XMM–Newton
Reflection Grating Spectrometer observations of the prototypical starburst galaxy M82 |
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| Authors: | Andrew M Read Ian R Stevens |
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| Institution: | School of Physics and Astronomy, University of Birmingham, Edgbaston, Birmingham B15 2TT |
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| Abstract: | We present results from XMM–Newton Reflection Grating Spectrometer observations of the prototypical starburst galaxy M82. These high-resolution spectra represent the best X-ray spectra to date of a starburst galaxy. A complex array of lines from species over a wide range of temperatures is seen, the most prominent being due to Lyman α emission from abundant low- Z elements such as N, O, Ne, Mg and Si. Emission lines from helium-like charge states of the same elements are also seen in emission, as are strong lines from the entire Fe L series. Further, the O vii line complex is resolved and is seen to be consistent with gas in collisional ionization equilibrium.
Spectral fitting indicates emission from a large mass of gas with a differential emission measure over a range of temperatures (from ～ 0.2 to ～ 1.6 keV, peaking at ～ 0.7 keV), and evidence for super-solar abundances of several elements is indicated. Spatial analysis of the data indicates that low-energy emission is more extended to the south and east of the nucleus than to the north and west. Higher energy emission is far more centrally concentrated. |
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| Keywords: | ISM: jets and outflows galaxies: haloes galaxies: individual: M82 galaxies: ISM galaxies: starburst X-rays: galaxies |
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