A Spitzer Survey for Dust in Type Iin Supernovae

The source of the large amounts of dust observed in high redshift galaxies has remained uncertain for nearly 40 years. Despite the success of models in producing dust within supernova explosions, only a handful of supernovae show direct observational evidence for dust condensation, and these examples all yield 2-3 orders of magnitude less dust than predicted by the models. Recent observations suggest Type IIn supernovae may condense more dust than typical core-collapse events. Few Type IIn observations, however, exist. The few dust forming Type IIn supernovae show late-time infrared emission sometimes more than five or six years following their initial detection, making remnant archeology possible. A Spitzer/IRAC follow-up survey of all observable Type IIn supernovae from the past ten years will determine the extent to which this subclass produces dust. Ground-based observations are insufficient. Spitzer/IRAC provides the necessary sensitivity at wavelengths spanning the peak of the blackbody emission from the warmest grains, as well as the tail-end emission from colder dust. I present here a preliminary overview of an ongoing Spitzer survey of 71 Type IIn supernovae from the past 10 years. Subject headings: circumstellar matter — supernovae: general — supernovae: individual — dust,extinction — infrared: stars