Kalita, Boris S.Boris S.KalitaDaddi, EmanueleEmanueleDaddiD'Eugenio, ChiaraChiaraD'EugenioValentino, FrancescoFrancescoValentinoRich, R. MichaelR. MichaelRichGómez-Guijarro, CarlosCarlosGómez-GuijarroCoogan, Rosemary T.Rosemary T.CooganDELVECCHIO, IVANIVANDELVECCHIOElbaz, DavidDavidElbazNeill, James D.James D.NeillPuglisi, AnnagraziaAnnagraziaPuglisiSTRAZZULLO, VERONICAVERONICASTRAZZULLO2022-03-222022-03-2220212041-8205http://hdl.handle.net/20.500.12386/31782Deep Atacama Large Millimeter/submillimeter Array and Hubble Space Telescope observations reveal the presence of a quenched massive galaxy within the z = 2.91 galaxy group RO-1001. With a mass-weighted stellar age of 1.6 ± 0.4 Gyr this galaxy is one of the oldest known at z ~ 3, implying that most of its 10<SUP>11</SUP> M<SUB>⊙</SUB> of stars were rapidly formed at z > 6-8. This is a unique example of the predominantly passive evolution of a galaxy over at least 3 < z < 6 following its high-redshift quenching and a smoking-gun event pointing to the early imprint of an age-environment relation. At the same time, being in a dense group environment with extensive cold gas reservoirs as betrayed by a giant Lyα halo, the existence of this galaxy demonstrates that gas accretion shutdown is not necessary for quenching and its maintenance....STAMPAenArticle10.3847/2041-8213/ac16dc2-s2.0-85113398147https://iopscience.iop.org/article/10.3847/2041-8213/ac16dcFIS/05 - ASTRONOMIA E ASTROFISICA