Abstract for Proposal 089103

A BROAD-BAND X-RAY VIEW OF THE MOST EXTREME MASS-LOSS WITH NUSTAR+XMM

Contrary to expectations from current stellar evolutionary models, recent observations uncovered the ejection of shells of material by massive stars in the years before the supernova (SN) explosion. The physical mechanism behind the impulsive mass ejection synchronized with the stellar core-collapse is unclear. Here we propose a coordinated XMM-NuSTAR effort to map the evolution of the broad-band X-ray spectrum of 1 nearby (d<50 Mpc) strongly interacting SN and enable progress. Our program has the immediate goal to characterize the medium around strongly interacting SN, which originate from stellar progenitors with the most extreme mass loss before explosion. This programs has the potential enlarge the very small sample of two strongly interacting SNe with broad-band X-ray detections.

Details on Observing Strategy and Trigger Criteria
Targets are SN (d<50 Mpc) that develop signs of strong shock-CSM interaction in their optical spectra in the form of narrow lines (i.e. type IIn-like features) at some point during their evolution. Two observing epochs are requested. The first epoch of 10ks of XMM and 50ks of NuSTAR will be acquired within 15 days of development of strong interaction features and the second approximately 100 days after the first epoch.