Kiloparsec-Scale Dust Disks in High-Redshift Luminous Submillimeter Galaxies
Journal article, 2016

We present high-resolution (0 ''.6) 870 mu m Atacama Large Millimeter/submillimeter Array (ALMA) imaging of 16 luminous (LIR similar to 4 x 10(12) L-circle dot) submillimeter galaxies (SMGs) from the ALESS survey of the Extended Chandra Deep Field South. This dust imaging traces the dust-obscured star formation in these z similar to 2.5 galaxies on similar to 1.3 kpc scales. The emission has a median effective radius of R-e = 0 ''.24 +/- 0 ''.02, corresponding to a typical physical size of R-e= 1.8 +/- 0.2 kpc. We derive a median Sersic index of n = 0.9 +/- 0.2, implying that the dust emission is remarkably disk-like at the current resolution and sensitivity. We use different weighting schemes with the visibilities to search for clumps on 0 ''.12. (similar to 1.0 kpc) scales, but we find no significant evidence for clumping in the majority of cases. Indeed, we demonstrate using simulations that the observed morphologies are generally consistent with smooth exponential disks, suggesting that caution should be exercised when identifying candidate clumps in even moderate signal-to-noise ratio interferometric data. We compare our maps to comparable-resolution Hubble Space Telescope H-160-band images, finding that the stellar morphologies appear significantly more extended and disturbed, and suggesting that major mergers may be responsible for driving the formation of the compact dust disks we observe. The stark contrast between the obscured and unobscured morphologies may also have implications for SED fitting routines that assume the dust is co-located with the optical/near-IR continuum emission. Finally, we discuss the potential of the current bursts of star formation to transform the observed galaxy sizes and light profiles, showing that the z similar to 0 descendants of these SMGs are expected to have stellar masses, effective radii, and gas surface densities consistent with the most compact massive (M* similar to 1-2 x 10(11) M-circle dot) early-type galaxies observed locally.

submillimeter: galaxies

galaxies: high-redshift

galaxies: starburst

galaxies: evolution

galaxies: formation


J. A. Hodge

Leiden University

A. M. Swinbank

Durham University

J. M. Simpson

University of Edinburgh

I. Smail

Durham University

F. Walter

Max Planck Society

D. M. Alexander

Durham University

F. Bertoldi

University of Bonn

A. D. Biggs

European Southern Observatory (ESO)

W. N. Brandt

Pennsylvania State University

S. C. Chapman

Dalhousie University

C. C. Chen

Durham University

K. E. K. Coppin

McGill University

P. Cox

Atacama Large Millimeter-submillimeter Array (ALMA)

H. Dannerbauer

University of Vienna

Instituto Astrofisico de Canarias

A. C. Edge

Durham University

T. R. Greve

University College London (UCL)

R. J. Ivison

University of Edinburgh

Royal Observatory

A. Karim

University of Bonn

Kirsten Kraiberg Knudsen

Chalmers, Earth and Space Sciences, Radio Astronomy and Astrophysics

K. M. Menten

University of Bonn

H. W. Rix

Max Planck Society

E. Schinnerer

Max Planck Society

J. L. Wardlow

Durham University

A. Weiss

Max Planck Society

P. van der Werf

Leiden University

Astrophysical Journal

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

Vol. 833 1 103

Subject Categories

Astronomy, Astrophysics and Cosmology


Basic sciences



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