The Cambridge-Cambridge ROSAT Serendipity Survey -- V. Catalogue and optical identifications
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CitationBoyle, B. J., B. J. Wilkes, and M. Elvis. 1997. “The Cambridge-Cambridge ROSAT Serendipity Survey -- V. Catalogue and Optical Identifications.” Monthly Notices of the Royal Astronomical Society 285 (3) (March 1): 511–528. doi:10.1093/mnras/285.3.511.
AbstractWe report the results of a medium-depth X-ray survey of 20 ROSAT Position Sensitive Proportional Counter (PSPC) fields. 123 X-ray sources were detected down to a flux limit of S(0.5–2 keV) > 2 × 10−14 erg s−1 cm−2 lying between that of the Einstein Extended Medium Sensitivity Survey (EMSS) and the deepest ROSAT surveys. Optical identifications of 110 of these sources have revealed 68 QSOs, 12 narrow-emission-line X-ray-luminous galaxies (NLXGs), 24 stars, two BL Lac objects, two galaxies and two clusters. CCD imaging reveals the possible presence of galaxy groups or clusters at the positions of a further four X-ray sources. The number-redshift and log N-log S relations of the 68 QSOs are in better agreement with the faster rate of cosmological evolution for X-ray QSOs derived from ROSAT deep surveys [Lx∝(1 +z)3.34±01, zmax = 1.79] than with the evolution obtained from the EMSS [Lx∝(1 +z)2.55±01, the latter being rejected at greater than the 3σ level as a model for the current sample. We present the optical spectra and measurements of the emission lines. The equivalent-width distributions are consistent with those of QSO samples selected in other wavebands. We find no evidence for an inverse correlation between line width and X-ray spectral slope as recently reported for other ROSAT QSO samples.
Citable link to this pagehttp://nrs.harvard.edu/urn-3:HUL.InstRepos:30212141
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