The quenching and morphological evolution of central galaxies is facilitated by the feedback-driven expulsion of circumgalactic gas

Understand

We examine the connection between the properties of the circumgalactic medium (CGM) and the quenching and morphological evolution of central galaxies in the EAGLE and IllustrisTNG simulations.

• The simulations yield very different median CGM mass fractions, $f_{\rm CGM}$, as a function of halo mass, $M_{200}$, with low-mass haloes being significantly more gas-rich in IllustrisTNG than in EAGLE.
• Nonetheless, in both cases scatter in $f_{\rm CGM}$ at fixed $M_{200}$ is strongly correlated with the specific star formation rate and the kinematic morphology of central galaxies.
• The correlations are strongest for $\sim L^\star$ galaxies, corresponding to the mass scale at which AGN feedback becomes efficient.