Speaker
Description
Galactic outflows are thought to be a primary channel for transporting dust grains out of galaxies, especially in dwarf galaxies due to their shallower gravitational potential. However, the existence of CGM dust challenges our understanding of dust evolution, as the conditions in outflows are hostile, where dust grains are expected to be rapidly destroyed by sputtering. We present three-dimensional simulations of an isolated dwarf galaxy coupled with dust sputtering using GIZMO. We find that sputtering occurs primarily within the disc, as efficient sputtering is largely suppressed in outflows due to low densities. Small grains are most severely depleted by thermal sputtering, whereas micron-sized grains survive due to longer sputtering timescales. In a single-SN ejection, warm gas carries the majority of grains, which largely survive as the gas has never reached conditions that allow efficient sputtering. In addition, the warm gas is not energetic enough to escape the gravitational potential of the halo. With multiple SNe, when the subsequently launched hot gas catches up with the warm gas, it is still unable to drive the warm gas to conditions favorable for efficient grain sputtering. This suggests that dust grains can survive in galactic outflows and be transported efficiently into the CGM.
| Participate the oral/poster presentation award competition | Yes |
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