Connecting galaxies to the cosmic web

将星系连接到宇宙网

• 批准号: 1642746
• 金额: --
• 依托单位: University of St Andrews
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2015
• 资助国家: 英国
• 起止时间: 2015 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-1642746
• 关键词: Connecting; galaxies; cosmic; web

This project will work on current and future galaxy redshift surveys BOSS / eBOSS / DESI which provide spectroscopic redshifts for an unprecedented volume of the Universe up to a redshift of 1. These surveys are incredibly powerful tools for cosmology in terms of improving constraints on dark energy and measuring the expansion history of the universe, but also have the potential for being useful tools for studying galaxy evolution due to the large number of galaxy observations.However, with the focus being firmly on cosmology, these surveys target galaxies to maximise the volume surveyed. This results in incomplete samples (with respect to, e.g., a magnitude limited survey) with complex selection functions. The use of such surveys for galaxy evolution studies would be significantly improved if such a completeness could be estimated. If populations of galaxies with photometric and spectroscopic redshifts exist in the same region, then by cross correlating the two populations it is possible to recover the redshift distribution of the photometric sample. The initial goal of the project will be to use cross correlations to reconstruct the completeness of these surveys, re-instating them as versatile tools for galaxy evolution.With this computed, more information can be obtained about the galaxy populations. This project will focus on modelling how galaxies in these surveys populate dark matter halos and how one can identify progenitors across redshifts and surveys. The results will allow better cosmological constraints as well as revealing the mass assembly in massive galaxies over the last 7 billion years of cosmic history.

该项目将致力于当前和未来的星系红移调查BOSS / eBOSS / DESI，这些调查提供了前所未有的宇宙体积的光谱红移，最高红移为1。这些巡天观测在改善暗能量约束和测量宇宙膨胀历史方面是非常强大的宇宙学工具，但由于大量的星系观测，这些巡天观测也有可能成为研究星系演化的有用工具。然而，由于重点集中在宇宙学上，这些巡天观测的目标是星系，以最大限度地扩大调查的体积。这导致不完整的样本（例如，幅值有限的勘测）与复杂的选择函数。如果能够估计这种完整性，将大大改进利用这种巡天进行星系演化研究的情况。如果在同一个区域内存在具有光度红移和光谱红移的星系群，那么通过互相关这两个星系群就有可能恢复光度样本的红移分布。该项目的最初目标是利用互相关来重建这些调查的完整性，使它们重新成为星系演化的通用工具。通过计算，可以获得更多关于星系人口的信息。该项目将侧重于模拟这些调查中的星系如何填充暗物质晕，以及如何在红移和调查中识别祖先。这些结果将允许更好的宇宙学约束，并揭示过去70亿年宇宙历史中大质量星系的质量组装。