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Chaotic and clumpy galaxy formation in an extremely massive reionization-era halo

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DOIResolve DOI: https://doi.org/10.3847/2041-8213/ac61e6
AuthorSearch for: ORCID identifier: https://orcid.org/0000-0003-3256-5615; Search for: ORCID identifier: https://orcid.org/0000-0003-4073-3236; Search for: ORCID identifier: https://orcid.org/0000-0002-2367-1080; Search for: ORCID identifier: https://orcid.org/0000-0002-6290-3198; Search for: ORCID identifier: https://orcid.org/0000-0002-3915-2015; Search for: ORCID identifier: https://orcid.org/0000-0001-8706-1268; Search for: 1; Search for: ORCID identifier: https://orcid.org/0000-0002-2554-1837; Search for: ; Search for: ORCID identifier: https://orcid.org/0000-0002-8669-5733; Search for: ; Search for: ORCID identifier: https://orcid.org/0000-0002-4208-3532; Search for: ORCID identifier: https://orcid.org/0000-0001-7964-5933; Search for: ORCID identifier: https://orcid.org/0000-0001-6919-1237; Search for: ORCID identifier: https://orcid.org/0000-0001-7089-7325; Search for: ORCID identifier: https://orcid.org/0000-0002-7064-4309; Search for: ORCID identifier: https://orcid.org/0000-0001-7946-557X; Search for: ORCID identifier: https://orcid.org/0000-0001-7477-1586; Search for: ORCID identifier: https://orcid.org/0000-0002-2718-9996; Search for: ORCID identifier: https://orcid.org/0000-0002-3187-1648; Search for: ORCID identifier: https://orcid.org/0000-0001-7192-3871; Search for: ORCID identifier: https://orcid.org/0000-0001-7610-5544; Search for: ORCID identifier: https://orcid.org/0000-0003-4678-3939
Affiliation
  1. National Research Council of Canada. Herzberg Astronomy and Astrophysics
FunderSearch for: Space Telescope Science Institute; Search for: National Science Foundation
FormatText, Article
Subjecthigh-redshift galaxies; starburst galaxies
Abstract
The SPT 0311–58 system at z = 6.900 is an extremely massive structure within the reionization epoch and offers a chance to understand the formation of galaxies at an extreme peak in the primordial density field. We present 70 mas Atacama Large Millimeter/submillimeter Array observations of the dust continuum and [C ii] 158 μm emission in the central pair of galaxies and reach physical resolutions of ∼100–350 pc, among the most detailed views of any reionization-era system to date. The observations resolve the source into at least a dozen kiloparsec-size clumps. The global kinematics and high turbulent velocity dispersion within the galaxies present a striking contrast to recent claims of dynamically cold thin-disk kinematics in some dusty galaxies just 800 Myr later at z ∼ 4. We speculate that both gravitational interactions and fragmentation from massive parent disks have likely played a role in the overall dynamics and formation of clumps in the system. Each clump individually is comparable in mass to other 6 < z < 8 galaxies identified in rest-UV/optical deep field surveys, but with star formation rates elevated by a factor of ~3-5. Internally, the clumps themselves bear close resemblance to greatly scaled-up versions of virialized cloud-scale structures identified in low-redshift galaxies. Our observations are qualitatively similar to the chaotic and clumpy assembly within massive halos seen in simulations of high-redshift galaxies.
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  • The Astrophysical Journal Letters 929, no. 1, 1 (8 April 2022).
LanguageEnglish
Peer reviewedYes
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Record identifier221e73c7-6de3-414f-9a9a-945985e20ff0
Record created2023-10-06
Record modified2023-10-06
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