JWST Reveals a Possible z ∼ 11 Galaxy Merger in Triply Lensed MACS0647–JD
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Published:2023-06-01
Issue:2
Volume:949
Page:L34
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ISSN:2041-8205
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Container-title:The Astrophysical Journal Letters
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language:
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Short-container-title:ApJL
Author:
Hsiao Tiger Yu-YangORCID, Coe DanORCID, Abdurro’uf ORCID, Whitler LilyORCID, Jung IntaeORCID, Khullar GouravORCID, Meena Ashish KumarORCID, Dayal PratikaORCID, Barrow Kirk S. S.ORCID, Santos-Olmsted LillianORCID, Casselman AdamORCID, Vanzella ErosORCID, Nonino MarioORCID, Jiménez-Teja YolandaORCID, Oguri MasamuneORCID, Stark Daniel P., Furtak Lukas J.ORCID, Zitrin AdiORCID, Adamo AngelaORCID, Brammer GabrielORCID, Bradley LarryORCID, Diego Jose M.ORCID, Zackrisson ErikORCID, Finkelstein Steven L.ORCID, Windhorst Rogier A.ORCID, Bhatawdekar RachanaORCID, Hutchison Taylor A.ORCID, Broadhurst TomORCID, Dimauro PaolaORCID, Andrade-Santos FelipeORCID, Eldridge Jan J.ORCID, Acebron AnaORCID, Avila Roberto J.ORCID, Bayliss Matthew B.ORCID, Benítez AlexORCID, Binggeli ChristianORCID, Bolan PatriciaORCID, Bradač MarušaORCID, Carnall Adam C.ORCID, Conselice Christopher J.ORCID, Donahue MeganORCID, Frye BrendaORCID, Fujimoto SeijiORCID, Henry AlainaORCID, James Bethan L.ORCID, Kassin Susan A.ORCID, Kewley LisaORCID, Larson Rebecca L.ORCID, Lauer TodORCID, Law DavidORCID, Mahler GuillaumeORCID, Mainali RameshORCID, McCandliss StephanORCID, Nicholls DavidORCID, Pirzkal NorbertORCID, Postman MarcORCID, Rigby Jane R.ORCID, Ryan RussellORCID, Senchyna PeterORCID, Sharon KerenORCID, Shimizu Ikko, Strait VictoriaORCID, Tang MengtaoORCID, Trenti MicheleORCID, Vikaeus AntonORCID, Welch BrianORCID
Abstract
Abstract
MACS0647–JD is a triply lensed z ∼ 11 galaxy originally discovered with the Hubble Space Telescope. The three lensed images are magnified by factors of ∼8, 5, and 2 to AB mag 25.1, 25.6, and 26.6 at 3.5 μm. The brightest is over a magnitude brighter than other galaxies recently discovered at similar redshifts z > 10 with JWST. Here, we report new JWST imaging that clearly resolves MACS0647–JD as having two components that are either merging galaxies or stellar complexes within a single galaxy. The brighter larger component “A” is intrinsically very blue (β ∼ −2.6 ± 0.1), likely due to very recent star formation and no dust, and is spatially extended with an effective radius ∼70 ± 24 pc. The smaller component “B” (r ∼ 20
−
5
+
8
pc) appears redder (β ∼ −2 ± 0.2), likely because it is older (100–200 Myr) with mild dust extinction (A
V
∼ 0.1 mag). With an estimated stellar mass ratio of roughly 2:1 and physical projected separation ∼400 pc, we may be witnessing a galaxy merger 430 million years after the Big Bang. We identify galaxies with similar colors in a high-redshift simulation, finding their star formation histories to be dissimilar, which is also suggested by the spectral energy distribution fitting, suggesting they formed further apart. We also identify a candidate companion galaxy “C” ∼3 kpc away, likely destined to merge with A and B. Upcoming JWST Near Infrared Spectrograph observations planned for 2023 January will deliver spectroscopic redshifts and more physical properties for these tiny magnified distant galaxies observed in the early universe.
Funder
Space Telescope Science Institute
Publisher
American Astronomical Society
Subject
Space and Planetary Science,Astronomy and Astrophysics
Cited by
11 articles.
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