Investigating the Dominant Environmental Quenching Process in UVCANDELS/COSMOS Groups

TL;DR

This study investigates how galaxy quenching in groups depends on location, redshift, and stellar mass, finding evidence that slow environmental processes like strangulation dominate in the redshift range 0.2 to 0.8.

Contribution

It provides new insights into the timescales and processes of environmental quenching using UV data and the zCOSMOS group catalog.

Findings

Quenched galaxy fraction increases with decreasing redshift.

Quenching timescale is approximately 4.9 Gyrs.

Slow quenching processes like strangulation are supported.

Abstract

We explore how the fraction of quenched galaxies changes in groups of galaxies with respect to the distance to the center of the group, redshift, and stellar mass to determine the dominant process of environmental quenching in $0.2 < z < 0.8$ groups. We use new UV data from the UVCANDELS project in addition to existing multiband photometry to derive new galaxy physical properties of the group galaxies from the zCOSMOS 20k Group Catalog. Limiting our analysis to a complete sample of log$(M_*/M_{\odot})>10.56$ group galaxies we find that the probability of being quenched increases slowly with decreasing redshift, diverging from the stagnant field galaxy population. A corresponding analysis on how the probability of being quenched increases with time within groups suggests that the dominant environmental quenching process is characterized by slow ($\sim$Gyr) timescales. We find a quenching time of approximately $4.91^{+0.91}_{-1.47} $Gyrs, consistent with the slow processes of strangulation (Larson et al. 1980) and delayed-then-rapid quenching (Wetzel et al. 2013 arXiv:1206.3571v2 [astro-ph.CO]), although more data are needed to confirm this result.