Dust Emission in Galaxies at Millimeter Wavelengths: Cooling of star
  forming regions in NGC6946
  Interstellar dust plays an important role in the formation of molecular gas
and the heating and cooling of the interstellar medium. The spatial
distribution of the mm-wavelength dust emission from galaxies is largely
unexplored. The NIKA2 Guaranteed Time Project IMEGIN (Interpreting the
Millimeter Emission of Galaxies with IRAM and NIKA2) has recently mapped the mm
emission in the grand design spiral galaxy NGC6946. By subtracting the
contributions from the free-free, synchrotron, and CO line emission, we map the
distribution of the pure dust emission at 1:15mm and 2mm. Separating the
arm/interarm regions, we find a dominant 2mm emission from interarms indicating
the significant role of the general interstellar radiation field in heating the
cold dust. Finally, we present maps of the dust mass, temperature, and
emissivity index using the Bayesian MCMC modeling of the spectral energy
distribution in NGC6946.
