Satellite galaxies in groups in the CIELO Project I. Gas removal from galaxies and its re-distribution in the intragroup medium

TL;DR

This study uses hydrodynamical simulations to analyze how environmental factors like tidal forces and ram pressure strip gas from satellite galaxies, affecting their star formation and orientation within a Local Group analogue.

Contribution

It provides detailed insights into the combined effects of tidal torque and ram pressure on gas removal and galaxy evolution in a simulated Local Group environment.

Findings

Gas removal episodes are strongest when disc orientation is perpendicular to motion.

Multiple peripassages are needed to significantly alter galaxy disc orientations.

Satellites continue star formation after first peripassage, losing about 90% of gas.

Abstract

We study the impact of the environment on galaxies as they fall in and orbit in the potential well of a Local Group (LG) analogue, following them with high cadence. The analysis is performed on eight disc satellite galaxies from the CIELO suite of hydrodynamical simulations. All galaxies have stellar masses within the range $[10^{8.1} - 10^{9.56}] M_{\sun} $h$^{-1}$. We measure tidal torques, ram pressure and specific star formation rates (sSFR) as a function of time, and correlate them with the amount of gas lost by satellites along their orbits. Stronger removal episodes occur when the disc plane is oriented perpendicular to the direction of motion. More than one peripassage is required to significantly modify the orientations of the discs with respect to the orbital plane. The gas removed during the interaction with the central galaxies may be also found opposite to the direction of motion, depending on the orbital configuration. Satellites are not totally quenched when the galaxies reach their first peripassage, and continue forming about $10\%$ of the final stellar mass after this event. The fraction of removed gas is found to be the product of the joint action of tidal torque and ram pressure, which can also trigger new star formation activity and subsequent supernova feedback.