The H3 Spectroscopic Survey and the Origin of the Galaxy

H3 光谱巡天和银河系的起源

• 批准号: 2107253
• 负责人: Charles Conroy
• 金额: $ 57万
• 依托单位: Harvard University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-09-01 至 2024-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2107253&HistoricalAwards=false
• 关键词: H3; Spectroscopic; Survey; Origin; Galaxy

A main component of our Milky Way galaxy is its stellar halo, a spherical distribution of stars extending 10 times further than the stellar disk. Galaxy formation theories predict that our Milky Way's stellar halo was formed from "shredding" of smaller galaxies. However, this theory has not yet been confirmed observationally. In this project the investigators will measure the basic stellar properties (velocities, distances, and "chemistry") of 300,000 stars in the stellar halo. With these data they will provide a full inventory of the building blocks that formed our stellar halo. Stellar ages, which are measured as part of this project, will be used to deduce the timeline of star formation and galaxy merger events. Finally, the investigators will use these observations to predict the effect of the Milky Way's largest satellite companion, the Large Magellanic Cloud, on the stellar halo. Such observations may provide unique insight into the nature of dark matter and gravity. Educationally, this project will support a graduate student who will be trained on the analysis of stellar spectra and the application of dynamical models to the Galaxy. The project will also support the training of summer undergraduates from under-represented backgrounds as part of the Banneker Institute. The Banneker Institute has a summer program aimed at developing students’ research skills and social justice education.The “Hectochelle in the Halo at High Resolution” (H3) Survey will deliver high resolution spectra of stars in high Galactic latitude fields in the Northern hemisphere to measure radial velocities, spectrophotometric distances, [Fe/H], and [alpha/Fe] relative abundances. Determining these parameters will be used to explain the origin of structures in phase plus chemistry space. These observations will enable detailed constraints on the assembly history of the Galaxy, measurements of the mass profile of the outer Galaxy, the origin of the in-situ stellar halo, and will be sensitive to a variety of interesting, rare populations such as chemically peculiar stars and high velocity stars.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.

我们银河系银河系的主要组成部分是其出色的光环，这是恒星的球形分布，比恒星磁盘延伸了10倍。银河形成理论预测，我们的银河系的恒星光环是由较小星系的“切碎”形成的。但是，该理论尚未在观察上得到证实。在该项目中，研究人员将在恒星光环中测量30万星的基本恒星性能（速度，距离和“化学”）。通过这些数据，他们将提供构成我们出色光环的构建块的完整库存。作为该项目的一部分测量的恒星年龄将用于推断恒星形成和星系合并事件的时间表。最后，调查人员将使用这些观察结果来预测银河系最大的卫星伴侣，大麦哲伦云对恒星光环的影响。这种观察可能会提供对暗物质和重力本质的独特见解。在教育上，该项目将支持一名研究生，该研究生将接受对恒星光谱分析以及动态模型应用于银河系的培训。该项目还将支持作为班纳克研究所（Banneker Institute）的一部分，从代表性不足的背景培训夏季大学生的培训。班纳克研究所（Banneker Institute为了解释阶段和化学空间中的结构的起源。通过使用基金会的智力优点和更广泛影响的评论标准进行评估。

项目成果

Distant Echoes of the Milky Way’s Last Major Merger

• DOI: 10.3847/1538-4357/accf13
• 发表时间: 2022-12
• 期刊: The Astrophysical Journal
• 作者: V. Chandra;R. Naidu;C. Conroy;A. Ji;H. Rix;A. Bonaca;P. Cargile;Jiwon Jesse Han;Benjamin D. Johnson;Y. Ting 丁;T. Woody;D. Zaritsky

Wide binaries from the H3 survey: the thick disc and halo have similar wide binary fractions

H3 巡天的宽双星：厚盘和光环具有相似的宽双星分数

• DOI: 10.1093/mnras/stac650
• 发表时间: 2022
• 期刊: Monthly Notices of the Royal Astronomical Society
• 影响因子: 4.8
• 作者: Hwang, Hsiang-Chih;Ting, Yuan-Sen;Conroy, Charlie;Zakamska, Nadia L.;El-Badry, Kareem;Cargile, Phillip;Zaritsky, Dennis;Chandra, Vedant;Han, Jiwon Jesse;Speagle, Joshua S.
• 通讯作者: Speagle, Joshua S.

The Stellar Halo of the Galaxy is Tilted and Doubly Broken

• DOI: 10.3847/1538-3881/ac97e9
• 发表时间: 2022-08
• 期刊: The Astronomical Journal
• 作者: Jiwon Jesse Han;C. Conroy;Benjamin D. Johnson;J. Speagle 沈;A. Bonaca;V. Chandra;R. Naidu;Y. Ting