|
Description
The ROSAT Bright Survey (RBS) is an identification program of the more than 2000 X-ray sources at high galactic latitude (absolute latitude b > 30 degrees) with a count rate of more than 0.2 ct/s detected during the ROSAT All-Sky Survey (Voges et al. 1999, A&A, 349, 389). The RBS identification program is more than 99.5% complete. A sub-sample of 931 sources with a count rate of more than 0.2 ct/s in the hard spectral band from 0.5 to 2.0 keV is 100% identified. The total survey area comprises 20391 square degrees at a flux limit of 2.4 x 10<sup>-12</sup> erg/s/cm<sup>2</sup> in the 0.5 to 2.0 keV band. About 1500 sources of the complete sample were identified by correlating the RBS with the SIMBAD and NED databases. The remaining ~500 sources were identified by low-resolution optical spectroscopy and CCD imaging utilizing various telescopes. The RBS Catalog contains optical and X-ray information for each source, including the most massive complete sample of X-ray selected AGN ever assembled, with a total of 669 members, and a well-populated X-ray selected sample of 302 clusters of galaxies with redshifts of up to 0.52. Three X-ray sources in the RBS remain without optical counterparts, RBS 378, RBS 1223, and RBS 1556. While the first is a possible X-ray transient, the latter two sources are isolated neutron star candidates (Motch et al. 1999, A&A, 351, 177; Schwope et al. 1999, 341, L51). As noted elsewhere, this electronic version of the RBS Catalog has a small number of additions/corrections compared to the published version. This database was created by the HEASARC in August 2000 based on a machine-readable table supplied to the HEASARC by Axel Schwope in April 2000. Note that this table is an expanded version of Table 2 in the published paper and contains the following additional parameters: HR2 (hardness_ratio_2), and the Galactic hydrogen column density (nh_21cm). This is a service provided by NASA HEASARC .
|
