Toward more robust numerical and observational comparisons

这个建议提出了一个研究计划，旨在帮助我们进一步了解使用星系形成的数值模拟的适用性和局限性，以帮助从现象学和统计学的角度解释观测结果。这一调查主题的动机是将在21世纪20年代进行的下一代大规模调查，例如大型综合调查望远镜和欧洲欧几里得任务（仅举两个主要项目），它们将提供超大尺寸和保真度的星系统计样本。***该提案主要集中在进一步理解模拟的三个关键组成部分：首先，模拟中混沌演化产生的星系特性的差异，这是一个在社区内日益关注的问题。其次，在观测推导出的星系属性相关性中，例如星系的恒星形成速率（SFR）与推断出的黑洞吸积速率（BHAR），对进化和环境问题进行了检查；第三，对孤立矮系统的演化是否足够简单，可以直接约束恒星形成模型进行检查。***所有模拟工作将使用最先进的“GIZMO代码”进行，需要进行有限的开发以添加新的计算技术。对混沌的研究将包括在不同情况下多次重新模拟星系，以观察类混沌进化水平如何通过两个独立的潜在通道分解，即光晕和盘进化。分析的圆盘演化部分将使用一种新开发的算法进行，该算法提供了对局部混合水平的简单测量。一项补充性的研究将研究不同的恒星形成能量返回模型，即“反馈”，如何产生不同程度的混沌，因为目前的研究在添加更复杂的物理方面提供了相互矛盾的结果。研究主题侧重于理解srr - bhar相关性，将首先检查一套300个模拟星团，以关注星系中核吸积活动的环境影响，然后转向一个更大的模拟项目，精确地限制星系晕中质量的积累，以确定是否可以用作更好地理解观察到的相关性的手段。恒星形成模型约束项目还将使用一套模拟星系模型，对恒星形成效率和各种反馈参数对宇宙再电离时代的敏感性进行分析。***这项研究将得到一个获奖的外联组合的支持，该组合将扩大到与米克马克艺术家梅丽莎·苏·拉布拉多（Melissa Sue Labrador）的合作，她对宇宙进化特别感兴趣，并将其与土著认识方式联系起来。PI和研究小组将本着“两只眼睛看”的精神与拉布拉多一起探索

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."**