Intracluster light in the infall region of simulated protoclusters of galaxies
Abstract
Intracluster light (ICL) is a diffuse stellar component in galaxy clusters, made of stars following the potential of the cluster. Despite its potential to unveil the accretion history of clusters, the ICL in protoclusters remains poorly understood in simulations and observations. We analyse protoclusters in TNG-Cluster and Manhattan Suite simulations to investigate when ICL forms, its host progenitors, and environments where it forms. We find a considerable amount of ICL in the infall region of protoclusters at 2<z<4, ranging from 0.1×1011<M*/M⊙<3×1011. ICL star formation in protoclusters peaks at 3<z<4, with stars formed in the main halo forming earlier than those born in the infall regions. We find that 74.2−1.7+1.7% of ICL stars in TNG-Cluster and 69.2−3.7+3.6% in Manhattan Suite were stripped from galaxies within the main halo. However, most ICL stars in protoclusters at z=2 formed in the infall region, accounting for 57.6−1.6+1.7% and 55.6−2.3+2.3% in TNG-Cluster and Manhattan Suite, respectively. By the time the ICL stars are stripped, their host galaxies are 3-4 times more massive than the galaxies in which the stars originally formed, implying growth of the progenitor galaxies and/or accretion of the stars onto more massive galaxies prior to stripping. The ICL stellar masses measured in simulations agree with observations at z≤2. Our findings highlight the importance of investigating the diffuse light in the outer regions of protoclusters to constrain the formation and assembly of the ICL and galaxy clusters.
Related
- The youth of the intracluster medium. I. A non-parametric characterisation of the gas and electron number density profiles of z ≃ 2 protoclusters
- Monitoring the power spectrum of magnetic field fluctuations across the simulated intracluster medium
- A Consistent Comparison of Intracluster Light Assembly in Simulations I. Redshift Evolution and Progenitor Galaxies
- The progenitor galaxies of the intracluster light
- Probing Multi-formation Channels of Dark Matter-Deficient Galaxies in a Simulated Universe
BibTeX
@misc{werner2026intracluster,
title = {{Intracluster light in the infall region of simulated protoclusters of galaxies}},
author = {S.V Werner and M Jauzac and M Montes and D Rennehan and G Mahler and A Niemiec and Y Jiménez-Teja},
howpublished = {HAL},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.20560},
eprint = {2609.20560},
archivePrefix = {arXiv},
url = {https://hal.science/hal-05763093v1},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Intracluster light in the infall region of simulated protoclusters of galaxies
AU - S.V Werner
AU - M Jauzac
AU - M Montes
AU - D Rennehan
AU - G Mahler
AU - A Niemiec
AU - Y Jiménez-Teja
PY - 2026
DA - 2026/09/17
PB - HAL
DO - 10.48550/arxiv.2609.20560
UR - https://hal.science/hal-05763093v1
AB - Intracluster light (ICL) is a diffuse stellar component in galaxy clusters, made of stars following the potential of the cluster. Despite its potential to unveil the accretion history of clusters, the ICL in protoclusters remains poorly understood in simulations and observations. We analyse protoclusters in TNG-Cluster and Manhattan Suite simulations to investigate when ICL forms, its host progenitors, and environments where it forms. We find a considerable amount of ICL in the infall region of protoclusters at 2<z<4, ranging from 0.1×10^11<M_*/M_⊙<3×10^11. ICL star formation in protoclusters peaks at 3<z<4, with stars formed in the main halo forming earlier than those born in the infall regions. We find that 74.2_−1.7^+1.7% of ICL stars in TNG-Cluster and 69.2_−3.7^+3.6% in Manhattan Suite were stripped from galaxies within the main halo. However, most ICL stars in protoclusters at z=2 formed in the infall region, accounting for 57.6_−1.6^+1.7% and 55.6_−2.3^+2.3% in TNG-Cluster and Manhattan Suite, respectively. By the time the ICL stars are stripped, their host galaxies are 3-4 times more massive than the galaxies in which the stars originally formed, implying growth of the progenitor galaxies and/or accretion of the stars onto more massive galaxies prior to stripping. The ICL stellar masses measured in simulations agree with observations at z≤2. Our findings highlight the importance of investigating the diffuse light in the outer regions of protoclusters to constrain the formation and assembly of the ICL and galaxy clusters.
ER -