The usage of the radius-luminosity (R-L) relation for the determination of black hole masses across the cosmic history as well as its application for cosmological studies motivates us to analyze its scatter, which has recently increased significantly both for the optical (H$β$) and UV (Mg II) lines. To this purpose, we determined the scatter along the R-L relation for an up-to-date reverberation-mapped Mg II sample. Studying linear combinations of the luminosity at 3000 A with independent parameters such as the Full Width at Half Maximum (FWHM), Fe II strength (R$_\mathrm{FeII}$), and the fractional variability ($F\mathrm{_{var}}$) for the whole sample, we get only a small decrease in the scatter ($σ{_{\rm rms}}=0.29-0.30$ dex). Linear combinations with the dimensionless accretion rate ($\dot{\mathcal{M}}$) and the Eddington ratio ($α_\mathrm{Edd}$) lead to significant reductions of the scatter ($σ_{\rm rms}\sim 0.1$ dex), albeit both suffering from the inter-dependency on the observed time-delay. After the division into two sub-samples considering the median value of the $\dot{\mathcal{M}}$ in the full sample, we find that the scatter decreases significantly for the highly accreting sub-sample. In particular, the smallest scatter of $σ{_{\rm rms}}=0.17$ dex is associated with the independent parameter R$_\mathrm{FeII}$, followed by the combination with $F\mathrm{_{var}}$, with $σ{_{\rm rms}}=0.19$ dex. Both of these independent observationally-inferred parameters are in turn correlated with $\dot{\mathcal{M}}$ and $α_\mathrm{Edd}$. These results suggest that the large scatter along the R-L relation is driven $\textit{mainly}$ by the accretion rate intensity.
Using different kinds of velocity tracers derived from the broad H$β$ profile (in the mean or rms spectrum) and the corresponding virial factors $f$, the central supermassive black hole (SMBH) masses ($M_{\rm BH}$) are calculated for a compiled sample of 120 reverberation-mapped (RM) AGNs. For its subsample of RM AGNs with measured stellar velocity dispersion ($σ_{\rm \ast}$), the multivariate linear regression technique is used to calibrate the mean value $f$, as well as the variable FWHM-based $f$. It is found that, whether excluding the pseudo-bulges or not, $M_{\rm BH}$ from the H$β$ line …
We present HI 21 cm spectroscopy from the GBT for the host galaxies of 31 nearby AGNs with direct M$_{\textrm{BH}}$ measurements from reverberation mapping. These are the first published HI detections for 12 galaxies, and the spectral quality is generally an improvement over archival data for the remainder of the sample. We present measurements of emission-line fluxes, velocity widths, and recessional velocities from which we derive HI mass, total gas mass, and redshifts. Combining M$_{\textrm{GAS}}$ with constraints on M$_{\textrm{STARS}}$ allows exploration of the baryonic content of these g…
We present Tully-Fisher distances for 24 AGN host galaxies with black hole mass ($M_\textrm{BH}$) measurements from reverberation mapping, as well as the first calibration of the $V-$band Tully-Fisher relation. Combining our measurements of HI 21cm emission with $HST$ and ground-based optical and near-infrared images allows multiple distance measurements for 19 galaxies and single measurements for the remaining 5. Separation of the nucleus from its host galaxy via surface brightness decomposition yields galaxy-only luminosities, thus allowing measurements of the distance moduli free of contami…
Using a compiled sample of 34 broad-line active galactic nuclei (AGNs) with measured H$β$ time lags from the reverberation mapping (RM) method and measured bulge stellar velocity dispersions $σ_*$, we calculate the virial factor $f$ by assuming that the RM AGNs intrinsically obey the same $M_{\rm BH}-σ_*$ relation as quiescent galaxies, where $M_{\rm BH}$ is the mass of the supermassive black hole (SMBH). Considering four tracers of the velocity of the broad-line regions (BLRs), i.e., the H$β$ line width or line dispersion from the mean or rms spectrum, there are four kinds of the factor $f$. …
Reverberation mapping technique is an important milestone in AGN demographics, kinematics and the structure of the Broad Line Region (BLR) based on the time-delay response between the continuum and emission line. The time delay is directly related to the size of BLR which is related to the continuum luminosity of the source, producing the well-known Radius-Luminosity (RL) relation. The majority of sources have been monitored for their H$β$ emission line in low redshift sources ($z<0.1$), while there are some attempts using the MgII line for higher redshifts. We present a recent MgII monitoring…
For a compiled sample of 120 reverberation-mapped AGNs, the bivariate correlations of the broad-line regions (BLRs) size ($R_{\rm BLR}$) with the continuum luminosity at 5100 Å ($L_{5100}$) and the dimensionless accretion rates ($\dot{\mathscr{M}}$) are investigated. Using our recently calibrated virial factor $f$, and the velocity tracer from the H$β$ Full-width at half-maximum (FWHM(H$β$)) or the line dispersion ($σ_{\rm Hβ}$) measured in the mean spectra, three kinds of SMBH masses and $\dot{\mathscr{M}}$ are calculated. An extended \RL relation including $\dot{\mathscr{M}}$ is found to be …
