An MSX Infrared Analysis of the Superbubble around the Giant HII Region NGC3603

Using the MSX mid-infrared observation, we reveal a 100 pc-scale superbubble surrounding the giant HII region NGC3603. We suggest that the diffuse surrounding infrared emission in bands A, C, and D is dominated by that of PAH and the emission in band E is dominated by that of dust grains. The fitted dust temperature is consistent with the heating by the central cluster's UV photons. The derived gas-to-dust mass ratio for the bubble shell is of order 10^2.