Aggressively Dissipative Dark Dwarfs: The Effects of Atomic Dark Matter on the Inner Densities of Isolated Dwarf Galaxies
We present the first suite of cosmological hydrodynamical zoom-in simulations of isolated dwarf galaxies for a dark sector that consists of cold dark matter and a strongly dissipative subcomponent. The simulations are implemented in GIZMO and include standard baryons following the FIRE-2 galaxy form...
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2025-01-01
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| Online Access: | https://doi.org/10.3847/1538-4357/adb02b |
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| author | Sandip Roy Xuejian Shen Jared Barron Mariangela Lisanti David Curtin Norman Murray Philip F. Hopkins |
| author_facet | Sandip Roy Xuejian Shen Jared Barron Mariangela Lisanti David Curtin Norman Murray Philip F. Hopkins |
| author_sort | Sandip Roy |
| collection | DOAJ |
| description | We present the first suite of cosmological hydrodynamical zoom-in simulations of isolated dwarf galaxies for a dark sector that consists of cold dark matter and a strongly dissipative subcomponent. The simulations are implemented in GIZMO and include standard baryons following the FIRE-2 galaxy formation physics model. The dissipative dark matter is modeled as atomic dark matter (aDM), which forms a dark hydrogen gas that cools in direct analogy to the Standard Model. Our suite includes seven different simulations of ∼10 ^10 M _⊙ systems that vary over the aDM microphysics and the dwarf’s evolutionary history. We identify a region of aDM parameter space where the cooling rate is aggressive and the resulting halo density profile is universal. In this regime, the aDM gas cools rapidly at high redshifts, and only a small fraction survives in the form of a central dark gas disk; the majority collapses centrally into collisionless dark “clumps,” which are clusters of subresolution dark compact objects. These dark clumps rapidly equilibrate in the inner galaxy, resulting in an approximately isothermal distribution that can be modeled with a simple fitting function. Even when only a small fraction (∼5%) of the total dark matter is strongly dissipative, the central densities of classical dwarf galaxies can be enhanced by over an order of magnitude, providing a sharp prediction for observations. |
| format | Article |
| id | doaj-art-b3c87bcbae34466090278dc26c0ce05b |
| institution | DOAJ |
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| language | English |
| publishDate | 2025-01-01 |
| publisher | IOP Publishing |
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| series | The Astrophysical Journal |
| spelling | doaj-art-b3c87bcbae34466090278dc26c0ce05b2025-08-20T02:54:04ZengIOP PublishingThe Astrophysical Journal1538-43572025-01-01982217510.3847/1538-4357/adb02bAggressively Dissipative Dark Dwarfs: The Effects of Atomic Dark Matter on the Inner Densities of Isolated Dwarf GalaxiesSandip Roy0https://orcid.org/0000-0002-7638-7454Xuejian Shen1https://orcid.org/0000-0002-6196-823XJared Barron2https://orcid.org/0000-0001-9043-6577Mariangela Lisanti3https://orcid.org/0000-0002-8495-8659David Curtin4https://orcid.org/0000-0003-0263-6195Norman Murray5https://orcid.org/0000-0002-8659-3729Philip F. Hopkins6https://orcid.org/0000-0003-3729-1684Department of Physics, Princeton University , Princeton, NJ 08544, USADepartment of Physics, Massachusetts Institute of Technology , Cambridge, MA 02139, USA; Kavli Institute for Astrophysics and Space Research , Massachusetts Institute of Technology, Cambridge, MA 02139, USAC.N. Yang Institute for Theoretical Physics, Stony Brook University , Stony Brook, NY 11794-3800, USADepartment of Physics, Princeton University , Princeton, NJ 08544, USA; Center for Computational Astrophysics, Flatiron Institute , New York, NY 10010, USADepartment of Physics, University of Toronto , Toronto, Ontario M5S 1A7, CanadaCanadian Institute for Theoretical Astrophysics, University of Toronto , Toronto, ON M5S 3H8, CanadaTAPIR , California Institute of Technology, Pasadena, CA 91125, USAWe present the first suite of cosmological hydrodynamical zoom-in simulations of isolated dwarf galaxies for a dark sector that consists of cold dark matter and a strongly dissipative subcomponent. The simulations are implemented in GIZMO and include standard baryons following the FIRE-2 galaxy formation physics model. The dissipative dark matter is modeled as atomic dark matter (aDM), which forms a dark hydrogen gas that cools in direct analogy to the Standard Model. Our suite includes seven different simulations of ∼10 ^10 M _⊙ systems that vary over the aDM microphysics and the dwarf’s evolutionary history. We identify a region of aDM parameter space where the cooling rate is aggressive and the resulting halo density profile is universal. In this regime, the aDM gas cools rapidly at high redshifts, and only a small fraction survives in the form of a central dark gas disk; the majority collapses centrally into collisionless dark “clumps,” which are clusters of subresolution dark compact objects. These dark clumps rapidly equilibrate in the inner galaxy, resulting in an approximately isothermal distribution that can be modeled with a simple fitting function. Even when only a small fraction (∼5%) of the total dark matter is strongly dissipative, the central densities of classical dwarf galaxies can be enhanced by over an order of magnitude, providing a sharp prediction for observations.https://doi.org/10.3847/1538-4357/adb02bDark matterCold dark matterDwarf galaxiesHydrodynamical simulationsN-body simulationsParticle astrophysics |
| spellingShingle | Sandip Roy Xuejian Shen Jared Barron Mariangela Lisanti David Curtin Norman Murray Philip F. Hopkins Aggressively Dissipative Dark Dwarfs: The Effects of Atomic Dark Matter on the Inner Densities of Isolated Dwarf Galaxies The Astrophysical Journal Dark matter Cold dark matter Dwarf galaxies Hydrodynamical simulations N-body simulations Particle astrophysics |
| title | Aggressively Dissipative Dark Dwarfs: The Effects of Atomic Dark Matter on the Inner Densities of Isolated Dwarf Galaxies |
| title_full | Aggressively Dissipative Dark Dwarfs: The Effects of Atomic Dark Matter on the Inner Densities of Isolated Dwarf Galaxies |
| title_fullStr | Aggressively Dissipative Dark Dwarfs: The Effects of Atomic Dark Matter on the Inner Densities of Isolated Dwarf Galaxies |
| title_full_unstemmed | Aggressively Dissipative Dark Dwarfs: The Effects of Atomic Dark Matter on the Inner Densities of Isolated Dwarf Galaxies |
| title_short | Aggressively Dissipative Dark Dwarfs: The Effects of Atomic Dark Matter on the Inner Densities of Isolated Dwarf Galaxies |
| title_sort | aggressively dissipative dark dwarfs the effects of atomic dark matter on the inner densities of isolated dwarf galaxies |
| topic | Dark matter Cold dark matter Dwarf galaxies Hydrodynamical simulations N-body simulations Particle astrophysics |
| url | https://doi.org/10.3847/1538-4357/adb02b |
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