Standardizing reverberation-mapped H$β$ active galactic nuclei using time-averaged radius$-$luminosity relations with 5100\,Å\,, broad H$β$, and narrow \OIII\ luminosities
Standardizing reverberation-mapped H$α$ and H$β$ active galactic nuclei using radius--luminosity relations involving monochromatic and broad H$α$ luminosities
Standardizing a larger, higher-quality, homogeneous sample of reverberation-mapped H$β$ active galactic nuclei using the broad-line region radius-luminosity relation
Effects of heterogeneous data sets and time-lag measurement techniques on cosmological parameter constraints from MgII and CIV reverberation-mapped quasar data
Reverberation mapping (RM) of active galactic nuclei (AGNs) has been used over the past three decades to determine AGN broad-line region (BLR) sizes and central black-hole masses, and their relations with the AGN's luminosity. Until recently the sample of objects with RM data was limited to low-luminosity AGNs ($L_{\rm opt} \lesssim 10^{46}$ ergs s$^{-1}$) and low redshifts ($z \lesssim 0.5$). Here we present results from a reverberation-mapping project of some of the most luminous and highest redshift quasars that have been mapped to date. The study is based on almost twenty years of photomet…
In the near future, new surveys promise a significant increase in the number of quasars (QSO) at large redshifts. This will help to constrain the dark energy models using quasars. The Large Synoptic Survey Telescope (LSST) will cover over 10 million QSO in six photometric bands during its 10-year run. QSO will be monitored and subsequently analyzed using the photometric reverberation mapping (RM) technique. In low-redshift quasars, the combination of reverberation-mapped and spectroscopic results have provided important progress. However, there are still some facts which have to be taken into …
We present reverberation mapping results from the first year of combined spectroscopic and photometric observations of the Sloan Digital Sky Survey Reverberation Mapping Project. We successfully recover reverberation time delays between the $g+i$-band emission and the broad H$β$ emission line for a total of 44 quasars, and for the broad H$α$ emission line in 18 quasars. Time delays are computed using the JAVELIN and CREAM software and the traditional interpolated cross-correlation function (ICCF): Using well defined criteria, we report measurements of 32 H$β$ and 13 H$α$ lags with JAVELIN, 42 …
We present reverberation mapping results for the MgII 2800 A broad emission line in a sample of 193 quasars at 0.35<z<1.7 with photometric and spectroscopic monitoring observations from the Sloan Digital Sky Survey Reverberation Mapping project during 2014 - 2017. We find significant time lags between the MgII and continuum lightcurves for 57 quasars and define a "gold sample" of 24 quasars with the most reliable lag measurements. We estimate false-positive rates for each lag that range from 1-24%, with an average false-positive rate of 11% for the full sample and 8% for the gold sample. There…
Here we give an observational method for measurements of the equatorial scattering region radius using variability in the polarized broad lines in Type 1 active galactic nuclei (AGNs). The polarization in broad lines of Type 1 AGNs is mostly caused by equatorial scattering, where specific features allow one to separate its contribution from the total polarized flux. We propose to monitor variability in the polarized line flux and find the time lag between the nonpolarized continuum and polarized broad line variability. The distance to the scattering screen can then be determined from the time …
Reverberation mapping measurements have been used to constrain the relationship between the size of the broad-line region and luminosity of active galactic nuclei (AGN). This $R-L$ relation is used to estimate single-epoch virial black hole masses, and has been proposed for use to standardise AGN to determine cosmological distances. We present reverberation measurements made with H$β$ from the six-year Australian Dark Energy Survey (OzDES) Reverberation Mapping Program. We successfully recover reverberation lags for eight AGN at $0.12<z< 0.71$, probing higher redshifts than the bulk of H$β$ me…
We measure the correlation between black-hole mass $M_{\rm BH}$ and host stellar mass $M_*$ for a sample of 38 broad-line quasars at $0.2\lesssim z\lesssim 0.8$ (median redshift $z_{\rm med}=0.5$). The black-hole masses are derived from a dedicated reverberation mapping program for distant quasars, and the stellar masses are estimated from two-band optical+IR HST imaging. Most of these quasars are well centered within $\lesssim 1$kpc from the host galaxy centroid, with only a few cases in merging/disturbed systems showing larger spatial offsets. Our sample spans two orders of magnitude in stel…
The Intermediate-Mass Black Hole Reverberation Mapping Project: Scientific Overview and Sample Characteristics
