The XMM-Newton wide-field survey in the COSMOS field

N. Cappelluti, M. Brusa, G. Hasinger, A. Comastri, G. Zamorani, A. Finoguenov, R. Gilli, S. Puccetti, T. Miyaji, M. Salvato, C. Vignali, T. Aldcroft, H. Böhringer, H. Brunner, F. Civano, M. Elvis, F. Fiore, A. Fruscione, R. E. Griffiths, L. GuzzoA. Iovino, A. M. Koekemoer, V. Mainieri, N. Z. Scoville, P. Shopbell, J. Silverman, C. M. Urry

Research output: Contribution to journalArticlepeer-review

224 Scopus citations


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 (LX > 1042 erg/s) although they do not show any clear signature of nuclear activity in the optical spectrum.

Original languageEnglish (US)
Pages (from-to)635-648
Number of pages14
JournalAstronomy and Astrophysics
Issue number2
StatePublished - Apr 2009
Externally publishedYes


  • Galaxies: active
  • Large-scale structure of Universe
  • X-rays: diffuse background
  • X-rays: galaxies

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science


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