Star formation in ram pressure stripped galactic tails


E-mail: (ST); (GLB)


We investigate the impact of star formation and feedback on ram pressure stripping using high-resolution adaptive mesh simulations, building on a previous series of papers that systematically investigated stripping using a realistic model for the interstellar medium, but without star formation. We find that star formation does not significantly affect the rate at which stripping occurs, and only has a slight impact on the density and temperature distribution of the stripped gas, indicating that our previous (gas-only) results are unaffected. For our chosen (moderate) ram pressure strength, stripping acts to truncate star formation in the disc over a few hundred million years, and does not lead to a burst of star formation. Star formation in the bulge is slightly enhanced, but the resulting change in the bulge-to-disc ratio is insignificant. We find that stars do form in the tail, primarily from gas that is ablated from the disc and the cools and condenses in the turbulent wake. The star formation rate in the tail is low, and any contribution to the intracluster light is likely to be very small. We argue that star formation in the tail depends primarily on the pressure in the intracluster medium, rather than the ram pressure strength. Finally, we compare to observations of star formation in stripped tails, finding that many of the discrepancies between our simulation and observed wakes can be accounted for by different intracluster medium pressures.