Witnessing the onset of reionization through Lyman-α emission at redshift 13

• 成果类型: Article
• 署名作者: Witstok, Joris; Jakobsen, Peter; Maiolino, Roberto; Helton, Jakob M.; Johnson, Benjamin D.; Robertson, Brant E.; Tacchella, Sandro; Cameron, Alex J.; Smit, Renske; Bunker, Andrew J.; Saxena, Aayush; Sun, Fengwu; Alberts, Stacey; Arribas, Santiago; Baker, William M.; Bhatawdekar, Rachana; Boyett, Kristan; Cargile, Phillip A.; Carniani, Stefano; Charlot, Stephane; Chevallard, Jacopo; Curti, Mirko; Curtis-Lake, Emma; D'Eugenio, Francesco; Eisenstein, Daniel J.; Hainline, Kevin N.; Jones, Gareth C.; Kumari, Nimisha; Maseda, Michael V.; Perez-Gonzalez, Pablo G.; Rinaldi, Pierluigi; Scholtz, Jan; Ubler, Hannah; Williams, Christina C.; Willmer, Christopher N. A.; Willott, Chris; Zhu, Yongda
• 署名单位: University of Cambridge; University of Cambridge; University of Copenhagen; Niels Bohr Institute; University of London; University College London; University of Arizona; Smithsonian Institution; University of California System; University of California Santa Cruz; University of Oxford; Liverpool John Moores University; Consejo Superior de Investigaciones Cientificas (CSIC); CSIC - Centro de Astrobiologia (INTA); European Space Agency; European Space Astronomy Center; Scuola Normale Superiore di Pisa; Centre National de la Recherche Scientifique (CNRS); CNRS - National Institute for Earth Sciences & Astronomy (INSU); Sorbonne Universite; European Southern Observatory; University of Hertfordshire; Istituto Nazionale Astrofisica (INAF); Space Telescope Science Institute; University of Wisconsin System; University of Wisconsin Madison; Max Planck Society; National Research Council Canada
• 刊物名称: Nature
• ISSN/ISSBN: 0028-1801
• DOI: 10.1038/s41586-025-08779-5
• 发表日期: 2025-03-27
• 关键词: damped ly-alpha; active galactic nucleus; webb-space-telescope; population iii stars; emitting galaxies; black-holes; radiation; quasar; distributions; spectroscopy

摘要

Cosmic reionization began when ultraviolet (UV) radiation produced in the first galaxies began illuminating the cold, neutral gas that filled the primordial Universe(1,2). Recent James Webb Space Telescope (JWST) observations have shown that surprisingly UV-bright galaxies were in place beyond redshift z = 14, when the Universe was less than 300 Myr old(3,4,5). Smooth turnovers of their UV continua have been interpreted as damping-wing absorption of Lyman-alpha (Ly-alpha), the principal hydrogen transition(6,7,8,9). However, spectral signatures encoding crucial properties of these sources, such as their emergent radiation field, largely remain elusive. Here we report spectroscopy from the JWST Advanced Deep Extragalactic Survey (JADES(10)) of a galaxy at redshift z = 13.0 that reveals a singular, bright emission line unambiguously identified as Ly-alpha, as well as a smooth turnover. We observe an equivalent width of EWLy-alpha > 40 & Aring; (rest frame), previously only seen at z < 9 where the intervening intergalactic medium becomes increasingly ionized(11). Together with an extremely blue UV continuum, the unexpected Ly-alpha emission indicates that the galaxy is a prolific producer and leaker of ionizing photons. This suggests that massive, hot stars or an active galactic nucleus have created an early reionized region to prevent complete extinction of Ly-alpha, thus shedding new light on the nature of the earliest galaxies and the onset of reionization only 330 Myr after the Big Bang.