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

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Zeng, Zhichao Carton, Peter, Annika H. G., Du, Xiaolong, Yang, Shengqi, Benson, Andrew, Cyr-Racine, Francis-Yan, Jiang, Fangzhou, Mace, Charlie, Metcalf, R. Benton
Format: Preprint
Published: 2023
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866912610019966976
author Zeng, Zhichao Carton
Peter, Annika H. G.
Du, Xiaolong
Yang, Shengqi
Benson, Andrew
Cyr-Racine, Francis-Yan
Jiang, Fangzhou
Mace, Charlie
Metcalf, R. Benton
author_facet Zeng, Zhichao Carton
Peter, Annika H. G.
Du, Xiaolong
Yang, Shengqi
Benson, Andrew
Cyr-Racine, Francis-Yan
Jiang, Fangzhou
Mace, Charlie
Metcalf, R. Benton
contents One of the hottest questions in the cosmology of self-interacting dark matter (SIDM) is whether scatterings can induce detectable core-collapse in halos by the present day. Because gravitational tides can accelerate core-collapse, the most promising targets to observe core-collapse are satellite galaxies and subhalo systems. However, simulating small subhalos is computationally intensive, especially when subhalos start to core-collapse. In this work, we present a hierarchical framework for simulating a population of SIDM subhalos, which reduces the computation time to linear order in the total number of subhalos. With this method, we simulate substructure lensing systems with multiple velocity-dependent SIDM models, and show how subhalo evolution depends on the SIDM model, subhalo mass and orbits. We find that an SIDM cross section of $\gtrsim 200$ cm$^2$/g at velocity scales relevant for subhalos' internal heat transfer is needed for a significant fraction of subhalos to core-collapse in a typical lens system at redshift $z=0.5$, and that core-collapse has unique observable features in lensing. We show quantitatively that core-collapse in subhalos is typically accelerated compared to field halos, except when the SIDM cross section is non-negligible ($\gtrsim \mathcal{O}(1)$ cm$^2$/g) at subhalos' orbital velocities, in which case evaporation by the host can delay core-collapse. This suggests that substructure lensing can be used to probe velocity-dependent SIDM models, especially if line-of-sight structures (field halos) can be distinguished from lens-plane subhalos. Intriguingly, we find that core-collapse in subhalos can explain the recently reported ultra-steep density profiles of substructures found by lensing with the \emph{Hubble Space Telescope}
format Preprint
id arxiv_https___arxiv_org_abs_2310_09910
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Till the core collapses: the evolution and properties of self-interacting dark matter subhalos
Zeng, Zhichao Carton
Peter, Annika H. G.
Du, Xiaolong
Yang, Shengqi
Benson, Andrew
Cyr-Racine, Francis-Yan
Jiang, Fangzhou
Mace, Charlie
Metcalf, R. Benton
Astrophysics of Galaxies
Cosmology and Nongalactic Astrophysics
High Energy Astrophysical Phenomena
High Energy Physics - Phenomenology
One of the hottest questions in the cosmology of self-interacting dark matter (SIDM) is whether scatterings can induce detectable core-collapse in halos by the present day. Because gravitational tides can accelerate core-collapse, the most promising targets to observe core-collapse are satellite galaxies and subhalo systems. However, simulating small subhalos is computationally intensive, especially when subhalos start to core-collapse. In this work, we present a hierarchical framework for simulating a population of SIDM subhalos, which reduces the computation time to linear order in the total number of subhalos. With this method, we simulate substructure lensing systems with multiple velocity-dependent SIDM models, and show how subhalo evolution depends on the SIDM model, subhalo mass and orbits. We find that an SIDM cross section of $\gtrsim 200$ cm$^2$/g at velocity scales relevant for subhalos' internal heat transfer is needed for a significant fraction of subhalos to core-collapse in a typical lens system at redshift $z=0.5$, and that core-collapse has unique observable features in lensing. We show quantitatively that core-collapse in subhalos is typically accelerated compared to field halos, except when the SIDM cross section is non-negligible ($\gtrsim \mathcal{O}(1)$ cm$^2$/g) at subhalos' orbital velocities, in which case evaporation by the host can delay core-collapse. This suggests that substructure lensing can be used to probe velocity-dependent SIDM models, especially if line-of-sight structures (field halos) can be distinguished from lens-plane subhalos. Intriguingly, we find that core-collapse in subhalos can explain the recently reported ultra-steep density profiles of substructures found by lensing with the \emph{Hubble Space Telescope}
title Till the core collapses: the evolution and properties of self-interacting dark matter subhalos
topic Astrophysics of Galaxies
Cosmology and Nongalactic Astrophysics
High Energy Astrophysical Phenomena
High Energy Physics - Phenomenology
url https://arxiv.org/abs/2310.09910