The effects of self-interacting dark matter on the stripping of galaxies that fall into clusters

Sirks, Ellen L.; Oman, Kyle A.; Robertson, Andrew; Massey, Richard; Frenk, Carlos

Abstract

We use the Cluster-EAGLE (C-EAGLE) hydrodynamical simulations to investigate the effects of self-interacting dark matter (SIDM) on galaxies as they fall into clusters. We find that SIDM galaxies follow similar orbits to their cold dark matter (CDM) counterparts, but end up with ∼25 per cent less mass by the present day. One in three SIDM galaxies is entirely disrupted, compared to one in five CDM galaxies. However, the excess stripping will be harder to observe than suggested by previous DM-only simulations because the most stripped galaxies form cores and also lose stars: The most discriminating objects become unobservable. The best test will be to measure the stellar-to-halo mass relation (SHMR) for galaxies with stellar mass 1010−1011M⊙⁠. This is 8 times higher in a cluster than in the field for a CDM universe, but 13 times higher for an SIDM universe. Given intrinsic scatter in the SHMR, these models could be distinguished with noise-free galaxy–galaxy strong lensing of ∼32 cluster galaxies.

Citation

Sirks, E. L., Oman, K. A., Robertson, A., Massey, R., & Frenk, C. (2022). The effects of self-interacting dark matter on the stripping of galaxies that fall into clusters. Monthly Notices of the Royal Astronomical Society, 511(4), 5927-5935. https://doi.org/10.1093/mnras/stac406

• Journal Article Type: Article
• Acceptance Date: Feb 7, 2022
• Online Publication Date: Feb 17, 2022
• Publication Date: 2022-04
• Deposit Date: Sep 29, 2021
• Publicly Available Date: May 26, 2022
• Journal: Monthly Notices of the Royal Astronomical Society
• Print ISSN: 0035-8711
• Electronic ISSN: 1365-2966
• Publisher: Royal Astronomical Society
• Peer Reviewed: Peer Reviewed
• Volume: 511
• Issue: 4
• Pages: 5927-5935
• DOI: https://doi.org/10.1093/mnras/stac406
• Related Public URLs: https://ui.adsabs.harvard.edu/abs/2021arXiv210903257S