Dust destruction by the reverse shock in the supernova remnant Cassiopeia A
Nordita Astrophysics seminars
Wednesday 22 May 2019
to 14:30 at
Florian Kirchschlager (UCL)
It is well known that dust grains form in the ejecta of supernovae. However, due to interactions with the circumstellar and interstellar medium,
reverse shocks will traverse the ejecta which could potentially destroy large amounts of the newly formed dust material by sputtering or grain-grain
collisions. Hydrodynamic simulations help us to model the temporal evolution of gas density and temperature for the passage of a reverse shock in
a clumpy supernova ejecta. Subsequently, dust trajectories and destruction rates can be computed using our newly developed post-processing
code Paperboats, which includes gas drag, grain charging, sputtering, gas accretion, and grain-grain collisions. I will present the influence of different
initial conditions such as the shock velocity and the grain size distribution on the dust destruction processes.
Moreover, the oxygen-rich supernova remnant Cassiopeia A provides a unique laboratory to investigate the destruction of dust by the reverse shock.
I will present destruction rates as a function of initial grain sizes and clump gas densities for this unique system. The results show that grain-grain
collisions and sputtering are synergistic and that grain-grain collisions can play a crucial role in determining the surviving dust budget in supernova remnants.