RSAA Colloquium: Luca Cortese (UWA)

Beyond gas removal: early insights into star formation quenching from MAUVE

One of the key questions in galaxy evolution is why galaxies stop forming stars. Environmental processes such as gas stripping are known to play an important role, especially in the local Universe, yet many galaxies, even in massive clusters, retain significant gas reservoirs long after star formation begins to decline. Understanding what happens to this remaining gas, and why it ultimately fails to form stars, has therefore emerged as a key missing piece of the quenching puzzle. 

In this colloquium, I will present recent results from the Multiphase Astrophysics to Unveil the Virgo Environment (MAUVE), a new observational program designed to probe the state, dynamics and chemistry of the gas and stars in galaxies undergoing transformation within the Virgo Cluster. By combining observations from VLT/MUSE, the Hubble Space Telescope and ALMA, MAUVE follows galaxies across different stages of quenching while resolving physical scales of only 100-200 parsecs. In a nutshell, MAUVE aims to provide for cluster galaxies the same physical insight that PHANGS has delivered for nearby main sequence systems. Although still in its early stages, MAUVE is already revealing a more complex picture of the quenching process, in which outflows remain important beyond the peak of star formation activity, ionised gas can persist after star formation has largely ceased, and residual gas reservoirs frequently exhibit disturbed kinematics rather than settled rotating discs. 

I will also discuss emerging evidence that the relationship between metallicity and star formation may be more complicated than traditionally assumed. Together, these results suggest that quenching is not simply a consequence of gas removal, but reflects a broader transformation of the physical, dynamical and chemical state of the gas itself.