Feedback-driven anisotropy in the circumgalactic medium for quenching galaxies in the SIMBA simulations

Yang, Tianyi; Davé, Romeel; Cui, Weiguang; Cai, Yan-Chuan; Peacock, John A; Sorini, Daniele

Abstract

We use the SIMBA galaxy formation simulation suite to explore anisotropies in the properties of circumgalactic gas that result
from accretion and feedback processes. We particularly focus on the impact of bipolar active galactic nuclei (AGNs) jet feedback
as implemented in SIMBA , which quenches galaxies and has a dramatic effect on large-scale gas properties. We show that jet
feedback at low redshifts is most common in the stellar mass range (1–5) × 1010 M, so we focus on galaxies with active jets in
this mass range. In comparison to runs without jet feedback, jets cause lower densities and higher temperatures along the galaxy
minor axis (SIMBA jet direction) at radii 0.5r200c − 4r200c and beyond. This effect is less apparent at higher or lower stellar
masses, and is strongest within green valley galaxies. The metallicity also shows strong anisotropy out to large scales, driven
by star formation feedback. We find substantially stronger anisotropy at 0.5r200c, but this also exists in runs with no explicit
feedback, suggesting that it is due to anisotropic accretion. Finally, we explore anisotropy in the bulk radial motion of the gas,
finding that both star formation and AGN wind feedback contribute to pushing the gas outwards along the minor axis at 1
Mpc, but AGN jet feedback further causes bulk outflow along the minor axis out to several Mpc, which drives quenching via
gas starvation. These results provide observational signatures for the operation of AGN feedback in galaxy quenching.

Citation

Yang, T., Davé, R., Cui, W., Cai, Y., Peacock, J. A., & Sorini, D. (2024). Feedback-driven anisotropy in the circumgalactic medium for quenching galaxies in the SIMBA simulations. Monthly Notices of the Royal Astronomical Society, 527(2), 1612–1632. https://doi.org/10.1093/mnras/stad3223

• Journal Article Type: Article
• Acceptance Date: Oct 17, 2023
• Online Publication Date: Oct 21, 2023
• Publication Date: 2024-01
• Deposit Date: Jan 31, 2024
• Publicly Available Date: Jan 31, 2024
• Journal: Monthly Notices of the Royal Astronomical Society
• Print ISSN: 0035-8711
• Publisher: Royal Astronomical Society
• Peer Reviewed: Peer Reviewed
• Volume: 527
• Issue: 2
• Pages: 1612–1632
• DOI: https://doi.org/10.1093/mnras/stad3223
• Public URL: https://durham-repository.worktribe.com/output/2188296
• Publisher URL: https://doi.org/10.1093/mnras/stad3223