The globular cluster system mass-halo mass relation in the E-MOSAICS simulations. (arXiv:2005.05991v1 [astro-ph.GA])
<a href="http://arxiv.org/find/astro-ph/1/au:+Bastian_N/0/1/0/all/0/1">Nate Bastian</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Pfeffer_J/0/1/0/all/0/1">Joel Pfeffer</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kruijssen_J/0/1/0/all/0/1">J.M. Diederik Kruijssen</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Crain_R/0/1/0/all/0/1">Robert A. Crain</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Trujillo_Gomez_S/0/1/0/all/0/1">Sebastian Trujillo-Gomez</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Reina_Campos_M/0/1/0/all/0/1">Marta Reina-Campos</a>
Linking globular clusters (GCs) to the assembly of their host galaxies is an
overarching goal in GC studies. The inference of tight scaling relations
between GC system properties and the mass of both the stellar and dark halo
components of their host galaxies are indicative of an intimate physical
connection, yet have also raised fundamental questions about how and when GCs
form. Specifically, the inferred correlation between the mass of a GC system
(M_gc) and the dark matter halo mass (M_halo) of a galaxy has been posited as a
consequence of a causal relation between the formation of dark matter
mini-haloes and GC formation during the early epochs of galaxy assembly. We
present the first results from a new simulation of a cosmological volume
(L=34.4cMpc on a side) from the E-MOSAICS suite, which includes treatments of
the formation and evolution of GCs within the framework of a detailed galaxy
formation model. The simulated M_gc-M_halo relation is linear for halo masses
$>5times10^{11}$ Msun, and is driven by the hierarchical assembly of galaxies,
in agreement with previous studies. Below this halo mass, the simulated
relation features a downturn, which we show is consistent with observations,
and is driven by the underlying stellar mass (M_star)-halo mass relation of
galaxies. Our fiducial model reproduces the observed M_gc-M_star relation
across the full mass range, which we argue is more physically relevant than the
M_gc-M_halo relation. We also explore the physical processes driving the
observed constant value of M_gc / M_halo $sim 5times10^{-5}$ and find that it
is the result of a combination of cluster formation physics and cluster
disruption.
Linking globular clusters (GCs) to the assembly of their host galaxies is an
overarching goal in GC studies. The inference of tight scaling relations
between GC system properties and the mass of both the stellar and dark halo
components of their host galaxies are indicative of an intimate physical
connection, yet have also raised fundamental questions about how and when GCs
form. Specifically, the inferred correlation between the mass of a GC system
(M_gc) and the dark matter halo mass (M_halo) of a galaxy has been posited as a
consequence of a causal relation between the formation of dark matter
mini-haloes and GC formation during the early epochs of galaxy assembly. We
present the first results from a new simulation of a cosmological volume
(L=34.4cMpc on a side) from the E-MOSAICS suite, which includes treatments of
the formation and evolution of GCs within the framework of a detailed galaxy
formation model. The simulated M_gc-M_halo relation is linear for halo masses
$>5times10^{11}$ Msun, and is driven by the hierarchical assembly of galaxies,
in agreement with previous studies. Below this halo mass, the simulated
relation features a downturn, which we show is consistent with observations,
and is driven by the underlying stellar mass (M_star)-halo mass relation of
galaxies. Our fiducial model reproduces the observed M_gc-M_star relation
across the full mass range, which we argue is more physically relevant than the
M_gc-M_halo relation. We also explore the physical processes driving the
observed constant value of M_gc / M_halo $sim 5times10^{-5}$ and find that it
is the result of a combination of cluster formation physics and cluster
disruption.
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