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M. Cappi (ITeSRE/CNR), W. Pietsch (MPE), M. Ward (Univ. of Leicester), P. Ferrando (CEA), M. Sako, S. Kahn (Columbia Univ.), G. Branduardi-Raymont (MSSL), K. Borozdin (LANL), B. Shirey (Univ. of California), M.J. Freyberg (MPE), T. Roberts (Univ. of Leicester), A. Ptak (Carnegie Mellon U.)
ROSAT, ASCA and BeppoSAX observations of nearby starburst galaxies have established the multi-component nature of their X-ray properties which include: X-ray emission from a considerable number of disk+haloes point sources, extended soft X-ray emission (superwinds), long and short-term flux variability of the nuclear source (e.g. in M82), an absorbed hard X-ray component possibly produced by a nuclear LLAGN, a hot superwind and/or contribution from unresolved X-ray binaries and SNRs. Interpretation of current data remains ambiguous mainly because of the difficulty in disentangling these various components.
Here we concentrate on the spectral and spatial results for the X-ray bright nuclear region of NGC253 derived from the XMM PV observations. The emission from the apparently slightly extended nuclear source (showing a rich line spectrum, including the 6.7 keV line of FeK) is most easily explained by a combination of increasingly absorbed thermal components. Thermal emission from the plume is less absorbed and dominates below 2 keV. The bright source about 30" to the south of the nucleus can be modeled by an absorbed power law, and is most likely a black hole X-ray binary.
The author(s) of this abstract have provided an email address for comments about the abstract: mcappi@tesre.bo.cnr.it