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We constrain the neutrino-dark matter cross section using properties of the dark matter density profiles of Milky Way dwarf spheroidal galaxies. The constraint arises from core-collapse supernova neutrinos scattering on dark matter as a form of energy injection, allowing the transformation of the dark matter density profile from a cusped profile to a flatter profile. We assume a standard cosmology of dark energy and cold, collisionless, and non-self-interacting dark matter. By requiring that the dark matter cores do not lose too much mass or overshoot constraints from stellar kinematics, we place an upper limit on the cross section of, which is stronger than previous bounds for these energies. Consideration of baryonic feedback or host galaxy effects on the dark matter profile can strengthen this constraint.
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This content will become publicly available on October 21, 2026
Effects of Dark Matter Self-interactions on Sagittarius and its Stream
Abstract This work explores how assumptions regarding the particle-physics nature of dark matter can alter the evolution of the Sagittarius (Sgr) dwarf spheroidal galaxy and its expansive stellar stream. We run a large suite ofN-body simulations to model the infall of a spherically symmetric Sgr-like dwarf, exploring how the presence of dark matter self-interactions impacts its evolution. For a scattering cross section ofσ/mχ = 30 cm2g−1(at orbital velocity scales), these interactions result in significantly less stellar mass and little to no dark matter bound to the progenitor at the present day. To isolate the cause of this mass loss, we introduce a novel technique for controlling which pairs of dark matter simulation particles can interact. This enables us to identify ram-pressure evaporation—the scattering of satellite and host dark matter particles—as the primary source of the enhanced mass loss. The rapid disintegration of the Sgr progenitor when self-interactions are allowed alters some key properties of the resulting stellar stream, most dramatically suppressing the presence of a “spur” on the apocenter of the trailing stream arm that correlates with the mass of the satellite at last pericenter. We demonstrate how the effects on the Sgr system scale with the particular choice of self-interaction cross section, which affects the degree of ram-pressure evaporation. These findings generalize beyond the Sgr system, underscoring that dwarf stellar streams and dwarf galaxies with close passages may serve as sensitive probes for dark matter self-interactions.
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- Award ID(s):
- 2210498
- PAR ID:
- 10690280
- Publisher / Repository:
- The Astrophysical Journal
- Date Published:
- Journal Name:
- The Astrophysical Journal
- Volume:
- 993
- Issue:
- 1
- ISSN:
- 0004-637X
- Page Range / eLocation ID:
- 6
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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