Looking Out for the Little Guy: A Comprehensive Study of Star Formation in Dwarf Galaxies

寻找小家伙：矮星系恒星形成的综合研究

• 批准号: 1813871
• 负责人: Alyson Brooks
• 金额: $ 28.06万
• 依托单位: Rutgers University New Brunswick
• 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: 2018-08-15 至 2022-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1813871&HistoricalAwards=false
• 关键词: Looking; Out; Little; Guy; Comprehensive

In 2010, the Large Synoptic Survey Telescope (LSST) was named the top-ranked ground-based astronomy project for the coming decade. The telescope will begin gathering light in 2019, and begin a full survey of the visible sky two years later. The survey will discover billions of new astronomical objects, including hundreds of new galaxies nearby to our own Milky Way galaxy. The new galaxies that we will discover are so faint that they could not be found by previous telescopes. These tiny galaxies are also ideal places to test fundamental questions about the origin of galaxies in our Universe. This research focuses on the fact that these tiny galaxies are very sensitive to the first stars that formed in our Universe. This fact has not been sufficiently explored in previous research. To prepare astronomers to understand what these galaxies tell us about the origins of our Universe, this research focuses on three key areas. First, they will predict the number of faint galaxies that the National Science Foundation's LSST should discover. Second, they will predict how far away from the Milky Way the LSST might find the faint galaxies. Third, they will predict whether any of these galaxies is still forming stars today, or whether they all stopped forming stars billions of years ago. The research advances the scientific leadership of the United States and help to safeguard the United States' investment in LSST. The project focuses on training students who are first-generation college students, with the goal of diversifying the US technical workforce. An expanded and diversified scientific workforce helps to ensure that the US remains a leader in innovation and economic growth.The LSST will revolutionize our knowledge of dwarf galaxies, especially in the ultra-faint regime. However, simulators have barely begun to extend their successful models to stellar masses below 1 million solar masses. Now is the critical time to understand whether our current simulations can continue to explain galaxy formation down into the ultra-faint range, or whether a new understanding of star formation in low mass dark matter halos will be required. The goal of this work is to gain substantial knowledge about the processes that control early star formation in dwarf galaxies and subsequent quenching. The number of observed galaxies with stellar masses below 10 thousand solar masses depends strongly on the density of gas from which the first stars could form in the early Universe. The proposed work will generate hundreds of simulated dwarf galaxies, with stellar masses ranging from one billion solar masses (roughly 1/10 the mass of the Milky Way) down to 1000 solar masses in the range of ultra-faint dwarf galaxies. This work utilizes the simulations to (1) pinpoint the role of star formation density threshold on the number of galaxies that form, and the resulting stellar mass function; (2) make predictions for the number of ultra-faint dwarf galaxies as function of radius from the Milky Way; (3) study the processes that quench dwarf galaxies as function of mass and environment, and make predictions for the quenched fraction in the field that can be observed by future facilities. This work also establishes a program to support and mentor first-generation college students (many of whom are likely to also be from groups historically underrepresented in STEM) as they transition to being undergraduates. The program will (1) develop a mentoring relationship between students and members of the Rutgers Physics & Astronomy department, (2) utilize cohort building activities to develop the students into a peer support network for each other, (3) introduce the students to basic research tools and get them involved in original research. These three goals have been shown to increase the retention of underrepresented students in science. The overall aim is to improve the demographic diversity of both the Rutgers Physics & Astronomy undergraduate majors, but also of the Physics and Astronomy community. This program will also train graduate students to teach and mentor the first-year students, and educate the graduate student mentors on issues of equity and barriers to education that first-year/underrepresented students face.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.

