Nonthermal X-ray emission from the shell-type supernova remnant G347.3-0.5

Recent ASCA observations of G347.3-0.5, a supernova remnant (SNR) discovere d in the ROSAT All-Sky Survey, reveal nonthermal emission from a region alo ng the northwestern shell. Here we report on new pointed ASCA observations of G347.3-0.5 that confirm this result for all the bright shell regions and also reveal similar emission, although with slightly different spectral pr operties, from the remainder of the SNR. Curiously, no thermal X-ray emissi on is detected anywhere in the remnant. We derive limits on the amount of t hermal emitting material present in G347.3-0.5 and present new radio contin uum, CO, and infrared results that indicate that the remnant is distant and of moderate age. We show that our observations are broadly consistent with a scenario that has most of the supernova remnant shock wave still within the stellar wind bubble of its progenitor star, while part of it appears to be interacting with denser material. A point source at the center of the r emnant has spectral properties similar to those expected for a neutron star and may represent the compact relic of the supernova progenitor.