The Role of Environment in Shaping the Assembly Timelines of Massive Quiescent Galaxies at Cosmic Noon

Abstract

JWST observations of massive quiescent galaxies (MQGs) at $z\sim2$ have revealed diverse star formation histories (SFHs). In this letter, we investigate whether these variations are linked to the environment in which MQGs reside, as quantified by the host dark matter halo mass. We identify 12 MQGs from a representative sample of galaxies at $1.6<z<3.5$ obtained by the Blue Jay survey, a JWST Cycle 1 program, and infer their SFHs via modelling of the deep NIRSpec medium-resolution spectra along with multi-band photometry. By correlating the formation and quenching epochs of individual MQGs with their respective host halo masses from the 3D-HST survey, we find that after accounting for the redshift range of the sample ($1.8<z<2.5$), MQGs in more massive haloes formed at significantly earlier cosmic epochs. Meanwhile, although these galaxies also quenched earlier overall, the scatter in quenching epochs across similar halo masses indicates that the quenching process likely involves other contributing factors and is not solely determined by halo mass.