Description
The formation and evolution of cosmic structures can be probed by studying the evolution of the luminosity function of the Active Galactic Nuclei (AGNs), galaxies and clusters of galaxies and of the clustering of the X-ray active Universe, compared to the IR-UV active Universe. To this purpose, the authors have surveyed with XMM-Newton the central ~0.6 deg<sup>2</sup> region of the ELAIS-S1 field down to flux limits of ~5.5 x 10<sup>-16</sup> erg cm<sup>-2</sup> s<sup>-1</sup> (0.5-2 keV, soft band, S), ~2 x 10<sup>-15</sup> erg cm<sup>-2</sup> s<sup>-1</sup> (2-10 keV, hard band, H), and ~4 x 10<sup>-15</sup> erg cm<sup>-2</sup> s<sup>-1</sup> (5-10 keV, ultra-hard band, HH). They present here the analysis of the XMM-Newton observations, the number counts in different energy bands and the clustering properties of the X-ray sources. They have detected a total of 478 sources, 395 and 205 of which detected in the S and H bands respectively. They identified 7 clearly extended sources and estimated their redshift through X-ray spectral fits with thermal models. In four cases the redshift is consistent with z = 0.4, so they may have detected a large scale structure formed by groups and clusters of galaxies through their hot intra-cluster gas emission. The relative density of the S band sources is higher near the clusters and groups at z ~ 0.4 and extends toward East and the South/West. This suggests that the structure is complex, with a size comparable to the full XMM-Newton field. Conversely, the highest relative source densities of the H band sources are located in the central-west region of the field. The mosaic of four partially overlapping deep XMM-Newton pointings covers a large (~0.6 deg<sup>2</sup>) and contiguous area of the ELAIS-S1 region. The pointings are named <pre> ELAIS-S1-A (RA=8.91912, DE=-43.31344, J2000), ELAIS-S1-B (RA=8.92154, DE=-43.65575, J2000), ELAIS-S1-C (RA=8.42195, DE=-43.30488, J2000) and ELAIS-S1-D (RA=8.42375, DE=-43.65327, J2000). </pre> The X-ray observations were performed on May 2003 through July 2003 with XMM-Newton's European Photon Imaging Camera (EPIC) and two MOS-CCD cameras. This table was created by the HEASARC in June 2008 based on the <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/A+A/457/501">CDS Catalog J/A+A/457/501</a> files elaisxmm.dat and catalog.dat. This is a service provided by NASA HEASARC .
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