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Astrophysics and Cosmology from the Epoch of reionisation and the cosmic dawn with the Square Kilometre Array.

来自再电离时代的天体物理学和宇宙学以及平方公里阵列的宇宙黎明。

基本信息

批准号：
1810948
负责人：
金额：
--
依托单位：
Imperial College London
依托单位国家：
英国
项目类别：
Studentship
财政年份：
2016
资助国家：
英国
起止时间：
2016 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=studentship-1810948
关键词：
Astrophysics Cosmology Epoch reionisation cosmic

项目摘要

Currently Cosmological information can be obtained via the distribution of Hydrogen atoms in the Universe in two main ways. Firstly Quasars from the Hubble deep field are used to probe the Universe for the amount of Hydrogen via the Lyman Alpha Forest in any one direction up to about a redshift of z=6. Secondly the Cosmic Microwave Background (CMB) provides information of density fluctuations of the Universe around the time of recombination of Hydrogen atoms after the Big Bang, at a redshift of about z=1100. However the range in between these two techniques is not nearly as well known experimentally. The Square Kilometre Array (SKA) intends to shed light on the period of redshifts z=6 to z=27 by analysing fluctuations in the 21cm hyperfine emission line of neutral Hydrogen with a new generation of radio interferometers. Analysis of the powers spectrum should produce a model of the evolution of neutral Hydrogen atoms, as density perturbations shown in the CMB grow into Galaxies, until the majority of the Hydrogen in the Universe is re-ionised. This project is aimed towards looking at Bayesian statistical analyses used on theoretical data that will be similar to the real data produced by SKA when it is finished being built in Australia in 2020 (and also the data from HERA, a similar experiment under construction in South Africa). This semi-numerical simulation will hopefully allow us to understand the observations made by SKA in an astrophysical context, in terms of Galaxy formation during the Cosmic Dawn.

目前，通过氢原子在宇宙中的分布可以通过两种主要方式获得宇宙学信息。首先，来自哈勃深场的类星体被用来通过莱曼阿尔法森林在任何一个方向上探测宇宙中的氢气量，最高可达z=6的红移。其次，宇宙微波背景(CMB)提供了宇宙在大爆炸后氢原子重组时间附近的密度波动信息，红移约为z=1100。然而，这两种技术之间的范围在实验上并不是那么广为人知。平方公里阵列(SKA)打算用新一代射电干涉仪分析中性氢21厘米超精细发射线的波动，从而揭示z=6到z=27的红移周期。对功率谱的分析应该会产生一个中性氢原子演化的模型，因为CMB中显示的密度扰动会发展成星系，直到宇宙中的大部分氢被重新电离。该项目旨在研究对理论数据进行的贝叶斯统计分析，这些理论数据将与SKA于2020年在澳大利亚建成后产生的真实数据相似(也包括南非正在建设的类似实验HERA的数据)。这一半数值模拟将有望让我们理解SKA在天体物理背景下所做的观测，即宇宙黎明期间星系的形成。