XMM–Newton observations of 3C 273

Autor: Steve Sembay, James Reeves, Martin J. L. Turner, M. Stuhlinger, Chris Done, P. T. O'Brien, K. L. Page
Rok vydání: 2004
Předmět:
Zdroj: Monthly Notices of the Royal Astronomical Society. 349:57-67
ISSN: 1365-2966
0035-8711
DOI: 10.1111/j.1365-2966.2004.07499.x
Popis: A series of nine XMM-Newton observations of the radio-loud quasar 3C 273 are presented, concentrating mainly on the soft excess. Although most of the individual observations do not show evidence for iron emission, co-adding them reveals a weak, broad line (EW ~ 56 eV). The soft excess component is found to vary, confirming previous work, and can be well fitted with multiple blackbody components, with temperatures ranging between ~40 and ~330 eV, together with a power-law. Alternatively, a Comptonisation model also provides a good fit, with a mean electron temperature of ~350 eV, although this value is higher when the soft excess is more luminous over the 0.5-10 keV energy band. In the RGS spectrum of 3C 273, a strong detection of the OVII He-alpha absorption line at zero redshift is made; this may originate in warm gas in the local intergalactic medium, consistent with the findings of both Fang et al. (2003) and Rasmussen et al. (2003).
Comment: 12 pages, 19 figures, accepted for publication in MNRAS
Databáze: OpenAIRE
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