{ "abstract": "We report M1149-BSG-z5, a barred spiral galaxy at z = 5.102, identified in the parallel field of MACS J1149+2223 with JWST and the Hubble Space Telescope. M1149-BSG-z5 is the highest-redshift barred galaxy candidate to date. Both isophote ellipse fitting and structural modeling support a stellar bar of length ≈ 4.5 kpc, and extended spiral arms peaking at r ≈ 5.5 kpc. M1149-BSG-z5 is a massive star-forming main-sequence galaxy, with a stellar mass of 10 10.45 M ⊙ and a star formation rate of 144 M ⊙ yr ⁻¹ . A concentrated bulge is embedded in an extended disk with a global Sérsic index n = 2.37. With an effective radius of R e = 2.61 kpc measured from a stacked F277W + F356W + F444W image, M1149-BSG-z5 is larger than typical galaxies at z ∼ 5 and comparable to barred galaxies at 2 < z < 4. M1149-BSG-z5 also hosts a broad-line active galactic nucleus, with a relatively low black hole-to-stellar mass ratio of M BH / M * ∼ 10 ⁻³ . Its metal-enriched emission-line properties indicate that it is already chemically evolved. Taken together, these properties imply that M1149-BSG-z5 assembled early and is already structurally evolved. We also find that M1149-BSG-z5 resides in an overdense region with a nearby companion galaxy, suggesting interaction-driven bar formation. Its concentrated light distribution, early assembly, and location on the star-forming main sequence also suggest baryon-dominated, gas-rich conditions, where gravitational instability may further accelerate bar formation.", "abstract_shown": true, "affiliations": [ "Tsinghua University", "Westlake University", "Westlake Institute for Advanced Study", "Center for Astrophysics ∣Harvard & Smithsonian", "Dunlap Institute for Astronomy and Astrophysics", "The University of Tokyo", "Academia Sinica Institute of Astronomy and Astrophysics (ASIAA)", "East Asian Observatory", "Oklahoma State University", "Chinese Academy of Sciences South America Center for Astronomy", "Key Laboratory of Optical Astronomy", "University of Manchester", "University of Geneva", "Universidad de Granada", "Instituto Carlos I de Física Teórica y Computacional", "Department of Astronomy/Steward Observatory", "Max-Planck-Institut für extraterrestrische Physik", "University of Cambridge", "Faculty of Mathematics and Physics", "Nagoya University", "Universitá degli Studi di Milano-Bicocca", "Arizona State University", "Ben-Gurion University of the Negev" ], "article_type": null, "arxiv": null, "author_total": 23, "authors": [ { "affs": [ 0, 1, 2 ], "name": "Xiaohan Wang", "orcid": "0009-0002-8312-1002" }, { "affs": [ 1, 3 ], "name": "Fengwu Sun", "orcid": "0000-0002-4622-6617" }, { "affs": [ 4 ], "name": "Yoshihisa Asada", "orcid": "0000-0003-3983-5438" }, { "affs": [ 5 ], "name": "Yunjing Wu", "orcid": "0000-0003-0111-8249" }, { "affs": [ 0 ], "name": "Xiaojing Lin", "orcid": "0000-0001-6052-4234" }, { "affs": [ 1 ], "name": "Shude Mao", "orcid": "0000-0001-8317-2788" }, { "affs": [ 0 ], "name": "Sijia Cai", "orcid": "0009-0003-4133-0292" }, { "affs": [ 0 ], "name": "Zheng Cai", "orcid": "0000-0001-8467-6478" }, { "affs": [ 6, 7 ], "name": "Chian-Chou Chen", "orcid": "0000-0002-3805-0789" }, { "affs": [ 8 ], "name": "Wenlei Chen", "orcid": "0000-0003-1060-0723" }, { "affs": [ 9, 10 ], "name": "Cheng Cheng", "orcid": "0000-0003-0202-0534" }, { "affs": [ 11 ], "name": "Christopher J. Conselice", "orcid": "0000-0003-1949-7638" }, { "affs": [ 12 ], "name": "Miroslava Dessauges-Zavadsky", "orcid": "0000-0003-0348-2917" }, { "affs": [ 13, 14 ], "name": "Daneil Espada", "orcid": "0000-0002-8726-7685" }, { "affs": [ 15 ], "name": "Brenda L. Frye", "orcid": "0000-0003-1625-8009" }, { "affs": [ 16 ], "name": "Jean-Baptiste Jolly", "orcid": "0000-0002-3405-5646" }, { "affs": [ 5 ], "name": "Kotaro Kohno", "orcid": "0000-0002-4052-2394" }, { "affs": [ 0, 17 ], "name": "Mingyu Li", "orcid": "0000-0001-6251-649X" }, { "affs": [ 18 ], "name": "Nicholas Martis", "orcid": "0000-0003-3243-9969" }, { "affs": [ 19 ], "name": "Hideki Umehata", "orcid": "0000-0003-1937-0573" }, { "affs": [ 20 ], "name": "Weichen Wang", "orcid": "0000-0002-9593-8274" }, { "affs": [ 21 ], "name": "Rogier A. Windhorst", "orcid": "0000-0001-8156-6281" }, { "affs": [ 22 ], "name": "Adi Zitrin", "orcid": "0000-0002-0350-4488" } ], "bibtex": "https://research.draconitic.com/paper/be12fe08prz1x.bib", "cited_by": 0, "doi": "10.3847/1538-4357/aea414", "fulltext_url": null, "id": "be12fe08prz1x", "issns": [ "1538-4357", "0004-637X" ], "landing_url": "https://iopscience.iop.org/article/10.3847/1538-4357/aea414", "language": null, "licence": "CC-BY-4.0", "licence_label": "CC BY 4.0", "licence_source": "article", "licence_url": "https://creativecommons.org/licenses/by/4.0/", "metadata_licence": null, "native_subjects": [ [ "feed-journal", "astronomy/general" ], [ "openalex", "3103|Galaxies: Formation, Evolution, Phenomena" ] ], "openalex": "W7223798947", "pdf_url": "https://iopscience.iop.org/article/10.3847/1538-4357/aea414/pdf", "pmcid": null, "pmid": null, "published": "2026-10-27", "publisher": "American Astronomical Society", "ris": "https://research.draconitic.com/paper/be12fe08prz1x.ris", "sources": [ { "first_seen": "2026-10-30T12:17:17Z", "native_id": "10.3847/1538-4357/aea414", "source": "feed-iop", "url": "https://iopscience.iop.org/article/10.3847/1538-4357/aea414" }, { "first_seen": "2026-10-30T12:18:11Z", "native_id": "10.3847/1538-4357/aea414", "source": "crossref", "url": "https://iopscience.iop.org/article/10.3847/1538-4357/aea414" } ], "subjects": [ { "field": "astronomy", "origin": "openalex:3103|Galaxies: Formation, Evolution, Phenomena", "subfield": "galaxies" } ], "title": "A Massive Barred Spiral Galaxy at z = 5.102 Discovered by JWST", "title_text": "A Massive Barred Spiral Galaxy at z = 5.102 Discovered by JWST", "type": "peer-reviewed", "updated_at": "2026-10-30T12:18:11Z", "url": "https://research.draconitic.com/paper/be12fe08prz1x", "venue": "The Astrophysical Journal", "versions": [] }