Abstract
We report on a search for X-ray emission from quasars with redshifts greater than 4 using the ROSAT public database. Our search has doubled the number of z > 4 quasars detected in X-rays from six to 12. Most of those known prior to this work were radio-loud and X-ray-selected sources; our study increases the number of X-ray-detected, optically selected z > 4 quasars from one to seven. We present their basic X-ray properties and compare these with those of lower redshift quasars. We do not find any evidence for strong broadband spectral differences between optically selected z > 4 quasars and those at lower redshifts.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 2031-2037 |
| Number of pages | 7 |
| Journal | Astronomical Journal |
| Volume | 119 |
| Issue number | 5 |
| DOIs | |
| State | Published - May 2000 |
All Science Journal Classification (ASJC) codes
- Astronomy and Astrophysics
- Space and Planetary Science