Shanghai Astronomical Observatory, Chinese Academy of Sciences（中国科学院上海天文台）；Institute for Astronomy, School of Physics, Zhejiang University（浙江大学物理学院天体物理研究所）；Institute of Science and Technology for Deep Space Exploration, Suzhou Campus, Nanjing University（南京大学苏州校区深空探测研究院）；CSIRO Space and Astronomy（澳大利亚联邦科学与工业研究组织空间与天文部）；IPAC, Caltech（加州理工学院红外科学处理中心）；School of Physics & Astronomy, University of Southampton（南安普顿大学物理与天文学院）；Institute of Space Sciences (ICE, CSIC)（空间科学研究所（加泰罗尼亚高等研究理事会））
The Impact of Elliptical Broad-Line Regions on Reverberation-Based Black Hole Mass Estimates
Institute for Astronomy, School of Physics, Zhejiang University（浙江大学物理学院天体物理研究所）；Yunnan Observatories, Chinese Academy of Sciences（中国科学院云南天文台）；Department of Astronomy, School of Physics, Huazhong University of Science and Technology（华中科技大学物理学院天文学系）
Quasar broad emission lines are largely powered by photoionization from the accretion continuum. Increased central luminosity will enhance line emissivity in more distant clouds, leading to increased average distance of the broad-line-emitting clouds and decreased averaged line width, known as the broad-line region (BLR) "breathing". However, different lines breathe differently, and some high-ionization lines, such as C IV, can even show "anti-breathing" where the line broadens when luminosity increases. Using multi-year photometric and spectroscopic monitoring data from the Sloan Digital Sky …
Calibrating the correlation between black hole mass and X-ray variability amplitude: X-ray only black hole mass estimates for active galactic nuclei and ultra-luminous X-ray sources
We perform a systematic survey of active galactic nucleus (AGN) continuum lags using $\sim$3 day cadence $gri$-band light curves from the Zwicky Transient Facility. We select a sample of 94 type 1 AGN at $z<0.8$ with significant and consistent inter-band lags based on the interpolated cross-correlation function method and the Bayesian method JAVELIN. Within the framework of the lamp-post reprocessing model, our findings are: 1) The continuum emission (CE) sizes inferred from the data are larger than the disk sizes predicted by the standard thin disk model; 2) For a subset of the sample, the CE…
Broad Paschen lines as black hole mass tracers: A reverberation mapping calibration
Institute for Theoretical Physics, Heidelberg University（海德堡大学理论物理研究所）；Department of Astronomy, School of Physics, Peking University（北京大学物理学院天文学系）；Kavli Institute for Astronomy and Astrophysics, Peking University（北京大学卡尔·萨根天文与天体物理卡弗里研究所）；Max-Planck-Institut für Astronomie（马克斯·普朗克天文学研究所）
The Most Luminous H$β$ Reverberation Mapping of E1821+643 Indicates the Lower Boundary of the Radius-Luminosity Relation
Yunnan Observatories, Chinese Academy of Sciences（中国科学院云南天文台）；Key Laboratory for the Structure and Evolution of Celestial Objects, Chinese Academy of Sciences（中国科学院天体结构与演化重点实验室）；Center for Astronomical Mega-Science, Chinese Academy of Sciences（中国科学院天文大科学研究中心）；Key Laboratory of Radio Astronomy and Technology, Chinese Academy of Sciences（中国科学院射电天文与技术重点实验室）；Institute for Astronomy, School of Physics, Zhejiang University（浙江大学物理学院天体物理研究所）
The size of the dust torus in Active Galactic Nuclei (AGN) and their high-luminosity counterparts, quasars, can be inferred from the time delay between UV/optical accretion disk continuum variability and the response in the mid-infrared (MIR) torus emission. This dust reverberation mapping (RM) technique has been successfully applied to $\sim 70$ $z\lesssim 0.3$ AGN and quasars. Here we present first results of our dust RM program for distant quasars covered in the SDSS Stripe 82 region combining $\sim 20$-yr ground-based optical light curves with 10-yr MIR light curves from the WISE satellite…
The Seoul National University AGN Monitoring Project III: H$β$ lag measurements of 32 luminous AGNs and the high-luminosity end of the size--luminosity relation
Using bonafide black hole (BH) mass estimates from reverberation mapping and the line ratio [Si VI]1.963$μ$m/Br$γ_{\rm broad}$ as tracer of the Active Galactic Nuclei (AGN) ionizing continuum, we find a novel BH-mass scaling relation of the form log($M_{\rm BH}) = (6.40\pm 0.17) - (1.99\pm 0.37) \times$ log ([Si VI]/Br$γ_{\rm broad})$, over the BH mass interval, $10^6 - 10^8$ M$_{\odot}$. The current sample consists of 21 Type-1 AGNs with the overall dispersion in our scaling relation at 0.47 dex, one that emulates the well-established M-$σ$ relation which shows a dispersion $\sim$0.44 dex. Th…
The study of the broad-line region (BLR) using reverberation mapping has allowed us to establish an empirical relation between the size of this line emitting region and the continuum luminosity that drives the line emission (i.e. the R$_{\rm BLR}$-L$_{\rm 5100}$ relation). To realize its full potential, the intrinsic scatter in the R$_{\rm BLR}$-L$_{\rm 5100}$ relation needs to be understood better. The Eddington ratio plays a key role in addressing this problem. On the other hand, the Eigenvector 1 schema has helped to reveal an almost clear connection between the Eddington ratio and the stre…
