The Herschel Space Observatory view of dust in M81
  We use Herschel Space Observatory data to place observational constraints on
the peak and Rayleigh-Jeans slope of dust emission observed at 70-500 microns
in the nearby spiral galaxy M81. We find that the ratios of wave bands between
160 and 500 microns are primarily dependent on radius but that the ratio of 70
to 160 micron emission shows no clear dependence on surface brightness or
radius. These results along with analyses of the spectral energy distributions
imply that the 160-500 micron emission traces 15-30 K dust heated by evolved
stars in the bulge and disc whereas the 70 micron emission includes dust heated
by the active galactic nucleus and young stars in star forming regions.
