Related papers: Modelling the quasar spectra for super-Eddington s…
Using a large sample of Type 1 AGN spectra, we investigated the complex structure of the Fe II emission region in order to understand the atomic processes responsible for the enhancement of the Fe II emission. We explored correlations…
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…
Several AGN and black hole X-ray binaries show a clear very broad iron line which is strong evidence that the black holes are rapidly spinning. Detailed analysis of these objects shows that the emission line is not significantly affected by…
We employ a flexible Bayesian technique to estimate the black hole mass and Eddington ratio functions for Type 1 (i.e., broad line) quasars from a uniformly-selected data set of ~58,000 quasars from the SDSS DR7. We find that the SDSS…
The continuum emission from the hot and ionized inner regions of a supermassive black hole (SMBH) accretion disk that is strongly lensed by the light-ring (i.e., the unstable photon orbit), is always superimposed on that of the locally…
In the past few years more and more pieces of evidence have been presented for a revision of the widely accepted Unified Model of Active Galactic Nuclei. A model based solely on orientation cannot explain all the observed phenomenology. In…
Narrow-line Seyfert 1 galaxies (NLS1s) are a subclass of active galactic nuclei (AGN). It is often believed that these AGN have small black hole mass, which is responsible for the narrowness of the permitted lines. They are also…
The fundamental plane of black hole activity is a relation between X-ray luminosity, radio luminosity, and black hole mass for hard state Galactic black holes and their supermassive analogs. The fundamental plane suggests that, at…
In recent years, it was found that there are several low/hard state of X-ray binaries (XRBs) follow an `outliers' track of radio--X-ray correlation ($L_{\rm R}\propto L_{\rm X}^{b}$ and $b\sim1.4$), which is much steeper than the former…
Radio emission from the high- and super-Eddington accreting active galactic nuclei (AGNs) has various origins: a persistent jet, the magnetized corona and the wind-like outflows. It is now still unclear which is the leading mechanism…
Asymmetric, broad iron lines are a common feature in the X-ray spectra of both X-ray binaries (XRBs) and type-1 Active Galactic Nuclei (AGN). It was suggested that the distortion of the Fe K_alpha emission results from Doppler and…
We analyse 77 \textit{Fermi} sources and their potential low-energy counterparts previously proposed in the literature. These sources were classified as active galactic nuclei, mainly blazars, based on optical spectroscopy. The main goals…
We assemble a sample of 696 type 1 AGN up to a redshift of $z=2.5$, all of which have an SDSS spectrum containing at least one broad emission line (H $\alpha$, H $\beta$ or Mg II) and an XMM-Newton X-ray spectrum containing at least 250…
Simultaneous broadband spectral and temporal studies of blazars are an important tool for investigating active galactic nuclei (AGN) jet physics. We study the spectral evolution between quiescent and flaring periods of 22 radio-loud AGN…
We perform a spectral analysis of a sample of 11 medium redshift (1.5 < z < 2.2) quasars. Our sample all have optical spectra from the SDSS, infrared spectra from GNIRS and TSPEC, and X-ray spectra from XMM-Newton. We first analyse the…
Gaseous outflows appear to be a universal property of type-1 and type-2 active galactic nuclei (AGN). The main diagnostic is provided by emission features shifted to higher frequency via the Doppler effect, implying that the emitting gas is…
Jets are ubiquitous in accreting black holes. Often ignored, they may be a major contributor to the emitted spectral energy distribution for sub-Eddington black holes. For example, recent observations of radio-to-X-ray correlations and…
We present long-slit spectroscopy and imaging data obtained with FORS2 on the Very Large Telescope of 13 optically selected type 2 quasars at z~0.3-0.6 from the original sample of Zakamska et al. (2003). The sample is likely to be affected…
We present a comprehensive study of five nearby active galaxies featuring large (tens of kpc) extended emission-line regions (EELRs). The study is based on large-format integral field spectroscopic observations conducted with the Multi Unit…
Whether the X-ray emissions of strong jet sources originate from disk+coronas or jets is still controversial. In this work, we constructed a strong jet sample containing 50 flat-spectrum radio quasars, 51 low-synchrotron-peaked BL Lac…