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 |
Fingerprint
All Science Journal Classification (ASJC) codes
- Astronomy and Astrophysics
- Space and Planetary Science
Cite this
}
The X-ray properties of z > 4 quasars. / Kaspi, Shai; Brandt, W. N.; Schneider, Donald P.
In: Astronomical Journal, Vol. 119, No. 5, 05.2000, p. 2031-2037.Research output: Contribution to journal › Article
TY - JOUR
T1 - The X-ray properties of z > 4 quasars
AU - Kaspi, Shai
AU - Brandt, W. N.
AU - Schneider, Donald P.
PY - 2000/5
Y1 - 2000/5
N2 - 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.
AB - 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.
UR - http://www.scopus.com/inward/record.url?scp=0037799996&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0037799996&partnerID=8YFLogxK
U2 - 10.1086/301362
DO - 10.1086/301362
M3 - Article
AN - SCOPUS:0037799996
VL - 119
SP - 2031
EP - 2037
JO - Astronomical Journal
JF - Astronomical Journal
SN - 0004-6256
IS - 5
ER -