The Fates of the Circumgalactic Medium in the FIRE Simulations

Understand

We analyze the different fates of the circumgalactic medium (CGM) in FIRE-2 cosmological simulations, focusing on the redshifts z=0.25 and z=2 representative of recent surveys.

• Our analysis includes 21 zoom-in simulations covering the halo mass range Mh(z=0) ~ 10^10 - 10^12 Msun.
• We analyze both where the gas ends up after first leaving the CGM (its "proximate" fate), as well as its location at z=0 (its "ultimate" fate).
• Of the CGM at z=2, about half is found in the ISM or stars of the central galaxy by z=0 in Mh(z=2) ~ 5e11 Msun halos, but most of the CGM in lower-mass halos ends up in the IGM.