Toward more robust numerical and observational comparisons

进行更稳健的数值和观察比较

• 批准号: RGPIN-2019-06829
• 负责人: Thacker, Robert
• 金额: $ 1.75万
• 依托单位: Saint Mary's University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=716286
• 关键词: Toward; more; robust; numerical; observational

This proposal lays out a program of research designed to help us further understand both the applicability and limitations of using numerical simulations of galaxy formation to help explain observational results from both a phenomenological and statistical perspective. This investigation theme is motivated by the next generation of large scale surveys that will operate in the 2020s, such as the Large Synoptic Survey Telescope and the European Euclid mission (to name but two major projects), that will provide statistical samples of galaxies of exceptional size and fidelity. The proposal is primarily focused on further understanding three key components of simulations: Firstly the variance of galaxy properties produced by chaos-like evolution in simulations, an issue that is growing in concern within the community. Secondly an examination of evolutionary and environmental issues within observationally derived correlations of properties of galaxies, such as the star formation rate (SFR) of a galaxy versus the inferred black hole accretion rate (BHAR), and thirdly an examination of whether the evolution of isolated dwarf system is sufficiently simple to allow star formation models to be directly constrained. All simulation work will be conducted using the state-of-the-art' GIZMO code, with a limited amount of development necessary to add new computational techniques. The studies of chaos will involve resimulating galaxies multiple times under varying situations to see how the level of chaos-like evolution decomposes via two separate potential channels, namely halo, and disk evolution. The disk evolution part of the analysis will be conducted using a newly developed algorithm that provides a simple measure of the local level of mixing. A complementary investigation will examine how different models of the energy return from star formation, `feedback', produce different levels of chaos, as current investigations provide contradictory results on the addition of more complex physics. The research theme focused on understanding the SFR-BHAR correlation will first examine a suite of 300 simulated clusters to focus on environmental impacts on the activity of nuclear accretion in galaxies and then move on to a larger simulation project that precisely constrains the build-up of mass in galaxy halos to determine if that can be used as means to better understand observed correlations. The star formation model constraint project will also use a suite of simulated galaxy models to conduct a sensitivity analysis of the star formation efficiency and various feedback parameters versus the epoch of cosmic reionization. The research will be supported by an award winning outreach portfolio that will be broadened to build a collaboration with Mi'kmaq artist, Melissa Sue Labrador, who is especially interested in the cosmic evolution and relating this to indigenous ways of knowing. The PI & research group will explore with Labrador in the spirit of "Two-eyed seeing."

这一建议列出了一个研究计划，旨在帮助我们进一步了解使用星系形成的数值模拟来帮助从现象学和统计学角度解释观测结果的适用性和局限性。这一调查主题的动机是将在本世纪20年代开展的下一代大规模调查，如大型天文观测望远镜和欧洲欧几里德任务(仅举两个主要项目)，它们将提供超大星系和保真度星系的统计样本。 该提议主要集中在进一步了解模拟的三个关键组成部分：第一，模拟中类混沌演化所产生的星系属性的变化，这是一个在社区内日益受到关注的问题。其次，研究星系的演化和环境问题，通过观测得出星系性质的相关性，例如星系的恒星形成率(SFR)与推断的黑洞吸积率(BHAR)；第三，检查孤立的矮星系统的演化是否足够简单，从而允许恒星形成模型直接受到约束。 所有的模拟工作都将使用最先进的Gizmo代码进行，只需进行有限的开发就可以添加新的计算技术。对混沌的研究将涉及在不同的情况下多次重新模拟星系，以了解类混沌演化的水平是如何通过两个独立的潜在渠道分解的，即光晕和盘状演化。分析的圆盘演化部分将使用一种新开发的算法进行，该算法提供了局部混合水平的简单测量。一项补充研究将考察恒星形成过程中能量回报的不同模型--“反馈”--如何产生不同程度的混乱，因为目前的研究在增加更复杂的物理学方面提供了相互矛盾的结果。以理解SFR-Bhar关联为重点的研究主题将首先检查一套300个模拟星系团，重点关注环境对星系核吸积活动的影响，然后进入一个更大的模拟项目，精确地限制星系晕中的质量积累，以确定这是否可以用作更好地理解观测到的关联的手段。恒星形成模型约束项目还将使用一套模拟星系模型来进行恒星形成效率和各种反馈参数对宇宙再电离纪元的敏感性分析。 这项研究将得到一个获奖的推广组合的支持，该组合将扩大到与Mi‘kmaq艺术家Melissa Sue Labrador建立合作关系，Melissa Sue Labrador对宇宙进化特别感兴趣，并将其与土著的认识方式联系起来。PI&研究小组将本着“双眼看”的精神，与拉布拉多一起探索。