On the soft X-ray emission of M82
  We present a spatial analysis of the soft X-ray and H{\alpha} emissions from
the outflow of the starburst galaxy M82. We find that the two emissions are
tightly correlated on various scales. The O VII triplet of M82, as resolved by
X-ray grating observations of XMM-Newton, is dominated by the forbidden line,
inconsistent with the thermal prediction. The O VII triplet also shows some
spatial variations. We discuss three possible explanations for the observed O
VII triplet, including the charge exchange at interfaces between the hot
outflow and neutral cool gas, a collisional non-equilibrium-ionization
recombining plasma, and resonance scattering.
