Issue |
A&A
Volume 690, October 2024
|
|
---|---|---|
Article Number | A285 | |
Number of page(s) | 28 | |
Section | Extragalactic astronomy | |
DOI | https://doi.org/10.1051/0004-6361/202450671 | |
Published online | 17 October 2024 |
JWST’s PEARLS: Resolved study of the stellar and dust components in starburst galaxies at cosmic noon
1
INAF – Istituto di Astrofisica Spaziale e Fisica Cosmica Milano, Via A. Corti 12, I-20133 Milano, Italy
2
Steward Observatory, University of Arizona, 933 N Cherry Ave, Tucson, AZ 85721-0009, USA
3
Center for Astrophysics | Harvard & Smithsonian, 60 Garden Street, Cambridge, MA 02138, USA
4
Institut de Radioastronomie Millimétrique, 300 rue de la piscine, F-38406 Saint-Martin-d’Hères, France
5
European Southern Observatory, ESO Vitacura, Alonso de Córdova 3107, Vitacura, 19001 Casilla, Santiago, Chile
6
Joint ALMA Observatory, Alonso de Córdova 3107, Vitacura, 763-0355 Santiago, Chile
7
Université Paris-Saclay, CNRS, Institut d’Astrophysique Spatiale, 91405 Orsay, France
8
School of Earth and Space Exploration, Arizona State University, Tempe, AZ 85287-1404, USA
9
Univ Lyon, Univ Lyon1, Ens de Lyon, CNRS, Centre de Recherche Astrophysique de Lyon UMR5574, F-69230 Saint-Genis-Laval, France
10
International Centre for Radio Astronomy Research (ICRAR) and the International Space Centre (ISC), The University of Western Australia, M468, 35 Stirling Highway, Crawley, WA 6009, Australia
11
ARC Centre of Excellence for All Sky Astrophysics in 3 Dimensions (ASTRO 3D), Australia
12
Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218, USA
13
Association of Universities for Research in Astronomy (AURA) for the European Space Agency (ESA), STScI, Baltimore, MD 21218, USA
14
Center for Astrophysical Sciences, Department of Physics and Astronomy, The Johns Hopkins University, 3400 N Charles St., Baltimore, MD 21218, USA
15
Jodrell Bank Centre for Astrophysics, Alan Turing Building, University of Manchester, Oxford Road, Manchester M13 9PL, UK
16
National Research Council of Canada, Herzberg Astronomy & Astrophysics Research Centre, 5071 West Saanich Road, Victoria, BC V9E 2E7, Canada
17
INAF-Osservatorio Astronomico di Trieste, Via Bazzoni 2, 34124 Trieste, Italy
18
Department of Physics and Astronomy, University of Missouri, Columbia, MO 65211, USA
19
Chinese Academy of Sciences South America Center for Astronomy, National Astronomical Observatories, CAS, Beijing 100101, China
20
CAS Key Laboratory of Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100101, China
21
Department of Physics, Montana State University, Bozeman, MT 59717, USA
22
Department of Physics and Astronomy, University of Louisville, 102 Natural Science Building, Louisville, KY 40292, USA
23
Dept. of Physics and Astronomy, University of Alabama, Box 870324 Tuscaloosa, AL 35404, USA
24
Department of Astronomy, University of California, 501 Campbell Hall #3411, Berkeley, CA 94720, USA
25
Leiden Observatory, PO Box 9513 2300 RA Leiden, The Netherlands
26
Department of Astronomy, University of Massachusetts at Amherst, Amherst, MA 01003, USA
Received:
9
May
2024
Accepted:
29
June
2024
Dusty star-forming galaxies (DSFGs) significantly contribute to the stellar buildup in galaxies during “cosmic noon,” the peak epoch of cosmic star formation. Major mergers and gas accretion are often invoked to explain DSFGs’ prodigious star formation rates (SFRs) and large stellar masses. We conducted a spatially resolved morphological analysis of the rest-frame ultraviolet/near-infrared (∼0.25–1.3 μm) emission in three DSFGs at z ≃ 2.5. Initially discovered as carbon monoxide (CO) emitters by NOrthern Extended Millimeter Array (NOEMA) observations of a bright (S350 μm = 111 ± 10 mJy) Herschel source, we observed them with the James Webb Space Telescope/NIRCam as part of the PEARLS program. The NIRCam data reveal the galaxies’ stellar populations and dust distributions on scales of 250 pc. Spatial variations in stellar mass, SFR, and dust extinction are determined in resolved maps obtained through pixel-based spectral energy distribution fitting. The CO emitters are massive (Mstar ≃ (3 − 30)×1010 M⊙), dusty starburst galaxies with SFRs ranging from 340 to 2500 M⊙ yr−1, positioning them among the most active star-forming galaxies at 2 < z < 3. Notably, they belong to the ∼1.5% of the entire JWST population with extremely red colors. Their morphologies are disk like (Sérsic index n ≃ 1), with effective radii of 2.0–4.4 kpc, and exhibit substructures such as clumps and spiral arms. The galaxies have dust extinctions up to AV = 5–7 mag extending over several kiloparsecs with asymmetric distributions that include off-center regions resembling bent spiral arms and clumps. The near-infrared dust-attenuation curve in these sources deviates from standard laws, possibly implying different dust–star geometries or dust grain properties than commonly assumed in starburst galaxies. The proximity (< 5″) of galaxies with consistent redshifts, strong color gradients, an overall disturbed appearance, asymmetric dust obscuration, and widespread star formation collectively favor interactions (minor mergers and flybys) as the mechanism driving the CO galaxies’ exceptional SFRs. The galaxies’ large masses and rich environment hint at membership in two proto-structures, as initially inferred from their association with a Planck-selected high-z source.
Key words: dust / extinction / galaxies: starburst / galaxies: star formation / galaxies: structure / submillimeter: galaxies
© The Authors 2024
Open Access article, published by EDP Sciences, under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
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