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 delay. The method was, for the first time, applied to the observations of the Type 1 AGN Mrk 6, and we found that the size of the scattering region in this AGN is around 100 light days. That is significantly smaller than the dusty region size estimated by the infrared interferometric observations and also larger than known broad line region (BLR) size. This indicates that the scattering region lies between the BLR and the dusty region and could be used as a probe of the dust sublimation radius.
The time lag between optical and near-infrared (IR) flux variability can be taken as a means to determine the sublimation radius of the dusty "torus" around supermassive black holes in active galactic nuclei (AGN). I will show that data from big optical survey telescopes, e.g. the Large Synoptic Survey Telescope (LSST), can be used to measure dust sublimation radii as well. The method makes use of the fact that the Wien tail of the hot dust emission reaches into the optical and can be reliably recovered with high-quality photometry. Simulations show that dust sublimation radii for a large samp…
The most popular method of the broad-line region size estimation in active galactic nuclei (AGN) is the reverberation mapping based on measuring the time delay between the continuum flux and the flux in the emission lines. In our work, we apply the method of photometric reverberation mapping in mid-band filters, adapted for observations on the 1-m Zeiss-1000 telescope of Special Astrophysical Observatory of Russian Academy of Sciences, for the study of AGN with broad lines in the range of redshifts $0.1 < z < 0.8$. This paper provides a sample of 8 objects, describes the technique of observati…
The improvement of the calibration relation for determining the size of the broad-line region from the observed optical luminosity of active galactic nuclei (AGN) is a necessary task to study fundamental parameters of distant AGNs such as mass of the central supermassive black hole. The most popular method of the BLR size estimation is the reverberation mapping based on measuring the time delay between the continuum flux and the flux in the emission lines. In our work, we apply the method of photometric reverberation mapping in medium-band filters, adapted for observations at the Zeiss-1000 te…
Recently, Gandhi, Hönig, and Kishimoto submitted a manuscript to the arXiv e-print service on the location of the emitting region of the narrow FeK$α$ line that appears in the X-ray spectra of active galactic nuclei (AGNs) compared with the inner radius of the dust torus (arXiv:1502.02661). Prior to their manuscript, a similar discussion had already been presented in a section of Minezaki & Matsushita (2015), which had been accepted for publication in the Astrophysical Journal. Because Gandhi et al. made no reference to Minezaki & Matsushita (2015) apart from improperly citing it merely as an …
Earlier, we suggested the "reload" concept of the polarimetric reverberation mapping of active galactic nuclei (AGN), proposed for the first time more than 10 years ago. We have successfully tested this approach of reverberation mapping of the broad emission line on the galaxy Mrk 6. It was shown that such an idea allows one to look at the AGN central parsec structure literally in a new light. However, the method originally assumed the use of spectropolarimetric observations, expensive in terms of telescope time, and implemented on rare large telescopes. Currently, we propose an adaptation of …
It has been recently proposed that the broad line region in active galactic nuclei originates from dusty clouds driven from the accretion disk by radiation pressure, at a distance from the black hole where the disk is cooler than the dust sublimation temperature. We test this scenario by checking the consistency of independent broad line region and accretion disk reverberation measurements, for a sample of 11 well studied active galactic nuclei. We show that independent disk and broad line region reverberation mapping measurements are compatible with a universal disk temperature at the Hβ radi…
The size and structure of the dusty circumnuclear torus in active galactic nuclei (AGN) can be investigated by analyzing the temporal response of the torus's infrared (IR) dust emission to variations in the AGN ultraviolet/optical luminosity. This method, reverberation mapping, is applicable over a wide redshift range, but the IR response is sensitive to several poorly constrained variables relating to the dust distribution and its illumination, complicating the interpretation of measured reverberation lags. We have used an enhanced version of our torus reverberation mapping code (TORMAC) to c…
