The Dynamical Echoes Of Dark Matter Sub-Structure: In Simulations & In Spirals Out To z ~ 0.1

暗物质子结构的动态回声：模拟

• 批准号: 1517488
• 负责人: Sukanya Chakrabarti
• 金额: $ 32.51万
• 依托单位: Rochester Institute of Tech
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-08-01 至 2019-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1517488&HistoricalAwards=false
• 关键词: Dynamical; Echoes; Dark; Matter; Sub

The current cosmological paradigm includes two significant and unknown physical entities called "dark matter" and "dark energy," which are used to model the Universe as we know it. Understanding the distribution of dark matter remains one of the most fundamental problems in astronomy and is the focus of this project. There are many discrepancies between dark matter sub-structure in the existing computer simulations and in observations. There are too few massive satellites relative to simulations, and at low Galactic latitudes there are hardly any Milky Way satellites. This project aims to extract essential information on the dark matter distribution in spiral galaxies by building on the investigator's ongoing work in characterizing galactic satellites from analysis of disturbances in extended disks of hydrogen gas.Communicating scientific results to a broad audience and promoting diversity benefits the astronomy community and our society at large. This project will be carried out at Rochester Institute of Technology (RIT), which has historically been primarily an undergraduate institution:(1) Women in Science: The PI will organize regular meetings with visiting women colloquium speakers, with the goal of gathering advice on professional development. Dr. Chakrabarti will also continue participating in the Expanding Your Horizons program, which is geared towards engaging middle school girls in science.(2) Computational Bootcamp: Every summer, the PI will provide a two-week, intensive computational bootcamp geared towards entering graduate students. The goal of this bootcamp is to serve as a bridge---providing an introduction to computational astrophysics, with hands-on lectures that illustrate the basics of computing and applications to astronomy. The PI will work through simple examples in IDL and Python, and she will encourage women and minority students to attend the bootcamp, and assign mentors for entering students.(3) Visualization Laboratory: The PI will continue producing 3-D animations of galaxy collisions, which will be showcased in the Viz-Lab at RIT. Three-D movies are becoming an increasingly popular tool to engage the public and are effective in widely disseminating research on galaxy evolution.The PI will carry out the following technical tasks:(1) The Milky Way: By matching simulated orbits of the Milky Way satellites with HST proper motions and tidal debris, the PI will derive constraints on the orbital parameters, as well as the initial stellar (and dark matter) distribution of the Milky Way satellites. The PI will produce models that are consistent with both the HI and stellar data of our galaxy, which displays large ripples in the outskirts, a prominent warp, and vertical waves in the galactic disk.(2) Probing The Dark Matter Halo: Dark matter halos evolve as a function of time, and they may have complex shapes. The PI will determine if the inference of the halo potential from stellar streams is viable for time-varying potentials. By deconstructing the hydrodynamical cosmological simulation ERIS, the PI will study if the distribution of satellites and the morphology of the gas and stellar disk is representative of the Milky Way or local spirals.(3) Shaking and Rattling The Local Spirals: By simulating a wide range of encounters with sub-halos from cosmological simulations, and mapping to multiple observational constraints in a statistically robust manner using a Monte Carlo Markov Chain analysis, the PI will produce realistic mock catalogs and evolutionary histories of HI disks and their satellite populations.(4) Strong Spiral Lenses in HI: As the SWELLS sample is a sufficiently low redshift sample of strong spiral lenses (z_avg ~ 0.1) showing visible signs of interaction, the PI will compare and contrast the team's HI analysis and gravitational lensing to derive two independent constraints on the dark matter distribution.

当前的宇宙学范式包括两个重要且未知的物理实体，称为“暗物质”和“暗能量”，它们用于模拟我们所知的宇宙。 了解暗物质的分布仍然是天文学中最基本的问题之一，也是该项目的重点。 现有的计算机模拟和观测中的暗物质子结构存在许多差异。 与模拟相比，大型卫星太少，并且在低银河系纬度，几乎没有任何银河系卫星。 该项目旨在通过研究人员正在进行的工作，通过分析扩展的氢气盘中的扰动来表征银河卫星，从而提取有关螺旋星系中暗物质分布的基本信息。向广大受众传播科学成果并促进多样性有利于天文学社区和我们整个社会。 该项目将在罗彻斯特理工学院 (RIT) 进行，该学院历来主要是一所本科院校：(1) 科学领域的女性：PI 将定期与来访的女性研讨会发言人组织会议，目的是收集关于科学领域的建议专业发展。 Chakrabarti 博士还将继续参加“扩展你的视野”计划，该计划旨在吸引中学生参与科学。(2) 计算训练营：每年夏天，PI 将提供为期两周的强化计算训练营，旨在帮助进入研究生学生。该训练营的目标是充当一座桥梁，介绍计算天体物理学，并通过实践讲座来说明计算基础知识和天文学应用。 PI 将使用 IDL 和 Python 完成简单的示例，她将鼓励女性和少数族裔学生参加训练营，并为进入的学生指派导师。(3) 可视化实验室：PI 将继续制作星系碰撞的 3D 动画，将在 RIT 的 Viz-Lab 中展示。 3D电影正在成为越来越受欢迎的公众参与工具，能够有效地广泛传播星系演化研究。PI将执行以下技术任务：（1）银河系：通过匹配银河系的模拟轨道对于具有 HST 自行和潮汐碎片的卫星，PI 将导出对轨道参数的约束，以及银河系卫星的初始恒星（和暗物质）分布。 PI将制作与我们星系的HI和恒星数据一致的模型，该模型显示了星系外围的大波纹、明显的扭曲以及银盘中的垂直波。(2)探测暗物质晕：暗物质光晕随着时间的变化而演变，并且它们可能具有复杂的形状。 PI 将确定从恒星流推断光环势能对于时变势能是否可行。 通过解构流体动力学宇宙学模拟ERIS，PI将研究卫星的分布以及气体和恒星盘的形态是否代表银河系或局部螺旋。（3）摇动局部螺旋：通过模拟广泛的螺旋宇宙学模拟中与子光晕的遭遇范围，并使用蒙特卡洛马尔可夫链分析以统计稳健的方式映射到多个观测约束，PI 将产生真实的结果HI 盘及其卫星群的模拟目录和演化历史。(4) HI 中的强螺旋透镜：由于 SWELLS 样本是强螺旋透镜 (z_avg ~ 0.1) 的红移足够低的样本，显示出可见的相互作用迹象，因此 PI 将比较和对比团队的 HI 分析和引力透镜，得出对暗物质分布的两个独立约束。