SIMBAD references

2001AJ....121.2889L - Astron. J., 121, 2889-2894 (2001/June-0)

FIRST observations of the second-brightest quasar.

LEIGHLY K.M., HALPERN J.P., HELFAND D.J., BECKER R.H. and IMPEY C.D.

Abstract (from CDS):

We report the discovery of a new bright quasar, PHL 1811, as part of a follow-up program to identify bright quasars in the FIRST radio survey. With B=13.9, R=13.9, and z=0.192, this quasar is now the second-brightest quasar (in apparent magnitude) known beyond z=0.1. Optically classified as a narrow-line Seyfert 1 galaxy (NLS1), PHL 1811 is unusual for an object in this class in that it was not detected in X-rays in the ROSAT All-Sky Survey or in any previous X-ray survey. A follow-up BeppoSAX observation confirms that it is deficient in X-rays compared with other quasars, but poor signal-to-noise ratio prevents a definitive characterization of the X-ray spectrum. We consider three alternative hypotheses to explain why PHL 1811 is a weak X-ray source: (1) it is a broad absorption line quasi-stellar object and suffers X-ray absorption; (2) like several other luminous NLS1s, it exhibits high-amplitude X-ray variability and has been observed only when it is in an X-ray-quiescent state; and (3) it is intrinsically weak because it simply lacks an X-ray-emitting region.

Abstract Copyright: ∼

Journal keyword(s): Galaxies: Active - Galaxies: Quasars: Individual: Alphanumeric: PHL 1811 - X-Rays

CDS comments: Par. 2 RX J1034.2-4258 misprint for RX J0134.2-4258.

Simbad objects: 7

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