Mid-IR FORCAST/SOFIA Observations of M82

We present 75 " x 75 " size maps of M82 at 6.4 mu m, 6.6 mu m, 7.7 mu m, 31.5 mu m, and 37.1 mu m with a resolution of similar to 4 " that we have obtained with the mid-IR camera FORCAST on SOFIA. We find strong emission from the inner 60 " (similar to 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 mu m 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 mu m and 37 mu m measurement. At the emission peaks the estimated dust masses are on the order of 10(4) M-circle dot.