{"about":{"site":"https://codewithpapers.app","non_affiliation":"Code with Papers and Syntology are not affiliated with, endorsed by, or sponsored by Papers with Code, Meta, or the pwc-archive mirror.","licence":"CC BY-SA 4.0","licence_url":"https://creativecommons.org/licenses/by-sa/4.0/legalcode","attribution":"https://codewithpapers.app/attribution","modified":"archive material modified by Syntology; see the attribution page"},"url":"/paper/jades-primeval-lyman-mathrma-emitting","title":"JADES: Primaeval Lyman-$\\mathrmα$ emitting galaxies reveal early sites of reionisation out to redshift $z \\sim 9$","arxiv_id":"2404.05724","date":"2024-04-08","proceeding":null,"authors":["Joris Witstok","Roberto Maiolino","Renske Smit","Gareth C. Jones","Andrew J. Bunker","Jakob M. Helton","Benjamin D. Johnson","Sandro Tacchella","Aayush Saxena","Santiago Arribas","Rachana Bhatawdekar","Kristan Boyett","Alex J. Cameron","Phillip A. Cargile","Stefano Carniani","Stéphane Charlot","Jacopo Chevallard","Mirko Curti","Emma Curtis-Lake","Francesco D'Eugenio","Daniel J. Eisenstein","Kevin Hainline","Ryan Hausen","Nimisha Kumari","Isaac Laseter","Michael V. Maseda","Marcia Rieke","Brant Robertson","Jan Scholtz","Irene Shivaei","Christina C. Williams","Christopher N. A. Willmer","Chris Willott"],"abstract":"$\\require{mediawiki-texvc}$Given the sensitivity of the resonant Lyman-$\\mathrm{\\alpha}$ (Ly$\\mathrm{\\alpha}$) transition to absorption by neutral hydrogen, observations of Ly$\\mathrm{\\alpha}$ emitting galaxies (LAEs) have been widely used to probe the ionising capabilities of reionisation-era galaxies and their impact on the intergalactic medium (IGM). However, prior to JWST our understanding of the contribution of fainter sources and of ionised `bubbles' at earlier stages of reionisation remained uncertain. Here, we present the characterisation of three exceptionally distant LAEs at $z>8$, newly discovered by JWST/NIRSpec in the JADES survey. These three similarly bright ($M_\\text{UV} \\approx -20\\,\\mathrm{mag}$) LAEs exhibit small Ly$\\mathrm{\\alpha}$ velocity offsets from the systemic redshift, $\\Delta v_\\mathrm{Ly\\alpha} \\lesssim 200\\,\\mathrm{km\\,s^{-1}}$, yet span a range of Ly$\\mathrm{\\alpha}$ equivalent widths ($15\\,\\AA$, $31\\,\\AA$, and $132\\,\\AA$). The former two show moderate Ly$\\mathrm{\\alpha}$ escape fractions ($f_\\mathrm{esc,Ly\\alpha} \\approx 10\\%$), whereas Ly$\\mathrm{\\alpha}$ escapes remarkably efficiently from the third ($f_\\mathrm{esc,Ly\\alpha} \\approx 72\\%$), which moreover is very compact (half-light radius of $90\\pm10\\,\\mathrm{pc}$). We find these LAEs are low-mass galaxies dominated by very recent, vigorous bursts of star formation accompanied by strong nebular emission from metal-poor gas. We infer the two LAEs with modest $f_\\mathrm{esc,Ly\\alpha}$, one of which reveals evidence for ionisation by an active galactic nucleus, may have reasonably produced small ionised bubbles preventing complete IGM absorption of Ly$\\mathrm{\\alpha}$. The third, however, requires a $\\sim 3\\,\\text{physical Mpc}$ bubble, indicating faint galaxies have contributed significantly. The most distant LAEs thus continue to be powerful observational probes into the earlier stages of reionisation.","url_abs":"https://arxiv.org/abs/2404.05724v4","url_pdf":"https://arxiv.org/pdf/2404.05724v4.pdf","source":{"archive":"pwc-archive (Hugging Face), CC BY-SA 4.0","snapshot":"2025-07-28","licence_url":"https://creativecommons.org/licenses/by-sa/4.0/legalcode","row_kind":"links_only","authors_date_abstract":"arXiv metadata, CC0 1.0 (https://info.arxiv.org/help/license), from the Kaggle arXiv metadata snapshot of 2026-09-12"},"code_links":[{"paper_slug":"jades-primeval-lyman-mathrma-emitting","repo_url":"https://github.com/joriswitstok/emission_line_fitting","is_official":1,"mentioned_in_paper":1,"mentioned_in_github":0,"framework":"none","reach":null}],"tasks":[],"methods":[],"datasets_introduced":[],"methods_introduced":[],"results":[],"syntology":{"syntology_url":null,"atlas_url":null,"mcp":null,"developers":"https://syntology.ai/developers"},"arxiv_metadata":null,"syntology_extracted_results":null}