Related papers: Exploring possible relations between optical varia…
We study the optical variability characteristics of Active Galactic Nuclei (AGN) from the Swift Burst Alert Telescope (BAT) AGN catalogue by utilising approximately five years of optical light curves from the Zwicky Transient Facility (ZTF)…
Variability of active galactic nuclei is not well understood. One possible explanation is existence of supermassive binary black holes (SMBBH) in their centres. It is expected that major mergers are common in the Universe. It is expected…
The spectral variability of active galactic nuclei (AGN) is one of their key features that enables us to study in more details the structure of AGN emitting regions. Especially, the broad line profiles, that vary both in flux and shape,…
Radiation from the blazar class of of active galactic nuclei (AGN) exhibits fast time variability which is usually ascribed to instabilities in the emission region near the central supermassive black hole. The variability time scale is…
Here we discuss the effects of strong gravity that can be observed in electromagnetic spectra of active galactic nuclei (AGN). According to the unification model of an AGN, there is a supermassive black hole ($10^7 - 10^9 M_\odot$) in its…
The innermost regions in active galactic nuclei (AGNs) were not being spatially resolved so far but spectropolarimetry can provide us insight about their hidden physics and the geometry. From spectropolarimetric observations in broad…
The masses of supermassive black holes in active galactic nuclei (AGN) can be derived spectroscopically via virial mass estimators based on selected broad optical/ultraviolet emission lines. These estimates commonly use the line width as a…
A long-standing question is whether active galactic nuclei (AGN) vary like Galactic black hole systems when appropriately scaled up by mass (refs 1-3). If so, we can then determine how AGN should behave on cosmological timescales by…
We present our statistical analysis of the connection between active galactic nuclei (AGN) variability and physical properties of the central supermassive black hole (SMBH). We constructed optical light curves using data from the QUEST-La…
We investigate the relationship among the jet magnetic field, black hole spin, black hole mass, Eddington ratio, and optical variability timescales in jetted active galactic nuclei (AGNs). By fitting a damped random walk (DRW) model to the…
Graham et al. found a sample of active galactic nuclei (AGNs) and quasars from the Catalina Real-time Transient Survey (CRTS) that have long-term periodic variations in optical continuum, the nature of the periodicity remains uncertain. We…
We present a new method for supermassive black hole (SMBH) mass measurements in Type 1 active galactic nuclei (AGN) using polarization angle across broad lines. This method gives measured masses which are in a good agreement with…
The variability of submillimeter emission provides a useful tool to probe the accretion physics in low-luminosity active galactic nuclei. We accumulate four years of observations using Submillimeter Array for Centaurus A, NGC 4374, NGC…
Active galactic nuclei (AGNs) exhibit variability in their luminosities with timescales that correlate with the mass of the black hole at the centre of the AGN. Presently, the empirical correlation lacks sufficient precision to confidently…
Type II AGNs with polarimetric broad emission line provided strong evidence for the orientation-based unified model for AGNs. We want to investigate whether the polarimetric broad emission line in type II AGNs can be used to calculate their…
We compiled a sample of 73 active galactic nuclei (AGNs) with reverberation mapping (RM) observations from RM campaigns including our ongoing campaign of monitoring super-Eddington accreting massive black holes (SEAMBHs). This sample covers…
Accreting supermassive black holes at the centres of galaxies are the engine of active galactic nuclei (AGN). X-ray light curves of unabsorbed AGN show dramatic random variability on timescales ranging from seconds to years. The power…
Apart from viewing-dependent obscuration, intrinsic broad-line emission from active galactic nuclei (AGNs) follows an evolutionary sequence: Type $1 \to 1.2/1.5 \to 1.8/1.9 \to 2$ as the accretion rate onto the central black hole is…
I review how AGN black hole masses are calculated from emission-line reverberation-mapping data, with particular attention to both assumptions and caveats. I discuss the empirical relationship between AGN luminosity and broad-line region…
We present the results of a long-term variability campaign of very broad-line AGNs with line widths broader than FWHM $>$ 5000 kms$^{-1}$. The main goal of our investigation was to study whether the widths of the optical broad emission…