An ALMA Survey of the SCUBA-2 Cosmology Legacy Survey UKIDSS/UDS Field: Number Counts of Submillimeter Galaxies
An ALMA Survey of the SCUBA-2 Cosmology Legacy Survey UKIDSS/UDS Field: Number Counts of Submillimeter Galaxies
复制标题
DOI：
10.3847/1538-4357/aac5e5
复制
发表时间：
2018-05
期刊：
影响因子：
--
通讯作者：
S. Stach;I. Smail;A. Swinbank;J. Simpson;J. Geach;F. An;O. Almaini;V. Arumugam;A. Blain;S. Chapman;Chian-Chou Chen;C. Conselice;E. Cooke;K. Coppin;J. Dunlop;D. Farrah;B. Gullberg;W. Hartley;R. Ivison;D. Maltby;M. Michałowski;D. Scott;C. Simpson;A. Thomson;J. Wardlow;P. Werf
中科院分区：
文献类型：
--
作者：
S. Stach;I. Smail;A. Swinbank;J. Simpson;J. Geach;F. An;O. Almaini;V. Arumugam;A. Blain;S. Chapman;Chian-Chou Chen;C. Conselice;E. Cooke;K. Coppin;J. Dunlop;D. Farrah;B. Gullberg;W. Hartley;R. Ivison;D. Maltby;M. Michałowski;D. Scott;C. Simpson;A. Thomson;J. Wardlow;P. Werf
我们报告了AS 2UDS的第一个结果，这是一个870 μm的连续测量，使用阿塔卡马大型毫米/亚毫米阵列（阿尔马），总面积为1050 arcmin 2，包括从UKIDSS/UDS场的SCUBA-2宇宙学遗产测量（S2 CLS）地图中绘制的716个亚毫米源的完整样本。S2 CLS母样品在σ850 = 0.90 ± 0.05 mJy梁−1处覆盖0.96度2的场。我们的深，高分辨率阿尔马观测与σ870 <$0. 25 mJy和0.“15-0.”30 FWHM合成光束，提供了精确的位置，695个亚毫米星系（SMG）负责的亚毫米辐射对应于606源在低分辨率，单碟地图。我们测量了亮度大于S870 ≥ 4 mJy的SMG的计数，没有混合效应的影响，结果表明，与SCUBA-2公布的计数相比，计数的归一化福尔斯了28% ± 2%，但形状保持不变。我们确定，S850 ≥ 9 mJy的较亮单碟源中有44 − 14 + 16%由两个或更多个ALMA可探测的SMG组成，亮度超过S870 <$1 mJy（对应于一个总红外光度为LIR <$1012 L <$），而S850 ≥ 5 mJy的单碟源中只有28% ± 2%。使用46个单碟亚毫米源，其中包含两个或更多的ALMA检测到的SMG与光度红移，我们表明，有一个显着的统计过量的SMG对具有相似的红移（<1%的概率发生的机会），这表明至少有30%的这些混合物来自物理相关的SMG对。
We report the first results of AS2UDS, an 870 μm continuum survey with the Atacama Large Millimeter/Submillimeter Array (ALMA) of a total area of ∼50 arcmin2 comprising a complete sample of 716 submillimeter sources drawn from the SCUBA-2 Cosmology Legacy Survey (S2CLS) map of the UKIDSS/UDS field. The S2CLS parent sample covers a 0.96 degree2 field at σ850 = 0.90 ± 0.05 mJy beam−1. Our deep, high-resolution ALMA observations with σ870 ∼ 0.25 mJy and a 0.″15–0.″30 FWHM synthesized beam, provide precise locations for 695 submillimeter galaxies (SMGs) responsible for the submillimeter emission corresponding to 606 sources in the low-resolution, single-dish map. We measure the number counts of SMGs brighter than S870 ≥ 4 mJy, free from the effects of blending and show that the normalization of the counts falls by 28% ± 2% in comparison with the SCUBA-2 published counts, but that the shape remains unchanged. We determine that 44 − 14 + 16 % of the brighter single-dish sources with S850 ≥ 9 mJy consist of a blend of two or more ALMA-detectable SMGs brighter than S870 ∼ 1 mJy (corresponding to a galaxy with a total-infrared luminosity of LIR ≳ 1012 L⊙), in comparison with 28% ± 2% for the single-dish sources at S850 ≥ 5 mJy. Using the 46 single-dish submillimeter sources that contain two or more ALMA-detected SMGs with photometric redshifts, we show that there is a significant statistical excess of pairs of SMGs with similar redshifts (<1% probability of occurring by chance), suggesting that at least 30% of these blends arise from physically associated pairs of SMGs.