Merge and strip: dark matter-free dwarf galaxies in clusters can be formed by galaxy mergers

Fuente: arXiv
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Main Authors: Ivleva, Anna, Remus, Rhea-Silvia, Valenzuela, Lucas M., Dolag, Klaus
Format: Preprint
Published: 2024
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author Ivleva, Anna
Remus, Rhea-Silvia
Valenzuela, Lucas M.
Dolag, Klaus
author_facet Ivleva, Anna
Remus, Rhea-Silvia
Valenzuela, Lucas M.
Dolag, Klaus
contents Recent observations of galaxy mergers inside galaxy cluster environments report high star formation rates in the ejected tidal tails, which point towards currently developing tidal dwarf galaxies. We test whether these dwarf objects could get stripped from the galaxy potential by the galaxy cluster and thus populate it with dwarf galaxies. To this end, we perform three high-resolution hydrodynamical simulations of mergers between spiral galaxies in a cluster environment, varying the initial orbit of the infalling galaxies with respect to the cluster center. We demonstrate that cluster environments are indeed capable of stripping tidal dwarf galaxies from the host potential in all tested setups. In the three orbit scenarios, we find 3, 7, and 8 tidal dwarf galaxies per merger, respectively, which survive longer than 1 Gyr after the merger event. Exposed to ram pressure, these gas dominated dwarf galaxies exhibit high star formation rates while also losing gas to the environment. Experiencing a strong headwind due to their motion through the intracluster medium, they quickly lose momentum and start spiraling towards the cluster center, reaching distances on the order of ~Mpc from their progenitor. About 4 Gyr after the merger event, we still find several intact dwarf galaxies, demonstrating that such objects can prevail for a significant fraction of the Hubble time. Comparing their contribution to the observed galaxy mass function in clusters, our results indicate that ~30% of dwarf galaxies in clusters could have been formed by stripping from galaxy mergers.
format Preprint
id arxiv_https___arxiv_org_abs_2402_09060
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Merge and strip: dark matter-free dwarf galaxies in clusters can be formed by galaxy mergers
Ivleva, Anna
Remus, Rhea-Silvia
Valenzuela, Lucas M.
Dolag, Klaus
Astrophysics of Galaxies
Recent observations of galaxy mergers inside galaxy cluster environments report high star formation rates in the ejected tidal tails, which point towards currently developing tidal dwarf galaxies. We test whether these dwarf objects could get stripped from the galaxy potential by the galaxy cluster and thus populate it with dwarf galaxies. To this end, we perform three high-resolution hydrodynamical simulations of mergers between spiral galaxies in a cluster environment, varying the initial orbit of the infalling galaxies with respect to the cluster center. We demonstrate that cluster environments are indeed capable of stripping tidal dwarf galaxies from the host potential in all tested setups. In the three orbit scenarios, we find 3, 7, and 8 tidal dwarf galaxies per merger, respectively, which survive longer than 1 Gyr after the merger event. Exposed to ram pressure, these gas dominated dwarf galaxies exhibit high star formation rates while also losing gas to the environment. Experiencing a strong headwind due to their motion through the intracluster medium, they quickly lose momentum and start spiraling towards the cluster center, reaching distances on the order of ~Mpc from their progenitor. About 4 Gyr after the merger event, we still find several intact dwarf galaxies, demonstrating that such objects can prevail for a significant fraction of the Hubble time. Comparing their contribution to the observed galaxy mass function in clusters, our results indicate that ~30% of dwarf galaxies in clusters could have been formed by stripping from galaxy mergers.
title Merge and strip: dark matter-free dwarf galaxies in clusters can be formed by galaxy mergers
topic Astrophysics of Galaxies
url https://arxiv.org/abs/2402.09060