Galaxy formation in the Planck cosmology – IV. Mass and environmental quenching, conformity and clustering

Henriques, Bruno M.B.; White, Simon D.M.; Thomas, Peter A.; Angulo, Raul E.; Guo, Qi; Lemson, Gerard; Wang, Wenting

Abstract

We study the quenching of star formation as a function of redshift, environment and stellar mass in the galaxy formation simulations of Henriques et al. (2015), which implement an updated version of the Munich semi-analytic model (L-GALAXIES) on the two Millennium Simulations after scaling to a Planck cosmology. In this model, massive galaxies are quenched by active galactic nucleus (AGN) feedback depending on both black hole and hot gas mass, and hence indirectly on stellar mass. In addition, satellite galaxies of any mass can be quenched by ram-pressure or tidal stripping of gas and through the suppression of gaseous infall. This combination of processes produces quenching efficiencies which depend on stellar mass, host halo mass, environment density, distance to group centre and group central galaxy properties in ways which agree qualitatively with observation. Some discrepancies remain in dense regions and close to group centres, where quenching still seems too efficient. In addition, although the mean stellar age of massive galaxies agrees with observation, the assumed AGN feedback model allows too much ongoing star formation at late times. The fact that both AGN feedback and environmental effects are stronger in higher density environments leads to a correlation between the quenching of central and satellite galaxies which roughly reproduces observed conformity trends inside haloes.

Citation

Henriques, B. M., White, S. D., Thomas, P. A., Angulo, R. E., Guo, Q., Lemson, G., & Wang, W. (2017). Galaxy formation in the Planck cosmology – IV. Mass and environmental quenching, conformity and clustering. Monthly Notices of the Royal Astronomical Society, 469(3), 2626-2645. https://doi.org/10.1093/mnras/stx1010

• Journal Article Type: Article
• Acceptance Date: Apr 25, 2017
• Online Publication Date: Apr 28, 2017
• Publication Date: Apr 28, 2017
• Deposit Date: Jul 5, 2017
• Publicly Available Date: Jul 5, 2017
• 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: 469
• Issue: 3
• Pages: 2626-2645
• DOI: https://doi.org/10.1093/mnras/stx1010
• Public URL: https://durham-repository.worktribe.com/output/1356181