Serendipitous active galactic nuclei in the XMM--Newton fields of Markarian 205 and QSO 0130-403

Autor: K. L. Page, M. J. L. Turner, J. N. Reeves, P. T. O'Brien, S. Sembay
Rok vydání: 2003
Předmět:
Zdroj: Monthly Notices of the Royal Astronomical Society. 338:1004-1012
ISSN: 1365-2966
0035-8711
DOI: 10.1046/j.1365-8711.2003.06144.x
Popis: The X-ray spectra of serendipitously observed AGN in the XMM-Newton fields of Mrk 205 and QSO 0130 403 are analysed. The sample consists of 23 objects, none of which is detected at radio frequencies, with a median X-ray luminosity of �4×10 44 erg s 1 and redshifts ranging from �0.1 to just over 3. The mean photon index was found to be 1.89 ± 0.04. In contrast to past ASCA and ROSAT observations of high-redshift radio-loud quasars, we find little evidence for excess intrinsic absorption in these radio-quiet objects, with only three sources requiring a column density in excess of the Galactic value. Comparing the measured spectral indices over the redshift range, we also find there is no X-ray spectral evolution of QSOs with time, up to redshift 3. Within the sample there is no evidence for evolution of the optical to X-ray spectral index, �ox, with redshift, the mean value being 1.66 ± 0.04. However, upon comparing the values from the Bright Quasar Survey at low redshift (z < 0.5) and
Databáze: OpenAIRE
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