Multitracer Cosmological Line Intensity Mapping Mock Light-cone Simulation
Multitracer Cosmological Line Intensity Mapping Mock Light-cone Simulation
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DOI：
10.3847/1538-4357/abec75
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发表时间：
2020-09
期刊：
影响因子：
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通讯作者：
Shengqi Yang;R. Somerville;A. Pullen;G. Popping;P. Breysse;A. Maniyar
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作者：
Shengqi Yang;R. Somerville;A. Pullen;G. Popping;P. Breysse;A. Maniyar
亚毫米发射线是星系冷气体和电离环境的重要示踪物，也是未来谱线强度测绘的目标。预测来自星际介质不同阶段的多条发射线的基于物理的模拟对于通过即将到来的线强度映射观测来约束星系的全球物理条件至关重要。在这项工作中，我们提出了一个基于物理接地的星系形成和亚毫米线发射模型来创建多踪迹模拟亚毫米线强度图的通用框架。我们模拟了红移范围0≤z≤10上2°2的模拟光锥，其中包括离散星系和星系[C II]，CO和[CI]发射。我们给出了两个基准调查的模拟谱线强度图，其中分辨率和观测频率窗口代表了COMAP和EXCREST。我们发现，我们的模拟预测的恒星形成率和线发射标度关系在低晕质量时与广泛使用的经验关系有很大不同，这些经验关系经常被校准为对低红移发光星系的观测。我们发现，这些差异导致了强度映射中使用的关键汇总统计量的显著变化，如一点强度概率密度函数和功率谱。关键是要使用更现实和更复杂的模型来预测未来线强度测绘调查测量宇宙恒星形成率密度等可观测性的能力。
Submillimeter emission lines are important tracers of the cold gas and ionized environments of galaxies and the targets for future line intensity mapping surveys. Physics-based simulations that predict multiple emission lines arising from different phases of the interstellar medium are crucial for constraining the global physical conditions of galaxies with upcoming line intensity mapping observations. In this work, we present a general framework for creating multitracer mock submillimeter line intensity maps based on physically grounded galaxy formation and submillimeter line emission models. We simulate a mock light cone of 2 deg2 over a redshift range 0≤z≤10 comprising discrete galaxies and galaxy [C ii], CO, and [C i] emission. We present simulated line intensity maps for two fiducial surveys with resolution and observational frequency windows representative of COMAP and EXCLAIM. We show that the star formation rate and line emission scaling relations predicted by our simulation significantly differ at low halo masses from widely used empirical relations, which are often calibrated to observations of luminous galaxies at lower redshifts. We show that these differences lead to significant changes in key summary statistics used in intensity mapping, such as the one-point intensity probability density function and the power spectrum. It will be critical to use more realistic and complex models to forecast the ability of future line intensity mapping surveys to measure observables such as the cosmic star formation rate density.