Atomic carbon as a powerful tracer of molecular gas in the high-redshift Universe: perspectives for ALMA
Atomic carbon as a powerful tracer of molecular gas in the high-redshift Universe: perspectives for ALMA
复制标题
DOI：
10.1093/mnrasl/slu137
复制
发表时间：
2014-05
影响因子：
4.8
通讯作者：
Matteo Tomassetti;C. Porciani;E. Romano-Díaz;A. Ludlow;P. Papadopoulos
中科院分区：
文献类型：
--
作者：
Matteo Tomassetti;C. Porciani;E. Romano-Díaz;A. Ludlow;P. Papadopoulos
我们使用一个高分辨率的流体动力学模拟，跟踪非平衡丰度的分子氢在一个巨大的高红移星系产生模拟阿塔卡马大毫米阵列（阿尔马）的精细结构线的碳原子，CI 1-0和CI 2-1的地图。受最近的观测和理论工作的启发，我们假设CI在巨大的分子云中完全混合，并证明其发射是H2的一个很好的代理。几乎所有与星系相关的H2都可以在红移z<4处使用紧凑的干涉配置与大合成光束（无法分辨目标星系）在不到4小时的积分时间内检测到。CI线的低分辨率成像（其中目标星系被分解为三到四个光束）将在不到12小时的孔径合成中检测到约80%的H2。在这种情况下，产生的数据立方体也提供了确定星系动态所需的关键信息。我们的结论是，阿尔马观测CI 1-0和2-1的排放是非常适合于延长宇宙回望时间的间隔，在此期间的H2分布，动力学质量，和Tully-Fisher关系的星系可以稳健地探测。
We use a high-resolution hydrodynamic simulation that tracks the non-equilibrium abundance of molecular hydrogen within a massive high-redshift galaxy to produce mock Atacama Large Millimeter Array (ALMA) maps of the fine-structure lines of atomic carbon, CI 1-0 and CI 2-1. Inspired by recent observational and theoretical work, we assume that CI is thoroughly mixed within giant molecular clouds and demonstrate that its emission is an excellent proxy for H2. Nearly all of the H2 associated with the galaxy can be detected at redshifts z<4 using a compact interferometric configuration with a large synthesized beam (that does not resolve the target galaxy) in less than 4 h of integration time. Low-resolution imaging of the \CI lines (in which the target galaxy is resolved into three to four beams) will detect ~80 per cent of the H2 in less than 12 h of aperture synthesis. In this case, the resulting data cube also provides the crucial information necessary for determining the dynamical state of the galaxy. We conclude that ALMA observations of the CI 1-0 and 2-1 emission are well-suited for extending the interval of cosmic look-back time over which the H2 distributions, the dynamical masses, and the Tully-Fisher relation of galaxies can be robustly probed.