Oral Presentation
Exploring the coevolution of two dynamically distinct protoclusters and their galaxy populations at the cosmic noon
Presenter: Jose Manuel Perez-martinez (Tohoku University)
The cosmic noon marks not only a key transitional epoch for star-formation and AGN activity within galaxies, it is also the period when protoclusters experience major albeit rapid changes in their internal structure, setting the (pre-)conditions for environmental effects over their galaxy populations. We use Keck/MOSFIRE and VLT/KMOS to investigate the role of protocluster assembly over the star formation and metal enrichment of more than 60 galaxies in two dynamically distinct protoclusters at z=2-3: USS1553 and PKS1138. Objects within the less dynamically evolved protocluster, USS1558, exhibit enhanced SFRs and gas-phase metallicity deficit with respect to the field, pointing to newborn galaxies experiencing a rapid phase of mass assembly mediated by prominent gas accretion. On the other hand, the star-forming population of the massive and en route to virialization PKS1138 protocluster is indistinguishable from the field in terms of SFR and shows early signs of metal enrichment, suggesting that the protocluster assembly stage significantly impacts the evolution of its galaxy populations. We put in context these results by exploring the gas fractions of a subsample of objects with molecular gas masses from ALMA and ATCA in both protoclusters and discuss the relative importance of in-/outflow processes on regulating star-formation and metal enrichment during protocluster assembly, thus yielding the ISM differential evolution we observe.
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