D. W. Silvia, B. D. Smith, J. M. Shull
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 metal-enriched, we consider gas metallicities from Z = 1
Z\bigodot to 100 Z\bigodot and their influence on 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 high metallicity regime, the balance between
increased radiative cooling and increased grain erosion depends on the impact
velocity of the reverse shock. For slow shocks (v \leq 3000 km/s), the amount
of dust destruction is comparable across metallicities, or in some cases is
decreased with increased metallicity. For higher shock velocities (v \geq 5000
km/s), an increase in metallicity from Z = 10 Z\bigodot to 100 Z\bigodot 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.
View original:
http://arxiv.org/abs/1111.0302
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