Related papers: Ensemble X-ray variability of Active Galactic Nucl…
We use $\sim 1,000$ X-ray sources in the COSMOS-Legacy survey and study the position of the AGN relative to the star forming main sequence (MS). We also construct a galaxy (non-AGN) reference sample that includes $\sim 90,000$ sources. We…
The cosmic X-ray background (XRB) spectrum and active galaxy number counts encode essential information about the spectral evolution of active galactic nuclei (AGNs) and have been successfully modeled by XRB synthesis models for many years.…
We discuss the spectral analysis of a sample of 63 Active Galactic Nuclei (AGN) detected above a limiting flux of $S(8-24$ keV$)=7\times10^{-14}$ erg/s/cm$^2$ in the multi-tiered NuSTAR Extragalactic Survey program. The sources span a…
The analysis of the variability of active galactic nuclei (AGNs) at different wavelengths and the study of possible correlations among different spectral windows are nowadays a major field of inquiry. Optical variability has been largely…
We present modeling and interpretation of the continuum and emission lines for a sample of 51 unobscured Type 1 active galactic nuclei (AGN). All of these AGNs have high quality spectra from both XMM-Newton and Sloan Digital Sky Survey…
Fifteen ROSAT PSPC observations available in the public archive are analyzed in order to study time and spectral variability of the 12 EMSS AGN detected by ROSAT with more than 2000 net counts. Time variability was investigated on 13…
X-ray spectroscopy of active galactic nuclei (AGN) offers the opportunity to directly probe the inner regions of the accretion disk. We present the results of our analysis of average AGN XMM-Newton X-ray spectra in the Chandra Deep Field…
We present the results from a detailed X-ray variability analysis of 66 AGN in the Lockman Hole, which have optical spectroscopic identifications. We compare, quantitatively, their variability properties with the properties of local AGN,…
AIMS: We present the optical classification and redshift of 348 X-ray selected sources from the XMM-Newton Bright Serendipitous Survey (XBS) which contains a total of 400 objects (identification level = 87%). About 240 are new…
We present the second Multi-Epoch X-ray Serendipitous AGN Sample (MEXSAS2), extracted from the 6th release of the XMM Serendipitous Source Catalogue (XMMSSC-DR6), cross-matched with Sloan Digital Sky Survey quasar catalogues DR7Q and DR12Q.…
This is the second paper of our investigation of the 0.5-2 keV soft X-ray luminosity function (SXLF) of active galactic nuclei (AGN) using results from ROSAT surveys of various depth. The large dynamic range of the combined sample, from…
A wide-frequency radio study of Active Galactic Nuclei (AGN) is crucial to evaluate the intervening radiative mechanisms responsible for the observed emission and relate them with the underlying accretion physics. We present wide frequency…
We study the space density evolution of active galactic nuclei (AGN) using the $610 \ \mathrm{MHz}$ radio survey of the XXL-North field, performed with the Giant Metrewave Radio Telescope (GMRT). The survey covers an area of $30.4 \…
The broadband X-ray spectra of AGNs contains information about the nuclear environment from Schwarzschild radii scales to distances of ~1 pc. In addition, the average shape of the X-ray spectrum is an important input into X-ray background…
We report on the results of the first XMM systematic "excess variance" study of all the radio quiet, X-ray un-obscured AGN. The entire sample consist of 161 sources observed by XMM for more than 10 ks in pointed observations which is the…
The X-ray luminosity function (XLF) of galaxies is dominated by AGN (classified by their optical spectra) above Lx=10**42 erg/s, below this value by normal galaxies. The X-ray flux of AGN at low X-ray luminosity therefore contains…
Motivated by upcoming photometric and spectroscopic surveys (Vera C. Rubin Observatory Legacy Survey of Space and Time (LSST), Manuakea Spectroscopic Explorer), we design the statistical proxies to measure the cadence effects on active…
Radio-loud active galactic nuclei (AGN) are among the most luminous objects in the Universe, emitting radiation from low-energy radio waves to high energy $\gamma$-rays. They are well known to exhibit flux variations at nearly all…
In the context of the upcoming SRG/eROSITA survey, we present an N-body simulation-based mock catalogue for X-ray selected AGN samples. The model reproduces the observed hard X-ray AGN luminosity function (XLF) and the soft X-ray logN-logS…
We analyse a sample of 21 `bare' Seyfert~1 Active Galactic Nuclei (AGNs), a sub-class of Seyfert~1s, with intrinsic absorption $\mathrm{N_{H}} \sim 10^{20}~ \mathrm{cm}^{-2}$, in the local universe (z $<$ 0.2) using {\it XMM-Newton} and…