Optical emission from shock waves. I - Abundances in N49

From models of plane-parallel radiating shock waves and the observations of Osterbrock and Dufour (1973), the abundances of oxygen, nitrogen, neon, and sulfur (and indirectly, of carbon) are derived for the Large Magellanic Cloud supernova remnant N49. These are somewhat smaller than solar values, and it is concluded that the discrepancies between these and values derived for the LMC H II regions reflect the composition of 'ice' grains with low sublimation temperatures, which are destroyed in the supernova event.