Oral Presentation
Is Environment Playing a Role in Quenching Low-mass Galaxies in a Proto-cluster at z~2.6?
Presenter: Richard Pan (Tufts University)
Can proto-cluster environments efficiently quench low-mass galaxies (log(mstar)<9.5?Understanding the role of environment in quenching low-mass galaxies is essential to tracing galaxy evolution over cosmic time. While environmental quenching is well established at low redshift (z<0.3), its impact at z>2 remains unclear, as simulations suggest proto-clusters have not yet developed a dense intra-cluster medium (ICM) needed for efficient environmental quenching even at the low-mass end. Observationally, probing this regime has been challenging due to the depth of pre-JWST surveys, which typically missed low-mass quiescent galaxies at these redshifts.
We leverage the deep JWST/NIRCam imaging from the UNCOVER and MegaScience programs—featuring 20-band R~15 spectrophotometry—to identify a proto-cluster at z∼2.58 behind Abell 2744. The dataset enables accurate photometric redshifts and a mass-complete selection down to
log(mstar)∼8.5. Using Prospector, we compare the star formation histories (SFHs), quenched fractions, and structural properties of these low-mass quiescent galaxies in the proto-cluster to a matched sample in the field. I will present the results of this analysis, quantifying the role of environment in quenching low-mass galaxies when the Universe was ~2.5 Gyr old and providing critical insights into early galaxy evolution in proto-cluster environments.
asiaa.sinica.edu.tw