Chandra observations of shock kinematics in supernova remnant 1987A

We report the first results from deep X-ray observations of the supernova remnant SNR 1987A with the Chandra LETG. Temperatures inferred from line ratios range from ∼0.1 to 2 keV and increase with ionization potential. Expansion velocities inferred from X-ray line profiles range from ∼300 to 1700 km s^-1, much less than the velocities inferred from the radial expansion of the radio and X-ray images. We can account for these observations with a scenario in which the X-rays are emitted by shocks produced where the supernova blast wave strikes dense protrusions of the inner circumstellar ring, which are also responsible for the optical hot spots.