Revealing the complex nature of the strong gravitationally lensed system H-ATLAS J090311.6+003906 using ALMA
Revealing the complex nature of the strong gravitationally lensed system H-ATLAS J090311.6+003906 using ALMA
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DOI：
10.1093/mnras/stv1442
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发表时间：
2015-03
影响因子：
4.8
通讯作者：
S. Dye;C. Furlanetto;A. M. Swinbank;C. Vlahakis;J. Nightingale;L. Dunne;S. Eales;I. Smail;I. Oteo-Gomez;T. Hunter;M. Negrello;H. Dannerbauer;R. Ivison;R. Gavazzi;A. Cooray;P. Werf
中科院分区：
文献类型：
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作者：
S. Dye;C. Furlanetto;A. M. Swinbank;C. Vlahakis;J. Nightingale;L. Dunne;S. Eales;I. Smail;I. Oteo-Gomez;T. Hunter;M. Negrello;H. Dannerbauer;R. Ivison;R. Gavazzi;A. Cooray;P. Werf
我们已经模拟了阿塔卡马大毫米/亚毫米阵列的强引力透镜系统H-ATLASJ090311.6+003906(SDP.81)的长基线成像。我们重建了z=3.042源的6带和7带连续发射的分布，并通过重建4带和6带的CO(5-4)和CO(8-7)线发射确定了它的运动学性质。连续谱成像揭示了尘埃在∼200pC尺度上的高度不均匀分布和成团。与之相反，在倾角为(40±5)°，渐近自转速度为320 km S−1的旋转盘模型下，CO谱线发射呈现出相对光滑的圆盘状速度场。推算出1.5kPC范围内的动力学质量为(3.5±0.5)×1010M⊙，与尘埃连续发射的(2.7±0.5)×1010M⊙和CO排放的(3.5±0.6)×1010M⊙相当。我们新重建的透镜哈勃太空望远镜的近红外发射显示了两个似乎相互作用的物体，ALMA揭示的气体和尘埃旋转盘明显偏离了近红外发射。尘埃的块状性质和Q∼0.3Toomre参数的低值表明该圆盘处于坍塌状态。我们估计盘中的恒星形成率为470±80M⊙yr−1，其效率∼是典型的低红移星系的65倍。我们的发现增加了越来越多的证据，证明在高红移宇宙中，红外亮度最高、尘埃最模糊的星系代表着一群由合并引起的恒星爆发。
We have modelled Atacama Large Millimetre/sub-millimetre Array (ALMA) long baseline imaging of the strong gravitational lens system H-ATLAS J090311.6+003906 (SDP.81). We have reconstructed the distribution of band 6 and 7 continuum emission in the z = 3.042 source and determined its kinematic properties by reconstructing CO(5–4) and CO(8–7) line emission in bands 4 and 6. The continuum imaging reveals a highly non-uniform distribution of dust with clumps on scales of ∼200 pc. In contrast, the CO line emission shows a relatively smooth, disc-like velocity field which is well fitted by a rotating disc model with an inclination angle of (40 ± 5)° and an asymptotic rotation velocity of 320 km s−1. The inferred dynamical mass within 1.5 kpc is (3.5 ± 0.5) × 1010 M⊙ which is comparable to the total molecular gas masses of (2.7 ± 0.5) × 1010 M⊙ and (3.5 ± 0.6) × 1010 M⊙ from the dust continuum emission and CO emission, respectively. Our new reconstruction of the lensed Hubble Space Telescope near-infrared emission shows two objects which appear to be interacting, with the rotating disc of gas and dust revealed by ALMA distinctly offset from the near-infrared emission. The clumpy nature of the dust and a low value of the Toomre parameter of Q ∼ 0.3 suggest that the disc is in a state of collapse. We estimate a star formation rate in the disc of 470 ± 80 M⊙ yr−1 with an efficiency ∼65 times greater than typical low-redshift galaxies. Our findings add to the growing body of evidence that the most infrared luminous, dust obscured galaxies in the high-redshift Universe represent a population of merger-induced starbursts.