Astronomy and Astrophysics Xmm-newton Detection of a Comptonized Accretion Disc in the Quasar Pks 0558−504
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چکیده
Your thesaurus codes are: missing; you have not inserted them Abstract. We present XMM-Newton observations of the bright quasar PKS 0558−504. The 0.2–10 keV spectrum is dominated by a large, variable soft X-ray excess. The fastest flux variations imply accretion onto a Kerr black hole. The XMM-Newton data suggest the presence of a 'big blue bump' in PKS 0558−504 extending from the optical band to ∼ 3 keV. The soft X-ray spectrum shows no evidence for significant absorption or emission-line features. The most likely explanation for the hot big blue bump is Comptonization by the multi-temperature corona of a thermal accretion disc running at a high accretion rate.
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