Chandra Observation of the Magellanic Cloud Supernova Remnant 0454-672   in N9
  A Chandra observation has defined the extent of the SNR B 0454-692 in the LMC H II region N9. The remnant has dimension 2.3" x 3.6" and is elongated in the NS direction. The brightest emission comes from a NS central ridge which includes three bright patches. There is good agreement between X-ray and [O III] and [S II] morphology. The remnant is old enough so that optical data give more information about dynamics than do the X-ray data. The SN energy release was >= 4 x 10^50 ergs and the age is ~3 x 10^4 years. There are several unresolved sources nearby but none are clearly associated with the remnant. The X-ray spectrum is soft and indicates enhanced Fe abundance in the central region, consistent with a Type Ia SN origin, but a Type II origin cannot be ruled out. 
F. D. Seward (1), R. M. Williams (2), Y.-H. Chu (2), J. R. Dickel   (2,3), R. C. Smith (4) and S. D. Points (4) ((1) Smithso...