High Energy Large Area Surveys: from BeppoSAX to Chandra and XMM
Astrophysics
2009-11-06 v1
Abstract
Optical identification of hard X-ray selected BeppoSAX and Chandra sources indicates that a large fraction of the sources are ``intermediate'' AGN, i.e. type 1.8-1.9 AGN, broad-line quasars and even X-ray loud but optically dull (apparently normal) galaxies, all obscured in X-rays by columns of the order of logNH=22-23.5 cm-2. Because of this obscuring matter, these sources are more difficult to detect or select at other wavelengths, implying that a fraction of the accretion power in the Universe may have been missed so far.
Cite
@article{arxiv.astro-ph/0102041,
title = {High Energy Large Area Surveys: from BeppoSAX to Chandra and XMM},
author = {F. Fiore and A. Comastri and F. La Franca and C. Vignali and G. Matt and G. C. Perola},
journal= {arXiv preprint arXiv:astro-ph/0102041},
year = {2009}
}
Comments
to appear in Proc. of the ESO/ECF/STSCI workshop on "Deep Fields", Garching October 2000