The X-Ray Properties of z > 4 Quasars
The X-Ray Properties of z > 4 Quasars
复制标题
z > 4 类星体的 X 射线特性
DOI:
10.1086/301362
复制
发表时间:
2000
期刊:
影响因子:
--
通讯作者:
D. Schneider
中科院分区:
文献类型:
--
作者:
S. Kaspi;W. Brandt;D. Schneider
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.