Spitzer Measurements of Atomic and Molecular Abundances in the Type IIP SN 2005af

Abstract

We present results based on mid-infrared (3.6–30 mm) observations with the Spitzer Space Telescope of the nearby Type IIP supernova 2005af. We report the first ever detection of the SiO molecule in a Type IIP supernova. Together with the detection of the CO fundamental, this is an exciting finding as it may signal the onset of dust condensation in the ejecta. From a wealth of fine-structure lines we provide abundance estimates for stable Ni, Ar, and Ne that, via spectral synthesis, may be used to constrain nucleosynthesis models. Subject headings: supernovae: general — supernovae: individual (SN 1987A, SN 2004dj, SN 2005af)