𝔖 Bobbio Scriptorium
✦   LIBER   ✦

The BeppoSAX HELLAS survey: the nature of the hard X-ray selected sources

✍ Scribed by F. Fiore; F. La Franca; HELLAS Collaboration

Publisher
John Wiley and Sons
Year
1999
Tongue
English
Weight
74 KB
Volume
320
Category
Article
ISSN
0004-6337

No coin nor oath required. For personal study only.

✦ Synopsis

The BeppoSAX High Energy Large Area Survey (HELLAS) has found so far 200 sources with a 5-10 flux higher than 5 Γ— 10 -14 erg cm -2 s -1 in ∼ 80 deg 2 of sky. A summary on the optical identifications of a subsample of these sources is presented here. Most of the identified sources are AGN at 0.04<z<3.5. The fraction of sources showing absorption/extinction in X-ray/optical to the total is 0.53Β±0.10, higher than in previous ROSAT, and ASCA-ROSAT surveys, but in line with scenarios in which the bulk of the hard Cosmic X-ray background (XRB) is made by highly obscured AGN (e.g. Setti & Woltjer 1989, Comastri et al. 1995).

πŸ“œ SIMILAR VOLUMES

Unlocking the nature of ultraluminous X-
Unlocking the nature of ultraluminous X-ray sources using their X-ray spectra
✍ J.C. Gladstone; T.P. Roberts; C. Done πŸ“‚ Article πŸ“… 2011 πŸ› John Wiley and Sons 🌐 English βš– 167 KB πŸ‘ 2 views

## Abstract We explore the nature of ultraluminous X‐ray sources through detailed investigations of their spectral shape using some of the highest quality data available in the XMM‐Newton public archives. Phenomenological models allow us to characterise their spectra, while more β€˜physically‐motivat

Surveying the hard X-ray sky: imaging in
Surveying the hard X-ray sky: imaging in space and time
✍ J. E. Grindlay πŸ“‚ Article πŸ“… 1998 πŸ› John Wiley and Sons 🌐 English βš– 382 KB πŸ‘ 2 views

One of the few remaining astronomical bands (factor of -10 in energy range) still without an all-sky imaging survey is the hard x-ray band (10-600 keV). This is in spite of sensitive imaging all-sky surveys already conducted at soft x-ray (0.2-2 keV; ROSAT) and soft/hard y-ray (-750 keV -10 GeV; COM