Abstract for Proposal 094087

Constraining the CSM Interaction Engine in Type II Supernovae

Late-time observations of type II supernovae (SNe II) are a window into the uncertain mass-loss history of their red supergiant (RSG) star progenitors as well as a direct probe of the physics of shock interaction as SN ejecta collide with distant circumstellar material (CSM). We propose target of opportunity (ToO) XMM observations of SNe II following UV/optical imaging through an approved HST snapshot program. The novel combination of X-ray, UV and optical wavelengths will construct the first spectral energy distribution of its kind, capable of directly constraining the unknown thermalization efficiency of radiation produced by the SN shock. These observations will also directly constrain the highly debated mass-loss histories of RSGs.

Details on Observing Strategy and Trigger Criteria
Triggering criteria are: (i) successful observation with HST during Cycle 31 and (ii) pre-explosion XMM images available of the SN location. All observations will be slow ToO requests i.e., weeks to 1-2 months after HST observations are acquired.