First-look XMM-Newton EPIC observations of the prototypical starburst galaxy M82

Abstract

We present initial XMM-Newton EPIC observations of the prototypical starburst galaxy M82. The superwind is seen to extend continuously from the starburst region to the X-ray emission associated with the Ha 'cap'. We also find evidence for a ridge feature, probably associated with the superwind interacting with an HI streamer. Narrow-band images, centred on individual X-ray lines, show differences in morphology, with higher energy lines being less spatially extended, and a systematic shift with energy in the region of peak emission. Spectral fits with two thermal and one power-law component provide a good fit to the spectra of the nuclear and inner wind regions, indicating a multiphase superwind. We discuss the implications of these observations on our understanding of superwinds.