Central densities of dark matter haloes in FIRE-2 simulations of low-mass galaxies with cold dark matter and self-interacting dark matter
Creators
-
1.
The University of Texas at Austin
-
2.
University of California, Irvine
-
3.
California Institute of Technology
-
4.
Massachusetts Institute of Technology
Abstract
We investigate the central density structure of dark matter haloes in cold dark matter (CDM) and self-interacting dark matter (SIDM) models using simulations that are part of the Feedback In Realistic Environments (fire) project. For simulated haloes of dwarf galaxy scale (M_(halo)(z=0) ≈ 10¹⁰M⊙, we study the central structure in both dissipationless simulations and simulations with full fire-2 galaxy formation physics. As has been demonstrated extensively in recent years, both baryonic feedback and self-interactions can convert central cusps into cores, with the former process doing so in a manner that depends sensitively on stellar mass at fixed M_(halo). Whether the two processes (baryonic feedback and self-interactions) are distinguishable, however, remains an open question. Here we demonstrate that, compared to feedback-induced cores, SIDM-induced cores transition more quickly from the central region of constant density to the falling density at larger radial scales. This result holds true even when including identical galaxy formation modelling in SIDM simulations as is used in CDM simulations, since self-interactions dominate over galaxy formation physics in establishing the central structure of SIDM haloes in this mass regime. The change in density profile slope as a function of radius therefore holds the potential to discriminate between self-interactions and galaxy formation physics as the driver of core formation in dwarf galaxies.
Copyright and License
Acknowledgement
We thank the referee for insightful comments that helped improved this paper. We thank Manoj Kaplinghat for helpful discussions. MCS acknowledges support from the National Science Foundation Graduate Research Fellowship Programme under grant no. DGE 2137420 and from the UT Austin Astronomy Department REU Programme ‘Frontier Research and Training in Astronomy for the 21st Century’ funded by NSF grant AST 1757983 from the NSF REU programme and the Department of Defense ASSURE programme. MBK acknowledges support from NSF CAREER award AST-1752913, NSF grants AST-1910346 and AST-2108962, NASA grant 80NSSC22K0827,HST-GO-16686, HST-AR-17028, HST-AR-17043, JWST-GO-03788, and JWST-AR-06278 from the Space Telescope Science Institute, which is operated by AURA, Inc., under NASA contract NAS5-26555; and from the Samuel T. and Fern Yanagisawa Regents Professorship in Astronomy at UT Austin. XS acknowledges the support from NASA grant JWST-AR04814. LN is supported by the Sloan Fellowship, the NSF CAREER award 2337864, NSF award 2307788, and by the NSF award PHY2019786 (The NSF AI Institute for Artificial Intelligence and Fundamental Interactions, http://iaifi.org/). We thank the developers of the Python packages used in preparing this paper: numpy (Harris et al. 2020), scipy (Virtanen et al. 2020), and matplotlib (Hunter 2007). This work used computational resources of the University of Texas at Austin and the Texas Advanced Computing Center (TACC; http://www.tacc.utexas.edu), the NASA Advanced Supercomputing (NAS) Division and the NASA Center for Climate Simulation (NCCS), and the Extreme Science and Engineering Discovery Environment (XSEDE), which is supported by National Science Foundation grant number OCI-1053575.
Data Availability
The fire-2 simulations are publicly available (Wetzel et al. 2023) at http://flathub.flatironinstitute.org/fire. Additional fire simulation data is available at https://fire.northwestern.edu/data. A public version of the gizmo code is available at http://www.tapir.caltech.edu/~phopkins/Site/GIZMO.html. Data products from this paper will be made available upon reasonable request to the corresponding author.
Files
staf1539.pdf
Additional details
Related works
- Is new version of
- Discussion Paper: arXiv:2501.16602 (arXiv)
Funding
- National Science Foundation
- DGE-2137420
- National Science Foundation
- AST-1757983
- National Science Foundation
- AST-1752913
- National Science Foundation
- AST-1910346
- National Science Foundation
- AST-2108962
- National Aeronautics and Space Administration
- 80NSSC22K0827
- National Aeronautics and Space Administration
- HST-GO-16686
- National Aeronautics and Space Administration
- HST-AR-17028
- National Aeronautics and Space Administration
- HST-AR-17043
- National Aeronautics and Space Administration
- JWST-GO-03788
- National Aeronautics and Space Administration
- JWST-AR-06278
- Space Telescope Science Institute
- National Aeronautics and Space Administration
- NAS5-26555
- The University of Texas at Austin
- National Aeronautics and Space Administration
- JWST-AR04814
- Alfred P. Sloan Foundation
- National Science Foundation
- 2337864
- National Science Foundation
- 2307788
- National Science Foundation
- PHY2019786
- National Science Foundation
- OCI-1053575
Dates
- Submitted
-
2025-01-28
- Accepted
-
2025-09-08
- Available
-
2025-09-13Published
- Available
-
2025-10-06Corrected and typeset
Caltech Custom Metadata
- Caltech groups
- Astronomy Department , TAPIR , Walter Burke Institute for Theoretical Physics , Division of Physics, Mathematics and Astronomy (PMA) , Physics Department
- Publication Status
- Published