In:
The Astrophysical Journal Letters, American Astronomical Society, Vol. 929, No. 1 ( 2022-04-01), p. L3-
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 μ m 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.
Type of Medium:
Online Resource
ISSN:
2041-8205
,
2041-8213
DOI:
10.3847/2041-8213/ac61e6
Language:
Unknown
Publisher:
American Astronomical Society
Publication Date:
2022
detail.hit.zdb_id:
2207648-7
detail.hit.zdb_id:
2006858-X
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