Fast Iron Ejecta in a Very Young Core-Collapse Supernova Remnant: G350.1--0.3

We propose a deep EPIC observation of the highly asymmetric young (< 600 yearsold) corecollapse (CC) supernova remnant G350.10.3, whose spectrum isdominated by ironrich ejecta expanding at up to 6,000 km/s away from analmoststationary thermally emitting neutron star (CCO), and for which a veryhigh nickel abundance has been claimed. We shall quantify emission from Ni andCr, in addition to Fe, to derive constraints on nucleosynthesis in explosiveSiburning regions. We shall also pursue hints of nonthermal emission, searchfor faint ejecta elsewhere near the CCO, search for the blast wave, and obtain avery deep spectrum of the CCO. G350.10.3 may join Cassiopeia A as a majorsource for understanding of CC processes, and we expect this long observation to have archival value. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]