Different roles played by Types II and Ia supernovae in the gas loss in dwarf spheroidal galaxies: results from 3D hydrodynamic simulations

ABSTRACT The absence of neutral gas in Local Group dwarf spheroidal galaxies is a well-known fact. However, the physical mechanism that led to the removal or consumption of their gas remains an unsolved puzzle. It is possible that galactic winds triggered by supernovae or external physical processes such as ram pressure or tidal stripping could have played a significant role in removing a considerable portion of gas from these galaxies. This study utilizes a non-cosmological 3D hydrodynamic simulation code to explore the impact of feedback from Types Ia and II supernovae on the dynamics of the gas of a typical dwarf spheroidal galaxy. The simulation code considers a fixed and cored dark matter potential and a ratio of baryonic to dark matter based on cosmic background radiation, and it takes into account the effects of both Type II and Type Ia supernova feedback. The gas distribution inside the tidal radius of the galaxy is allowed to evolve over 1 billion years considering different prescriptions for the spatial and temporal distribution of the supernovae. Our results suggest that Type Ia supernovae are more effective in expelling the gas out of the galaxy whereas Type II supernovae remove the gas from the central regions of the system. Whereas the spatial distribution of supernovae is more influential on gas loss than their temporal distribution, both factors should be considered in stellar feedback studies. Moreover, both types of supernovae, with their distinct time-scales, should be incorporated into these investigations.