Probing Galaxy Feedback across Cosmic Time with a 3-Dimensional Census of Quasar Absorption Lines

布里特伦德格伦博士被授予NSF天文学和天体物理学博士后奖学金，在威斯康星大学麦迪逊分校开展研究和教育计划。 天体物理学中一个长期存在的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演化的以及深入了解我们银河系的起源是必要的。 了解星系演化的一个重要方面是研究某些星系中新形成的恒星的大区域如何与这些星系中心（核）的大质量黑洞相互作用，这是该研究员项目的中心主题。通过使用类星体吸收线（QAL）的最大样本，该研究员将解决有关星系际介质的富集历史及其与来自星星形成和活动星系核（AGN）的反馈的联系等悬而未决的问题在星系中。 QAL提供了在红移的巨大范围内对银河系环境的独特无偏探测，但直到最近才有光谱观测到的高红移类星体的数量密度，再加上深星系调查的规模，提供了足够的统计数据，以研究星系之间的关联和吸收功能，在近源类星体的视线范围广泛的红移和星系的属性。通过她参与斯隆数字巡天III的重子振荡光谱巡天（BOSS）将在未来三年内获得160，000个红移z 2.2类星体的光谱，该研究员将提取红移范围z = 0.35至4的金属吸收线的三维普查。 使用这个数据集，已经比现有的样本大一个数量级，她将精确测量星系际介质中最多产的金属从红移z约4到现在的数量密度和等效宽度分布的演变。 利用这些数据与她目前参与的许多深星系调查，她将揭示高红移QAL的典型星系环境，并限制星系和活动星系核外流延伸的物理距离作为星系属性和红移的函数。 总之，这些调查将有可能彻底改变我们对星星形成和活动星系核反馈的理解，以及它在大约90%的宇宙历史中星系和星系际介质共同进化中的作用。 该研究员将与位于麦迪逊的一个完善的天文学外展中心--华盛顿大学空间中心合作开展一项教育外展计划。 在这个设施内，她将进行一系列的周末研讨会，为学生在6年级至8年级使用一个良好的测试课程的探究为基础的现代天文学活动，她为以前的教育计划设计。 该研究员将补充这些以学生为中心的会议，为当地高中科学教师举办一系列较短的晚间研讨会，旨在使教育工作者熟悉使用斯隆数字巡天（Skyserver）公共界面的活动。 这些计划将为下一代科学家提供服务，为处于关键年龄的学生提供对现代天文学研究的积极介绍，并为他们未来的教育工作者提供工具，以促进高中课堂的进一步探索。

Dr. Britt Lundgren is awarded an NSF Astronomy and Astrophysics Postdoctoral Fellowship to carry out a program of research and education at the University of Wisconsin-Madison. A longstanding problem in astrophysics is to understand how galaxies form and develop---or evolve---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 evolution is to study how large region of newly forming stars in certain galaxies interact with the massive black holes at the centers (nuclei) of these galaxies, which is the central theme of this fellow's project.By using the largest sample of quasar absorption lines (QALs), the fellow will address outstanding questions regarding the enrichment history of the intergalactic medium and its connection to feedback from star formation and Active Galactic Nuclei (AGN) in galaxies. QALs provide uniquely unbiased probes of galactic environments over vast ranges in redshift, but only recently has the number density of spectroscopically observed high-redshift quasars, combined with the scale of deep galaxy surveys, provided sufficient statistics to study the associations between galaxies and absorption features in proximate quasar sightlines over wide ranges in redshift and galaxy properties.Through her participation in the Sloan Digital Sky Survey III's Baryon Oscillation Spectroscopic Survey (BOSS), which will obtain spectra for 160,000 redshift z 2.2 quasars over the next three years, the fellow will extract a 3-dimensional census of metal absorption lines in the redshift range z = 0.35 to 4. Using this data set, already one order of magnitude larger than existing samples, she will precisely measure the evolution of the number density and equivalent width distribution for the most prolific metals in the intergalactic medium from redshift z around 4 to present. Leveraging these data with her existing participation in numerous deep galaxy surveys, she will reveal the typical galactic environments of QALs from high redshift and constrain the physical distances to which galaxy and AGN outflows extend as a function of galaxy properties and redshift. Together, these investigations will potentially revolutionize our understanding of feedback from star formation and AGN and its role in the co-evolution of galaxies and the intergalactic medium throughout about 90% of cosmic history.The broader impacts of this project include a significant educational component. The fellow will undertake a program of educational outreach in partnership with the UW Space Place, a well-established astronomy outreach center in Madison. Within this facility she will conduct a series of weekend workshops for students in grades 6 through 8 using a well-tested curriculum of inquiry-based modern astronomy activities that she designed for a previous educational program. The fellow will supplement these student-focussed sessions with a shorter series of evening workshops for local high school science teachers that are designed to familiarize educators with activities using the public interface to the Sloan Digital Sky Survey, the Skyserver. These programs will serve the next generation of scientists by providing students at a critical age with a positive introduction to modern astronomy research in addition to providing their future educators with the tools to foster further explorations in the high school classroom.