Related papers: Narrow Iron K$\alpha$ Lines in Active Galactic Nuc…
We present the hard-band ($2-10\,\mathrm{keV}$) X-ray luminosity function (HXLF) of $0.5-2\,\mathrm{keV}$ band selected AGN at high redshift. We have assembled a sample of 141 AGN at $3<z\lesssim5$ from X-ray surveys of different size and…
The X-ray variability of the Active Galactic Nuclei (AGN) has been most often investigated with studies of individual, nearby, sources, and only a few ensemble analyses have been applied to large samples in wide ranges of luminosity and…
We present the first unambiguous evidence of a broad (Gaussian width ~330 eV) component of the iron K-alpha fluorescent emission line in the X-ray obscured Narrow Line Seyfert 1 Galaxy NGC5506. This is the main results of a spectroscopic…
We have generated a series of composite QSO spectra using over 22000 individual low resolution (~8A) QSO spectra obtained from the 2dF (18.25<bj<20.85) and 6dF (16<bj<18.25) QSO Redshift Surveys. The large size of the catalogue has enabled…
Motivated by theoretical expectations that Nuclear Star Clusters (NSCs) in galactic centers may provide a favorable environment for super-massive black holes to form and/or efficiently grow, we set out to measure the fraction of nearby…
The origin and the profile of the iron K-alpha line from active galactic nuclei is being studied. The model with a quasi-spherical distribution of clouds around a compact galactic nucleus is explored in which the intrinsic spectral feature…
Changing-state active galactic nuclei (CSAGNs) exhibit rapid variability, with mass accretion rates that can change by several orders of magnitude in a few years. This provides us with a unique opportunity to study the evolution of the…
The nature of the so-called ``changing-look'' (CL) active galactic nucleus (AGN), which is characterized by spectral-type transitions within $\sim10$~yr, remains an open question. As the first in our series of studies, we here attempt to…
We present new results on the cosmological evolution of unabsorbed (type-1) active galactic nuclei (AGN) selected in the soft (0.5-2 keV) X-ray band. From a variety of ROSAT, XMM-Newton and Chandra surveys we selected a total of ~1000 AGN…
Our aim is to explore the nature of emission line galaxies by combining high-resolution observations obtained in different bands to understand which objects are powered by an Active Galactic Nucleus(AGN). From the spectroscopic Palomar…
Merger simulations predict that tidally induced gas inflows can trigger kpc-scale dual active galactic nuclei (dAGN) in heavily obscured environments. Previously with the Very Large Array, we have confirmed four dAGN with redshifts between…
Highly ionized, z=0 metal absorption lines detected in the X-ray spectra of background active galactic nuclei (AGNs) provide an effective method to probe the hot ($T\sim10^6$ K) gas and its metal content in and around the Milky Way. We…
We present the results of five NuSTAR observations of the type 2 active galactic nucleus (AGN) in IC 751, three of which were performed simultaneously with XMM-Newton or Swift/XRT. We find that the nuclear X-ray source underwent a clear…
This letter presents a revised radiative transfer model for the infrared (IR) emission of active galactic nuclei (AGN). While current models assume that the IR is emitted from a dusty torus in the equatorial plane of the AGN, spatially…
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 examine the accretion properties in a sample of 42 hard (3-60keV) X-ray selected nearby broad-line AGNs. The energy range in the sample is harder than that usually used in the similar previous studies. These AGNs are mainly complied from…
From a parent catalog of 561 changing-look active galactic nuclei (CL-AGNs) identified by Guo et al. (2025), we investigate the evolutionary sequence of broad emission lines using a redshift-selected subset (0.35 < z < 0.45) of 54 CL-AGNs…
The presence of an active galactic nucleus (AGN) can strongly affect its host. Due to the copious radiative power of the nucleus, the effects of radiative feedback can be detected over the entire host galaxy and sometimes well into the…
We present X-ray observations of the ultraluminous infrared galaxy, UGC 5101, thought to contain a buried active galactic nucleus (AGN) based on observations in other wavebands. We detected an absorbed hard component at >3 keV, as well as…
We apply an analytic Markov Chain Monte Carlo model to a sample of 18 AGN-driven biconical outflows that we identified from a sample of active galaxies with double-peaked narrow emission lines at z < 0.1 in the Sloan Digital Sky Survey. We…