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711. Reverberation mapping & opt. spectra data of AGNs
ID:
ivo://CDS.VizieR/J/ApJ/886/42
Title:
Reverberation mapping & opt. spectra data of AGNs
Short Name:
J/ApJ/886/42
Date:
21 Oct 2021
Publisher:
CDS
Description:
The radius-luminosity (R_H{beta}_-L_5100_) relationship of active galactic nuclei (AGNs) established by the reverberation mapping (RM) observations has been widely used as a single-epoch black hole mass estimator in the research of large AGN samples. However, the recent RM campaigns discovered that the AGNs with high-accretion rates show shorter time lags by factors of a few comparing with the predictions from the R_H{beta}_-L_5100_ relationship. The explanation of the shortened time lags has not been finalized yet. We collect eight different single-epoch spectral properties to investigate how the shortening of the time lags correlates with those properties and to determine the origin of the shortened lags. We find that the flux ratio between FeII and H{beta} emission lines shows the most prominent correlation, thus confirming that accretion rate is the main driver for the shortened lags. In addition, we establish a new scaling relation including the relative strength of FeII emission. This new scaling relation can provide less biased estimates of the black hole mass and accretion rate from the single-epoch spectra of AGNs.
712. Revisited jet bending in {gamma}-ray AGNs
ID:
ivo://CDS.VizieR/J/ApJ/784/159
Title:
Revisited jet bending in {gamma}-ray AGNs
Short Name:
J/ApJ/784/159
Date:
21 Oct 2021
Publisher:
CDS
Description:
We investigate the hypothesis that {gamma}-ray-quiet active galactic nuclei (AGNs) have a greater tendency for jet bending than {gamma}-ray-loud AGNs, revisiting the analysis of Tingay et al. We perform a statistical analysis using a large sample of 351 radio-loud AGNs along with {gamma}-ray identifications from the Fermi Large Area Telescope (LAT). Our results show no statistically significant differences in jet-bending properties between {gamma}-ray-loud and {gamma}-ray-quiet populations, indicating that jet bending is not a significant factor for {gamma}-ray detection in AGNs.
713. R-Gamma correlation of Swift/BAT AGN
ID:
ivo://CDS.VizieR/J/A+A/640/A31
Title:
R-Gamma correlation of Swift/BAT AGN
Short Name:
J/A+A/640/A31
Date:
21 Oct 2021
Publisher:
CDS
Description:
The reflection hump is a prominent feature in the hard X-ray spectrum of active galactic nuclei (AGN). Its exact shape and its correlation to other quantities provide valuable information about the inner and outer regions of an AGN. Our main goal is to study the reflection hump in a large sample of nearby AGN. We aim to investigate the evolution of reflection with absorption and its correlation with the spectral index. We analysed archived NuSTAR observations of the 70-month BAT catalogue AGN. By performing a detailed spectral analysis, we were able to constrain the spectral parameters and to investigate the reflection emission in a large sample of individual sources. The reflection strength was found to be strongly correlated with the power-law slope in unabsorbed sources, pointing towards disc reflection for these sources. Different possible explanations were tested and the most likely one is that the corona is moving either towards or away from the disc with a moderately relativistic velocity. An R-Gamma correlation was not detected for absorbed sources. In addition, these AGN feature harder spectra, suggesting intrinsic differences between the two classes or a slab geometry for the X-ray source.
714. R light curves of 5 blazars
ID:
ivo://CDS.VizieR/J/AZh/81/925
Title:
R light curves of 5 blazars
Short Name:
J/AZh/81/925
Date:
21 Oct 2021
Publisher:
CDS
Description:
We monitored five active galactic nuclei in the R optical band with a CCD mounted on the 1-m Zeiss-1000 telescope of the Special Astrophysical Observatory from April 2001 to August 2003. Three sources displayed intraday variability on several nights. Stronger variability was detected on time scales from two days to a week. The two-year light curves are presented for four of the observed objects.
715. RM AGNs accretion rates and BH masses
ID:
ivo://CDS.VizieR/J/ApJ/818/L14
Title:
RM AGNs accretion rates and BH masses
Short Name:
J/ApJ/818/L14
Date:
21 Oct 2021
Publisher:
CDS
Description:
Broad emission lines in active galactic nuclei (AGNs) mainly arise from gas photoionized by continuum radiation from an accretion disk around a central black hole. The shape of the broad-line profile, described by D_H{beta}_=FWHM/{sigma}_H{beta}_, the ratio of full width at half maximum to the dispersion of broad H{beta}, reflects the dynamics of the broad-line region (BLR) and correlates with the dimensionless accretion rate (dM/dt) or Eddington ratio (L_bot_/L_Edd_). At the same time, dM/dt and (L_bot_/L_Edd_ correlate with R_Fe_, the ratio of optical Fe ii to H{beta} line flux emission. Assembling all AGNs with reverberation mapping measurements of broad H{beta}, both from the literature and from new observations reported here, we find a strong bivariate correlation of the form log((dM/dt.L_bot_/L_Edd_)={alpha}+{beta}D_H{beta}_+{gamma}R_Fe_ where {alpha}=(2.47,0.31), {beta}=-(1.59,0.82), and {gamma}=(1.34,0.80). We refer to this as the fundamental plane of the BLR. We apply the plane to a sample of z<0.8 quasars to demonstrate the prevalence of super-Eddington accreting AGNs are quite common at low redshifts.
