The absence of [C II] 158um emission in spectroscopically confirmed galaxies at z > 8
The absence of [C II] 158um emission in spectroscopically confirmed galaxies at z > 8
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经光谱证实 z > 8 的星系中不存在 [C II] 158um 发射
DOI：
10.1093/mnrasl/slz094
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发表时间：
2019
影响因子：
--
通讯作者：
Tamura Y
中科院分区：
文献类型：
--
作者：
Laporte N;Katz H;Ellis R S;Lagache G;Bauer F E;Boone F;Inoue A K;Hashimoto T;Matsuo H;Mawatari K;Tamura Y
[Cii] 158 m发射强度与高红移星星形成速率之间关系的离散性是最近引起人们极大兴趣的原因。虽然这种关系在局部已经很好地建立起来，但已经发现了几个强烈的恒星形成星系，它们的[Cii] 158 m发射要么很弱，要么不存在，要么在空间上偏离年轻恒星。在这里，我们提出了新的阿尔马数据的两个最遥远的引力透镜和光谱证实的星系，A2744_YD4 atz = 8.38和MACS 1149_JD 1 atz = 9.11，这两个都揭示了强烈的[Oiii] 88米的排放。在这两种情况下，我们提供严格的上限存在[Cii] 158米相对于[Oiii] 88米。我们审查可能的解释，这种明显的红移依赖[Cii]赤字的背景下，我们最近的流体动力学模拟。我们的研究结果突出了使用几个发射线诊断与阿尔马调查星际介质的性质在早期星系的重要性。
The scatter in the relationship between the strength of [Cii] 158m emission and the star formation rate at high redshift has been the source of much recent interest. Although the relationship is well established locally, several intensely star-forming galaxies have been found whose [Cii] 158m emission is either weak, absent, or spatially offset from the young stars. Here we present new ALMA data for the two most distant gravitationally lensed and spectroscopically confirmed galaxies, A2744_YD4 atz= 8.38 and MACS1149_JD1 atz= 9.11, both of which reveal intense [Oiii] 88m emission. In both cases we provide stringent upper limits on the presence of [Cii] 158m with respect to [Oiii] 88m. We review possible explanations for this apparent redshift-dependent [Cii] deficit in the context of our recent hydrodynamical simulations. Our results highlight the importance of using several emission line diagnostics with ALMA to investigate the nature of the interstellar medium in early galaxies.