Large-Scale Investigations of Quasar Wind Variability with the Sloan Digital Sky Survey

天体物理学中的一个长期问题是了解星系在其一生中是如何形成和发展的。这样的理解对于揭示我们的宇宙是如何进化的以及洞察我们银河系的起源是必要的。理解星系形成和演化的一个重要方面是研究星系中心的超大质量黑洞(SMBH)，以及这些SMBH是如何与其宿主星系联系在一起的。类星体风从根本上与快速增长的SMBH的质量吸积有关，它们也可能作为SMBH反馈到典型大质量星系的媒介。这个项目将通过对大约2100个BAL类星体的多年紫外线宽吸收线(BAL)变化性的光谱调查，促进对类星体风的几个关键方面的理解。这项调查主要基于正在进行的斯隆数字天空调查(SDSS)的光谱，比过去的可比调查大了大约两个数量级；支持目标光谱的也是通过宾夕法尼亚州立大学的排队安排的Hobby-Eberly望远镜获得的。PI的年度暑期研讨会将作为一种高杠杆的方式，帮助大约50名宾夕法尼亚州的高中教师更好地教育他们的数千名学生关于空间、时间、重力、黑洞和科学方法。来自服务不足的农村和城市学区的教师，包括代表不足的少数民族和妇女，将用奖学金资金专门招聘。研讨会的计划将包括对该项目的科学发现和相关活动的概述，博士后研究助理将帮助研讨会的规划和演示。博士后研究员还将作为Pi小组的核心成员工作，从而发展他或她的研究、教学和推广技能。他或她将领导大部分分析以及许多高影响力的期刊文章和演示文稿。博士后研究员也将是本科生研究人员的主要导师，本科生研究人员将通过明确的项目发展实践研究技能。更技术上，该项目将利用其数据库提供以下具体进展：(1)限制BAL-风反馈到星系的BAL加速和减速的无与伦比的大规模测量/限制；(2)BAL与发射线性质的测量，以测试BAL可变性和类星风模型的驱动因素；(3)BAL消失和出现之间的深度关系的确定，以及直接BAL寿命估计的相关改进；(4)对异常稳定的BAL的性质及其与正在进行的大尺度星系反馈的可能关系的理解；以及(5)确定显著红移的BAL槽是由旋转主导的外流还是高速流入物质引起的。这些结果将在将多年BAL变率研究领域转变为提供严格的大样本约束条件以有效指导类星体风模型及其反馈方面发挥重要作用。预计这将是至少十年来最好的结果。

A longstanding problem in astrophysics is to understand how galaxies form and develop throughout their lifetimes. Such understanding is necessary to uncover how our Universe evolved and to gain insight into the origin of our own Milky Way Galaxy. One important aspect of understanding galaxy formation and evolution is to study supermassive black holes (SMBHs) at the centers of galaxies and how these SMBHs are linked to their host galaxies. Quasar winds are fundamentally linked to mass accretion onto rapidly growing SMBHs, and they also likely serve as agents of SMBH feedback into typical massive galaxies. This project will advance understanding of several key aspects of quasar winds using an unprecedentedly large---and still growing---spectroscopic survey of multi-year ultraviolet broad absorption line (BAL) variability in about 2100 BAL quasars. This survey is primarily based on spectra from the ongoing Sloan Digital Sky Survey (SDSS) and is about two orders of magnitude larger than past comparable surveys; supporting targeted spectroscopy is also obtained via Penn State's access to the queue-scheduled Hobby-Eberly Telescope.The PI's annual summer workshops will serve as a high-leverage way of helping about 50 Pennsylvania high school teachers educate their thousands of students better about space, time, gravity, black holes, and the scientific method. Teachers from underserved rural and urban school districts, including underrepresented minorities and women, will be specifically recruited with scholarship funds. The workshops' programs will include an overview of the project's scientific discoveries and an associated activity, and the postdoctoral research associate will help with workshop planning and presentation. The postdoctoral researcher will also work as a central member of PI's group, thereby developing his or her research, teaching, and outreach skills. He or she will lead much of the analysis as well as many of the high-impact journal articles and presentations. The postdoctoral researcher will also be a primary mentor of the undergraduate researcher, who will develop hands-on research skills via well-defined projects.More technically, this project will use its database to provide the following specific advances: (1) unmatched large-scale measurements/limits of BAL acceleration and deceleration that constrain BAL-wind feedback into galaxies; (2) measurements of BAL vs. emission-line properties that test the drivers of BAL variability and quasar-wind models; (3) determination of the in-depth relations between BAL disappearance and emergence with associated improvements in direct BAL-lifetime estimates; (4) an understanding of the nature of unusually stable BALs and their possible relation to ongoing large-scale galactic feedback; and (5) determination of whether remarkable redshifted BAL troughs arise from rotationally dominated outflows or high-velocity infalling material. These results will play an important role in transforming the field of multi-year BAL variability studies into one that supplies rigorous, large-sample constraints that can effectively guide models of quasar winds and their feedback. They are expected to be the best such results available for at least a decade.