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arXiv · astro-ph/0001299

The X-ray Properties of z>4 Quasars

Shai Kaspi·W. N. Brandt·Donald P. Schneider
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Abstract

We report on a search for X-ray emission from quasars with redshifts greater than four using the ROSAT public database. Our search has doubled the number of z>4 quasars detected in X-rays from 6 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 to those of lower redshift quasars. We do not find any evidence for strong broad-band spectral differences between optically selected z>4 quasars and those at lower redshifts.

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Shai Kaspi, W. N. Brandt, Donald P. Schneider. 2000-01-17. The X-ray Properties of z>4 Quasars. https://doi.org/10.1086/301362

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