Till the core collapses: the evolution and properties of self-interacting dark matter subhalos

• DOI: 10.48550/arxiv.2310.09910
• Publication Date: 2023-01-01
• Authors: Zhichao Carton Zeng; Annika H. G. Peter; Xiaolong Du; Shengqi Yang; Andrew Benson; Francis-Yan Cyr-R...; Fangzhou Jiang; Charlie Mace; R. B. Metcalf
• Keywords: Substructure

One of the hottest questions in cosmology self-interacting dark matter (SIDM) is whether scatterings can induce detectable core-collapse halos by present day. Because gravitational tides accelerate core-collapse, most promising targets to observe are satellite galaxies and subhalo systems. However, simulating small subhalos computationally intensive, especially when start core-collapse. In this work, we a hierarchical framework for population SIDM subhalos, which reduces computation time linear order total number subhalos. With method, simulate substructure lensing systems with multiple velocity-dependent models, show how evolution depends on model, mass orbits. We find that an cross section $\gtrsim 200$ cm$^2$/g at velocity scales relevant subhalos' internal heat transfer needed significant fraction typical lens system redshift $z=0.5$, has unique observable features lensing. quantitatively typically accelerated compared field halos, except non-negligible ($\gtrsim \mathcal{O}(1)$ cm$^2$/g) orbital velocities, case evaporation host delay This suggests be used probe if line-of-sight structures (field halos) distinguished from lens-plane Intriguingly, explain recently reported ultra-steep density profiles substructures found \emph{Hubble Space Telescope}