1. PDS 456: An extreme accretion rate quasar?
- Author
-
Reeves, J., O’Brien, P., Vaughan, S., Law-Green, D., Ward, M., Simpson, C., Pounds, K., and Edelson, R.
- Subjects
QUASARS ,SPECTRAL energy distribution - Abstract
X-ray and multi-wavelength observations of the most luminous known local (z < 0.3) AGN, the recently discovered radio-quiet quasar PDS 456, are presented. The spectral energy distribution shows that PDS 456 has a bolometric luminosity of 10[sup 47] erg/s, peaking in the UV. The X-ray spectrum obtained by ASCA and RXTE shows considerable complexity. The most striking feature observed is a deep, highly-ionised, iron K edge (8.7 keV, rest-frame), originating via reprocessing from highly ionised material, possibly the inner accretion disk. PDS 456 was found to be remarkably variable for its luminosity; in one flare the X-ray flux doubled in just ∼ 15 ksec. If confirmed this would be an unprecedented event in a high-luminosity source, with a light-crossing time corresponding to ∼ 2R[sub S]. The implications are that either flaring occurs within the very central regions, or else that PDS 456 is a 'super-Eddington' or relativistically beamed system. [ABSTRACT FROM AUTHOR]
- Published
- 2001