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Revealing the Stellar Mass and Dust Distributions of Submillimeter Galaxies at Redshift 2

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journal contribution
posted on 05.08.2019, 13:50 by P Lang, E Schinnerer, I Smail, U Dudzeviciute, AM Swinbank, D Liu, SK Leslie, O Almaini, FX An, F Bertoldi, AW Blain, SC Chapman, C-C Chen, C Conselice, EA Cooke, KEK Coppin, JS Dunlop, D Farrah, Y Fudamoto, JE Geach, B Gullberg, KC Harrington, JA Hodge, RJ Ivison, EF Jimenez-Andrade, B Magnelli, MJ Michalowski, P Oesch, D Scott, JM Simpson, V Smolcic, SM Stach, AP Thomson, S Toft, E Vardoulaki, JL Wardlow, A Weiss, P van der Werf
We combine high-resolution ALMA and HST/CANDELS observations of 20 submillimeter galaxies (SMGs), predominantly from the AS2UDS survey at z ~= 2, with bright rest-frame optical counterparts (Ks <~ 22.9) to investigate the resolved structural properties of their dust and stellar components. We derive two-dimensional stellar-mass distributions that are inferred from spatial mass-to-light ratio (M / L*) corrections based on rest-frame optical colors. Due to the high central column densities of dust in our SMGs, our mass distributions likely represent a lower limit to the true central mass density. The centroid positions between the inferred stellar-mass and the dust distributions agree within 1.1 kpc, indicating an overall good spatial agreement between the two components. The majority of our sources exhibit compact dust configurations relative to the stellar component (with a median ratio of effective radii R(e,dust) / R(e,*) = 0.6). This ratio does not change with specific star formation rate over the factor of 30 spanned by our targets, sampling the locus of “normal” main-sequence galaxies up to the starburst regime, log( sSFR / sSFR(MS)) >= 0.5. Unlike typical spiral galaxies in the local universe, our results imply that massive SMGs are experiencing centrally enhanced star formation. The sizes and stellar densities of our SMGs are in agreement with those of the passive population at z = 1.5, which is consistent with these systems being the descendants of z ~= 2 SMGs.


This paper makes use of ALMA data ADS/JAO.ALMA#2011.0.00294.S; #2012.0.00307.S; #2013.1.00118.S; #2012.1.00090.S; #2015.1.01528.S; #2016.1.00434.S; and #2017.1.01492.S. ALMA is a partnership of ESO (representing its member states), NSF (USA) and NINS (Japan), together with NRC (Canada), MOST and ASIAA (Taiwan), and KASI (Republic of Korea), in cooperation with the Republic of Chile. The Joint ALMA Observatory is operated by ESO, AUI/NRAO and NAOJ. This work is based on observations taken by the CANDELS Multi-Cycle Treasury Program with the NASA/ESA HST, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555. P.L., D.L., and E.S., acknowledge support from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (grant agreement No. 694343). I.R.S. and A.M.S. acknowledge support from STFC (ST/P000541/1). F.B., B.M., E.V., K.H. and EFJA acknowledge support of the Collaborative Research Center 956, subproject A1, funded by the Deutsche Forschungsgemeinschaft (DFG). S.L. acknowledges funding from Deutsche Forschungsgemeinschaft (DFG) Grant BE 1837/13-1 r. E.A.C. acknowledges support from the ERC Advanced Investigator Grant DUSTYGAL (321334) and STFC (ST/P000541/1). M.J.M. acknowledges the support of the National Science Centre, Poland, through the POLONEZ grant 2015/19/P/ST9/04010; this project has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No. 665778. S.T. acknowledges support from the ERC Consolidator Grant funding scheme (project ConTExt, grant No. 648179). The Cosmic Dawn Center is funded by the Danish National Research Foundation. E.V. acknowledges funding from the DFG grant BE 1837/13-1. J.L.W. acknowledges support from an STFC Ernest Rutherford Fellowship (ST/P004784/2), and additional support from STFC (ST/P000541/1).



Astrophysical Journal, 2019, 879 (1)

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/Organisation/COLLEGE OF SCIENCE AND ENGINEERING/Department of Physics and Astronomy


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American Astronomical Society, IOP Publishing





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