Related papers: X-Ray Evidence for Multiple Absorbing Structures i…
X-ray spectroscopy of Seyfert 1 galaxies often reveal absorption edges resulting from photoionized gas along the line-of-sight to the central engine, the so-called warm absorber. I discuss how recent ASCA observations of warm absorber…
We discuss the spectral properties of a sample of type-2 Seyfert galaxies based upon the analysis of \asca data. In this paper we consider the sources for which the X-ray spectra appear to be dominated by the nuclear continuum, transmitted…
We use the database from Paper III to quantify the global and nuclear properties of emission-line nuclei in the Palomar spectroscopic survey of nearby galaxies. We show that the host galaxies of Seyferts, LINERs, and transition objects…
We find a very strong correlation between the intrinsic spectral slope in X-rays and the amount of Compton reflection from a cold medium in Seyfert AGNs and in hard state of X-ray binaries with either black holes or weakly-magnetized…
The central engines of Seyfert galaxies are thought to be enshrouded by geometrically thick gas and dust structures. In this article, we derive observable properties for a self-consistent model of such toroidal gas and dust distributions,…
The optical classification of a Seyfert galaxy and whether it is considered X-ray absorbed are often used interchangeably. But there are many borderline cases and also numerous examples where the optical and X-ray classifications appear to…
The current status of understanding of the X-ray emission from Seyfert galaxies involves Comptonization of soft photons by hot subrelativistic electrons. After briefly reviewing the early theoretical basis for the presence of hot optically…
Plots of equivalent width (or neutral hydrogen column density) versus impact parameter (between the galaxy and quasar line of sight) have been used to support a variety of conclusions about the relationship between galaxies and Ly\alpha…
We present a deep study of the average hard X-ray spectra of Seyfert galaxies. We analyzed all public INTEGRAL IBIS/ISGRI data available on all the 165 Seyfert galaxies detected at z<0.2. Our final sample consists of 44 Seyfert 1's, 29…
We have analyzed spectra for all active galactic nuclei in the Rossi X-ray Timing Explorer (RXTE) archive. We present long-term average values of absorption, Fe line equivalent width, Compton reflection and photon index, as well as…
We discuss the X-ray properties of the cooling flows in a sample of thirty highly X-ray luminous clusters of galaxies observed with the ASCA and ROSAT satellites. We demonstrate the need for multiphase models to consistently explain the…
In this work, the analysis of multi-epoch (1995-2010) X-ray observations of the Seyfert 1 galaxy H0557-385 is presented. The wealth of data presented in this analysis show that the source exhibits dramatic spectral variability, from a…
We present a statistical study of a large, homogeneously analyzed sample of narrow-line Seyfert 1 (NLS1) galaxies, accompanied by a comparison sample of broad-line Seyfert 1 (BLS1) galaxies. Optical emission-line and continuum properties…
Results obtained from an X-ray spectral survey of nearby Seyfert galaxies using XMM--Newton are reported. The sample was optically selected, well defined, complete in B mag, and distance limited: it consists of the nearest (D<22 Mpc) 27…
The Absorption Measure Distribution (AMD) in the X-ray outflows of Seyfert active galactic nuclei (AGN) describes the distribution of absorbing column density as a function of ionization parameter. Up to now, AMD has been measured only for…
X-ray spectroscopy offers an opportunity to study the complex mixture of emitting and absorbing components in the circumnuclear regions of active galactic nuclei, and to learn about the accretion process that fuels AGN and the feedback of…
We study the relation between gaseous absorbing column density (N$_{\rm H}$), infrared colors and detectability of the broad lines in a large sample of Seyfert 2 galaxies(Sy2s). We confirm that Sy2s without polarized broad lines tend to…
We present evidence for a strong correlation between the gaseous absorbing column density towards type 2 Seyfert nuclei and the presence of a stellar bar in their host galaxies. Strongly barred Seyfert 2 galaxies have an average Nh that is…
In about half of Seyfert galaxies, the X-ray emission is absorbed by an optically thin, ionized medium, the so-called "Warm Absorber", whose origin and location is still a matter of debate. The aims of this paper is to put more constraints…
The $BeppoSAX$ archive is currently the largest reservoir of high sensitivity simultaneous soft and hard-X ray data of Seyfert galaxies. From this database all the Seyfert galaxies (105 objects of which 43 are type I and 62 are type II)…