The Extreme SED of the Quasar [HB89] 0102-272
Abstract
We have studied the spectral energy distribution of the quasar [HB89] 0102-272. The available multiwavelength data in the observers frame are one optical spectrum between 3000 and 8000 Å, 7 HST FOS spectra between 1600 and 2300 Å, and 3 ROSAT PSPC pointed observations in the 0.1-2.4 keV energy band. The αox value obtained from the HST FOS spectra and the optical spectrum is extreme with -2.2 and -2.1, respectively and is one of the steepest values reported so far. The 2500 Å luminosity density is about 5 orders of magnitude larger than the 2 keV flux density. The object is as bright as the brightest SDSS quasars but X-ray weak at 2 keV. We compare our αox findings with the mean quasar SED from [14] and conclude that [HB89] 0102-292 is unusual for any type of quasar SED's. In addition an extreme steep soft X-ray photon index of Γ = (6.0+/-1.3) has been detected, the steepest value reported so far. When fitting the X-ray and optical and HST UV data simultaneously with a simple black body model an extreme discrepancy becomes apparent. While the rest frame UV photons appear to be emitted from an accretion disc, the X-ray's must arise from something else and are not related to the UV photons.
- Publication:
-
SIMBOL-X: Focusing on the Hard X-ray Universe
- Pub Date:
- May 2009
- DOI:
- 10.1063/1.3149422
- Bibcode:
- 2009AIPC.1126..235B
- Keywords:
-
- 95.75.Fg;
- 98.62.Ra;
- 98.62.Js;
- 95.85.Nv;
- 98.62.Mw;
- Spectroscopy and spectrophotometry;
- Intergalactic matter;
- quasar absorption and emission-line systems;
- Lyman forest;
- Galactic nuclei circumnuclear matter and bulges;
- X-ray;
- Infall accretion and accretion disks