Park, MinjungBelli, SirioConroy, CharlieJohnson, Benjamin D.Davies, Rebecca L.Leja, JoelTacchella, SandroMendel, J. TrevorBenton, ChloëBugiani, LetiziaEmami, RaziehKhoram, Amir H.Li, YijiaMaheson, GabrielMathews, Elijah P.Naidu, Rohan P.Nelson, Erica J.Terrazas, Bryan A.Weinberger, Rainer2025-05-232025-05-230004-637Xhttp://www.scopus.com/inward/record.url?scp=85209752689&partnerID=8YFLogxKhttps://hdl.handle.net/1885/733752895Massive quiescent galaxies in the young Universe are expected to be quenched rapidly, but it is unclear whether they all experience starbursts before quenching and what physical mechanism drives rapid quenching. We study 14 massive quiescent galaxies ( log ( M ⋆ / M ⊙ ) > 10 ) at z ∼ 2 selected from a representative sample of the Blue Jay survey. We reconstruct their star formation histories (SFHs) by fitting spectral energy distribution models to the JWST/NIRSpec R ∼ 1000 spectra. We find that massive quiescent galaxies can be split into three categories with roughly equal numbers of galaxies according to their SFHs: (1) relatively old galaxies quenched at early epochs; (2) galaxies that are rapidly and recently quenched after a flat or bursty formation history (depending on the assumed prior); and (3) galaxies that are rapidly and recently quenched after a major starburst. Most recently quenched galaxies show neutral gas outflows, probed by blueshifted Na i D absorption, and ionized gas emission, with line ratios consistent with active galactic nucleus (AGN) diagnostics. This suggests that AGN activity drives multiphase gas outflows, leading to rapid quenching. By tracing back the SFHs of the entire sample, we predict the number density of massive quiescent galaxies at z = 4-6: n = (1.5-6.0) × 10−5 Mpc−3. The two old massive quiescent galaxies in our sample appear to have extremely early formation and quenching (z ≳ 6) and are possibly descendants of early post-starbursts at z > 3. These galaxies still show neutral gas reservoirs and weak Hα emission, perhaps because the ejective AGN feedback that caused rapid quenching has weakened over time.The Blue Jay Survey is funded in part by STScI Grant JWST-GO-01810. S.B. and L.B. are supported by the ERC Starting Grant \u201CRed Cardinal,\u201D GA 101076080. B.D.J. acknowledges support by JWST-GO-01810. R.L.D. is supported by the Australian Research Council through the Discovery Early Career Researcher Award (DECRA) Fellowship DE240100136 funded by the Australian Government. J.L. and Y.L. are supported under Program number JWST-GO-01810.004-A, provided through a grant from STScI under NASA contract NAS503127. R.E. acknowledges the support from grant Nos. 21-atp21-0077, NSF AST-1816420, and HST-GO-16173.001-A, as well as from the Institute for Theory and Computation at the Center for Astrophysics. R.W. acknowledges the funding of a Leibniz Junior Research Group (project number J131/2022). This work is based on observations made with the NASA/ESA/CSA James Webb Space Telescope. The JWST data presented in this article were obtained from the Mikulski Archive for Space Telescopes at the Space Telescope Science Institute (and can be accessed via doi: 10.17909/t11e-xh37 ), which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-03127 for JWST. These observations are associated with program GO 1810. This work also makes use of observations taken by the 3D-HST Treasury Program (GO 12177 and 12328) with the NASA/ESA HST, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555. The photometric catalog of all galaxies from the Blue Jay survey is publicly available at doi: 10.5281/zenodo.13292819 . The JWST spectra and the best-fit SED models for the quiescent sample studied in this work are presented at doi: 10.5281/zenodo.13365382 .enPublisher Copyright: © 2024. The Author(s). Published by the American Astronomical Society.2024-11-0110.3847/1538-4357/ad7e1585209752689