Dark matter stripping in galaxy clusters: a look at the Stellar to Halo Mass relation in the Illustris simulation. (arXiv:1811.04996v1 [astro-ph.GA])
<a href="http://arxiv.org/find/astro-ph/1/au:+Niemiec_A/0/1/0/all/0/1">Anna Niemiec</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Jullo_E/0/1/0/all/0/1">Eric Jullo</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Giocoli_C/0/1/0/all/0/1">Carlo Giocoli</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Jauzac_M/0/1/0/all/0/1">Mathilde Jauzac</a>
Satellite galaxies in clusters represent a significant fraction of the global
galaxy population, and because of the unusual dense environment they live in,
their evolution is driven by mechanisms that are different from the ones
affecting field or central galaxies. Understanding the different interactions
they are subject to, and how they affect them, is therefore an important step
towards explaining the global picture of galaxy evolution. In this paper, we
use the high resolution hydrodynamical simulation Illustris-1 to study the
satellite galaxies in the three most massive host haloes, corresponding to
masses $M_{200} > 10^{14},h^{-1}M_{odot}$. We measure the stellar-to-halo
mass relation for the galaxies, and find that it is shifted towards lower halo
masses compared to the relation for central galaxies. To explain this shift, we
follow the satellite galaxies since their time of accretion in the clusters,
and quantify the impact of dark matter stripping and star formation. We find
that subhaloes start losing their dark matter as soon as they reach $sim
1.5times R_{rm{vir}}$ from the centre of their host, and that up to 80% of
their dark matter content get stripped during infall. On the other hand, star
formation quenching appears to be delayed and the galaxies continue to form
stars for a few Gyr after being accreted into their host. The combination of
these two effects makes the ratio of stellar mass to dark matter mass to vary
drastically during infall, going from 0.03 to 0.3.
Satellite galaxies in clusters represent a significant fraction of the global
galaxy population, and because of the unusual dense environment they live in,
their evolution is driven by mechanisms that are different from the ones
affecting field or central galaxies. Understanding the different interactions
they are subject to, and how they affect them, is therefore an important step
towards explaining the global picture of galaxy evolution. In this paper, we
use the high resolution hydrodynamical simulation Illustris-1 to study the
satellite galaxies in the three most massive host haloes, corresponding to
masses $M_{200} > 10^{14},h^{-1}M_{odot}$. We measure the stellar-to-halo
mass relation for the galaxies, and find that it is shifted towards lower halo
masses compared to the relation for central galaxies. To explain this shift, we
follow the satellite galaxies since their time of accretion in the clusters,
and quantify the impact of dark matter stripping and star formation. We find
that subhaloes start losing their dark matter as soon as they reach $sim
1.5times R_{rm{vir}}$ from the centre of their host, and that up to 80% of
their dark matter content get stripped during infall. On the other hand, star
formation quenching appears to be delayed and the galaxies continue to form
stars for a few Gyr after being accreted into their host. The combination of
these two effects makes the ratio of stellar mass to dark matter mass to vary
drastically during infall, going from 0.03 to 0.3.
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