The XMM-Newton wide-field survey in the COSMOS field. The point-like X-ray source catalogue
Abstract
Context: The COSMOS survey is a multiwavelength survey aimed to study the evolution of galaxies, AGN and large scale structures. Within this survey XMM-COSMOS a powerful tool to detect AGN and galaxy clusters. The XMM-COSMOS is a deep X-ray survey over the full 2 deg2 of the COSMOS area. It consists of 55 XMM-Newton pointings for a total exposure of ~1.5 Ms with an average vignetting-corrected depth of 40 ks across the field of view and a sky coverage of 2.13 deg2.
Aims: We present the catalogue of point-like X-ray sources detected with the EPIC CCD cameras, the log N - log S relations and the X-ray colour-colour diagrams.
Methods: The analysis was performed using the XMM-SAS data analysis package in the 0.5-2 keV, 2-10 keV and 5-10 keV energy bands. Source detection has been performed using a maximum likelihood technique especially designed for raster scan surveys. The completeness of the catalogue as well as log N -log S and source density maps have been calibrated using Monte Carlo simulations.
Results: The catalogs contains a total of 1887 unique sources detected in at least one band with likelihood parameter det_ml >10. The survey, which shows unprecedented homogeneity, has a flux limit of ~1.7× 10 -15 erg cm-2 s-1, ~9.3 × 10 -15 erg cm-2 s-1 and ~1.3 × 10-14 erg cm-2 s-1 over 90% of the area (1.92 deg2) in the 0.5-2 keV, 2-10 keV and 5-10 keV energy band, respectively. Thanks to the rather homogeneous exposure over a large area, the derived log N - log S relations are very well determined over the flux range sampled by XMM-COSMOS. These relations have been compared with XRB synthesis models, which reproduce the observations with an agreement of ~10% in the 5-10 keV and 2-10 keV band, while in the 0.5-2 keV band the agreement is of the order of ~20%. The hard X-ray colors confirmed that the majority of the extragalactic sources in a bright subsample are actually type I or type II AGN. About 20% of the sources have a X-ray luminosity typical of AGN (L_X> 1042 erg/s) although they do not show any clear signature of nuclear activity in the optical spectrum.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- April 2009
- DOI:
- 10.1051/0004-6361/200810794
- arXiv:
- arXiv:0901.2347
- Bibcode:
- 2009A&A...497..635C
- Keywords:
-
- galaxies: active;
- large-scale structure of Universe;
- X-rays: diffuse background;
- X-rays: galaxies;
- Astrophysics - High Energy Astrophysical Phenomena
- E-Print:
- Astronomy and Astrophysics, accepted, language edited. The XMM-COSMOS source catalog and science data products are available at http://irsa.ipac.caltech.edu/data/COSMOS/ by A&