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arXiv · 2510.11006

Three Birds with One Stone: Core-Collapsed SIDM Halos as the Common Origin of Dense Perturbers in Lenses, Streams, and Satellites

Hai-Bo Yu
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Abstract

We show that core-collapsed self-interacting dark matter halos of mass $\sim 10^6\,{M_\odot}$, originally simulated to explain the dense perturber of the GD-1 stellar stream, also reproduce the structural properties inferred for the dense perturber detected in the strong lensing system JVAS B1938+666 from radio observations. Furthermore, these halos are sufficiently compact and dense to gravitationally capture field stars in satellite galaxies of the Milky Way, providing a natural explanation for the origin of Fornax 6, a stellar cluster in the Fornax dwarf spheroidal galaxy. Our results demonstrate that observations of halos with similar masses but residing in different cosmic environments offer a powerful and complementary probe of self-interacting dark matter.

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Hai-Bo Yu. 2025-10-13. Three Birds with One Stone: Core-Collapsed SIDM Halos as the Common Origin of Dense Perturbers in Lenses, Streams, and Satellites. https://doi.org/10.1103/txxx-97ln

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