X-ray Properties of a Thousand Quasars: \\ ROSAT Observations of the LBQS
Session 59 -- General Properties of AGN
Oral presentation, Tuesday, 10, 1995, 10:00am - 11:30am

## [59.02] X-ray Properties of a Thousand Quasars: \\ ROSAT Observations of the LBQS

Paul J. Green (SAO), Norbert Schartel (MPE), Scott F. Anderson (UWa), Paul C. Hewett (IoA), Craig B. Foltz (UAz), Wolfgang Brinkmann, Henner Fink, Joachim Tr\"umper (MPE), and Bruce Margon (UWa)

Ninety percent of the more than 1000 QSOs in the Large Bright Quasar Survey (LBQS), were observed in soft X-rays during the ROSAT All-Sky Survey (RASS). These data constitute among the largest, most homogeneous X-ray surveys of QSOs to date, and as such are well-suited to the study of the multiwavelength properties of QSOs. By stacking X-ray counts, we obtain effectively much more sensitive observations for an average QSO in bins of redshift or luminosity, and for several classes of QSOs. We confirm a correlation of $\alpha_{ox}$ with luminosity for the overall sample. For higher redshifts and optical luminosities, radio-loud QSOs appear to become progressively more luminous in X-rays than radio-quiet QSOs. The X-ray properties of a subsample of 36 BAL QSOs suggest that they may be unusually X-ray quiet, while a subsample of 22 FeII-strong QSOs is anomalously X-ray bright.