Probing Cosmic Reionization and Molecular Gas Growth with TIME
Probing Cosmic Reionization and Molecular Gas Growth with TIME
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DOI：
10.3847/1538-4357/abfe62
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发表时间：
2020-12
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通讯作者：
Guochao Sun;T. Chang;B. Uzgil;J. Bock;C. Bradford;V. Butler;Tessalie Caze-Cortes;Yun-Ting Cheng-Yun-Ting-C
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作者：
Guochao Sun;T. Chang;B. Uzgil;J. Bock;C. Bradford;V. Butler;Tessalie Caze-Cortes;Yun-Ting Cheng-Yun-Ting-C
线强度测绘（LIM）通过测量所有星系在红移范围内的聚集线辐射，为探索宇宙结构提供了一种独特而有力的手段。该方法是补充传统的星系红移调查是基于对象和要求精致的点源灵敏度。电离碳层析成像测绘实验（TIME）将通过观测LIM区域中红移的[C ii] 158 μm线（6 μ z <$9）来测量宇宙再电离期间的星星形成率。《时代》杂志将通过观测星系在0.5赫兹2处发出的旋转CO谱线，同时研究星星形成高峰时期分子气体的丰度。我们提出的建模框架，预测的约束力量的时间上的一些观测，包括线光度函数和自相关和互相关功率谱，包括协同作用与外部星系示踪剂。基于一个优化的调查策略和基准模型参数通知现有的观测，我们预测约束的物理量相关的再电离和星系演化，如逃逸分数的电离光子在再电离过程中，在高红移的星系光度函数的暗端斜率，和宇宙分子气体密度在宇宙中午。我们讨论了这些约束如何能够促进我们对宇宙学星系演化的理解，从2021年开始，在两个不同的宇宙时代，以及如何在未来的实验阶段中改进它们。
Line intensity mapping (LIM) provides a unique and powerful means to probe cosmic structures by measuring the aggregate line emission from all galaxies across redshift. The method is complementary to conventional galaxy redshift surveys that are object based and demand exquisite point-source sensitivity. The Tomographic Ionized-carbon Mapping Experiment (TIME) will measure the star formation rate during cosmic reionization by observing the redshifted [C ii] 158 μm line (6 ≲ z ≲ 9) in the LIM regime. TIME will simultaneously study the abundance of molecular gas during the era of peak star formation by observing the rotational CO lines emitted by galaxies at 0.5 ≲ z ≲ 2. We present the modeling framework that predicts the constraining power of TIME on a number of observables, including the line luminosity function and the auto- and cross-correlation power spectra, including synergies with external galaxy tracers. Based on an optimized survey strategy and fiducial model parameters informed by existing observations, we forecast constraints on physical quantities relevant to reionization and galaxy evolution, such as the escape fraction of ionizing photons during reionization, the faint-end slope of the galaxy luminosity function at high redshift, and the cosmic molecular gas density at cosmic noon. We discuss how these constraints can advance our understanding of cosmological galaxy evolution at the two distinct cosmic epochs for TIME, starting in 2021, and how they could be improved in future phases of the experiment.