Detailed mapping of extreme mass loss with coordinated XMM-NuSTAR observations

Contrary to expectations from current stellar evolutionary models, recentobservations uncovered the ejection of shells of material by massive stars inthe years before the supernova (SN) explosion. The physical mechanism behind theimpulsive mass ejection synchronized with the stellar corecollapse is unclear.Here we propose a coordinated XMMNuSTAR effort to map the evolution of thebroadband Xray spectrum of 1 nearby (d<50 Mpc) strongly interacting SN andenable progress. Our program has the immediate goal to characterize the mediumaround strongly interacting SN, which originate from stellar progenitors withthe most extreme mass loss before explosion. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]