JWST Reveals a Possible z ∼ 11 Galaxy Merger in Triply Lensed MACS0647-JD
Author
Hsiao, T.Y.Coe, D.

Abdurro'uf
Whitler, L.
Jung, I.
Khullar, G.
Meena, A.K.
Dayal, P.
Barrow, K.S.S.
Santos-Olmsted, L.
Casselman, A.
Vanzella, E.
Nonino, M.
Jiménez-Teja, Y.
Oguri, M.
Stark, D.P.
Furtak, L.J.
Zitrin, A.

Adamo, A.

Brammer, G.
Bradley, L.
Diego, J.M.
Zackrisson, E.

Finkelstein, S.L.
Windhorst, R.A.
Bhatawdekar, R.
Hutchison, T.A.
Broadhurst, T.
Dimauro, P.
Andrade-Santos, F.
Eldridge, J.J.
Acebron, A.
Avila, R.J.
Bayliss, M.B.
Benítez, A.
Binggeli, C.
Bolan, P.
Bradač, M.
Carnall, A.C.
Conselice, C.J.
Donahue, M.

Frye, B.
Fujimoto, S.

Henry, A.
James, B.L.
Kassin, S.A.
Kewley, L.
Larson, R.L.
Lauer, T.
Law, D.
Mahler, G.
Mainali, R.
McCandliss, S.
Nicholls, D.
Pirzkal, N.
Postman, M.
Rigby, J.R.
Ryan, R.
Senchyna, P.
Sharon, K.
Shimizu, I.
Strait, V.
Tang, M.
Trenti, M.
Vikaeus, A.
Welch, B.
Affiliation
Steward Observatory, University of ArizonaIssue Date
2023-06-02
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American Astronomical SocietyCitation
Tiger Yu-Yang Hsiao et al 2023 ApJL 949 L34Journal
Astrophysical Journal LettersRights
© 2023. The Author(s). Published by the American Astronomical Society. Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence.Collection Information
This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at repository@u.library.arizona.edu.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. © 2023. The Author(s). Published by the American Astronomical Society.Note
Open access journalISSN
2041-8205Version
Final Published Versionae974a485f413a2113503eed53cd6c53
10.3847/2041-8213/acc94b
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Except where otherwise noted, this item's license is described as © 2023. The Author(s). Published by the American Astronomical Society. Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence.