Collaborative Research: Galactic Winds and the Multiphase Structure of the Circum-Galactic Medium

大质量星系埋藏在一个动态的粒子和暗物质储存库中，称为环星系介质(CGM)。CGM不仅代表了星系形成的化石记录，它还通过冷却的流入气体与由恒星风和超新星驱动的流出气体的相互作用，继续塑造它们的演化。这个研究小组将开发一种最先进的流体力学星系模拟代码，以研究恒星形成诱导的外流和CGM之间的复杂相互作用。从这些模拟得到的合成紫外吸收线谱将直接与哈勃太空望远镜的数据进行比较，以促进我们对CGM结构和动力学的理解。这些模拟还将用于一个针对代表人数不足的群体的理科预科专业学生的项目。该计划将向他们介绍在天体物理学中使用计算机模拟，并鼓励他们考虑一个以技术为导向的主要学习计划。研究小组将首先将PHEW(物理演化的风)子网格模型纳入流体力学星系模拟程序CHAGA中，并验证其准确性。一旦得到验证，他们将开始对当前纪元类银河系的CGM进行建模，并开始将合成的UV光谱与HST数据进行比较。通过一系列这样的模拟，系统地探索一系列的演化路径，该团队将试图评估CGM的吸收线属性的哪些方面相对于星系历史是健壮的，哪些与恒星形成更直接相关。最后，该团队将通过运行一个模拟宇宙体积(Romulus25；25Mpc侧面立方体)内星系演化的模拟，来探索CGM结构是如何作为星系质量和环境的函数受PHEW影响的。这将允许调查模拟的HST/COS光谱如何随着星系类型、质量和环境的变化而变化，以及CGM如何在这些参数中演变。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。

Massive galaxies are embedded in a dynamic reservoir of particles and dark matter called the circumgalactic medium (CGM). The CGM not only represents a fossil record of galaxy formation, it also continues to shape their evolution through the interaction of cool infalling gas with outflows driven by stellar winds and supernovae. This research team will develop a state-of-the-art hydrodynamic galaxy simulation code to study the complex interplay between star formation induced outflows and the CGM. Synthetic UV absorption line spectra derived from these simulations will be directly compared with Hubble Space Telescope data to advance our understanding of the structure and dynamics of the CGM. These simulations will also be used in a program for pre-majors in science from underrepresented groups. The program will introduce them to the use of computer simulations in astrophysics and encourage them to consider a technically oriented major program of study. The research team will first incorporate the PhEW (Physically Evolved Winds) sub-grid model into the hydrodynamic galaxy simulation code ChaNGa and verify its accuracy. Once validated, they will begin modeling the CGM of current epoch Milky Way-like galaxies and begin making comparisons between the synthetic UV spectra with HST data. Through a series of such simulations that systematically explore a range of evolutionary paths, the team will try to assess which aspects of the CGM's absorption line properties are robust against galaxy history and which are more directly connected to star formation. Finally, the team will explore how CGM structure is affected by PhEW as a function of galaxy mass and environment by running a simulation that evolves galaxies within a cosmological volume (Romulus25; 25 Mpc sided cube). This will allow investigations of how the simulated HST/COS spectra vary as a function of galaxy type, mass, and environment and how the CGM evolves across these parameters.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.