J0107a: A Barred Spiral Dusty Star-forming Galaxy at z = 2.467
Abstract
Dusty star-forming galaxies (DSFGs) are among the most massive and active star-forming galaxies during the cosmic noon. Theoretical studies have proposed various formation mechanisms of DSFGs, including major merger-driven starbursts and secular star-forming disks. Here, we report J0107a, a bright (~8 mJy at observed-frame 888 μm) DSFG at z = 2.467 that appears to be a gas-rich massive disk and might be an extreme case of the secular disk scenario. J0107a has a stellar mass M ⋆ ~ 5 × 1011 M ⊙, molecular gas mass M mol ≳ 1011 M ⊙, and a star formation rate of ~500M ⊙ yr-1. J0107a does not have a gas-rich companion. The rest-frame 1.28 μm JWST NIRCam image of J0107a shows a grand-design spiral with a prominent stellar bar extending ~15 kpc. The Atacama Large Millimeter/submillimeter Array Band 7 continuum map reveals that the dust emission originates from both the central starburst and the stellar bar. 3D disk modeling of the CO(4-3) emission line indicates a dynamically cold disk with rotation-to-dispersion ratio ${V}_{\max }/\sigma \sim 8$ . The results suggest a bright DSFG may have a nonmerger origin, and its vigorous star formation may be triggered by the bar and/or rapid gas inflow.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- December 2023
- DOI:
- 10.3847/2041-8213/acff63
- arXiv:
- arXiv:2310.01782
- Bibcode:
- 2023ApJ...958L..26H
- Keywords:
-
- Barred spiral galaxies;
- CO line emission;
- Galaxy formation;
- High-redshift galaxies;
- Ultraluminous infrared galaxies;
- 136;
- 262;
- 595;
- 734;
- 1735;
- Astrophysics - Astrophysics of Galaxies
- E-Print:
- 9 pages, 4 figures. Accepted for publication in ApJL