ALMA Reveals Potential Evidence for Spiral Arms, Bars, and Rings in High-redshift Submillimeter Galaxies
ALMA Reveals Potential Evidence for Spiral Arms, Bars, and Rings in High-redshift Submillimeter Galaxies
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DOI：
10.3847/1538-4357/ab1846
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发表时间：
2018-10
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通讯作者：
J. Hodge;I. Smail;F. Walter;E. D. Cunha;A. Swinbank;M. Rybak;B. Venemans;W. Brandt;G. Rivera;S. Chapman;Chian-Chou Chen;P. Cox;H. Dannerbauer;R. Decarli;T. Greve;R. Ivison;K. Knudsen;K. Menten;E. Schinnerer;J. Simpson;P. Werf;J. Wardlow;A. Weiss
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作者：
J. Hodge;I. Smail;F. Walter;E. D. Cunha;A. Swinbank;M. Rybak;B. Venemans;W. Brandt;G. Rivera;S. Chapman;Chian-Chou Chen;P. Cox;H. Dannerbauer;R. Decarli;T. Greve;R. Ivison;K. Knudsen;K. Menten;E. Schinnerer;J. Simpson;P. Werf;J. Wardlow;A. Weiss
我们展示了从扩展钱德拉深场南部的ALESS调查中获得的6个发光(LIR类似于5 × 10（12)L（圆点））亚毫米星系（smg）的870 μ m ALMA连续辐射的亚千秒尺度映射。我们的高保真度0”。07分辨率成像（类似于500pc）揭示了在（主要的）指数尘盘中嵌入的反卷积尺寸小于或类似0.5-1 KPC的结构的有力证据。一些星系内部结构的大尺度形态显示出清晰的曲率和/或团块状结构，包围着细长的核发射，暗示着条形，恒星形成环和旋臂。在这种解释中，“环状”和“棒状”半径的比值（1.9 +/- 0.3）与在本地星系中测量到的这类特征一致。这些潜在的螺旋/环状/棒状结构与潮汐扰动的想法是一致的，它们的详细性质意味着平坦的内部旋转曲线和图姆不稳定盘（Q < 1）。如果最大结构的尺寸与Jeans长度相当，则推断出的一维速度色散(sigma（r)小于或类似于70-160 km s(-1)）与所隐含的极限大致一致。我们创建了类似500pc尺度的恒星形成速率密度（Sigma(SFR)）图，并表明smg能够在更大的物理尺度上维持给定的（星系平均的）E-SFR，而不是本地（超）发光的红外星系。然而，在500pc的尺度上，它们不会超过Eddington对尘埃的辐射压力设定的极限。如果得到运动学的证实，非轴对称结构的潜在存在将为净角动量损失和有效的恒星形成提供一种手段，有助于解释在SMGs中测量到的非常高的恒星形成率。
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.