ChandraLETG Observations of Supernova Remnant 1987A

We discuss the results from deep Chandra LETG observations of the supernovaremnant 1987A (SNR 1987A). We find that a distribution of shocks, spanning thesame range of velocities (from 300 to 1700 km/s) as deduced in the first partof our analysis (Zhekov et al. 2005, ApJL, 628, L127), can account for theentire X-ray spectrum of this object. The post-shock temperature distributionis bimodal, peaking at kT 0.5 and 3 keV. Abundances inferred from the X-rayspectrum have values similar to those for the inner circumstellar ring, exceptthat the abundances of nitrogen and oxygen are approximately a factor of twolower than those inferred from the optical/UV spectrum. The velocity of theX-ray emitting plasma has decreased since 1999, apparently because the blastwave has entered the main body of the inner circumstellar ring.Comment: Accepted for publication in the Ap