Related papers: X-ray absorption in distant type II QSOs

XMM-Newton observations of 29 high redshift (z>2) quasars, including seven radio-quiet, 16 radio-loud and six Broad Absorption Line (BAL) objects, are presented; due to the high redshifts, the rest-frame energy bands extend up to \~30-70…

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…

Accretion onto SMBH is believed to occur mostly in obscured AGN. Such objects are proving rather elusive in surveys of distant galaxies, including those at X-ray energies. Our main goal is to determine whether the revised IRAC criteria of…

Recent X-ray surveys with Chandra and XMM-Newton have found several genuine Type II quasars, the long sought-after population of high-luminosity (high-redshift) Seyfert 2 galaxies, and a sizable number of Type II quasar candidates. However,…

Here we present the results obtained from the analysis of 75 ksec of XMM-Newton observations of a sample of EROs selected from one MUNICS field (K'<19.5 mag). We find 6 EROs with a X-ray counterpart down to a 2--10 keV flux limit of…

We investigate the possibility of using the ratio between the 2-10 keV flux and the [Ne V]3426 emission line flux (X/NeV) as a diagnostic diagram to discover heavily obscured, possibly Compton-Thick Active Galactic Nuclei (AGN) up to z~1.5.…

We present new mid-infrared and submillimetre observations for a sample of eight high redshift type-2 QSOs located in the Chandra Deep Field South. The sources are X-ray absorbed with luminosities in excess of 10^44 erg/s. Two of the…

In contradiction to the simple AGN unification schemes, there exists a significant population of broad line, z~2 QSOs which have heavily absorbed X-ray spectra. These objects have luminosities and redshifts characteristic of the sources…

We present a survey of six low to moderate redshift quasars with Chandra and XMM-Newton. The primary goal is to search for the narrow X-ray absorption lines produced by highly ionized metals in the Warm-Hot Intergalactic Medium. All the…

We present X-ray spectra of 185 bright sources detected in the XMM-Newton deep survey of the Chandra Deep Field South, combining the three EPIC cameras. The 2-10 keV flux limit of the sample is 2e-15 erg/s/cm2. The sources are distributed…

The spectroscopic analysis of 117 serendipitous sources in the HELLAS2XMM 1df (1 degree field) survey is described. Of these, 106 sources, of which 86% have a spectroscopic redshift, are used to evaluate the fraction of X-ray absorbed (log…

We present the XMM-Newton and the optical-VLT spectra along with the optical and the near-infrared photometric data of one of the brightest X-ray (F(2-10 keV)~1e-13 erg/s cm^2) extremely red objects (R-K>=5) discovered so far. The source,…

We present the first results of the spectroscopy of distant, obscured AGN as obtained with the ultra-deep (~3.3 Ms) XMM-Newton survey in the Chandra Deep Field South (CDFS). One of the primary goals of the project is to characterize the…

We present the results of the X-ray spectral analysis of the deep survey obtained with the XMM-Newton observatory on the Lockman Hole. The X-ray data and the cumulative source counts were reported by Hasinger et al. (2001). Our sample…

We present the first comprehensive analysis of the argon K-edge absorption region (3.1-4.2 \AA) using high-resolution HETGS {\it Chandra} spectra of 33 low-mas X-ray binaries. Utilizing R-matrix theory, we computed new K photoabsorption…

We perform a detailed investigation of moderate-to-high quality X-ray spectra of ten of the most luminous active galactic nuclei (AGNs) known at z>4 (up to z~6.28). This study includes five new XMM observations and five archived X-ray…

We present Chandra and Spitzer data of the 186, extragalactic, hard 2-10 keV X-ray selected sources, which lie in the central part of the Chandra Deep Field South (CDFS). For the vast majority of sources (99.5%) there is a spectroscopic or…

We present an analysis of the X-ray spectral properties of 61 hard X-ray selected (2-8 keV) sources from the bright ($f_{2-8 keV}>10^{-14}$ \funits) {\it XMM-Newton}/2dF survey. This comprises of 9 {\it XMM-Newton} pointings in the North…

We present an analysis of the X-ray properties of sources detected in the 13H XMM-Newton deep (200ks) field. In order to constrain the absorbed AGN population, we use extensive Monte Carlo simulations to directly compare the X-ray colours…

Recently, convincing evidence was found for extremely large X-ray absorption by column densities $> 10^{23} cm^{-2}$ in broad absorption line quasars. One consequence of this is that any soft X-ray emission from these QSOs would be the…