Nanayakkara Themiya, Glazebrook Karl, Jacobs Colin, Kawinwanichakij Lalitwadee, Schreiber Corentin, Brammer Gabriel, Esdaile James, Kacprzak Glenn G, Labbe Ivo, Lagos Claudia, Marchesini Danilo, Marsan Z Cemile, Oesch Pascal A, Papovich Casey, Remus Rhea-Silvia, Tran Kim-Vy H
Centre for Astrophysics and Supercomputing, Swinburne University of Technology, P.O. Box 218, Hawthorn, VIC, 3122, Australia.
IBEX Innovations, Sedgefield, Stockton-on-Tees, TS21 3FF, UK.
Sci Rep. 2024 Feb 14;14(1):3724. doi: 10.1038/s41598-024-52585-4.
Here we present a sample of 12 massive quiescent galaxy candidates at [Formula: see text] observed with the James Webb Space Telescope (JWST) Near Infrared Spectrograph (NIRSpec). These galaxies were pre-selected from the Hubble Space Telescope imaging and 10 of our sources were unable to be spectroscopically confirmed by ground based spectroscopy. By combining spectroscopic data from NIRSpec with multi-wavelength imaging data from the JWST Near Infrared Camera (NIRCam), we analyse their stellar populations and their formation histories. We find that all of our galaxies classify as quiescent based on the reconstruction of their star formation histories but show a variety of quenching timescales and ages. All our galaxies are massive ([Formula: see text] M[Formula: see text]), with masses comparable to massive galaxies in the local Universe. We find that the oldest galaxy in our sample formed [Formula: see text] M[Formula: see text] of mass within the first few hundred million years of the Universe and has been quenched for more than a billion years by the time of observation at [Formula: see text] ([Formula: see text] billion years after the Big Bang). Our results point to very early formation of massive galaxies requiring a high conversion rate of baryons to stars in the early Universe.
在这里，我们展示了12个大质量静止星系候选样本，这些样本是利用詹姆斯·韦布空间望远镜（JWST）近红外光谱仪（NIRSpec）在[公式：见正文]观测到的。这些星系是从哈勃空间望远镜成像中预先挑选出来的，其中10个源无法通过地面光谱进行光谱确认。通过将NIRSpec的光谱数据与JWST近红外相机（NIRCam）的多波长成像数据相结合，我们分析了它们的恒星族群及其形成历史。我们发现，根据它们恒星形成历史的重建，所有星系都被归类为静止星系，但显示出各种淬灭时间尺度和年龄。我们所有的星系都是大质量的（[公式：见正文]M[公式：见正文]），其质量与本地宇宙中的大质量星系相当。我们发现，样本中最古老的星系在宇宙最初的几亿年内形成了[公式：见正文]M[公式：见正文]的质量，到在[公式：见正文]（大爆炸后[公式：见正文]亿年）观测时，已经淬灭了超过10亿年。我们的结果表明，大质量星系的形成非常早，这需要在早期宇宙中重子到恒星的转化率很高。
