CDROM/APJ/V450/P051 X-rays from Large Optical QSO Sample (Green+ 1995) ================================================================================ The Soft X-Ray Properties of a Large Optical QSO Sample: ROSAT Observations of the Large Bright Quasar Survey Paul J. Green, Norbert Schartel, Scott F. Anderson, Paul C. Hewett, Craig B. Foltz, Wolfgang Brinkmann, Henner Fink, Joachim Trumper, & Bruce Margon <1995, ApJS, 450, 51> =1995ApJ...450...51G ================================================================================ Abstract: Of the more than 1000 QSOs in the Large Bright Quasar Survey (LBQS), we study the X-ray properties of 908 that were covered by 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. Due to the ~600 s RASS exposure times, only 10% of the QSOs are detected in X-rays. However, 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 broad absorption line QSOs suggest that they are strongly absorbed or underluminous in the X-rays, while a subsample of 22 Fe II-strong QSOs is anomalously X-ray bright. Keywords: galaxies: active -- quasars: general -- surveys -- X-rays: galaxies File Summary: -------------------------------------------------------------------------------- File Name Lrecl Records Explanations -------------------------------------------------------------------------------- table1.dat 94 908 Raw data and luminosities of detected LBQS/RASS QSOs table2.dat 45 9 WOR regressions of alpha_ox(log l_opt) table1.tex 146 955 AASTeX version of table1.dat table2.tex 68 35 AASTeX version of table2.dat -------------------------------------------------------------------------------- Byte-by-byte Description of file: table1.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 9 A9 --- Name Name of the LBQS QSO 10-16 F7.3 --- z Redshift 17-22 F6.1 mag B_J B_J magnitude 23-28 F6.2 mag A_B Extinction 29-33 F5.1 10-20cm-2 N_H Galactic hygrogen column density 34-40 F7.1 --- Csrc RASS source counts 41-45 F5.1 --- e_Csrc Csrc uncertainty 46-51 F6.1 --- Cbkg RASS source counts normalized to the source aperture area 52-55 F4.1 --- e_Cbkg CBkg uncertainty 56-62 F7.1 s T RASS exposure time 63-64 2X --- --- Blank 65 A1 --- l_Lx [< ] Lx limiting character 66-70 F5.2 erg/s/Hz Lx Logarithm of X-ray luminosity 71-77 F7.2 erg/s/Hz Lo Logarithm of optical luminosity 78-79 2X --- --- Blank 80 A1 --- l_Alp_ox [> ] Alp_ox limiting character 81-84 F4.1 --- Alp_ox Slope of a hypothetical power law connecting 2500 A and 2 keV 85-86 2X --- --- Blank 87-94 A8 --- Notes *Notes -------------------------------------------------------------------------------- Notes for file: table1.dat -------------------------------------------------------------------------------- Notes: RL Radio loud RL * Radio loud, data from Molonglo Reference Catalog, Large et al. (1981, MNRAS, 194, 693) or from Condon et al. (1994, AJ, 107, 461) RQ Radio quiet RA Radio ambiguous, when a radio flux upper limit is consistent with either a radio-loud or a radio-quiet designation BAL Clear broad absorption lines Fe Strong Fe II QSO -------------------------------------------------------------------------------- Byte-by-byte Description of file: table2.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 4 A4 --- Sample Either 'Full', 'RQ' for radio quiet, or 'RL' for radio loud 5 1X --- --- Blank 6-19 A14 --- Parm Bin parameters 20-24 A5 --- Bins Number of bins, nn/nn 25-30 F6.2 --- Slope Slope 31-35 F5.2 --- e_Slope Slope uncertainty 36-41 F6.1 --- Int Intercept 42-45 F4.1 --- e_Int Intercept uncertainty -------------------------------------------------------------------------------- ================================================================================ (End) Lee Brotzman [ADS] 10-Oct-95