We present the first results of an Atacama Large Millimeter Array survey of the lower fine-structure line of atomic carbon [C i] in far-infrared-selected galaxies on the main sequence at z?~?1.2 in the COSMOS field. We compare our sample with a comprehensive compilation of data available in the literature for local and high-redshift starbursting systems and quasars. We show that the [C i] (3 P 1 → 3 P 0) luminosity correlates on global scales with the infrared luminosity , similar to low-J CO transitions. We report a systematic variation of / as a function of the galaxy type, with the ratio being larger for main-sequence galaxies than for starbursts and submillimeter galaxies at fixed . The / and / mass ratios are similar for main-sequence galaxies and for local and high-redshift starbursts within a 0.2?dex intrinsic scatter, suggesting that [C i] is a good tracer of molecular gas mass as CO and dust. We derive a fraction of of the total carbon mass in the atomic neutral phase. Moreover, we estimate the neutral atomic carbon abundance, the fundamental ingredient to calibrate [C i] as a gas tracer, by comparing and available gas masses from CO lines and dust emission. We find lower [C i] abundances in main-sequence galaxies than in starbursting systems and submillimeter galaxies as a consequence of the canonical α CO and gas-to-dust conversion factors. This argues against the application to different galaxy populations of a universal standard [C i] abundance derived from highly biased samples.
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机译：我们介绍了在Atmosama大毫米波阵列中对COSMOS场中z？〜？1.2主序列中远红外选择星系中较低碳原子结构[C i]的较低精细结构线的初步结果。我们将样本与本地和高红移星暴系统和类星体文献中的可用数据全面汇编进行比较。我们显示[C i]（3 P 1→3 P 0）发光度在全球范围内与红外发光度相关，类似于低J CO跃迁。我们报告了/作为星系类型的函数的系统变化，固定序列的主序星系比星暴和亚毫米星系的比率更大。 /和/的质量比与主要序列星系以及0.2？dex本征散射内的局部和高红移星暴相似，这表明[C i]是分子气体质量（如CO和粉尘）的良好示踪剂。我们得出原子中性相中总碳质量的一部分。此外，我们通过比较和从CO管线和粉尘排放中获得的气体质量，估算了中性原子碳的丰度，这是校准[C i]作为气体示踪剂的基本成分。由于规范的αCO和气尘转换因子，我们发现主序星系中的[C i]丰度低于星爆系统和亚毫米星系中的[C i]丰度。这与从高偏差样本得出的通用标准[C i]丰度在不同星系种群上的应用相矛盾。
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