Harrison Souchereau: Ism Fallback in Ram Pressure Stripped Galaxies

The evolution of the cold ISM in galaxies is an important factor in how galaxies evolve while undergoing ram pressure stripping (RPS), as cold molecular clouds are the most difficult ISM component to strip and are also the sites of star formation. Using a suite of ENZO "wind tunnel" simulations, we explore the evolution of gas in the "inner tail" of a galaxy experiencing a strong ram pressure wind. Even if the ultimate fate of a stripped satellite galaxy is complete removal of its ISM gas reservoir, we find that cold gas evolves through a cycle of outflow and inflow (fallback) in the inner tail, which is elevated for more highly inclined (closer to edge-on) ram pressure winds. Using an idealized dynamical model, we demonstrate how different mechanisms can contribute to fallback.