Cosmological Radiative Transfer Simulations

再电离时代是发生在宇宙中的一个相变，是几个非线性事件的结合。为了理解这种转变及其后续影响，我们正在利用大规模的辐射宇宙学模拟。我们目前的重点是通过ATON（一种后处理辐射传输代码）将氦添加到模拟中。为了最佳地研究这一点，我们采用了多频率方法，并使用较小的模拟盒来限制所需频率箱的数量。我们已经用已知的解析解通过天体物理测试验证了代码。氦的加入为研究平均自由程、光子分布、氦分数等不同的观测数据开辟了场所，同时使我们能够了解氦和氢之间的相互作用。我们还计划改变光晕的源光谱，以纳入类星体的影响。长期目标是研究再电离时代星系和星系间介质的物理性质，并对与Lyman-alpha森林数据相匹配的晚期再电离历史进行辐射传输模拟。

The epoch of reionization, a phase transition that occurred in the Universe, is a combination of several non-linear events. In an effort to understand this transition and its subsequent effects, we are utilizing large scale radiative cosmological simulations. Our current focus is to add helium to simulations through ATON - a post processing radiative transfer code. To optimally study this, we have undertaken a multi-frequency approach and are using smaller simulation boxes to constrain the number of frequency bins required. We have validated the code through astrophysical tests with known analytical solutions. Addition of helium have opened up venues to study different observables such as the mean free path, photon distribution, helium fractions while allowing us to understand the interplay between helium and hydrogen. We are also planning to change the source spectrum of the halos to incorporate the effect of quasars. The long term aim is to study reionization epoch galaxies and the physical properties of the Intergalactic Medium with radiative transfer simulations for late-end reionization histories that match Lyman-alpha forest data.