Sputtering of grains in C-type shocks

Parametrization of C-shocks. Evolution of the Sputtering of Grains

Context. The detection of a narrow SiO line emission toward the young shocks of the L1448-mm outflow has been interpreted as a signature of the magnetic precursor of C-shocks. In contrast with the very low SiO abundances (≤10−12) derived from the ambient gas, the narrow SiO emission in the precursor component at almost ambient velocities reveals enhanced SiO abundances of ∼10−11. This enhanceme...

Grain-grain collisions and sputtering in oblique C-type shocks

We use a model of the dissipation regions in C-type shocks in which two grain fluids are included to evaluate the rates at which grain-grain collisions and sputtering inject elemental silicon and water into the gas phase. For physical parameters typical of star forming regions, and on the assumption that a substantial fraction of the evaporated silicon is efficiently converted in SiO, the two g...

PRESOLAR SiC GRAINS OF TYPE C

Shocks in ion sputtering sharpen steep surface features.

We report a regime of ion beam sputtering that occurs for sufficiently steep slopes. High slopes propagate over large distances without dissipating the steepest features. Both the propagation velocity and the dynamically selected slope are universal, independent of the details of the initial shape of the surface. The resulting behavior can be understood as the propagation of a shock front that ...

Time-dependent simulations of steady C-type shocks

Using a time-dependent multifluid, magnetohydrodynamic code, we calculated the structure of steady perpendicular and oblique C-type shocks in dusty plasmas. We included relevant processes to describe mass transfer between the different fluids, radiative cooling by emission lines and grain charging and studied the effect of singlesized and multiple sized grains on the shock structure. Our models...