CFHT UM2019 - Presentation Details

Abstract Details

Title: On the Environment- and Mass-driven Quenching of the Star Formation in Galaxies: the NUVrK Big Picture

Presenter: Thibaud Moutard


The fact that galaxies can be classified between “blue/star-forming" and “red/quiescent" populations is now well established and this bimodality, clearly observed to redshift z~4, is the statistical expression of a (rapid) phenomenon called “quenching”. The processes that are involved in the quenching of low-mass galaxies may, however, be quite different from what is involved in the quenching of massive galaxies after billion years of star formation on the main sequence. I will present a review of results we obtained regarding the connection between the regulation of the star formation histories of galaxies and large-scale structures on the basis of extensive use of u–to–Ks imaging from the Canada-France-Hawaii Telescope (CFHT) over ~27 deg2, as part of the VIPERS Multi-Lamba Survey. In particular, I will discuss the different quenching channels that can be identified between star-forming and quiescent galaxies in the rest-frame NUV-r vs. r-K colour (NUVrK) diagram: 1) the slow quenching channel followed by evolved and massive galaxies, typically when their stellar masses reaches M* (~10^10.6 M⊙), which is consistent with a critical dark-matter halo mass of Mh (~10^12 M⊙), and 2) the fast quenching channel affecting young low-mass (≤10^9.6 M⊙) quiescent galaxies and responsible for the low-mass upturn observed in the stellar mass function of quiescent galaxies. I will notably show how the quenching of low-mass galaxies is consistent with being driven by environment in addition to being fast, and I will discuss how the slow and mass-related quenching of M* galaxies may preferentially happen along cosmic filaments.