Searching for absorbed AGN in the 2XMM-Newton pre-release EPIC Serendipitous Source Catalogue

Abstract

Aims:We aim to test a method of efficiently selecting X-ray obscured AGN in the 2XMM-Newton EPIC Serendipitous Source Catalogue.
Methods: By means of a strong correlation established using the XMM-Newton Hard Bright Sample between the intrinsic absorption and the hardness ratio to the 0.5-2.0 keV and 2.0-4.5 keV bands, an efficient way of selecting absorbed sources has been worked out. A hardness ratio selection based on the 2XMM-Newton pre-release Source Catalogue led us to the definition of candidates likely to be obscured in X-rays.
Results: X-ray and optical spectral analysis were performed for three objects. Strong absorption (N_H > 10²² cm^-2) was detected from the X-ray analysis, confirming the efficiency of the method used to select obscured sources. The presence of absorption is also revealed in the optical band, although at a significantly lower level than inferred from the X-ray band.

Based on observations performed at the European Southern Observatory, La Silla, Chile and on observations obtained with XMM-Newton,an ESA science mission with instruments and contributions directly funded by ESA Member States and the USA (NASA).