Using cosmological hydrodynamical zoom-in simulations, we explore the properties of subhalos in Milky Way analogs that contain a subcomponent of atomic dark matter (ADM). ADM differs from cold dark matter (CDM) due to the presence of self-interactions that lead to energy dissipation, analogous to standard model baryons. This model can arise in 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 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 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.
Dissipative Dark Substructure: The Consequences of Atomic Dark Matter on Milky Way Analog Subhalos
Abstract
Copyright and License
© 2024. The Author(s). Published by the American Astronomical Society. Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.
Acknowledgement
We would like to thank Arpit Arora, Ting Li, Tri Nguyen, Xiaowei Ou, Nondh Panithanpaisal, Robyn Sanderson, and Nora Shipp for helpful discussions during the completion of this project. The research of D.C. and C.G. was supported in part by Discovery Grants from the Natural Sciences and Engineering Research Council of Canada and the Canada Research Chair program. The research of D.C. was also supported by the Alfred P. Sloan Foundation, the Ontario Early Researcher Award, and the University of Toronto McLean Award. The work of C.G. was also supported by the University of Toronto Connaught International Scholarship, the McDonald Institute Graduate Student Exchange program, and the Canada First Research Excellence Fund. M.L. is supported by the Department of Energy (DOE) under award No. DE-SC0007968, as well as the Simons Investigator in Physics Award. This work was performed in part at the Aspen Center for Physics, which is supported by National Science Foundation grant PHY-2210452. The work presented in this paper was performed on computational resources managed and supported by Princeton Research Computing. This research also made extensive use of the publicly available codes IPython (Pérez & Granger 2007), matplotlib (Hunter 2007), Rockstar (Behroozi et al. 2012), Jupyter (Kluyver et al. 2016), AGAMA (Vasiliev 2018), HaloAnalysis (Wetzel & Garrison-Kimmel 2020), NumPy (Harris et al. 2020), SciPy (Virtanen et al. 2020), and gizmo-analysis (Wetzel et al. 2020).
Files
Name | Size | Download all |
---|---|---|
md5:1a5e401ddd3fdec0be32bbb9728824a4
|
1.9 MB | Preview Download |
Additional details
- ISSN
- 1538-4357
- Canada Research Chairs
- Natural Sciences and Engineering Research Council
- Alfred P. Sloan Foundation
- University of Toronto
- United States Department of Energy
- DE-SC0007968
- Simons Foundation
- National Science Foundation
- PHY-2210452
- Caltech groups
- Astronomy Department, TAPIR, Walter Burke Institute for Theoretical Physics