论文标题
使用光子保存半数字模型脚本的即将到来的21 cm观测的电离参数的有效探索
Efficient exploration of reionization parameters for the upcoming 21 cm observations using a photon conserving semi-numerical model SCRIPT
论文作者
论文摘要
限制宇宙电离历史的最有希望的探针之一是中性氢21 cm发射波动的功率谱。相应的分析需要进行计算有效的电源建模，通常是通过半数字模拟实现的。我们研究了一个这样的半数字代码（脚本）的能力，以约束电离参数。我们的研究涉及创建与即将到来的SKA-LOW相对应的模拟数据集，然后是贝叶斯推理方法来限制模型参数。特别是，我们详细探讨了相对于用于模拟的输入的推断参数是否没有偏见，以及推断是否对模拟的分辨率不敏感。我们发现该模型在两个方面都取得了成功。我们还开发了一个简单的电离模型模型，该模型可以模仿复杂的物理过程，例如不均匀的重组和辐射反馈，并表明它可以通过中等的计算成本可靠地恢复全球电离历史记录。但是，这样的简单模型不适合约束电离源的性质。我们的结果与使用未来望远镜中预期的高质量数据来限制电源有关。
One of the most promising probes to constrain the reionization history of the universe is the power spectrum of neutral hydrogen 21 cm emission fluctuations. The corresponding analyses require computationally efficient modelling of reionization, usually achieved through semi-numerical simulations. We investigate the capability of one such semi-numerical code, SCRIPT, to constrain the reionization parameters. Our study involves creating a mock data set corresponding to the upcoming SKA-Low, followed by a Bayesian inference method to constrain the model parameters. In particular, we explore in detail whether the inferred parameters are unbiased with respect to the inputs used for the mock, and also if the inferences are insensitive to the resolution of the simulation. We find that the model is successful on both fronts. We also develop a simple template model of reionization which can mimic the complex physical processes like inhomogeneous recombinations and radiative feedback and show that it can recover the global reionization history reliably with moderate computational cost. However, such simple models are not suitable for constraining the properties of the ionizing sources. Our results are relevant for constraining reionization using high-quality data expected in future telescopes.