Reverberation mapping is now a well-established technique for investigating spatially-unresolved structures in the nuclei of distant galaxies with actively-accreting supermassive black holes. Structural parameters for the broad emission-line region, with angular sizes of microarcseconds, can be constrained through the substitution of time resolution for spatial resolution. Many reverberation experiments over the last 30 years have led to a practical understanding of the requirements necessary for a successful program. With reverberation measurements now in hand for 60 active galaxies, and more…
Unveiling the structure of the Broad Line Region (BLR) of AGN is critical to understand the quasar phenomenon. Detail study of the geometry and kinematic of these objects can answer the basic questions about the central BH mass, accretion mechanism and rate, growth and evolution history. Observing the response of the BLR clouds to continuum variations, Reverberation Mapping (RM) provides size vs luminosity and mass vs luminosity relations for QSOs and Sy1 AGNs with the goal to use these objects as standard candles and mass tags. However, the RM size can receive different interpretations depend…
A Meta-Learning Framework for Multitask Reverberation Mapping in Active Galactic Nuclei
University of Belgrade（贝尔格莱德大学）；Niels Bohr Institute, University of Copenhagen（哥本哈根大学尼尔斯·玻尔研究所）；Hamburger Sternwarte, Universitat Hamburg（汉堡天文台，汉堡大学）；Tor Vergata University of Rome（罗马托维尔加塔大学）；INAF – Astronomical Observatory of Roma（意大利国家天体物理研究所罗马天文台）；INFN – Rome Tor Vergata（意大利国家核物理研究所罗马托维尔加塔分部）；Astronomical Observatory, Volgina 7（伏尔吉纳街7号天文台）；Université Côte d’Azur, Observatoire de la Côte d’Azur, CNRS, Laboratoire Lagrange（蔚蓝海岸大学、蔚蓝海岸天文台、法国国家科学研究中心拉格朗日实验室）；European Southern Observatory（欧洲南方天文台）；Rubin Observatory Project Office（鲁宾天文台项目办公室）
The 2MIG isolated AGNs. 3. Optical--IR variability and dust reverberation in the NLSy1 galaxies Mrk~42 and Mrk~493
Main Astronomical Observatory of the NAS of Ukraine（乌克兰国家科学院主天文台）；International Center for Astronomical, Medical and Ecological Research (ICAMER)（国际天文、医学和生态研究中心）；Instituto de Astrofísica de Canarias（加那利群岛天体物理研究所）；Universidad de la Laguna（拉古纳大学）
In Yoshii et al. (2014), we described a new method for measuring extragalactic distances based on dust reverberation in active galactic nuclei (AGNs), and we validated our new method with Cepheid variable stars. In this paper, we validate our new method with Type Ia supernovae (SNe Ia) which occurred in two of the AGN host galaxies during our AGN monitoring program: SN 2004bd in NGC 3786 and SN 2008ec in NGC 7469. Their multicolor light curves were observed and analyzed using two widely accepted methods for measuring SN distances, and the distance moduli derived are $μ=33.47\pm 0.15$ for SN 20…
The dust reverberation mapping is one of powerful methods to investigate the structure of the dusty tori in AGNs, and it has been performed on more than a hundred type 1 AGNs. However, no clear results have been reported on type 2 AGNs because their strong optical-UV extinction completely hides their accretion disc emission. Here we focus on an X-ray-bright type 2 AGN, NGC 2110, and utilize 2-20 keV X-ray variation monitored by MAXI to trace disc emission, instead of optical-UV variation. Comparing it with light curves in the WISE infrared (IR) W1 band ($λ= 3.4$ $μ$m) and W2 band ($λ= 4.6$ $μ$…
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…
As part of the OzDES spectroscopic survey we are carrying out a large scale reverberation mapping study of $\sim$500 quasars over five years in the 30 deg$^2$ area of the Dark Energy Survey (DES) supernova fields. These quasars have redshifts ranging up to 4 and have apparent AB magnitudes between $16.8<r<22.5$ mag. The aim of the survey is to measure time lags between fluctuations in the quasar continuum and broad emission line fluxes of individual objects in order to measure black hole masses for a broad range of AGN and constrain the radius-luminosity ($R-L$) relationship. Here we investiga…
The obscuring circumnuclear torus of dusty molecular gas is one of the major components of active galactic nuclei (AGN). The torus can be studied by analyzing the time response of its infrared (IR) dust emission to variations in the AGN continuum luminosity, a technique known as reverberation mapping. The IR response is the convolution of the AGN ultraviolet/optical light curve with a transfer function that contains information about the size, geometry, and structure of the torus. Here, we describe a new computer model that simulates the reverberation response of a clumpy torus. Given an input…
