Diversity in density profiles of self-interacting dark matter satellite halos

Journal Article · 04 December 2019 · Journal of Cosmology and Astroparticle Physics

DOI: https://doi.org/10.1088/1475-7516/2019/12/010 · OSTI ID:1623311

Kahlhoefer, Felix ^[1]; Kaplinghat, Manoj ^[2]; Slatyer, Tracy R. ^[3]; Wu, Chih-Liang ^[3]

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1. RWTH Aachen Univ. (Germany)
2. Univ. of California, Irvine, CA (United States)
3. Institute for Advanced Study, Princeton, NJ (United States). School of Natural Sciences; Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)

We introduce findings from N-body simulations of self-interacting dark matter (SIDM) subhalos, which could host ultra-faint dwarf spheroidal galaxies, inside a Milky-Way-like main halo. We find that high-concentration subhalos are driven to gravothermal core collapse, while low-concentration subhalos develop large (kpc-sized) low-density cores, with both effects depending sensitively on the satellite's orbit and the self-interaction cross section over mass σ/m. The overall effect for σ/m 3 cm²/g is to increase the range of inner densities, potentially explaining the observed diversity of Milky Way satellites, which include compact systems like Draco and Segue 1 that are dense in dark matter, and less dense, diffuse systems like Sextans and Crater II . We discuss possible ways of distinguishing SIDM models from collisionless dark matter models using the inferred dark matter densities and stellar sizes of the dwarf spheroidal galaxies.

• Research Organization: Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)
• Sponsoring Organization: USDOE Office of Science (SC), High Energy Physics (HEP); National Science Foundation (NSF)
• Grant/Contract Number: SC0012567; SC0013999; PHY-1620638
• OSTI ID: 1623311
• Journal Information: Journal of Cosmology and Astroparticle Physics, Vol. 2019, Issue 12; ISSN 1475-7516
• Publisher: Institute of Physics (IOP)Copyright Statement
• Country of Publication: United States
• Language: English