Related papers: Hard X-ray emission from elliptical galaxies
We report the detection of relativistically broadened iron K alpha emission in the X-ray spectra of AGN detected in the 4Ms CDF-S. Using the Bayesian X-ray analysis (BXA) package, we fit 199 hard band (2-7 keV) selected sources in the…
The Galactic Center Region has been surveyed in 1997-1998 with the Narrow Field Instruments on-board the BeppoSAX satellite (2-10keV energy range). The X-ray emission from SgrA*, the putative supermassive black hole at the center of our…
We present hard X-ray observations of the nearby radio galaxy M87 and the core of the Virgo cluster using the Rossi X-ray Timing Explorer. These are the first hard X-ray observations of M87 not affected by contamination from the nearby…
The Galactic Ridge X-ray Emission (GRXE) is apparently extended X-ray emission along the Galactic Plane. The X-ray spectrum is characterized by hard continuum with a strong Fe K emission feature in the 6-7 keV band. A substantial fraction…
We present an analysis of the X-ray properties of the Magellanic-type galaxy NGC 55 based on two contiguous XMM-Newton observations. We detect a total of 137 X-ray sources in the field of view, 42 of which are located within the optical…
Our Galaxy harbours a large population of X-ray sources of intermediate to low X-ray luminosity (typically Lx from 10^27 to 10^34 erg/s). At energies below 2 keV, active coronae completely dominate the X-ray landscape. However, the nature…
We report on our search for very-long-term variability (weeks to years) in X-ray binaries (XRBs) in the giant elliptical galaxy M87. We have used archival Chandra imaging observations to characterise the long-term variability of 8 of the…
A subset of galaxies have dense nuclei, and when these galaxies are accreted and tidally stripped, the nuclei can masquerade as globular clusters in the halos of large galaxies. If these nuclei contain massive central black holes, some may…
We report results of a Chandra observation of the X-ray luminous star-forming galaxy Arp299 (NGC3690/IC694). We detect 18 discrete X-ray sources with luminosities above ~10^39 erg\s (0.5-8.0 keV band), which contribute ~40% of the total…
X-ray emission from counterparts of historical classical novae (CNe) in our Galaxy is studied. To this end, we use data from three SRG/eROSITA sky surveys in the hemisphere analyzed by the RU eROSITA consortium. Out of 309 historical CNe,…
We exploit the 7 Ms \textit{Chandra} observations in the \chandra\,Deep Field-South (\mbox{CDF-S}), the deepest X-ray survey to date, coupled with CANDELS/GOODS-S data, to measure the total X-ray emission arising from 2076 galaxies at…
We present an X-ray spectral study of the prototype far-infrared galaxy NGC6240 from ASCA. The soft X-ray spectrum (below 2 keV) shows clear signatures of thermal emission well described with a multi-temperature optically-thin plasma, which…
A number of radio galaxies has been detected by Fermi/LAT in the gamma-ray domain. In some cases, like Cen A and M 87, these objects have been seen even in the TeV range by Cherenkov telescopes. Whereas the gamma-ray emission is likely to…
Using the X-ray data taken with ASCA, a detailed analysis was made of intensity and spectral variations of three ultra-luminous extra-galactic compact X-ray sources (ULXs); IC 342 source 1, M81 X-6, and NGC 1313 source B, all exhibiting…
Chandra observations of low-luminosity supermassive black holes in nearby elliptical galaxies provide tight limits on both their nuclear luminosities and on their Bondi accretion rates. We examine Chandra constraints on NGC 6166, the…
We present ASCA results on four prototype powerful far-infrared galaxies, Mrk231, Mrk273, Arp220 and NGC6240. The soft X-ray spectra show signatures of thermal emission with temperatures of (0.5-1) keV, which is probably produced in…
Massive halos of hot plasma exist around some, but not all elliptical galaxies. There is evidence that this is related to the age of the galaxy. In this paper new X-ray observations are presented for three early-type galaxies that show…
We present the results of Chandra observations of off-nuclear X-ray sources in the spiral galaxy M51 (NGC 5194). 113 X-ray sources have been detected in the field of view and 84 among them project within the disk of NGC 5194. Six and twenty…
We found several extranuclear (r >~ 3") X-ray nebulae within 40" (6.3 kpc at 32.5 Mpc) of the nucleus of the Seyfert galaxy NGC 2992. The net X-ray luminosity from the extranuclear sources is ~2-3 E39 erg/s (0.3-8.0 keV). The X-ray core…
Several models for the hard X-ray Background (XRB) suggest that it is due to the emission from heavily obscured AGN. Recent studies have revealed the presence of a new population of hard X-ray sources which must contribute significantly to…