Spectroastrometry measures source astrometry as a function of wavelength/velocity. Reverberations of spectroastrometric signals naturally arise in broad-line regions (BLRs) of active galactic nuclei (AGNs) as a result of the continuum variations that drive responses of the broad emission lines with time delays. Such signals provide a new diagnostic for mapping BLR kinematics and geometry, complementary to the traditional intensity reverberation mapping (RM) technique. We present the generic mathematical formalism for spectroastrometric RM and show that under realistic parameters of a phenomeno…
We present the accretion disk size estimates for a sample of 19 active galactic nuclei (AGN) using the optical $g$, $r$, and $i$ band light curves obtained from the Zwicky Transient Facility (ZTF) survey. All the AGN have reliable supermassive black hole (SMBH) mass estimates based on previous reverberation mapping measurements. The multi-band light curves are cross-correlated, and the reverberation lag is estimated using the Interpolated Cross-Correlation Function (ICCF) method and the Bayesian method using the {\sc javelin} code. As expected from the disk reprocessing arguments, the $g-r$ ba…
The nuclear region of Type 1 AGNs has only been partially resolved so far in the near-infrared (IR) where we expect to see the dust sublimation region and the nucleus directly without obscuration. Here we present the near-IR interferometric observation of the brightest Type 1 AGN NGC4151 at long baselines of ~250 m using the CHARA Array, reaching structures at hundred micro-arcsecond scales. The squared visibilities decrease down to as low as ~0.25, definitely showing that the structure is resolved. Furthermore, combining with the previous visibility measurements at shorter baselines but at di…
The Fe Kalpha emission line is the most ubiquitous feature in the X-ray spectra of active galactic nuclei (AGN), but the origin of its narrow core remains uncertain. Here, we investigate the connection between the sizes of the Fe core emission regions and the measured sizes of the dusty tori in 13 local Type 1 AGN. The observed Fe K emission radii (R_fe) are determined from spectrally resolved line widths in X-ray grating spectra, and the dust sublimation radii (R_dust) are measured either from optical/near-infrared reverberation time lags or from resolved near-infrared interferometric data. T…
The AGN Black Hole Mass Database is a compilation of all published spectroscopic reverberation-mapping studies of active galaxies. We have created a public web interface, where users may get the most up-to-date black hole masses from reverberation mapping for any particular active galactic nucleus (AGN), as well as obtain the individual measurements upon which the masses are based and the appropriate references. While the database currently focuses on the measurements necessary for black hole mass determinations, we also plan to expand it in the future to include additional useful information,…
High cadence, high quality observations of active galactic nuclei (AGN) clearly show continuum variations with lags, relative to the shortest observed variable UV continuum, that increase with wavelength ("lag spectra"). These have been attributed to the irradiation and heating of the central accretion disk by the central X-ray emitting corona. An alternative explanation, connecting the observed lag-spectra to line and continuum emission from gas in the broad line region (BLR), has also been proposed. In this paper I show the clear spectral signature of the time-dependent diffuse gas emission …
According to the standard paradigm, the strong and compact luminosity of active galactic nuclei (AGN) is due to multi-temperature black body emission originating from an accretion disk formed around a supermassive black hole. This central engine is thought to be surrounded by a dusty region along the equatorial plane and by ionized winds along the poles. The innermost regions cannot yet be resolved neither in the optical nor in the infrared and it is fair to say that we still lack a satisfactory understanding of the physical processes, geometry and composition of the central (sub-parsec) compo…
