Expansion and Age of the Supernova Remnant G350.1–0.3: High-velocity Iron Ejecta from a Core-collapse Event

We report Chandra observations of the highly asymmetric core-collapse supernova remnant G350.1−0.3. We document expansion over 9 yr away from the roughly stationary central compact object, with sky-plane velocities up to 5000 d4.5 km s−1 (d4.5 is the distance in units of 4.5 kpc), redshifts ranging from 900 to 2600 km s−1, and three-dimensional space velocities approaching 6000 km s−1. Most of the bright emission comes from heavy-element ejecta particularly strong in iron. Iron-enhanced ejecta are seen at 4000–6000 km s−1, strongly suggesting that the supernova was not a common Type IIP event. While some fainter regions have roughly solar abundances, we cannot identify clear blast-wave features. Our expansion proper motions indicate that G350.1−0.3 is no more than about 600 yr old, independent of distance: the third youngest known core-collapse supernova in the Galaxy, and one of the most asymmetric.