well as the relationship between the intrinsic composite spectral indices {alpha}_xox_ and {alpha}_{gamma}x{gamma}_ for this sample. The relationship between {alpha}_xox_ and {alpha}_{gamma}x{gamma}_ reveals that flat spectrum radio quasars and low-energy peaked BL Lacertae follow a continuous trend, which is consistent with previous results, whereas high-energy peaked BL Lacertae follow a separate distinct trend. Even so, a unified scheme is also revealed from {alpha}_xox_-{alpha}_{gamma}x{gamma}_ diagram when all three subclasses of blazars are considered.
- ID:
- ivo://CDS.VizieR/J/MNRAS/438/1288
- Title:
- SEDs of type I AGN in XMM-COSMOS. II.
- Short Name:
- J/MNRAS/438/1288
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The mid-infrared-to-ultraviolet (0.1-10{mu}m) spectral energy distribution (SED) shapes of 407 X-ray-selected radio-quiet type 1 active galactic nuclei (AGN) in the wide-field 'Cosmic Evolution Survey' (COSMOS) have been studied for signs of evolution. For a sub-sample of 200 radio-quiet quasars with black hole mass estimates and host galaxy corrections, we studied their mean SEDs as a function of a broad range of redshift, bolometric luminosity, black hole mass and Eddington ratio, and compared them with the Elvis et al. (1994ApJS...95....1E, Cat. J/ApJS/95/1, hereafter E94) type 1 AGN mean SED. We found that the mean SEDs in each bin are closely similar to each other, showing no statistical significant evidence of dependence on any of the analysed parameters. We also measured the SED dispersion as a function of these four parameters, and found no significant dependences. The dispersion of the XMM-COSMOS SEDs is generally larger than E94 SED dispersion in the ultraviolet, which might be due to the broader 'window function' for COSMOS quasars, and their X-ray-based selection.
