# Satellite dwarf galaxies: Stripped but not quenched

**Authors:** L. Hausammann, Y. Revaz, P. Jablonka

arXiv: 1902.02340 · 2019-04-03

## TL;DR

This study uses high-resolution simulations to analyze how ram pressure and tidal forces from a host galaxy influence dwarf satellite galaxies, revealing that cold gas removal and star formation quenching depend on specific conditions and infall timing.

## Contribution

It provides the first self-consistent, high-resolution simulation analysis of dwarf galaxy interactions with host galaxy halos, incorporating cosmological growth and hot halo profiles.

## Key findings

- Ram pressure efficiently strips hot, diffuse gas from dwarfs.
- Cold gas can only be removed under specific conditions.
- Star formation can be prolonged depending on infall timing.

## Abstract

In the Local Group, quenched gas-poor dwarfs galaxies are most often found close to the Milky Way and Andromeda, while star forming gas-rich ones are located at greater distances. This so-called morphology-density relation is often interpreted as the consequence of the ram pressure stripping of the satellites during their interaction with the Milky Way hot halo gas. While this process has been often investigated, self-consistent high resolution simulations were still missing. In this study, we have analysed the impact of both the ram pressure and tidal forces induced by a host galaxy on dwarf models as realistic as possible emerging from cosmological simulations. These models were re-simulated using both a wind tunnel and a moving box technique. The secular mass growth of the central host galaxy, as well as the gas density and temperature profiles of its hot halo have been taken into account. We show that while ram pressure is very efficient at stripping the hot and diffuse gas of the dwarf galaxies, it can remove their cold gas ($T < 10^3$~[K]) only in very specific conditions. Depending on the infall time of the satellites relatively to the build-up stage of the massive host, star formation can thus be prolonged instead of being quenched. This is the direct consequence of the clumpy nature of the cold gas and the thermal pressure the hot gas exerts onto it. We discuss the possibility that the variety in satellite populations among Milky Way-like galaxies reflects their accretion histories.

## Full text

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## Figures

19 figures with captions in the complete paper: https://tomesphere.com/paper/1902.02340/full.md

## References

102 references — full list in the complete paper: https://tomesphere.com/paper/1902.02340/full.md

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Source: https://tomesphere.com/paper/1902.02340