Rescuing the intracluster medium of NGC 5813

Noam Soker, Shlomi Hillel, Assaf Sternberg

Published 2015-04-29Version 1

We argue that the intracluster medium (ICM) of the cooling flow galaxy group NGC 5813 is more likely to be heated by mixing of post-shock jets' gas residing in hot bubbles with the ICM, than by shocks or turbulent-heating. Efficient shocks-heating of the inner cooling flow region would have caused overheating of the rest of the ICM, leading to its ejection from the group. Heating by mixing, that was found to be much more efficient than turbulent-heating and shocks-heating, hence, rescues the outer ICM of NGC 5813 from its predestined fate according to cooling flow feedback scenarios that are based on heating by shocks.