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.
submillimeter: galaxies
galaxies: starburst
galaxies: high-redshift
galaxies: evolution
galaxies: formation
Författare
J. A. Hodge
Universiteit Leiden
I Smail
Durham University
F. Walter
Max-Planck-Gesellschaft
E. da Cunha
Australian National University
A. M. Swinbank
Durham University
M. Rybak
Universiteit Leiden
B. Venemans
Max-Planck-Gesellschaft
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 de Astrofísica de Canarias
R. Decarli
Istituto nazionale di astrofisica (INAF)
T. R. Greve
Danmarks Tekniske Universitet (DTU)
Köpenhamns universitet
University College London (UCL)
Kirsten Kraiberg Knudsen
Chalmers, Rymd-, geo- och miljövetenskap, Onsala rymdobservatorium
K. M. Menten
Max-Planck-Gesellschaft
E. Schinnerer
Australian National University
J. M. Simpson
Academia Sinica
P. van der Werf
Universiteit Leiden
J. L. Wardlow
Lancaster University
A. Weiss
Max-Planck-Gesellschaft
Astrophysical Journal
0004-637X (ISSN) 1538-4357 (eISSN)
Vol. 876 2 130Ämneskategorier
Astronomi, astrofysik och kosmologi
Annan fysik
Strukturbiologi
Infrastruktur
Onsala rymdobservatorium
DOI
10.3847/1538-4357/ab1846