ALESS-JWST: Joint (Sub)kiloparsec JWST and ALMA Imaging of z ∼ 3 Submillimeter Galaxies Reveals Heavily Obscured Bulge Formation Events
Journal article, 2025
We present JWST NIRCam imaging targeting 13 z similar to 3 infrared-luminous (L-IR similar to 5 x 10(12)L(circle dot)) galaxies from the ALESS survey with uniquely deep, high-resolution (0.'' 08-0.'' 16) Atacama Large Millimeter/submillimeter Array 870 mu m imaging. The 2.0-4.4 mu m (observed frame) NIRCam imaging reveals the rest-frame near-infrared stellar emission in these submillimeter-selected galaxies at the same (sub)kiloparsec resolution as the 870 mu m dust continuum. The newly revealed stellar morphologies show striking similarities with the dust continuum morphologies at 870 mu m, with the centers and position angles agreeing for most sources, clearly illustrating that the spatial offsets reported previously between the 870 mu m and Hubble Space Telescope morphologies were due to strong differential dust obscuration. The F444W sizes are 78% +/- 21% larger than those measured at 870 mu m, in contrast to recent results from hydrodynamical simulations that predict larger 870 mu m sizes. We report evidence for significant dust obscuration in F444W for the highest-redshift sources, emphasizing the importance of longer-wavelength MIRI imaging. The majority of the sources show evidence that they are undergoing mergers/interactions, including tidal tails/plumes-some of which are also detected at 870 mu m. We find a clear correlation between NIRCam colors and 870 mu m surface brightness on similar to 1 kpc scales, indicating that the galaxies are primarily red due to dust-not stellar age-and we show that the dust structure on similar to kpc scales is broadly similar to that in nearby galaxies. Finally, we find no strong stellar bars in the rest-frame near-infrared, suggesting the extended bar-like features seen at 870 mu m are highly obscured and/or gas-dominated structures that are likely early precursors to significant bulge growth.
Author
J. A. Hodge
Leiden University
E. da Cunha
University of Western Australia
ARC Centre of Excellence for All Sky Astrophysics in 3 Dimensions (ASTRO 3D)
S. Kendrew
European Space Agency (ESA)
J. Li
University of Western Australia
I. Smail
Durham University
B. A. Westoby
Leiden University
O. Nayak
European Space Agency (ESA)
National Aeronautics and Space Administration (NASA)
A. M. Swinbank
Durham University
C. -C Chen
Academia Sinica
F. Walter
Max Planck Society
P. van der Werf
Leiden University
M. Cracraft
Space Telescope Science Institute (STScI)
A. Battisti
ARC Centre of Excellence for All Sky Astrophysics in 3 Dimensions (ASTRO 3D)
Australian National University
University of Western Australia
W. N. Brandt
Pennsylvania State University
G. Calistro Rivera
German Aerospace Center (DLR)
European Southern Observatory (ESO)
S. C. Chapman
National Research Council Canada
Eureka Scientific
Dalhousie University
University of British Columbia (UBC)
P. Cox
Inst Astrophys Paris
Sorbonne University
H. Dannerbauer
Instituto de Astrofísica de Canarias
R. Decarli
Istituto nazionale di astrofisica (INAF)
M. Frias Castillo
Leiden University
T. R. Greve
University College London (UCL)
Technical University of Denmark (DTU)
University of Copenhagen
Kirsten Knudsen
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
S. Leslie
Leiden University
K. M. Menten
Max Planck Society
M. Rybak
Netherlands Institute for Space Research (SRON)
Leiden University
Delft University of Technology
E. Schinnerer
Max Planck Society
J. L. Wardlow
Lancaster University
A. Weiss
Max Planck Society
Astrophysical Journal
0004-637X (ISSN) 1538-4357 (eISSN)
Vol. 978 2 165Subject Categories (SSIF 2025)
Astronomy, Astrophysics, and Cosmology
DOI
10.3847/1538-4357/ad9a52