2010年，大型的天气调查望远镜（LSST）被评为未来十年中排名最高的基于地面的天文学项目。 望远镜将于2019年开始收集灯光，并在两年后开始对可见天空进行全面调查。 该调查将发现数十亿个新的天文学物体，包括我们自己的银河系附近的数百个新星系。 我们会发现的新星系是如此微弱，以至于以前的望远镜找不到它们。 这些微小的星系也是测试有关我们宇宙中星系起源的基本问题的理想场所。 这项研究的重点是这些微小的星系对我们宇宙中的第一批恒星非常敏感。 在先前的研究中，这一事实尚未得到充分探讨。 为了准备天文学家了解这些星系告诉我们有关宇宙起源的信息，这项研究的重点是三个关键领域。 首先，他们将预测国家科学基金会LSST应该发现的微弱星系数量。 其次，他们将预测LSST可能会发现微弱的星系的距离。 第三，他们将预测这些星系中的任何一个是否仍在今天构成恒星，或者是否都停止在数十亿年前形成明星。该研究推动了美国的科学领导，并有助于维护美国对LSST的投资。 该项目的重点是培训第一代大学生的学生，目的是使美国技术劳动力多样化。 扩大而多元化的科学劳动力有助于确保美国仍然是创新和经济增长的领导者。LSST将彻底改变我们对矮星系的了解，尤其是在超级物业政权中。 但是，模拟器几乎没有开始将其成功的模型扩展到低于100万个太阳能块以下的恒星群众。 现在是了解我们当前的模拟是否可以继续解释到超生殖范围的关键时刻，或者是否需要对低质量暗物质光环中的恒星形成的新理解。这项工作的目的是获得有关控制矮星系中早期恒星形成的过程和随后的淬火。恒星质量的观测星系低于1万太阳能块的数量在很大程度上取决于早期宇宙中第一颗恒星可能形成的气体密度。拟议的工作将产生数百个模拟的矮星系，其恒星质量的范围从十亿个太阳能（大约1/10个银河质量）到一系列超强dwarf Galaxies范围内的1000个太阳能团块。 这项工作利用模拟来（1）查明恒星形成密度阈值在形成星系的数量以及所得的恒星质量功能上的作用； （2）对银河系的radius函数进行预测，对银河系的函数进行预测； （3）研究淬灭星系作为质量和环境功能的过程，并对未来设施可以观察到的田间淬灭分数进行预测。 这项工作还建立了一项计划，以支持和指导第一代大学生（其中许多人也可能来自历史上的STEM中人数不足的团体），因为他们过渡到本科生。该计划（1）将在学生与罗格斯物理与天文学系的成员之间建立指导关系，（2）利用队列建筑活动将学生互相发展为彼此的同伴支持网络，（3）向学生介绍基础研究工具并使他们参与原始研究。这三个目标已被证明可以增加代表性不足的科学学生的保留。总体目的是提高罗格物理学和天文学本科生的人口多样性，以及物理和天文学界的人口多样性。该计划还将培训研究生教授第一年的学生，并教育研究生导师有关公平和教育障碍的问题，这一奖项反映了NSF的法定任务，并被认为是值得通过基金会的智力和更广泛影响的评估来进行评估的审查审查审查审查的批评。

项目成果

Dancing in the Dark: Uncertainty in Ultrafaint Dwarf Galaxy Predictions from Cosmological Simulations

• DOI: 10.3847/1538-4357/ab0085
• 发表时间: 2018-10
• 期刊: The Astrophysical Journal
• 作者: F. Munshi;A. Brooks;C. Christensen;Elaad Applebaum;K. Holley-Bockelmann;T. Quinn;J. Wadsley

Ultrafaint Dwarfs in a Milky Way Context: Introducing the Mint Condition DC Justice League Simulations

• DOI: 10.3847/1538-4357/abcafa
• 发表时间: 2020-08
• 期刊: The Astrophysical Journal
• 作者: Elaad Applebaum;A. Brooks;C. Christensen;F. Munshi;T. Quinn;S. Shen;M. Tremmel

Quantifying Scatter in Galaxy Formation at the Lowest Masses

• DOI: 10.3847/1538-4357/ac0db6
• 发表时间: 2021-01
• 期刊: The Astrophysical Journal
• 作者: F. Munshi;A. Brooks;Elaad Applebaum;C. Christensen;T. Quinn;Serena K Sligh

A stochastically sampled IMF alters the stellar content of simulated dwarf galaxies

随机采样的 IMF 改变了模拟矮星系的恒星含量

• DOI: 10.1093/mnras/stz3331
• 发表时间: 2019
• 期刊: Monthly Notices of the Royal Astronomical Society
• 影响因子: 4.8
• 作者: Applebaum, Elaad;Brooks, Alyson M.;Quinn, Thomas R.;Christensen, Charlotte R.
• 通讯作者: Christensen, Charlotte R.