NUMERICAL SIMULATIONS OF SUPERNOVA DUST DESTRUCTION. II. METAL-ENRICHED EJECTA KNOTS

Following our previous work, we investigate through hydrodynamic simulations the destruction of newly formed dust grains by sputtering in the reverse shocks of supernova remnants. Using an idealized setup of a planar shock impacting a dense, spherical clump, we implant a population of Lagrangian particles into the clump to represent a distribution of dust grains in size and composition. We vary the relative velocity between the reverse shock and ejecta clump to explore the effects of shock heating and cloud compression. Because supernova ejecta will be metalenriched, we consider gas metallicities from Z/ Z(circle dot) = 1 to 100 and their influence on the cooling properties of the cloud and the thermal sputtering rates of embedded dust grains. We post- process the simulation output to calculate grain sputtering for a variety of species and size distributions. In the metallicity regime considered in this paper, the balance between increased radiative cooling and increased grain erosion depends on the impact velocity of the reverse shock. For slow shocks (v(shock) less than or similar to 3000 km s(-1)), the amount of dust destruction is comparable across metallicities or in some cases is decreased with increased metallicity. For higher shock velocities (v(shock) less than or similar to 5000 km s(-1)), an increase in metallicity from Z/Z(circle dot) = 10 to 100 can lead to an additional 24% destruction of the initial dust mass. While the total dust destruction varies widely across grain species and simulation parameters, our most extreme cases result in complete destruction for some grain species and only 44% dust mass survival for the most robust species. These survival rates are important in understanding how early supernovae contribute to the observed dust masses in high- redshift galaxies.