On the peculiar X-ray properties of the bright nearby radio-quiet quasar PDS 456
Abstract
BeppoSAX and ASCA observations of the nearby (z = 0.184), high-luminosity, radio-quiet quasar PDS 456 are presented. The X-ray spectrum is characterized by a prominent ionized edge at 8-9 keV (originally discovered by RXTE, Reeves et al. 2000) and by a soft excess below 1.5 keV. The lack of any significant iron Kalpha emission line suggests for the edge an origin from line-of-sight material rather than from reflection from a highly ionized accretion disc. The hard X-ray continuum is indeed well modelled by transmission through a highly-ionized medium with a large column density (NHwarm ~ 4.5 x 1024 cm-2) plus an additional cold absorber with a lower column density (NHcold ~ 2.7 x 1022 cm-2).
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- October 2000
- DOI:
- 10.48550/arXiv.astro-ph/0008090
- arXiv:
- arXiv:astro-ph/0008090
- Bibcode:
- 2000A&A...362...69V
- Keywords:
-
- GALAXIES: NUCLEI;
- GALAXIES: QUASARS: INDIVIDUAL: PDS 456;
- X-RAYS: GALAXIES;
- Astrophysics
- E-Print:
- 7 pages, 5 figures, accepted by Astronomy &