TY - JOUR
T1 - The origin of galaxy colour bimodality in the scatter of the stellar-to-halo mass relation
AU - Cui, Weiguang
AU - Davé, Romeel
AU - Peacock, John A.
AU - Anglés-Alcázar, Daniel
AU - Yang, Xiaohu
N1 - Funding Information:
We acknowledge helpful discussions with M. van Daalen, J. Matthee, K. Kraljic, D. Sorini, N. Thomas and Y. Zu. We thank R. Thompson for developing Caesar, and the yt team for development and support of yt. W.C. acknowledges the support from the China Manned Space Program through its Space Application System. W.C. and J.A.P. acknowledge support from the European Research Council under grant No. 670193 (the COSFORM project). R.D. acknowledges support from the Wolfson Research Merit Award programme of the UK Royal Society. W.C. and R.D. acknowledge support from the STFC AGP Grant ST/V000594/1. D.A.-A. acknowledges support by NSF grant AST-2009687 and by the Flatiron Institute, which is supported by the Simons Foundation. X.Y. acknowledges support from the National Science Foundation of China (grant Nos. 11833005, 11890692 and 11621303). This work used the DiRAC@ Durham facility managed by the Institute for Computational Cosmology on behalf of the STFC DiRAC HPC Facility. The equipment was funded by BEIS capital funding via STFC capital grants ST/P002293/1, ST/R002371/1 and ST/S002502/1, Durham University and STFC operations grant ST/R000832/1. DiRAC is part of the National e-Infrastructure.
Publisher Copyright:
© 2021, The Author(s), under exclusive licence to Springer Nature Limited.
PY - 2021/10
Y1 - 2021/10
N2 - Recent observations reveal that, at a given stellar mass, blue galaxies tend to live in haloes with lower mass, while red galaxies live in more massive host haloes. The physical driver behind this is still unclear because theoretical models predict that, at the same halo mass, galaxies with high stellar masses tend to live in early-formed haloes, which naively leads to the opposite trend. Here, we show that the Simba simulation quantitatively reproduces the colour bimodality in the stellar-to-halo mass relation and reveals an inverse relationship between halo formation time and galaxy transition time. It suggests that the origin of this bimodality is rooted in the intrinsic variations of the cold gas content due to halo assembly bias. Simba’s stellar-to-halo mass bimodality quantitatively relies on two aspects of its input physics: (1) jet-mode feedback from active galactic nuclei, which quenches galaxies and sets the qualitative trend, and (2) X-ray feedback from active galactic nuclei, which fully quenches galaxies and yields better agreement with observations. The interplay between the growth of cold gas and the quenching from active galactic nuclei in Simba results in the observed stellar-to-halo mass bimodality.
AB - Recent observations reveal that, at a given stellar mass, blue galaxies tend to live in haloes with lower mass, while red galaxies live in more massive host haloes. The physical driver behind this is still unclear because theoretical models predict that, at the same halo mass, galaxies with high stellar masses tend to live in early-formed haloes, which naively leads to the opposite trend. Here, we show that the Simba simulation quantitatively reproduces the colour bimodality in the stellar-to-halo mass relation and reveals an inverse relationship between halo formation time and galaxy transition time. It suggests that the origin of this bimodality is rooted in the intrinsic variations of the cold gas content due to halo assembly bias. Simba’s stellar-to-halo mass bimodality quantitatively relies on two aspects of its input physics: (1) jet-mode feedback from active galactic nuclei, which quenches galaxies and sets the qualitative trend, and (2) X-ray feedback from active galactic nuclei, which fully quenches galaxies and yields better agreement with observations. The interplay between the growth of cold gas and the quenching from active galactic nuclei in Simba results in the observed stellar-to-halo mass bimodality.
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U2 - 10.1038/s41550-021-01404-1
DO - 10.1038/s41550-021-01404-1
M3 - Article
AN - SCOPUS:85109601741
SN - 2397-3366
VL - 5
SP - 1069
EP - 1076
JO - Nature Astronomy
JF - Nature Astronomy
IS - 10
ER -