Reverberation mapping (RM) is one of the most efficient ways to investigate the broad-line region around the central supermassive black holes of active galactic nuclei (AGNs). A common way of performing the RM is to perform a long term spectroscopic monitoring of AGNs, but the spectroscopic monitoring campaign of a large number of AGNs requires an extensive amount of observing time of medium to large size telescopes. As an alternative way, we present the results of photometric RM with medium-band photometry. As the widths of medium-band filters match well with the widths of AGN broad emission …
We have started a long-term reverberation mapping project using the Wyoming Infrared Observatory 2.3 meter telescope titled "Monitoring AGNs with Hβ Asymmetry" (MAHA). The motivations of the project are to explore the geometry and kinematics of the gas responsible for complex Hβ emission-line profiles, ideally leading to an understanding of the structures and origins of the broad-line region (BLR). Furthermore, such a project provides the opportunity to search for evidence of close binary supermassive black holes. We describe MAHA and report initial results from our first campaign, from Decemb…
AGN Reverberation Mapping with LITMUS: Fundamental Limits on lag Recovery Rates
University of Queensland（昆士兰大学）；Macquarie University（麦考瑞大学）；The Ohio State University（俄亥俄州立大学）；Stanford University（斯坦福大学）；Australian National University（澳大利亚国立大学）；The University of Sydney（悉尼大学）
Reverberation mapping (RM) is an efficient method to investigate the physical sizes of the broad line region (BLR) and dusty torus in an active galactic nucleus (AGN). The Spectro-Photometer for the History of the Universe, Epoch of Reionization and Ices Explorer (SPHEREx) mission will provide multi-epoch spectroscopic data at optical and near-infrared wavelengths. These data can be used for RM experiments for bright AGNs. We present results of a feasibility test using SPHEREx data in the SPHEREx deep regions for the torus RM measurements. We investigate the physical properties of bright AGNs …
The Sloan Digital Sky Survey Reverberation Mapping (SDSS-RM) program monitors 849 active galactic nuclei (AGN) both spectroscopically and photometrically. The photometric observations used in this work span over four years 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 CFHT 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 cur…
Based on the gravitational redshift, one prediction of Einstein's general relativity theory, of broad optical emission lines in active galactic nuclei (AGNs), a new method is proposed to estimate the virial factors $f$ in measuring black hole masses $M_{\rm{RM}}$ by the reverberation mapping of AGNs. The factors $f$ can be measured on the basis of two physical quantities, i.e. the gravitational redshifts $z_{\rm{g}}$ and full widths at half maxima $v_{\rm{FWHM}}$ of broad lines. In the past it has been difficult to determine the factors $f$ for individual AGNs. We apply this new method to seve…
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 $f$. …
The near-IR emission in Type 1 AGNs is thought to be dominated by the thermal radiation from dust grains that are heated by the central engine in the UV/optical and are almost at the sublimation temperature. A brightening of the central source can thus further sublimate the innermost dust, leading to an increase in the radius of the near-IR emitting region. Such changes in radius have been indirectly probed by the measurements of the changes in the time lag between the near-IR and UV/optical light variation. Here we report direct evidence for such a receding sublimation region through the near…
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…
Many theoretical models of Active Galactic Nuclei (AGN) predict that the X-ray corona, lying above the black hole, constitutes the base of the X-ray jet. Thus, by studying the exact geometry of the close black hole environment, we can pinpoint the launching site of the jet. Detection of negative X-ray reverberation time delays (i.e. soft band X-ray variations lagging behind the corresponding hard band X-ray variations) can yield significant information about the geometrical properties of the AGN, such as the location of the X-ray source, as well as the physical properties of the the black hole…
We present the results of a new reverberation mapping campaign for the broad-lined active galactic nucleus (AGN) in the edge-on spiral IC4329A. Monitoring of the optical continuum with $V-$band photometry and broad emission-line flux variability with moderate-resolution spectroscopy allowed emission-line light curves to be measured for H$β$, H$γ$, and HeII $λ4686$. We find a time delay of $16.3^{+2.6}_{-2.3}$ days for H$β$, a similar time delay of $16.0^{+4.8}_{-2.6}$ days for H$γ$, and an unresolved time delay of $-0.6^{+3.9}_{-3.9}$ days for HeII. The time delay for H$β$ is consistent with t…
