Dynamical Evolution of Planetary Systems in Star Clusters

星团中行星系统的动力学演化

• 批准号: 1302765
• 负责人: Aaron Geller
• 金额: $ 8.9万
• 依托单位: Geller Aaron M
• 依托单位国家: 美国
• 项目类别: Fellowship Award
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-06-01 至 2017-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1302765&HistoricalAwards=false
• 关键词: Dynamical; Evolution; Planetary; Systems; Star

Dr. Aaron Geller is awarded an NSF Astronomy and Astrophysics Postdoctoral Fellowship to carry out a program of research and education at Northwestern University. The fellow's project involves exoplanets. Today, astronomers are discovering a rich panoply of exoplanets in our Galaxy. Many of these exoplanets are in multi-planet systems. Some show surprisingly different characteristics from our own Solar System that pose serious problems for standard isolated planet formation theories. Strong evidence indicates that the majority of stars form in clusters, many of which dissolve within the age of the Universe. Therefore, many of the exoplanets observed today---in stars clusters and the field of the Galaxy---may have been born inside star clusters and subjected to past perturbations from nearby stars. Understanding how stellar encounters within this birth environment affect the dynamical evolution of planetary systems is paramount to interpreting the characteristics of all the newly discovered exoplanets and how these relate to the planet formation epoch. To address these important questions, the fellow work with a team of experts to complete development of the first computer code to self-consistently simulate the dynamical evolution of multi-planet systems in realistic star clusters. Dr. Geller and collaborators have already completed a pilot code demonstrating the feasibility of the most critical and innovative components, and the full code will be completed early in the first year of the fellowship. The fellow will then use this code to model nine open star clusters, including four in the Kepler field that have been surveyed comprehensively for transiting exoplanets. Each cluster will be modeled with multiple different initial planet populations to cover the range in characteristics of observed exoplanets. The simulations will be analyzed, accounting for the unique sensitivity limits of each transit survey, and the results will be compared directly with the observations. This project will reveal---for the first time self-consistently---how stellar encounters within star clusters of a wide range in age, density, mass, etc., influence the dynamical evolution of multi-planet systems including those like our Solar System and how the characteristics of exoplanets observed today in both clusters and the field may have been modified in the past by their birth environment.The broader impacts of this project include a significant educational component. The fellow will undertake a program of educational outreach in partnership with the Northwestern's NSF-funded GK-12 and CE21 programs to develop, test, and disseminate about 15 high school lesson plans based on the scientific research of this project. The fellow will work directly with a Northwestern graduate student to develop around five classroom-tested high school lesson plans each year. To supplement the lesson plans, the fellow will also develop a web-based student-friendly interface to both analyze the products of the proposed simulations and to allow students to run simulations of their own. During years 2 and 3 the fellow will integrate these lesson plans into teacher professional development workshops, which the PI will co-lead. Through these workshops, the fellow will train about 20 Chicago Public School and area teachers to use his lesson plans, thereby reaching about 2000 students with his curricular materials by the end of the fellowship. Both the GK-12 and CE21 programs are well established at Northwestern University and have been running successfully for years. This is a natural and mutually beneficial partnership that will help train the fellow for a future career teaching computational thinking methods in undergraduate physics and astronomy courses.

亚伦·盖勒（Aaron Geller）博士被授予NSF天文学和天体物理学博士后奖学金，以在西北大学进行研究和教育计划。 同伴的项目涉及系外行星。 今天，天文学家正在我们的银河系中发现了丰富的系外行星。 这些系外行星中的许多都在多星际系统中。 一些人与我们自己的太阳系具有出人意料的不同特征，这些特征对于标准孤立的行星形成理论构成了严重的问题。 有力的证据表明，大多数恒星在簇中形成，其中许多恒星溶解在宇宙时代。 因此，今天观察到的许多系外行星 - 在星团和星系的田地中 - 可能出生在星形簇中，并受到附近恒星的过去扰动。 了解这种出生环境中的恒星遇到如何影响行星系统的动态演化对于解释所有新发现的系外行星的特征以及这些与行星形成时期的关系至关重要。为了解决这些重要的问题，与专家团队的同伴一起完成了第一个计算机代码的开发，以自一巧妙地模拟逼真的星团中多行星系统的动态演变。 Geller博士和合作者已经完成了一项试点代码，证明了最关键和最具创新性的组件的可行性，并且完整的代码将在奖学金的第一年初完成。 然后，该研究员将使用此代码对九个开放式星团进行建模，其中包括在开普勒字段中进行了全面调查的针对过境系外行星的四个。 每个群集将使用多个不同的初始行星种群进行建模，以涵盖观察到的系外行星的特征范围。 将分析模拟，考虑到每个运输调查的唯一灵敏度限制，并将结果直接与观测值进行比较。 该项目将首次揭示 - 首次 - - - 在年龄，密度，质量等广泛范围内的恒星遇到如何影响多行星系统的动态演化，包括像我们的太阳系诸如我们的太阳系和诸如我们的群体特征如何在簇和现场观察到的范围内的特征如何在整个环境中进行了重大影响。 该研究员将与西北NSF资助的GK-12和CE21计划合作进行教育宣传计划，以根据该项目的科学研究开发，测试和传播约15个高中课程计划。 该研究员将直接与西北研究生合作，每年制定大约五个教室测试的高中课程计划。 为了补充课程计划，该研究员还将开发一个基于网络的学生友好界面，以分析拟议的模拟的产品，并允许学生进行自己的模拟。 在第2年和第3年中，研究员将将这些课程计划纳入教师专业发展研讨会，PI将共同领导。 通过这些研讨会，这位研究员将培训约20名芝加哥公立学校和地区教师使用他的课程计划，从而在研究金结束前用他的课程材料到达约2000名学生。 GK-12和CE21计划都在西北大学建立了良好的建立，并且已经成功运行了多年。 这是一种自然而互惠互利的伙伴关系，它将帮助培训同伴的未来职业教学本科生和天文学课程中的计算思维方法。