Dissipative Dark Substructure: The Consequences of Atomic Dark Matter on Milky Way Analog Subhalos

Fuente: arXiv
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Main Authors: Gemmell, Caleb, Roy, Sandip, Shen, Xuejian, Curtin, David, Lisanti, Mariangela, Murray, Norman, Hopkins, Philip F.
Format: Preprint
Published: 2023
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author Gemmell, Caleb
Roy, Sandip
Shen, Xuejian
Curtin, David
Lisanti, Mariangela
Murray, Norman
Hopkins, Philip F.
author_facet Gemmell, Caleb
Roy, Sandip
Shen, Xuejian
Curtin, David
Lisanti, Mariangela
Murray, Norman
Hopkins, Philip F.
contents Using cosmological hydrodynamical zoom-in simulations, we explore the properties of subhalos in Milky Way analogs that contain a sub-component of Atomic Dark Matter (ADM). ADM differs from Cold Dark Matter (CDM) due to the presence of self interactions that lead to energy dissipation and bound-state formation, analogous to Standard Model baryons. This model can arise in complex dark sectors that are natural and theoretically-motivated extensions to the Standard Model. The simulations used in this work were carried out using GIZMO and utilize the FIRE-2 galaxy formation physics in the Standard Model baryonic sector. For the parameter points we consider, the ADM gas cools efficiently, allowing it to collapse to the center of subhalos. This increases a subhalo's central density and affects its orbit, with more subhalos surviving small pericentric passages. The subset of subhalos that host visible satellite galaxies have cuspier density profiles and smaller stellar-half-mass radii relative to CDM. The entire population of dwarf galaxies produced in the ADM simulations is much more compact than those seen in CDM simulations, unable to reproduce the entire diversity of observed dwarf galaxy structures. Additionally, we also identify a population of highly compact subhalos that consist nearly entirely of ADM and form in the central region of the host, where they can leave distinctive imprints in the baryonic disk. This work presents the first detailed exploration of subhalo properties in a strongly dissipative dark matter scenario, providing intuition for how other regions of ADM parameter space, as well as other dark sector models, would impact galactic-scale observables.
format Preprint
id arxiv_https___arxiv_org_abs_2311_02148
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Dissipative Dark Substructure: The Consequences of Atomic Dark Matter on Milky Way Analog Subhalos
Gemmell, Caleb
Roy, Sandip
Shen, Xuejian
Curtin, David
Lisanti, Mariangela
Murray, Norman
Hopkins, Philip F.
Astrophysics of Galaxies
Cosmology and Nongalactic Astrophysics
High Energy Physics - Phenomenology
Using cosmological hydrodynamical zoom-in simulations, we explore the properties of subhalos in Milky Way analogs that contain a sub-component of Atomic Dark Matter (ADM). ADM differs from Cold Dark Matter (CDM) due to the presence of self interactions that lead to energy dissipation and bound-state formation, analogous to Standard Model baryons. This model can arise in complex dark sectors that are natural and theoretically-motivated extensions to the Standard Model. The simulations used in this work were carried out using GIZMO and utilize the FIRE-2 galaxy formation physics in the Standard Model baryonic sector. For the parameter points we consider, the ADM gas cools efficiently, allowing it to collapse to the center of subhalos. This increases a subhalo's central density and affects its orbit, with more subhalos surviving small pericentric passages. The subset of subhalos that host visible satellite galaxies have cuspier density profiles and smaller stellar-half-mass radii relative to CDM. The entire population of dwarf galaxies produced in the ADM simulations is much more compact than those seen in CDM simulations, unable to reproduce the entire diversity of observed dwarf galaxy structures. Additionally, we also identify a population of highly compact subhalos that consist nearly entirely of ADM and form in the central region of the host, where they can leave distinctive imprints in the baryonic disk. This work presents the first detailed exploration of subhalo properties in a strongly dissipative dark matter scenario, providing intuition for how other regions of ADM parameter space, as well as other dark sector models, would impact galactic-scale observables.
title Dissipative Dark Substructure: The Consequences of Atomic Dark Matter on Milky Way Analog Subhalos
topic Astrophysics of Galaxies
Cosmology and Nongalactic Astrophysics
High Energy Physics - Phenomenology
url https://arxiv.org/abs/2311.02148