The Effect of Galactic Feedback on Gas Accretion and Wind Recycling

Understand

In the absence of galactic winds, the rate at which gas accretes onto galaxies is determined by the gravitational potential and by radiative cooling.

• However, outflows driven by supernovae and active galactic nuclei not only eject gas from galaxies, but also prevent gas from accreting in the first place.
• Furthermore, gas previously ejected from a galaxy can re-accrete onto (the same or a different) galaxy.
• Because this gas has a high metallicity, its cooling rate is relatively high, which will increase its chances to re-accrete.