Related papers: Modelling time delays from two reprocessors in act…
The variable continuum emission of an active galactic nucleus (AGN) produces corresponding responses in the broad emission lines, which are modulated by light travel delays, and contain information on the physical properties, structure, and…
Disk reverberation mapping of a handful of nearby AGN suggest accretion disk sizes which are a factor few too large for their luminosities, apparently at odds with the standard model. Here, we investigate the likely contribution to the…
Resolving the accretion disks and broad line regions (BLRs) of active galactic nuclei (AGNs) can probe the physics behind supermassive black holes (SMBHs) fueling and weigh SMBHs. With time-domain observations, the reverberation mapping…
According to the standard model, an active galactic nucleus (AGN) consists of an inner accretion disk with a jet around a central massive black hole, and a number of outer broad line regions (BLRs) and narrow line regions (NLRs). The…
The determination of the size and geometry of the broad line region (BLR) in active galactic nuclei is one of the major ingredients for determining the mass of the accreting black hole. This can be done by determining the delay between the…
Inconsistent conclusions are obtained from recent active galactic nuclei (AGNs) accretion disk inter-band time-lag measurements. While some works show that the measured time lags are significantly larger (by a factor of $\sim 3$) than the…
The origin of the observed time lags, in nearby active galactic nuclei (AGN), between hard and soft X-ray photons is investigated using new XMM-Newton data for the narrow-line Seyfert I galaxy Ark 564 and existing data for 1H0707-495 and…
Continuum reverberation mapping probes the size scale of the optical continuum-emitting region in active galactic nuclei (AGN). The source of this emission has long been thought to originate from the accretion disk, but recent studies…
We have measured the wavelength-dependent lags between the X-ray, UV and optical bands in the high accretion rate ($L/L_{\rm Edd}\approx40\%$) Active Galactic Nucleus Mrk 110 during two intensive monitoring campaigns in February and…
Over the last years, a number of broadband reverberation mapping campaigns have been conducted to explore the short-term UV and optical variability of nearby AGN. Despite the extensive data collected, the origin of the observed variability…
Models of active galactic nuclei often invoke a close physical association between the broad-line region and the accretion disk. We evaluate this theoretical expectation by investigating the relationship between the inclination angle of the…
Recent time-resolved spectral studies of a few Active Galactic Nuclei in hard X-rays revealed occultations of the X-ray primary source probably by Broad Line Region (BLR) clouds. An important open question on the structure of the…
We compile a sample of 92 active galactic nuclei (AGNs) at z<0.75 with $gri$ photometric light curves from the archival data of the Zwicky Transient Facility and measure the accretion disk sizes via continuum reverberation mapping. We…
Both long and short gamma-ray bursts (GRBs) are expected to occur in the dense environments of active galactic nuclei (AGN) accretion disks. As these bursts propagate through the disks they live in, they photoionize the medium causing…
Active Galactic Nuclei (AGN) are perfect laboratories to check General Relativity (GR) effects by using Broad Line Region (BLR) clouds eclipses to probe the innermost regions of the accretion disk. A new relativistic X-ray spectral model…
We develop models for time lag between maxima of the source brightness in different wavelengths during a transient flash of luminosity connected with a short period of increase of the mass flux onto the central compact object. We derive a…
Disk continuum reverberation mapping is one of the primary ways we learn about active galactic nuclei (AGN) accretion disks. Reverberation mapping assumes that time-varying X-rays incident on the accretion disk drive variability in…
Supermassive black holes in active galactic nuclei (AGNs) undergo a wide range of accretion rates, which lead to diversity of appearance. We consider the effects of anisotropic radiation from accretion disks on the broad-line region (BLR),…
Previous works concerning active galactic nuclei (AGN) variability (e.g., Blandford \& McKee 1982) have assumed that the emission characteristics of illuminated clouds are purely a function of the instant continuum flux to which they are…
The profiles of the broad emission lines of active galactic nuclei (AGNs) and the time delays in their response to changes in the ionizing continuum ("lags") give information about the structure and kinematics of the inner regions of AGNs.…