Artale, M. Celeste

Understanding the impact of environmental factors on galaxy formation and evolution remains a central challenge in astrophysics. The role of environmental quenching in shaping the evolution of galaxy clusters and their progenitors, known as proto-clusters, remains an open question. In this study, we investigate the evolution of galaxies within dense proto-cluster environments, focusing on Lyman-alpha emitters (LAEs) as key tracers. By employing the TNG300 simulation, we examine the 30 most massive clusters at z=0 and trace them back in time. Our analysis reveals environmental quenching in low-mass proto-cluster galaxies as early as z=2. In particular, we find that LAEs in high-density regions integrate into the main halo earlier than the LAEs in the lower-density environment leading to rapid decline in both SFR and gas mass and thus are responsible for subsequent quenching. 

Consequently, the present-day stellar mass of proto-cluster LAEs is lower on average than their counterparts in the field.

Our results suggest that environmental conditions during the high-redshift epoch play a pivotal role in the evolution of galaxies, predominantly driven by interactions and mergers.

These results provide clear expectations for the physical properties of proto-cluster galaxies and the evolution of proto-clusters across cosmic time. Our predictions will be tested by the ODIN survey, which will identify hundreds of proto-clusters at z=2.4, 3.1, and 4.5 as significant LAE overdensities.

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