The star-forming past and quenching of brightest cluster galaxies in TNG-Cluster
Abstract
The Brightest Cluster Galaxies (BCGs) in the most massive galaxy clusters of our Universe are, at present, mostly quiescent, elliptical, and red. However, their formation histories are unclear and likely different from those of massive ellipticals in lower-mass haloes. Simulations face the challenge of simultaneously requiring large volumes to sample massive clusters and sufficient resolution to model their stellar populations. Therefore, we make use of TNG-Cluster, one of the highest-resolution cosmological simulations of galaxy clusters, which returns 352 BCGs at z=0 with stellar masses M*, <30 pkpc = 1011.6−12.9 M⊙ and total halo masses M200c = 1014.3−15.4 M⊙. 93 per cent of the BCGs are quenched at z=0, whereas at redshift z>3 all their main progenitors were still star forming. The star-formation histories of individual BCGs are complex, including multiple (re)quenching episodes. They rejuvenate on average 2.1 ± 1.8 times since z=3. BCGs quench for the first time 9.9+0.9−1.4 Gyr ago (10th-90th percentiles; z=1.7+0.5−0.5), while the last and final quenching event occurred 7.0+2.8−5.0 Gyr ago (z=0.8+0.8−0.6). We find a large scatter in the halo, stellar, and SMBH masses at both first and last quenching, suggesting no characteristic mass at which quenching occurs. Instead, BCGs quench for the first time when the cumulative kinetic energy injected by their SMBH equals the BCG binding energy, corresponding to a delay of 2.3+1.2−1.2 Gyr after the first SMBH kinetic energy injection. Namely, TNG-Cluster BCGs quench when they experience significant gas expulsion. Our work shows that BCGs have complex and varied star-formation histories, with multiple rejuvenation episodes, but they ultimately quench due to SMBH feedback.
Related
- Forged in Quenching: Morphological Transformation across Star-forming and Quiescent Galaxies in EAGLE
- Spatially Resolved Physical Properties of Young Star Clusters and Star-forming Clumps in the Brightest z > 6 Galaxy, the Strongly Lensed Cosmic Spear at z = 6.2
- Quantifying the Dominance and Emergence of Brightest Cluster Galaxies in SPT and Planck Clusters: A Novel Application of the Gini Index
- Active galactic nucleus activity in brightest cluster galaxies at intermediate redshifts in Sunyaev-Zel'dovich--selected clusters
- Radar-Chart Analysis of Star-Formation Quenching Stages Across Circular Velocity Curve Classes in Nearby CALIFA Galaxies
BibTeX
@misc{gottschewski2026starforming,
title = {{The star-forming past and quenching of brightest cluster galaxies in TNG-Cluster}},
author = {Sunna Gottschewski and Joey Braspenning and Annalisa Pillepich and Katrin Lehle and Dylan Nelson},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.06634},
eprint = {2610.06634},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.06634},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - The star-forming past and quenching of brightest cluster galaxies in TNG-Cluster
AU - Sunna Gottschewski
AU - Joey Braspenning
AU - Annalisa Pillepich
AU - Katrin Lehle
AU - Dylan Nelson
PY - 2026
DA - 2026/10/05
PB - arXiv
DO - 10.48550/arxiv.2610.06634
UR - https://arxiv.org/abs/2610.06634
AB - The Brightest Cluster Galaxies (BCGs) in the most massive galaxy clusters of our Universe are, at present, mostly quiescent, elliptical, and red. However, their formation histories are unclear and likely different from those of massive ellipticals in lower-mass haloes. Simulations face the challenge of simultaneously requiring large volumes to sample massive clusters and sufficient resolution to model their stellar populations. Therefore, we make use of TNG-Cluster, one of the highest-resolution cosmological simulations of galaxy clusters, which returns 352 BCGs at z=0 with stellar masses M_*, <30 pkpc = 10^11.6−12.9 M_⊙ and total halo masses M_200c = 10^14.3−15.4 M_⊙. 93 per cent of the BCGs are quenched at z=0, whereas at redshift z>3 all their main progenitors were still star forming. The star-formation histories of individual BCGs are complex, including multiple (re)quenching episodes. They rejuvenate on average 2.1 ± 1.8 times since z=3. BCGs quench for the first time 9.9^+0.9_−1.4 Gyr ago (10th-90th percentiles; z=1.7^+0.5_−0.5), while the last and final quenching event occurred 7.0^+2.8_−5.0 Gyr ago (z=0.8^+0.8_−0.6). We find a large scatter in the halo, stellar, and SMBH masses at both first and last quenching, suggesting no characteristic mass at which quenching occurs. Instead, BCGs quench for the first time when the cumulative kinetic energy injected by their SMBH equals the BCG binding energy, corresponding to a delay of 2.3^+1.2_−1.2 Gyr after the first SMBH kinetic energy injection. Namely, TNG-Cluster BCGs quench when they experience significant gas expulsion. Our work shows that BCGs have complex and varied star-formation histories, with multiple rejuvenation episodes, but they ultimately quench due to SMBH feedback.
ER -