Collaborative Research: Dark Matter and Substructure in the Galactic Halo with Gaia and Multi-Object Spectroscopy

合作研究：利用盖亚和多目标光谱学研究银河晕中的暗物质和亚结构

• 批准号: 1815403
• 负责人: Mario Mateo
• 金额: $ 32.98万
• 依托单位: Regents of the University of Michigan - Ann Arbor
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-08-01 至 2024-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1815403&HistoricalAwards=false
• 关键词: Collaborative; Research; Dark; Matter; Substructure

The Galactic Halo encompasses the vast, seemingly empty volume surrounding our home galaxy, the Milky Way. But the Halo is not so empty as it appears. A rich variety of dwarf galaxies, stellar streams and star clusters pervade the Halo. These structures can reveal the nature of dark matter, how heavy elements are made, and how our Galaxy formed. This project advances the field by combining data from large public sky surveys with new data to be obtained with state-of-the art ground-based facilities. This project aims to identify new stellar structures, then probe their chemistry and dynamics. The results will test competing models of dark matter and galaxy formation. This project builds on previous NSF investments in instrumentation and the scientific workforce. The team will continue to operate the NSF-funded Michigan/Magellan Fiber System (M2FS) spectrograph, enabling innovative science by other astronomers. These activities promote science by continuing successful public outreach programs and training the next generation of astronomers.The primary scientific objectives include 1) the detection of faint and previously unknown star clusters, dwarf galaxies, and stellar streams within the Milky Way halo; 2) measurement of the velocities and chemical compositions of the stars within these structures; and 3) mapping the dark matter content of these structures. To discover new objects, the team will mine data from the Gaia space mission, exploiting its unprecedented combination of sky coverage, precision of stellar positions, and measurement of stellar motions. The team will use Gaia data to identify not only new stellar structures, but also rare stars within known structures. For all such targets, the team will use the M2FS spectrograph to measure stellar velocities and chemical composition. Finally, the team will combine the Gaia and M2FS data sets, exploiting the multi-dimensional information to infer the dark matter content and chemical evolution of these structures. These results will advance the frontiers of knowledge regarding the nature of dark matter, the origin of heavy elements, the formation and evolution of the smallest galaxies, and the processes that built up the stellar halo of our own Milky Way.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.

银河系光环涵盖了我们家乡银河系周围的巨大，看似空的卷，这是银河系的方式。 但是光环并不像看起来那样空。 各种各样的矮星系，出色的溪流和星形簇遍布光环。 这些结构可以揭示深色物质的本质，如何制作重量以及我们的银河系形成。 该项目通过将来自大型公共天空调查的数据与最先进的基于地面的设施相结合的新数据来推进该领域。 该项目旨在确定新的恒星结构，然后探究其化学和动态。 结果将测试暗物质和星系形成的竞争模型。 该项目以先前在仪器和科学劳动力的NSF投资为基础。 该团队将继续运营由NSF资助的密歇根州/麦哲伦纤维系统（M2FS）光谱仪，从而实现了其他天文学家的创新科学。 这些活动通过继续成功的公共宣传计划和训练下一代天文学家来促进科学。主要科学目标包括1）在银河系Halo中发现淡淡和未知的星形群，矮星系和恒星流； 2）测量这些结构内恒星的速度和化学成分； 3）映射这些结构的暗物质内容。 为了发现新物体，团队将从盖亚太空任务中挖掘数据，利用其空前的天空覆盖范围，恒星位置的精度和恒星动作的测量的组合。 该团队将使用Gaia数据不仅识别新的恒星结构，还可以识别已知结构中的稀有恒星。 对于所有此类目标，团队将使用M2FS光谱仪来测量恒星速度和化学成分。 最后，团队将结合GAIA和M2FS数据集，利用多维信息来推断这些结构的暗物质含量和化学演化。 这些结果将提高有关暗物质本质的知识，重元素的起源，最小星系的形成和演变以及构成我们自己银河系的出色光环的过程。使命，并被认为是通过基金会的知识分子优点和更广泛影响的审查标准通过评估值得支持的。

项目成果

Dynamical masses and mass-to-light ratios of resolved massive star clusters – II. Results for 26 star clusters in the Magellanic Clouds

• DOI: 10.1093/mnras/stab1065
• 发表时间: 2021-04
• 作者: Ying-Yi Song;M. Mateo;J. Bailey;M. Walker;I. Roederer;E. Olszewski;M. Reiter;A. Kremin

Vanadium Abundance Derivations in 255 Metal-poor Stars

255 颗贫金属恒星中钒丰度的推导

• DOI: 10.3847/1538-4357/abaa50
• 发表时间: 2020
• 期刊: The Astrophysical Journal
• 作者: Ou, Xiaowei;Roederer, Ian U.;Sneden, Christopher;Cowan, John J.;Lawler, James E.;Shectman, Stephen A.;Thompson, Ian B.
• 通讯作者: Thompson, Ian B.

Improved Atomic Transition Probabilities for UV and Optical Lines of Hf II and Determination of the Hf Abundance in Two Metal-poor Stars*

提高 Hf II 的紫外和光学谱线的原子跃迁概率以及确定两颗贫金属恒星中的 Hf 丰度*

• DOI: 10.3847/1538-4365/abe861
• 发表时间: 2021
• 期刊: The Astrophysical Journal Supplement Series
• 作者: Den Hartog, E. A.;Lawler, J. E.;Roederer, I. U.
• 通讯作者: Roederer, I. U.

High-resolution Optical Spectroscopy of Stars in the Sylgr Stellar Stream

Sylgr 恒星流中恒星的高分辨率光谱

• 发表时间: 2019
• 期刊: Astrophysical journal
• 影响因子: 4.9
• 作者: Roederer, Ian U.;Gnedin, Oleg Y.
• 通讯作者: Gnedin, Oleg Y.

Origin of a Massive Hyper-runaway Subgiant Star LAMOST-HVS1: Implication from Gaia and Follow-up Spectroscopy

• DOI: 10.3847/1538-4357/ab05c8
• 发表时间: 2018-10
• 期刊: The Astrophysical Journal
• 作者: Kohei Hattori;M. Valluri;N. Castro;I. Roederer;G. Mahler;G. Khullar