X-ray spectral features and classification of selected QSOs

Abstract

We present the results of a systematic analysis of the XMM-Newton spectra of nearby optically bright QSOs. The objects have been selected from X-ray Galaxy Catalog Xgal20. It is a catalog of 1172 manually identi(cid:28)ed and classi(cid:28)ed galaxies, obtained as a cross-correlation between the 4XMM-DR9 catalog and the Hyper-Linked Extragalactic Databases and Archives (HyperLeda) with an X-ray (cid:29)ux greater than F ≥ 10 − 13 erg / ( cm 2 · s ) . The goal of this work is to characterize the X-ray spectral properties of selected QSOs in the 0.1 (cid:21) 10 keV energy band. The majority of the sources (6 out of 11) are classi(cid:28)ed as radio-quiet QSOs. We studied optical spectra, hardness ratios and performed X-ray spectral (cid:28)ts for the 10 brighter sources. In most cases, the power law model with absorption is good enough to simulate observed continua. However, the details of the spectrum in some sources signi(cid:28)cantly complicate the model for (cid:28)tting. The majority of sources have steep spectra Γ > 2 . 1 . Extremely steep photon index ( ∼ 2 . 4 − 2 . 5 ) in our sample occurs for three radio-loud type I quasars. We detected Fe K α line for two radio-loud type II quasars. We (cid:28)nd no strong evidence for spectral hardening above 2 keV either for quasars, of type I, or for the obscured type II. For each quasar its type was established both based on the features and details of observed X-ray spectrum and previous data.