The circum-galactic gas around cosmologically simulated disks

TL;DR

This paper investigates the properties and infall rates of circum-galactic gas around simulated galactic disks, revealing insights into gas accretion processes and disk growth mechanisms at different redshifts.

Contribution

It provides a detailed analysis of circum-galactic gas properties and infall rates in cosmological simulations, highlighting the role of hot coronae and episodic tidal streams in galaxy growth.

Findings

Disks are surrounded by hot, tenuous coronae that supply non-enriched gas.

Infall rates match star formation rates, supporting inside-out disk growth.

Gas accretion occurs via hot coronae and episodic tidal streams.

Abstract

We analyze the physical properties and infall rates of the circum-galactic gas around disks obtained in multi-resolved, cosmological, AMR simulations. At intermediate and low redshifts, disks are embedded into an extended, hot, tenuous corona that contributes largely in fueling the disk with non-enriched gas whereas the accretion of enriched gas from tidal streams occurs throughout episodic events. We derive an infall rate close to the disk of the same value as the one of the star formation rate in the disk and its temporal evolution as a function of galacto-centric radius nicely shows that the growth of galactic disks proceeds according to an inside-out formation scenario.