Related papers: The Serendipitous Extragalactic X-Ray Source Ident…

AXIS (An XMM-Newton International Survey) is a survey of 36 high Galactic latitude XMM-Newton observations covering 4.8 deg2 and containing 1433 serendipitous X-ray sources detected with 5-sigma significance. We have studied the X-ray…

We describe the initial results of a programme to detect and identify extended X-ray sources found serendipitously in XMM-Newton observations. We have analysed 186 EPIC-PN images at high galactic latitude with a limiting flux of $1\times…

We cross-identified the ROSAT Bright Source Catalog (RBSC) and the NRAO VLA Sky Survey (NVSS) to construct the RBSC-NVSS sample of the brightest X-ray sources (>= 0.1 counts/s or ~1E-12 ergs/cm/cm/s in the 0.1-2.4 keV band) that are also…

We present optical and X-ray data for a sample of serendipitous XMM-Newton sources that are selected to have 0.5-2 keV vs 2-4.5 keV X-ray hardness ratios which are harder than the X-ray background. The sources have 2-4.5 keV X-ray flux >=…

We present an optical and NIR catalog for the X-ray sources in the 2 Ms Chandra observation of the Hubble Deep Field-North region. We have high-quality multicolor images of all 503 X-ray point sources and reliable spectroscopic redshifts…

Within the framework of our program of assessment of the nature of unidentified or poorly known INTEGRAL sources, we present here spectroscopy of optical objects, selected through positional cross-correlation with soft X-ray detections…

The radio-quiet neutron star 1E1207.4-5209 has been the target of several XMM-Newton observations, with a total exposure of ~350 ks. The source is located at intermediate galactic latitude (b~10 degrees), i.e. in a sky region with an…

Aims. We present a stand-alone software (named EXSdetect) for the detection of extended sources in X-ray images. Our goal is to provide a flexible tool capable of detecting extended sources down to the lowest flux levels attainable within…

We discuss ROSAT HRI X-ray observations of 33 very nearby galaxies, sensitive to X-ray sources down to a luminosity of approximately 10^38 erg/s. The galaxies are selected from a complete, volume limited sample of 46 galaxies with d<7 Mpc…

We report the detailed analysis of the X-ray properties of the discrete sources detected in a long (72 ks) \chandra ACIS-S observation of the Antennae galaxies. We detect 49 sources, down to a detection limit of ~ 10^{38} erg\s; 18 sources…

We present an analysis of the compact X-ray source population in the Seyfert~2 galaxy NGC 1068, imaged with Chandra. We find a total of 84 compact sources, of which 66 are projected onto the galactic disk of NGC 1068. Spectra of the…

We present preliminary results on the optical identifications of sources from the High Energy Large Area Survey performed with XMM-Newton (HELLAS2XMM). This survey covers about 3 square degrees of sky down to a 2-10 keV flux of 7 x 10^-15…

In this Paper we present the source catalog obtained from a 942 ks exposure of the Chandra Deep Field South (CDFS), using ACIS-I on the Chandra X-ray Observatory. Catalog generation proceeded simultaneously using two different methods; a…

We present the results of a detailed spectral analysis of optically faint hard X-ray sources in the Chandra deep fields selected on the basis of their high X-ray to optical flux ratio (X/O). The stacked spectra of high X/O sources in both…

It is assumed that the unresolved fraction of the X-ray background (XRB) consists of a truly diffuse component and a population of the weak sources below the present detection threshold. Albeit these weak sources are not observed directly,…

We present Chandra and XMM observations of 12 bright (f(2-10 keV) > 10^-13 cgs) sources from the ASCA SHEEP (Search for the High Energy Extragalactic Population) survey. Most of these have been either not observed or not detected previously…

We present results of a Chandra survey of the ultra-luminous X-ray sources (ULX) in 13 normal galaxies, in which we combine source detection with X-ray flux measurement. 22 ULX were detected, i.e. with L_x > 1 x 10^{39} erg s^{-1} (L_10),…

This paper presents the analysis of a statistically complete sample of 28 serendipitous X-ray sources selected in 82 pointed XMM-Newton fields down to a count-rate of 0.002 counts s^-1(4.5-7.5 keV energy band). This is the first sample…

We examine the X-ray spectra and variability of the sample of X-ray sources with L_X = 10^{31}-10^{33} erg s^{-1} identified within the inner 9' of the Galaxy. Very few of the sources exhibit intra-day or inter-month variations. We find…

We present a deep search for and analysis of X-ray sources in a sample of dwarf galaxies (M$_{r}$ < -15.5 mag) located within twelve galaxy clusters from the Kapteyn IAC WEAVE INT Cluster Survey (KIWICS) of photometric observations in the…