X-ray properties of the quasar HE0450-2958

Abstract

We present an {\it XMM-Newton} EPIC observation of HE0450-2958 which may be a ``naked''quasar as suggested by Magain et al. The \xmm EPIC spectra show a substantial soft X-ray excess, a steep photon index, as well as marginal evidence for a weak Fe K$\alpha$ line. The X-ray absorption is consistent with the galactic level. The 0.3-10 keV EPIC spectra can be fitted by a power law plus a blackbody model, however, the fit by the relativistically blurred photoionized disc reflection is better. We estimate the black hole mass of $2_{-1.3}^{+7}\times 10^7{M}_{\odot }$ from the X-ray variability. This broadly agrees with the value derived from the optical \hb line width. These results support a high-state Seyfert galaxy of the source. HE0450-2958 shares similar properties of transitionary objects from ultra-luminous infrared galaxies to quasars. We suggest that HE0450-2958 is just in the beginning of an optical quasar window.

23 pages, 8 figures, AJ in press

References in corpus (4)

• The Hard X-ray Spectral Slope as an Accretion-Rate Indicator in Radio-Quiet Active Galactic Nuclei
• On the origin of the Fe K-alpha line cores in Active Galactic Nuclei
• Discovery of a bright quasar without a massive host galaxy
• Confirming the high velocity outflow in PG 1211+143

Cited by in corpus (4)

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• The QSO HE0450-2958: Scantily dressed or heavily robed? A normal quasar as part of an unusual ULIRG
• Periods of the Long-Term Variability of the Blazar 0716+714 and Their Inter-Correlations in a Helical Jet Model