Gas Loss by Ram Pressure Stripping and Internal Feedback From Low Mass Milky Way Satellites

TL;DR

This study uses high-resolution simulations to analyze gas loss mechanisms in low-mass Milky Way satellites, finding ram pressure less effective than expected and highlighting the need for additional physics to explain rapid galaxy quenching.

Contribution

It provides new insights into the relative roles of ram pressure and internal feedback in gas loss of dwarf satellites, emphasizing the importance of additional physical processes.

Findings

Supernova feedback has negligible impact on gas stripping in low star formation rate galaxies.

Ram pressure stripping is less efficient than previously thought in these scenarios.

Additional physics like tidal interactions and dark matter profiles are needed to explain rapid quenching.

Abstract

The evolution of dwarf satellites of the Milky Way is affected by the combination of ram pressure and tidal stripping, and internal feedback from massive stars. We investigate gas loss processes in the smallest satellites of the Milky Way using three-dimensional, high resolution, idealized wind tunnel simulations, accounting for gas loss through both ram pressure stripping and expulsion by supernova feedback. Using initial conditions appropriate for a dwarf galaxy like Leo T, we investigate whether or not environmental gas stripping and internal feedback can quench these low mass galaxies on the expected timescales, shorter than 2 Gyr. We find that supernova feedback contributes negligibly to the stripping rate for these low star formation rate galaxies. However, we also find that ram pressure stripping is less efficient than expected in the stripping scenarios we consider. Our work suggests that, although ram pressure stripping can eventually completely strip these galaxies, other physics is likely at play to reconcile our computed stripping times with the rapid quenching timescales deduced from observations of low mass Milky Way dwarf galaxies. We discuss the roles additional physics may play in this scenario, including host-satellite tidal interactions, cored vs. cuspy dark matter profiles, reionization, and satellite pre-processing. We conclude that a proper accounting of these physics together is necessary to understand the quenching of low mass Milky Way satellites.