Webb, KristiBalogh, MichaelLeja, Joelvan der Burg, Remco F. J.Rudnick, GregoryMuzzin, AdamBoak, KevinCerulo, PierluigiGilbank, DavidLidman, ChrisOld, Lyndsay2023-03-232023-03-230035-8711http://hdl.handle.net/1885/287310We study the star formation histories (SFHs) and mass-weighted ages of 331 UVJ-selected quiescent galaxies in 11 galaxy clusters and in the field at 1 < z < 1.5 from the Gemini Observations of Galaxies in Rich Early ENvironments (GOGREEN) survey. We determine the SFHs of individual galaxies by simultaneously fitting rest-frame optical spectroscopy and broadband photometry to stellar population models. We confirm that the SFHs are consistent with more massive galaxies having on average earlier formation times. Comparing galaxies found in massive clusters with those in the field, we find galaxies with M∗ < 1011.3 M in the field have more extended SFHs. From the SFHs we calculate the mass-weighted ages, and compare age distributions of galaxies between the two environments, at fixed mass. We constrain the difference in mass-weighted ages between field and cluster galaxies to 0.31+0.51−0.33 Gyr, in the sense that cluster galaxies are older. We place this result in the context of two simple quenching models and show that neither environmental quenching based on time since infall (without pre-processing) nor a difference in formation times alone can reproduce both the average age difference and relative quenched fractions. This is distinctly different from local clusters, for which the majority of the quenched population is consistent with having been environmentally quenched upon infall. Our results suggest that quenched population in galaxy clusters at z > 1 has been driven by different physical processes than those at play at z = 0.This research is supported by the following grants: National Sciences and Engineering Research Council of Canada (NSERC) CGSD award (KW), Discovery grants (MLB and AM), and USRA award (KB); European Space Agency (ESA) Research Fellowship (LJO); National Science Foundation (NSF) grants AST-1517863 (GW), AST-1517815 (GR); NASA, through grants GO-15294 (GW), GO15294.012-A (GR), and the Astrophysics Data Analysis Program (ADAP) 80NSSC17K0019 (GW) and 80NSSC19K0592 (GR). JN acknowledges support from the UNAB Internal Project number DI12-19/R. BV acknowledges financial contribution from the grant PRIN MIUR 2017 n.20173ML3WW 001 (PI: Cimatti) and from the INAF main-stream funding programme (PI: Vulcani). RD gratefully acknowledges support from the Chilean Centro de Excelencia en Astrof´ısica y Tecnolog´ıas Afines (CATA) BASAL grant AFB170002. PC acknowledges the support from the ALMA-CONICYT grant no 31180051.application/pdfen-AU© 2020 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reservedgalaxies: clusters: generalgalaxies: evolution202010.1093/mnras/staa27522022-01-16