We probe the dusty environment of the archetypical type-1 AGN in NGC 4151 with comprehensive IR reverberation mapping over several decades, in J ($\sim1.22μ$m), H ($\sim1.63μ$m), K ($\sim2.19μ$m), L ($\sim3.45μ$m) and N-band ($\sim10.6μm$), plus multiple measurements at 20--40 $μ$m. At 1--4$μ$m, the hot dust reverberation signals come from two distinct dust populations at separate radii ($\sim$0.033 pc and $\sim$0.076 pc), with temperatures of $\sim$1500--2500 K and $\sim$900--1000 K, consistent with the expected properties of sublimating graphite and silicate dust grains. The domination of th…
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…
To understand the mass distribution and co-evolution of supermassive black holes with their host galaxy, it is crucial to measure the black hole mass of AGN. Reverberation mapping is a unique tool to estimate the black hole masses in AGN. We performed spectroscopic reverberation study using long-term monitoring data with more than 100 spectra of a radio-loud quasar PKS 0736+017 to estimate the size of the broad line region (BLR) and black hole mass. The optical spectrum shows strong H$\mathrmβ$ and H$\mathrmγ$ emission lines. We generated the light curves of 5100Å continuum flux ($f_{5100}$), …
The continued operation of the Wide-field Infrared Survey Explorer (WISE) combined with several ground-based optical transient surveys (e.g., CRTS, ASAS-SN and PTF) offer an unprecedented opportunity to explore the dust structures in luminous AGNs. We use these data for a mid-IR dust reverberation mapping (RM) study of 87 archetypal Palomar-Green quasars at $z\lesssim0.5$. To cope with various contaminations of the photometry data and the sparse time sampling of the light curves, procedures to combine these datasets and retrieve the dust RM signals have been developed. We find $\sim$70% of the…
NGC 2617 has attracted a lot of attention after the detection of the changes in spectral type, and its geometry and kinematics of broad-line region (BLR) are still ambiguous. In this paper, we present the high cadence ($\sim$ 2 days) reverberation mapping campaign of NGC 2617 from 2019 October to 2020 May undertaken at Lijiang 2.4 m telescope. For the first time, the velocity-resolved reverberation signature of the object was successfully detected. Both H$α$ and H$β$ show an asymmetrical profile with a peak in the velocity-resolved time lags. For each of both lines, the lag of the line core is…
We present the results of an intensive six-month optical continuum reverberation mapping campaign of the Seyfert 1 galaxy PG 2130+099 at redshift z=0.063. The ground-based photometric monitoring was conducted on a daily basis with the robotic 46cm telescope of the Wise observatory located in Israel. Specially designed narrowband filters were used to observe the central engine of the active galactic nucleus (AGN), avoiding line contamination from the broad-line region (BLR). We aim to measure inter-band continuum time lags across the optical range and determine the size-wavelength relation for …
Distance measurements for extragalactic objects are a fundamental problem in astronomy and cosmology. In the era of precision cosmology, we urgently need better measurements of cosmological distances to observationally test the increasing $H_{0}$ tension of the Hubble constant measured from different tools. Using spectroastrometry, GRAVITY at The Very Large Telescope Interferometer successfully revealed the structure, kinematics and angular sizes of the broad-line region (BLR) of 3C 273 with an unprecedentedly high spatial resolution. Fortunately, reverberation mapping (RM) of active galactic …
The unusual behavior of the spectral lines of NGC5548 during the STORM campaign demonstrated a missing piece in the structure of AGNs. For a two-month period in the middle of the campaign, the spectral lines showed a deficit in flux and a reduced response to the variations of the UV continuum. This was the first time that this behavior was unequivocally observed in an AGN. Our previous papers explained this as being due to a variable disk-wind which acts as a shield and alters the SED. Here we use Cloudy to create an atlas of photoionization models for a variety of disk-winds to study their ef…
