2012ApJ...749L..19N

We present 75''x75'' size maps of M82 at 6.4 µm, 6.6 µm, 7.7 µm, 31.5 µm, and 37.1 µm with a resolution of ∼4'' that we have obtained with the mid-IR camera FORCAST on SOFIA. We find strong emission from the inner 60'' (∼1 kpc) along the major axis, with the main peak 5'' west-southwest of the nucleus and a secondary peak 4'' east-northeast of the nucleus. The detailed morphology of the emission differs among the bands, which is likely due to different dust components dominating the continuum emission at short mid-IR wavelengths and long mid-IR wavelengths. We include Spitzer-IRS and Herschel/PACS 70 µm data to fit spectral energy distribution templates at both emission peaks. The best-fitting templates have extinctions of A_V= 18 and A_V= 9 toward the main and secondary emission peak and we estimated a color temperature of 68 K at both peaks from the 31 µm and 37 µm measurement. At the emission peaks the estimated dust masses are on the order of 10⁴ M_☉.