The z=5.8 Quasar SDSSp J1044-0125: A Peek at Quasar Evolution?
Abstract
The newly discovered z=5.8 quasar SDSSp J104433.04-012502.2 was recently detected in X-rays and found to be extremely X-ray weak. Here we present the hardness ratio analysis of the XMM-Newton observation. We consider various models to explain the detection in the soft X-ray band and nondetection in the hard band, together with its X-ray weakness. We show that the source may have a steep power-law slope, with an absorber partially covering the continuum. This may be X-ray evidence to support the recent argument of Mathur that narrow-line Seyfert 1 galaxies, which show steep power-law slopes, might be the low-redshift, low-luminosity analogs of the high-redshift quasars. Heavily shrouded and steep X-ray spectrum quasars may indeed represent the early stages of quasar evolution, and SDSSp J104433.04-012502.2 is possibly giving us a first glimpse of the physical evolution of quasar properties.
- Publication:
-
The Astronomical Journal
- Pub Date:
- October 2001
- DOI:
- 10.1086/323307
- arXiv:
- arXiv:astro-ph/0107163
- Bibcode:
- 2001AJ....122.1688M
- Keywords:
-
- Galaxies: Active;
- Galaxies: Evolution;
- Galaxies: Nuclei;
- Galaxies: Quasars: General;
- Galaxies: Quasars: Individual: Alphanumeric: SDSSp J104433.04-012502.2;
- X-Rays;
- Astrophysics
- E-Print:
- To appear in AJ