The role of gas stripping in the quenching of satellite galaxies using SHARK v2.0

TL;DR

This study combines SDSS observations with the SHARK v2.0 model to refine gas stripping prescriptions, revealing that hot halo gas removal primarily drives satellite galaxy quenching with shorter timescales in clusters.

Contribution

It calibrates the gas stripping processes in SHARK v2.0 against observations, demonstrating the importance of hot halo gas removal in satellite quenching.

Findings

Gas stripping prescriptions in SHARK v2.0 are too aggressive in previous models.

Calibrated model matches observed satellite quenched fractions.

Quenching timescales are shorter in clusters and decrease with stellar mass.

Abstract

Observational studies have made substantial progress in characterizing quenching as a function of stellar mass and environment, but they are often limited in their ability to constrain quenching timescales and to determine the dominant environmental process responsible for the shutting down of star formation. To address this, we combine recent Sloan Digital Sky Survey (SDSS) observations with the SHARK v2.0 semi-analytic model to study the quenching of satellite galaxies in groups and clusters. We generate mock SDSS-like observations to calibrate the hot halo and cold interstellar medium (ISM) gas stripping prescriptions against observed satellite quenched fractions, finding that the previously adopted stripping prescriptions in SHARK v2.0 are too aggressive and overestimate the quenched fraction of satellite galaxies. Reducing the efficiency of both hot and cold gas stripping yields excellent agreement with observations for low- and intermediate-mass satellite galaxies. We use the calibrated model to investigate quenching timescales and find that satellites quench more quickly in clusters compared to groups, with timescales that generally decrease with increasing stellar mass. The long (>2 Gyr) timescales we measure favour hot halo gas removal as the dominant driver of satellite quenching.