The Spitzer View of M101: Preliminary Results

K. D. Gordon, G. Rieke, C. Engelbracht, R. Kennicutt, J. Hinz, P. Perez-Gonzalez, K. Misselt, & J.D.T. Smith 2006, in "The Spitzer Space Telescope: New Views of the Cosmos," (ASP Conf. Ser.), eds. L. Armus & W.T. Reach, 357, 188

New Spitzer images of M101 from 3.5 to 160~\micron\ are presented. Preliminary analysis focusing on the dependence of the infrared spectral energy distribution of HII regions as a function of metallicity finds that the mid-infrared PAH features become weak or absent between metallicities of 8.5 and 8.1. There is also a trend towards hotter dust temperature as metallicity decreases.

[Preprint] [ADS Entry]