Journal Article

A deep X-ray observation of M82 with <i>XMM–Newton</i>

P. Ranalli, A. Comastri, L. Origlia and R. Maiolino

in Monthly Notices of the Royal Astronomical Society

Published on behalf of The Royal Astronomical Society

Volume 386, issue 3, pages 1464-1480
Published in print May 2008 | ISSN: 0035-8711
Published online April 2008 | e-ISSN: 1365-2966 | DOI: http://dx.doi.org/10.1111/j.1365-2966.2008.13128.x
A deep X-ray observation of M82 with XMM–Newton

Show Summary Details

Preview

We report on the analysis of a deep (100-ks) observation of the starburst galaxy M82 with the EPIC and RGS instruments onboard the X-ray telescope XMM–Newton. The broad-band (0.5–10 keV) emission is due to at least three spectral components: (i) continuum emission from point sources; (ii) thermal plasma emission from hot gas; and (iii) charge-exchange emission from neutral metals (Mg and Si). The plasma emission has a double-peaked differential emission measure, with the peaks at ∼0.5 and ∼7 keV. Spatially resolved spectroscopy has shown that the chemical absolute abundances are not uniformly distributed in the outflow, but are larger in the outskirts and smaller close to the galaxy centre. The abundance ratios also show spatial variations. The X-ray-derived oxygen abundance is lower than that measured in the atmospheres of red supergiant stars, leading to the hypothesis that a significant fraction of oxygen ions have already cooled off and no longer emit at energies ≳0.5 keV.

Keywords: atomic processes; plasmas; ISM: jets and outflows; galaxies: abundances; galaxies: individual: M82; X-rays: ISM

Journal Article.  11918 words.  Illustrated.

Subjects: Astronomy and Astrophysics

Full text: subscription required

How to subscribe Recommend to my Librarian

Users without a subscription are not able to see the full content. Please, subscribe or login to access all content.