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Dissipative Dark Matter on FIRE: II. Observational signatures and constraints from local dwarf galaxies

Shen, Xuejian and Hopkins, Philip F. and Necib, Lina and Jiang, Fangzhou and Boylan-Kolchin, Michael and Wetzel, Andrew (2022) Dissipative Dark Matter on FIRE: II. Observational signatures and constraints from local dwarf galaxies. . (Unpublished)

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We analyze the first set of cosmological baryonic zoom-in simulations of galaxies in dissipative self-interacting dark matter (dSIDM). The simulations utilize the FIRE-2 galaxy formation physics with the inclusion of dissipative dark matter self-interactions modelled as a constant fractional energy dissipation (f_(diss) = 0.5). In this paper, we examine the properties of dwarf galaxies with M∗ ∼ 10⁵-10⁹ M_⊙ in both isolation and within Milky Way-mass hosts. For isolated dwarfs, we find more compact galaxy sizes and promotion of stellar/neutral gas disk formation in dSIDM with (σ/m) ≤ 1 cm² g⁻¹ but they are still consistent with observed galaxy sizes and masses. In addition, as a result of the steeper central density profiles developed in dSIDM, the sub-kpc circular velocities of isolated dwarfs in models with (σ/m) ≥ 0.1 cm² g⁻¹ are enhanced by about a factor of two, which are still consistent with the measured stellar velocity dispersions of Local Group dwarfs but in tension with the HI rotation curves of more massive field dwarfs. Meanwhile, for satellites of the simulated Milky Way-mass hosts, the median circular velocity profiles are marginally affected by dSIDM physics, but dSIDM may help address the missing compact dwarf satellites in CDM. The number of satellites is slightly enhanced in dSIDM, but the differences are small compared with the large host-to-host variations. In conclusion, the dSIDM models with constant cross-section (σ/m) ≳ 0.1 cm² g⁻¹ (assuming f_(diss) = 0.5) are effectively ruled out in bright dwarfs (Mₕₐₗₒ ∼ 10¹¹ M_⊙) by circular velocity constraints. However, models with lower effective cross-sections (at this halo mass/velocity scale) are still viable and can give rise to non-trivial observable signatures.

Item Type:Report or Paper (Discussion Paper)
Related URLs:
URLURL TypeDescription Paper ItemCDM FIRE-2 simulations
Shen, Xuejian0000-0002-6196-823X
Hopkins, Philip F.0000-0003-3729-1684
Necib, Lina0000-0003-2806-1414
Jiang, Fangzhou0000-0001-6115-0633
Boylan-Kolchin, Michael0000-0002-9604-343X
Wetzel, Andrew0000-0003-0603-8942
Additional Information:Support for XS & PFH was provided by the National Science Foundation (NSF) Research Grants 1911233, 20009234, 2108318, the NSF Faculty Early Career Development Program (CAREER) grant 1455342, the National Aeronautics and Space Administration (NASA) grants 80NSSC18K0562, HST-AR-15800. Numerical calculations were run on the supercomputer Frontera at the Texas Advanced Computing Center (TACC) under the allocations AST21010 and AST20016 supported by the NSF and TACC, and NASA HEC SMD-16-7592. FJ is supported by the Troesh scholarship. MBK acknowledges support from NSF CAREER award AST-1752913, NSF grants AST-1910346 and AST-2108962, NASA grant NNX17AG29G, and HST-AR-15006, HST-AR-15809, HST-GO-15658, HST-GO-15901, HST-GO-15902, HST-AR-16159, and HST-GO-16226 from the Space Telescope Science Institute (STScI), which is operated by AURA, Inc., under NASA contract NAS5-26555. AW received support from: NSF grants CAREER 2045928 and 2107772; NASA Astrophysics Theory Program (ATP) grant 80NSSC20K0513; HST grants AR-15809, GO-15902, GO-16273 from STScI. This research made use of data from the SAGA Survey ( The SAGA Survey was supported by NSF collaborative grants AST-1517148 and AST-1517422 and by Heising–Simons Foundation grant 2019-1402. DATA AVAILABILITY. The simulation data of this work was generated and stored on the supercomputing system Frontera at the Texas Advanced Computing Center (TACC), under the allocations AST20010/AST20016 supported by the NSF and TACC, and NASA HEC SMD-16-7592. The CDM FIRE-2 simulations are publicly available (Wetzel et al. 2022) at However, the data of the dSIDM simulations used in this article cannot be shared publicly immediately, since the series of paper is still in development. The data will be shared on reasonable request to the corresponding author.
Group:Astronomy Department, TAPIR
Funding AgencyGrant Number
Texas Advanced Computing Center (TACC)UNSPECIFIED
Troesh ScholarshipUNSPECIFIED
Heising-Simons Foundation2019-1402
Subject Keywords:methods : numerical – galaxies : dwarf – galaxies : Local Group – galaxies : structure – cosmology : dark matter – cosmology : theory
Record Number:CaltechAUTHORS:20220816-222015071
Persistent URL:
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:116333
Deposited By: George Porter
Deposited On:18 Aug 2022 20:06
Last Modified:18 Aug 2022 20:06

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