ALMA Reveals Potential Evidence for Spiral Arms, Bars, and Rings in High-redshift Submillimeter Galaxies
Artikel i vetenskaplig tidskrift, 2019

We present subkiloparsec-scale mapping of the 870 mu m ALMA continuum emission in six luminous (LIR similar to 5 x 10(12 )L(circle dot)) submillimeter galaxies (SMGs) from the ALESS survey of the Extended Chandra Deep Field South. Our high-fidelity 0 ''.07-resolution imaging (similar to 500 pc) reveals robust evidence for structures with deconvolved sizes of less than or similar to 0.5-1 kpc embedded within (dominant) exponential dust disks. The large-scale morphologies of the structures within some of the galaxies show clear curvature and/or clump-like structures bracketing elongated nuclear emission, suggestive of bars, star-forming rings, and spiral arms. In this interpretation, the ratio of the "ring" and "bar" radii (1.9 +/- 0.3) agrees with that measured for such features in local galaxies. These potential spiral/ring/bar structures would be consistent with the idea of tidal disturbances, with their detailed properties implying flat inner rotation curves and Toomre-unstable disks (Q < 1). The inferred one-dimensional velocity dispersions (sigma(r) less than or similar to 70-160 km s(-1)) are marginally consistent with the limits implied if the sizes of the largest structures are comparable to the Jeans length. We create maps of the star formation rate density (Sigma(SFR)) on similar to 500 pc scales and show that the SMGs are able to sustain a given (galaxy-averaged) E-SFR over much larger physical scales than local (ultra)luminous infrared galaxies. However, on 500 pc scales, they do not exceed the Eddington limit set by radiation pressure on dust. If confirmed by kinematics, the potential presence of nonaxisymmetric structures would provide a means for net angular momentum loss and efficient star formation, helping to explain the very high star formation rates measured in SMGs.

galaxies: evolution

galaxies: starburst

galaxies: high-redshift

submillimeter: galaxies

galaxies: formation


J. A. Hodge

Universiteit Leiden

I Smail

Durham University

F. Walter


E. da Cunha

Australian National University

A. M. Swinbank

Durham University

M. Rybak

Universiteit Leiden

B. Venemans


W. N. Brandt

Pennsylvania State University

G. Calistro Rivera

Universiteit Leiden

S. C. Chapman

Dalhousie University

Chian-Chou Chen

European Southern Observatory Santiago

P. Cox

Centre national de la recherche scientifique (CNRS)

H. Dannerbauer

Universidad de la Laguna

Instituto Astrofisico de Canarias

R. Decarli

INAF OAS Bologna

T. R. Greve

University College London (UCL)

Köpenhamns universitet

Danmarks Tekniske Universitet (DTU)

Kirsten Kraiberg Knudsen

Chalmers, Rymd-, geo- och miljövetenskap, Onsala rymdobservatorium

K. M. Menten


E. Schinnerer

Australian National University

J. M. Simpson

Academia Sinica

P. van der Werf

Universiteit Leiden

J. L. Wardlow

Lancaster University

A. Weiss


Astrophysical Journal

0004-637X (ISSN) 1538-4357 (eISSN)

Vol. 876 2 130


Astronomi, astrofysik och kosmologi

Annan fysik



Onsala rymdobservatorium



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