Chandra and XMM-Newton Observations of the Nucleus of Centaurus A

Evans, D.A., Kraft, R.P., Worrall, D.M., Hardcastle, M.J., Jones, C., Forman, W.R. and Murray, S.S. (2004) Chandra and XMM-Newton Observations of the Nucleus of Centaurus A. The Astrophysical Journal, 612. pp. 786-796. ISSN 0004-637X
Copy

We present X-ray spectra of the nucleus of the nearby radio galaxy Centaurus A from observations with the XMM-Newton EPIC CCD cameras (two exposures separated by 12 months) and the Chandra HETGS. For the first time in an FR I type galaxy, we resolve fluorescent K emission from cold, neutral, or near-neutral iron at 6.4 keV, with an rms line width of 20 eV. The Fe line parameters observed are consistent with fluorescent emission from material at a large distance from the active galactic nucleus, either in the form of an absorber that nearly completely surrounds the central engine or a torus that lies predominantly out of the line of sight. Unresolved emission lines from neutral Si K at 1.74 keV and neutral S K at 2.30 keV are also detected. We find no evidence in the data for a previously reported 6.8 keV broadened Fe line. The continuum spectrum is well fitted with a combination of a heavily absorbed power-law component that we relate, using Bondi theory, to accretion phenomena in the form of a standard, geometrically thin, optically thick disk, and a second, less absorbed, power-law component that we associate with emission from the subparsec VLBI radio jet.


picture_as_pdf
100761.pdf

View Download

Atom BibTeX OpenURL ContextObject in Span OpenURL ContextObject Dublin Core MPEG-21 DIDL Data Cite XML EndNote HTML Citation METS MODS RIOXX2 XML Reference Manager Refer ASCII Citation
Export

Downloads