ALMA Reveals Potential Evidence for Spiral Arms, Bars, and Rings in High-redshift Submillimeter Galaxies

Research output: Contribution to journalJournal article – Annual report year: 2019Researchpeer-review

DOI

  • Author: Hodge, J. A.

    Leiden University, Netherlands

  • Author: Smail, I.

    University of Durham, United Kingdom

  • Author: Walter, F. King

    Max Planck Institute for Astronomy, Germany

  • Author: da Cunha, E.

    Australian National University, Australia

  • Author: Swinbank, A. M.

    University of Durham

  • Author: Rybak, M.

    Leiden University, Netherlands

  • Author: Venemans, B.

    Max Planck Institute for Astronomy, Germany

  • Author: Brandt, W. N.

    Pennsylvania State University, United States

  • Author: Rivera, G. Calistro

    Leiden University, Netherlands

  • Author: Chapman, S.C.

    Dalhousie University, Canada

  • Author: Chen, Chian Chou

    European Southern Observatory, Germany

  • Author: Cox, Peter

    Institut d 'Astrophysique de Paris, France

  • Author: Dannerbauer, H.

    Instituto de Astrofísica de Canarias, Spain

  • Author: Decarli, R.

    National Institute for Astrophysics, Italy

  • Author: Greve, T. R.

    Astrophysics and Atmospheric Physics, National Space Institute, Technical University of Denmark, Elektrovej, 2800, Kgs. Lyngby, Denmark

  • Author: Knudsen, K. K.

    Chalmers University of Technology, Sweden

  • Author: Menten, K. M.

    Max Planck Institute for Radio Astronomy, Germany

  • Author: Schinnerer, E.

    Australian National University, Australia

  • Author: Simpson, M. J. R. 

    Academia Sinica - Institute of Astronomy and Astrophysics, Taiwan, Province of China

  • Author: van der Werf, P.

    Leiden University, Netherlands

  • Author: Wardlow, J. L.

    Lancaster University, United Kingdom

  • Author: Weiß, A.

    Max Planck Institute for Radio Astronomy, Germany

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We present subkiloparsec-scale mapping of the 870 μm ALMA continuum emission in six luminous (LIR ∼ 5 × 1012L⊙) submillimeter galaxies (SMGs) from the ALESS survey of the Extended Chandra Deep Field South. Our high-fidelity 0.″07-resolution imaging (∼500 pc) reveals robust evidence for structures with deconvolved sizes of ≲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 (σr ≲ 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 (ΣSFR) on ∼500 pc scales and show that the SMGs are able to sustain a given (galaxy-averaged) ΣSFR 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.
Original languageEnglish
Article number130
JournalAstrophysical Journal
Volume876
Issue number2
Number of pages16
ISSN0004-637X
DOIs
Publication statusPublished - 2019
CitationsWeb of Science® Times Cited: No match on DOI

    Research areas

  • Galaxies: evolution, Galaxies: formation, Galaxies: high-redshift, Galaxies: starburst, Submillimeter: galaxies

ID: 179894548