The spatial distribution of satellites in galaxy clusters

Gu, Qing; Guo, Qi; Zhang, Tianchi; Cautun, Marius; Lacey, Cedric; Frenk, Carlos S; Shao, Shi

Abstract

The planar distributions of satellite galaxies around the Milky Way and Andromeda have been extensively studied as potential challenges to the standard cosmological model. Using the Sloan Digital Sky Survey and the Millennium simulation, we extend such studies to the satellite galaxies of massive galaxy clusters. We find that both observations and simulations of galaxy clusters show an excess of anisotropic satellite distributions. On average, satellites in clusters have a higher degree of anisotropy than their counterparts in Milky-Way-mass hosts once we account for the difference in their radial distributions. The normal vector of the plane of satellites is strongly aligned with the host halo’s minor axis, while the alignment with the large-scale structure is weak. At fixed cluster mass, the degree of anisotropy is higher at higher redshift. This reflects the highly anisotropic nature of satellites accretion points, a feature that is partly erased by the subsequent orbital evolution of the satellites. We also find that satellite galaxies are mostly accreted singly so group accretion is not the explanation for the high flattening of the planes of satellites.

Citation

Gu, Q., Guo, Q., Zhang, T., Cautun, M., Lacey, C., Frenk, C. S., & Shao, S. (2022). The spatial distribution of satellites in galaxy clusters. Monthly Notices of the Royal Astronomical Society, 514(1), 390-402. https://doi.org/10.1093/mnras/stac1292

• Journal Article Type: Article
• Acceptance Date: May 1, 2022
• Online Publication Date: May 10, 2022
• Publication Date: 2022-07
• Deposit Date: Jul 11, 2022
• Publicly Available Date: Jul 11, 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: 514
• Issue: 1
• Pages: 390-402
• DOI: https://doi.org/10.1093/mnras/stac1292
• Public URL: https://durham-repository.worktribe.com/output/1198376