The flux variations in the emission lines in active galactic nuclei (AGNs) are driven by variations in the ionizing continuum flux --which are usually reflected in the observable UV-optical continuum. The "Reverberation mapping" technique measures the delay between line and continuum variations to determine the size of the line emitting region, this is the basis for measurements of the central black hole mass in AGNs. The Space Telescope and Optical Reverberation Mapping Project (AGN STORM) on NGC 5548 in 2014 is the most intensive multi-wavelength AGN monitoring campaign ever. For most of the…
It is shown that broad-line region (BLR) line profiles ranging from the classic "logarithmic" profile to double-peaked, disk-like profiles are readily explained by the distribution of BLR gas proposed by Gaskell, Klimek, & Nazarova (2007; GKN) without any need to invoke fundamental differences in the AGNs other than differing viewing angles. It is argued that the highly-variable thermal energy generation in AGNs originates off axis in regions that cannot be axially symmetric. This off-axis model readily explains the varying degrees of temporal correlation found in multi-wavelength variability …
In this third paper of the series reporting on the reverberation mapping (RM) campaign of active galactic nuclei with asymmetric H$β$ emission-line profiles, we present results for 15 Palomar-Green (PG) quasars using spectra obtained between the end of 2016 to May 2021. This campaign combines long time spans with relatively high cadence. For 8 objects, both the time lags obtained from the entire light curves and the measurements from individual observing seasons are provided. Reverberation mapping of 9 of our targets has been attempted for the first time, while the results for 6 others can be …
The central engines of Active Galactic Nuclei (AGNs) are powered by accreting supermassive black holes, and while AGNs are known to play an important role in galaxy evolution, the key physical processes occur on scales that are too small to be resolved spatially (aside from a few exceptional cases). Reverberation mapping is a powerful technique that overcomes this limitation by using echoes of light to determine the geometry and kinematics of the central regions. Variable ionizing radiation from close to the black hole drives correlated variability in surrounding gas/dust, but with a time dela…
We present a revised analysis of the photometric reverberation mapping campaign of the narrow-line Seyfert 1 galaxy PKS 0558-504 carried out with the Swift Observatory during 2008--2010. Previously, Gliozzi et al.\ found using the Discrete Correlation Function (DCF) method that the short-wavelength continuum variations lagged behind variations at longer wavelengths, the opposite of the trend expected for thermal reprocessing of X-rays by the accretion disc, and they interpreted their results as evidence against the reprocessing model. We carried out new DCF measurements that demonstrate that t…
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…
The evidence from velocity-resolved reverberation mapping showing a net infall of the broad-line region (BLR) of AGNs is reviewed. Different lines in many objects at different epochs give a consistent picture of BLR motions. The motions are dominated by virialized motion (rotation plus turbulence) with significant net inflow. The BLR mass influx is sufficient to power the AGN. The increasing blueshifting of lines with increasing ionization potential is a consequence of scattering off infalling material. The high blueshiftings of the UV lines in Narrow-Line Seyfert 1s are due to enhanced BLR in…
We present the results of a reverberation campaign targeting MGC-06-30-15. Spectrophotometric monitoring and broad-band photometric monitoring over the course of 4 months in the spring of 2012 allowed a determination of a time delay in the broad H$β$ emission line of $τ=5.3\pm1.8$ days in the rest frame of the AGN. Combined with the width of the variable portion of the emission line, we determine a black hole mass of $M_{\rm BH} = (1.6 \pm 0.4) \times 10^6$ M$_{\odot}$. Both the H$β$ time delay and the black hole mass are in good agreement with expectations from the $R_{\rm BLR}$-$L$ and $M_{\…
We present the results from a spectroscopic monitoring campaign to obtain reverberation-mapping measurements and investigate the broad-line region kinematics for active galactic nuclei (AGN) of Mrk~817 and NGC~7469. This campaign was undertaken with the Lijiang 2.4-meter telescope, the median spectroscopic sampling is 2.0 days for Mrk~817 and 1.0 days for NGC~7469. We detect time lags of the broad emission lines including H$β$, H$γ$, He~{\sc ii} and He~{\sc i} for both AGNs, and including Fe~{\sc ii} for Mrk~817 with respect to the varying AGN continuum at 5100~Å. Investigating the relationshi…
