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Title: A Strongly Lensed Dusty Starburst of an Intrinsic Disk Morphology at a Photometric Redshift of z ph > 7
Abstract We present COSBO-7, a strong millimeter source known for more than 16 yr that just revealed its near-to-mid-IR counterpart with the James Webb Space Telescope (JWST). The precise pinpointing by the Atacama Large Millimeter/submillimeter Array on the exquisite NIRCam and MIRI images show that it is a background source gravitationally lensed by a single foreground galaxy, and the analysis of its spectral energy distribution by different tools is in favor of photometric redshift atzph> 7. Strikingly, our lens modeling based on the JWST data shows that it has a regular disk morphology in the source plane. The dusty region giving rise to the far-IR-to-millimeter emission seems to be confined to a limited region to one side of the disk and has a high dust temperature of >90 K. The galaxy is experiencing starburst both within and outside of this dusty region. After taking the lensing magnification ofμ≈ 2.5–3.6 into account, the intrinsic star formation rate is several hundredM⊙yr−1both within the dusty region and across the more extended stellar disk, and the latter already has >1010M⊙of stars in place. If it is indeed atz> 7, COSBO-7 presents an extraordinary case that is against the common wisdom about galaxy formation in the early Universe; simply put, its existence poses a critical question to be answered: how could a massive disk galaxy come into being so early in the Universe and sustain its regular morphology in the middle of an enormous starburst?  more » « less
Award ID(s):
2307447
PAR ID:
10531948
Author(s) / Creator(s):
; ; ; ; ;
Publisher / Repository:
IOP Publishing for the American Astronomical Society
Date Published:
Journal Name:
The Astrophysical Journal Letters
Volume:
969
Issue:
2
ISSN:
2041-8205
Page Range / eLocation ID:
L28
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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