Simulating Atomic Dark Matter in Milky Way Analogs
Journal Article
·
· The Astrophysical Journal. Letters
- Princeton University, NJ (United States)
- California Institute of Technology, Pasadena, CA (United States)
- Princeton University, NJ (United States); Flatiron Institute, New York, NY (United States)
- University of Toronto, ON (Canada)
Dark sector theories naturally lead to multicomponent scenarios for dark matter where a subcomponent can dissipate energy through self-interactions, allowing it to efficiently cool inside galaxies. We present the first cosmological hydrodynamical simulations of Milky Way analogs where the majority of dark matter is collisionless cold dark matter (CDM) but a subcomponent (6%) is strongly dissipative minimal atomic dark matter (ADM). The simulations, implemented in GIZMO and utilizing FIRE-2 galaxy formation physics to model the standard baryonic sector, demonstrate that the addition of even a small fraction of dissipative dark matter can significantly impact galactic evolution despite being consistent with current cosmological constraints. We show that ADM gas with roughly standard model–like masses and couplings can cool to form a rotating “dark disk” with angular momentum closely aligned with the visible stellar disk. The morphology of the disk depends sensitively on the parameters of the ADM model, which affect the cooling rates in the dark sector. The majority of the ADM gas gravitationally collapses into dark “clumps” (regions of black hole or mirror star formation), which form a prominent bulge and a rotating thick disk in the central galaxy. These clumps form early and quickly sink to the inner ∼kiloparsec of the galaxy, affecting the galaxy’s star formation history and present-day baryonic and CDM distributions.
- Research Organization:
- Princeton University, NJ (United States)
- Sponsoring Organization:
- NSF Faculty Early Career Development Program (CAREER); National Aeronautics and Space Administration (NASA); National Science Foundation (NSF); USDOE; USDOE Office of Science (SC), High Energy Physics (HEP)
- Grant/Contract Number:
- SC0007968
- OSTI ID:
- 2004635
- Alternate ID(s):
- OSTI ID: 2349396
OSTI ID: 3011024
- Journal Information:
- The Astrophysical Journal. Letters, Journal Name: The Astrophysical Journal. Letters Journal Issue: 2 Vol. 954; ISSN 2041-8213; ISSN 2041-8205
- Publisher:
- IOP PublishingCopyright Statement
- Country of Publication:
- United States
- Language:
- English