Collaborative Research: Constraining galaxy cluster merger dynamics with hydrodynamical simulations and novel multi-probe observations of 10 objects

星系团是揭开星系形成和演化背后的谜团的关键参与者，了解这些谜团对于揭示我们的宇宙是如何进化的，以及了解我们自己的银河系是如何开始的是必要的。这个项目的目标是更好地理解我们宇宙中最大束缚天体的主要增长机制：相似质量的星系团之间的主要合并。需要深度、多探头观测数据和先进的流体力学计算机模拟。这个项目旨在通过对十个星系团的研究来极大地提高我们的知识。该项目还将通过直接培训普通和计算天体物理学方面的研究生和博士后研究员来加强美国的科学队伍。项目计划还包括积极的教育和公众宣传计划。具体地说，研究人员将通过定期访问加布里埃利诺高中(加利福尼亚州圣加布里埃尔)来促进发现和理解；通过加州理工大学的暑期研究连接接待加布里埃利诺高中的学生，以及通过史密森学会天体物理天文台的拉丁裔倡议计划，接待马萨诸塞州东部大学的本科生；通过访问加州理工大学提供的参观加布里埃利诺高中的演示资源，加强研究和教育的基础设施。分析将重点放在十个天体上，这些天体利用哈勃空间望远镜的引力透镜模型绘制出天空平面(POS)的投影总质量密度；X射线光谱成像绘制出POS ICM的发射率和温度；星系团成员光谱绘制出暗物质的视线速度；以及Sunyaev-Zel‘dovich效应数据绘制LOS速度和ICM的投影密度图。研究人员将掌握暗物质和ICM气体的POS形态和视线速度的完整信息。他们将与专门为该项目制作的定制流体力学合并模拟的模拟观测进行比较。最终结果将是对样本中每个星系团的合并几何结构的强有力的限制，这将使搜索新的动力学过程和评估样本的人口统计数据成为可能。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Clusters of galaxies are key players in unraveling the mysteries behind galaxy formation and evolution, and understanding such mysteries is necessary to uncover how our Universe evolved and to learn how our own Milky Way Galaxy began. The goal of this project is to better understand the primary growth mechanism of the largest bound objects in our Universe: major mergers between galaxy clusters of similar masses. Deep, multi-probe observational data and advanced hydrodynamical computer simulations are required. This project aims to significantly advance our knowledge through the study of ten galaxy clusters. This project will also strengthen the US science workforce by directly training a graduate student and postdoctoral researcher in general and computational astrophysics. Project plans also include a vigorous education and public outreach program. Specifically, the investigators will advance discovery and understanding via regular visits to Gabrielino High School (San Gabriel, CA); broaden participation of underrepresented groups by hosting students from Gabrielino High School via the Summer Research Connection at Caltech, as well as undergraduates from colleges around Eastern Massashuetts via the Latino Initiative Program at the Smithsonian Institution Astrophysical Observatory; and enhance infrastructure for research and education by accessing the demonstration resources available from Caltech for visits to Gabrielino High School. The analysis will focus on ten objects that have gravitational lensing models from Hubble Space Telescope to map the plane-of-sky (POS) projected total mass density; X-ray spectroscopic imaging to map the POS ICM emissivity and temperature; cluster-member spectroscopy to map the line of sight (LOS) velocity of the dark matter; and Sunyaev-Zel’dovich effect data to map the LOS velocity and projected density of the ICM. The investigators will have complete information about the POS morphology and LOS velocity of both the dark matter and the ICM gas. They will compare with mock observations of custom hydrodynamical merger simulations produced specifically for this project. The end result will be a robust constraint on the merger geometry of each galaxy cluster in their sample that will enable a search for new dynamical processes and an assessment of population statistics for the sample.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.