|Matthias Ehle (firstname.lastname@example.org)
XMM-NEWTON OBSERVATIONS OF NEARBY EDGE-ON STARBURST GALAXIES
The high sensitivity of XMM-Newton enables us to conduct observations of fainter targets than before and to obtain a much more detailed picture of those known already. Increased sensitivity leads to significant progress in investigations of low surface-brightness emitters, such as for example hot gaseous halos around actively star-forming spiral galaxies.
We report on the results of XMM-Newton GT observations of nearby starburst galaxies that form part of a multi-wavelength study of all phases of extra-planar gas in external galaxies, which is conducted in order to assess the importance of halos as repositories of a metal-enriched medium and their significance in terms of galactic chemical evolution and possible metal enrichment of the intergalactic medium.
XMM-Newton observations of the starburst galaxy NGC 1511 reveal the presence of a previously unknown extended hot gaseous phase of its ISM, which partly extends out of the disk plane, similar to the halo detected in radio continuum emission. XMM-Newton observations of NGC 1808, a galaxy well known for its high star-forming activity, can be used to disentangle the nuclear emission (starburst and/or AGN) and show that the soft X-ray spectrum is dominated by thermal emission from a circum-nuclear starburst with similar emission lines as the prototypical starburst galaxy M82. XMM-Newton observations of the ‘superwind’ galaxy NGC 4666, which is known to have a huge extended radio halo and vertical magnetic field lines, confirm - via the detection of an extended and structured hot gas halo - the dependence of both radio and X-ray halo on the amount of star formation in the underlying galactic disk. EPIC data of NGC 3628 significantly improve the ROSAT detection of extended emission from the central part of this galaxy and confirm the rather collimated outflow from the nuclear area. The central X-ray emission of NGC 3628 can be resolved into emission from a rather weak nucleus, from a very bright point-like source offset from the nucleus by about 20 arcsec (also seen with Chandra and possibly explaining the strong variability of the central emission) and from surrounding extended hot gas.