716. Role of starburst-AGN composites in LIRG mergers
ID:
ivo://CDS.VizieR/J/ApJ/709/884
Title:
Role of starburst-AGN composites in LIRG mergers
Short Name:
J/ApJ/709/884
Date:
21 Oct 2021
Publisher:
CDS
Description:
We investigate the fraction of starbursts, starburst-active galactic nucleus (AGN) composites, Seyferts, and low-ionization narrow emission-line region galaxies (LINERs) as a function of infrared luminosity (LIR) and merger progress for ~500 infrared (IR)-selected galaxies. Using the new optical classifications afforded by the extremely large data set of the Sloan Digital Sky Survey, we find that the fraction of LINERs in IR-selected samples is rare (<5%) compared with other spectral types. The lack of strong IR emission in LINERs is consistent with recent optical studies suggesting that LINERs contain AGN with lower accretion rates than in Seyfert galaxies. Most previously classified IR-luminous LINERs are classified as starburst-AGN composite galaxies in the new scheme. Starburst-AGN composites appear to "bridge" the spectral evolution from starburst to AGN in ULIRGs. The relative strength of the AGN versus starburst activity shows a significant increase at high IR luminosity. In ULIRGs (LIR>10^12^L_{sun}_), starburst-AGN composite galaxies dominate at early-intermediate stages of the merger, and AGN galaxies dominate during the final merger stages.
717. ROSAT AGN Catalog in North Ecliptic Pole
ID:
ivo://CDS.VizieR/J/ApJ/617/192
Title:
ROSAT AGN Catalog in North Ecliptic Pole
Short Name:
J/ApJ/617/192
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a detailed description of the first direct measurement of the spatial correlation function of X-ray-selected active galactic nuclei (AGNs). This result is based on an X-ray flux-limited sample of 219 AGNs discovered in the contiguous 80.7{deg}^2^ region of the ROSAT North Ecliptic Pole (NEP) Survey (Cat. <J/ApJS/149/29>).
718. ROSAT AGN content
ID:
ivo://CDS.VizieR/J/A+AS/109/147
Title:
ROSAT AGN content
Short Name:
J/A+AS/109/147
Date:
21 Oct 2021
Publisher:
CDS
Description:
The cross-correlation of the source list from the ROSAT All-Sky Survey with the 5 GHz Green Bank survey yields a list of 2127 objects. About two thirds of them are optically unidentified. The majority of the objects with known optical counterparts are quasars and radio galaxies, most of them detected in X-rays for the first time. In this paper we present a list of the previously optically identified objects with their main characteristics and discuss their general (bulk) properties. We find strong correlations between luminosities in the radio, optical, and X-ray bands which differ for quasars and radio galaxies.
719. ROSAT Bright Survey
ID:
ivo://CDS.VizieR/IX/32
Title:
ROSAT Bright Survey
Short Name:
IX/32
Date:
21 Oct 2021
Publisher:
CDS
Description:
The ROSAT Bright Survey (RBS, table "rosat.dat") aims to completely optically identify the 2072 brightest sources detected in the ROSAT all-sky survey (Cat. <IX/10>) at galactic latitudes |b|>30{deg} (excluding LMC, SMC, Virgo cluster), with countrate above 0.2s^-1^; this program is 99.5% complete, and a sub-sample of 931 sources with countrate above 0.2s^-1^ in the hard spectral band between 0.5 and 2.0keV is 100% identified. The total survey area comprises 20391{deg}^2^ at a flux limit of 2.4x10^-12^erg/cm^2^/s in the 0.5-2.0keV band. Tables 1 and 3 examine the "RHS" sub-sample of 66 bright point-like ROSAT survey sources with almost hard PSPC spectra (hardness ratio HR1>0.5) which could be nearly completely identified by low-resolution optical spectroscopy with the following breakdown into object classes: 31 Seyfert galaxies (20 Sy1), 22 BL Lac candidates, 5 clusters of galaxies, 1 cataclysmic variable, and 5 bright stars. Only one object remained unidentified and one X-ray source was a spurious detection.
720. ROSAT-FIRST AGN correlation
ID:
ivo://CDS.VizieR/J/A+A/356/445
Title:
ROSAT-FIRST AGN correlation
Short Name:
J/A+A/356/445
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the results of a correlation of the ROSAT All-Sky Survey with the April 1997 release of the VLA 20cm FIRST (Cat. <VIII/59>) catalogue. We focus our analysis on the 843 X-ray sources which have unique radio counterparts. The majority of these objects (84%) have optical counterparts on the POSS 1 plates. Approximately 30% have been previously classified and we obtain new spectroscopic classifications for 85 sources by comparison with the ongoing FIRST Bright Quasar Survey and 106 additional sources from our own new spectroscopic data. Approximately 51% of the sources are presently classified, and the majority of the unclassified objects are optically faint. The newly classified sources are generally radio weak, exhibiting properties intermediate with previous samples of radio- and X-ray-selected AGN. This also holds for the subsample of 71 BL Lacs which includes many intermediate objects. The 146 quasars show no evidence for a bimodal distribution in their radio-loudness parameter, indicating that the supposed division between radio-quiet and radio-loud AGN may not be real. The X-ray and radio luminosities are correlated over two decades in radio luminosity, spanning the radio-loud and radio-quiet regimes, with radio-quiet quasars showing a linear correlation between the two luminosities. Many of the sources show peculiar or unusual properties which call for more detailed follow-up observations. We also give the X-ray and radio data for the 518 X-ray sources for which more than one radio object is found. Because of the difficulties inherent in identifying optical counterparts to these complex sources, we do not consider these data in the current analysis.