AAS 197, January 2001
Session 74. Surveys for Active Galaxies
Display, Wednesday, January 10, 2001, 9:30am-7:00pm, Exhibit Hall

## [74.09] The First X-ray Observation of the Second Brightest Quasar

K.M. Leighly (U. Oklahoma), J.P. Halpern (Columbia U.), E.B. Jenkins (Princeton), D.J. Helfand (Columbia U.), R.H. Becker (LLNL/UC Davis)

The VLA FIRST radio survey recently discovered a new, extremely bright quasar at z = 0.192. Its magnitudes on the POSS I plates are B = 13.9 and R = 13.9, and it is of similar brightness on a UK Schmidt plate taken in 1988. Its absolute magnitude is MV = -25.9 (for H0 = 70 km s-1 Mpc-1). These properties make it the second brightest quasar known (in apparent magnitude) at z > 0.1 after 3C 273. The only other mention of this object in the literature is as PHL 1811, one of the many blue stars" in the Palomar-Haro-Luyten plate survey.

Optically this quasar is classified as a Narrow-line Seyfert 1 galaxy (NLS1): it has narrow H\beta emission (1930 km s-1), no discernible [\ion{O}{3}] emission, strong optical \ion{Fe}{2}, and a blue optical continuum. NLS1s are known to be bright soft X-ray sources and therefore it was a complete surprise to find this object was not detected in the ROSAT All Sky Survey (RASS), with 95% confidence flux upper limit of 1.3 \times 10-2 counts s-1.

We observed PHL 1811 using BeppoSAX on May 16, 2000, for 38 ks. Only 65 photons were detected. The spectrum could be modelled by a power law (\alpha = 0.5) plus Galactic absorption only, or by a power law with index fixed at \alpha = 1.6 and intrinsic absorption best fitted as NH = 6.4 \times 1022 cm-2. The observed 2--10 keV X-ray luminosity is ~3 \times 1043 ergs s-1. The X-ray emission is very weak and the inferred \alphaox is 1.9--2.1, much smaller than the nominal value of 1.6 for quasars of this optical luminosity and comparable to the X-ray weakest quasars.

We do not know why PHL 1811 is so weak in soft X-rays. It may be unusually intrinsically weak. Alternatively, since BALQSOs and other UV absorbed objects are known to be soft X-ray weak, PHL 1811 may turn out to be a BALQSO.

Optical and BeppoSAX spectra will be presented and discussed. A preliminary FUSE spectrum will also be shown if it is observed, as planned, in the Fall of 2000.