THE NEW RADIO AND X-RAY BRIGHT QSOs

The FIRST Bright Quasar Survey (FBQS) was built by matching the VLA FIRST survey with the Cambridge Automated Plate Measuring Machine (APM) catalog of POSS-I objects (Irwin et al. 1994); it covers an area of 2682 deg² in the north Galactic cap; it contains 1238 objects brighter than 17.8 mag on the POSS-I E plates (White et al. 2000). About 1180 square degrees are within the FBS area; they contain 38 FIRST radio sources identified with an AGN brighter than B = 17.0 at |b| > 30$^\circ$; nine are bright QSOs ($O_{\rm APS} <$ 16.0), three (CSO 900, FIRSTJ1306+3915 and RXSJ17102+3344) being new. Although the numbers are small, this suggests that the ``complete" sample we built in Paper I is only 67$\pm$15% complete.

According to White et al. (2000), QSOs with radio emission above the FIRST 1 mJy limit constitute about 25% of all QSOs brighter than $B \sim$ 17.6, but for QSOs brighter than B = 16.4, the FBQS QSO density is indistinguishable from the density of optically selected QSOs. Nevertheless, of the 15 bright QSOs known prior to the FIRST survey in the area common to the FIRST and FBS surveys, only six (40%) have been detected as FIRST radio sources; therefore the complete identification of the FIRST sources with bright starlike objects could not yield a complete survey of bright QSOs.

A number of recent papers are devoted to the optical identification of RASS sources (Beuermann et al. 1999; Cao et al. 1999; Grazian et al. 2000; Schwope et al. 2000; Wei et al. 1999; Xu et al. 1999). One of the new identifications is RXSJ12043+4330, a QSO at z = 0.663 (Xu et al. 1999); it is also FBS1201+437 (FBS#302) or PG1201+436, which had been classified as a DC white dwarf by Green et al. (1986). Its APS O magnitude is 16.23; it is therefore not bright enough to be included in our ``complete" sample.

Nineteen RASS sources are now identified with a bright QSO in the area discussed in this paper (including the three new FIRST QSOs); of the 17 FBS or BQS bright QSOs in our sample (Table ), 12 (70%) are ROSAT All Sky Survey (RASS) X-ray sources, suggesting that the total number of bright QSOs is equal to 19/0.70 = 27 (if all optically bright, X-ray sources have been discovered).