The BeppoSAX High Energy Large Area Survey (HELLAS)
Astrophysics
2007-05-23 v1
Abstract
We have surveyed about 50 deg-2 of sky in the largely unexplored 5-10 keV band using the BeppoSAX MECS instrument, finding 180 sources. After correction for the non uniform sky coverage we find about 18 sources deg-2 with F(5-10keV) >= 5E-14 cgs, and resolve 30-40 % of the hard 5-10 keV Cosmic X-ray Background (XRB). Optical identification of a first small sample of sources show that most (11 out of 14) are AGN. Six of these show evidence of absorption/extinction in X-ray/optical, thus providing support to the scenario in which the hard XRB is largely made by obscured AGN (Setti & Woltjer 1989, Comastri et al. 1995).
Cite
@article{arxiv.astro-ph/9811149,
title = {The BeppoSAX High Energy Large Area Survey (HELLAS)},
author = {F. Fiore and P. Giommi and F. La Franca and G. Matt and G. C. Perola and A. Comastri and S. Molendi and M. Elvis and I Gioia and F. Tamburelli and D. Ricci and F. Pompilio},
journal= {arXiv preprint arXiv:astro-ph/9811149},
year = {2007}
}
Comments
6 pages, Proceeding of the first XMM workshop "Science with XMM" (30 Sep. - 2 Oct. 1998 ESTEC)