  Chandra High Energy Transmission Grating Spectrometer observations of the
supernova remnant 1E0102.2-7219 in the Small Magellanic Cloud reveal a spectrum
dominated by X-ray emission lines from hydrogen-like and helium-like ions of
oxygen, neon, magnesium and silicon, with little iron. The dispersed spectrum
shows a series of monochromatic images of the source in the light of individual
spectral lines. Detailed examination of these dispersed images reveals Doppler
shifts within the supernova remnant, indicating bulk matter velocities on the
order of 1000 km/s. These bulk velocities suggest an expanding ring-like
structure with additional substructure, inclined to the line of sight. A
two-dimensional spatial/velocity map of the SNR shows a striking spatial
separation of redshifted and blueshifted regions, and indicates a need for
further investigation before an adequate 3D model can be found. The radii of
the ring-like images of the dispersed spectrum vary with ionization stage,
supporting an interpretation of progressive ionization due to passage of the
reverse shock through the ejecta. Plasma diagnostics with individual emission
lines of oxygen are consistent with an ionizing plasma in the low density
limit, and provide temperature and ionization constraints on the plasma.
Assuming a pure metal plasma, the mass of oxygen is estimated at ~6 solar
masses, consistent with a massive progenitor.
