Revealing the Stellar Mass and Dust Distributions of Submillimeter Galaxies at Redshift 2
Revealing the Stellar Mass and Dust Distributions of Submillimeter Galaxies at Redshift 2
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DOI：
10.3847/1538-4357/ab1f77
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发表时间：
2019-05
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通讯作者：
P. Lang;E. Schinnerer;I. Smail;U. Dudzevivciut.e;A. Swinbank;Daizhong Liu;S. Leslie;O. Almaini;F. An;F. Bertoldi;A. Blain;S. Chapman;Chian-Chou Chen;C. Conselice;E. Cooke;K. Coppin;J. Dunlop;D. Farrah;Y. Fudamoto;J. Geach;B. Gullberg;K. Harrington;J. Hodge;R. Ivison;E. F. Jim'enez-Andrade;B. Magnelli;M. Michałowski;P. Oesch;D. Scott;J. Simpson;V. Smolvci'c;S. Stach;A. Thomson;S. Toft;E. Vardoulaki;J. Wardlow;A. Weiss;P. Werf
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作者：
P. Lang;E. Schinnerer;I. Smail;U. Dudzevivciut.e;A. Swinbank;Daizhong Liu;S. Leslie;O. Almaini;F. An;F. Bertoldi;A. Blain;S. Chapman;Chian-Chou Chen;C. Conselice;E. Cooke;K. Coppin;J. Dunlop;D. Farrah;Y. Fudamoto;J. Geach;B. Gullberg;K. Harrington;J. Hodge;R. Ivison;E. F. Jim'enez-Andrade;B. Magnelli;M. Michałowski;P. Oesch;D. Scott;J. Simpson;V. Smolvci'c;S. Stach;A. Thomson;S. Toft;E. Vardoulaki;J. Wardlow;A. Weiss;P. Werf
我们将 20 个亚毫米星系 (SMG) 的高分辨率 ALMA 和 HST/CANDELS 观测结果（主要来自 z ≃ 2 处的 AS2UDS 巡天）与明亮的静止框架光学对应物 ( ) 结合起来，以研究其尘埃和恒星成分的解析结构特性。我们推导出二维恒星质量分布，该分布是根据基于静止帧光学颜色的空间质量光比 ( ) 校正推断出来的。由于我们的 SMG 中灰尘的中心柱密度较高，我们的质量分布可能代表了真实中心质量密度的下限。推断的恒星质量和尘埃分布之间的质心位置一致在 1.1 kpc 范围内，表明两个分量之间总体上具有良好的空间一致性。我们的大多数来源都表现出相对于恒星成分的紧凑尘埃结构（有效半径中值比 = 0.6）。这个比率不会随着特定恒星形成率的变化而变化，超过我们目标跨越的30倍，对“正常”主序星系的轨迹进行采样，直到星暴状态，。与当地宇宙中的典型螺旋星系不同，我们的结果表明，巨大的 SMG 正在经历集中增强的恒星形成。我们的 SMG 的大小和恒星密度与 z = 1.5 时的被动星群一致，这与这些系统是 z ≃ 2 SMG 的后代是一致的。
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 ( ) 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 ( ) 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 = 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, . 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.