Star formation and molecular cloud structure at low metallicity

低金属丰度下的恒星形成和分子云结构

• 批准号: 1907492
• 负责人: Deidre Hunter
• 金额: $ 43.8万
• 依托单位: Lowell Observatory
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-09-01 至 2024-02-29
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1907492&HistoricalAwards=false
• 关键词: Star; formation; molecular; cloud; structure

New stars are continuously forming in galaxies like the Milky Way. Galaxies begin as mostly hydrogen atoms, but nuclear fusion inside of stars produces heavier atoms. These atoms, like carbon and oxygen, are spewed out by dying stars, changing the chemistry of the space between the stars. The process begins again with the formation of new giant clouds of gas, which become cold and dense enough that atoms bond together to form molecules. New molecular clouds begin to form the next generations of stars. These heavy atoms from the first generation of stars are caught up in a molecular cloud and absorb ultraviolet light from nearby stars. The absorption helps to protect the fragile molecules from being broken apart, again changing the chemistry of the clouds. The investigator seeks to understand these chemical processes by comparison of the Milky Way to the chemistry in nearby dwarf irregular galaxies. These small galaxies have much less of the heavy atoms compared to spiral galaxies like the Milky Way. As a result, the outer parts of molecular clouds in those dwarf galaxies are destroyed, leaving smaller molecular clouds than are found in spiral galaxies. The investigator is studying the structure of molecular clouds in tiny dwarf galaxies. The investigator seeks to understand the consequences on star formation in dwarf galaxies due to the differences in molecular abundance. Stars are forming in dwarf galaxies, and the investigator plans additional observations to understand the nature of the gas in these galaxies. The answers to these questions will help us to understand star formation in the early universe, before heavy atoms were formed. The investigator leads the Lowell Observatory Native American Astronomy Outreach Program, which pairs astronomers with 4th-8th grade teachers in the Navajo and Hopi Nations. The program holds tri-annual teacher workshops that introduce teachers to classroom activities enhancing their understanding of astronomy. The collaborators create culturally responsive curriculum that enables Native students to see themselves as scientists and addresses the tribal and educational standards.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.

新恒星在银河系中不断形成，例如银河系。星系开始主要是氢原子，但是恒星内部的核融合会产生较重的原子。这些原子（如碳和氧气）被垂死的恒星喷出，改变恒星之间的空间的化学反应。该过程再次从形成新的气体云的形成开始，它们变得冷且致密，以使原子结合在一起形成分子。新的分子云开始形成下一代恒星。第一代恒星中的这些重原子被分子云捕获，并吸收附近恒星的紫外线。吸收有助于保护脆弱的分子免于被裂解，再次改变云的化学性质。 研究人员试图通过将银河系与附近矮人不规则星系的化学方法进行比较来理解这些化学过程。 与银河系（如银河系）相比，这些小星系的重原子的重量要少得多。结果，那些矮星系中分子云的外部被破坏了，剩下的分子云比螺旋星系中发现的较小。研究者正在研究微小矮星系中分子云的结构。研究人员试图了解矮星系中恒星形成的后果，因为分子丰度的差异。 恒星在矮星系中形成，研究人员计划进行更多观察，以了解这些星系中气体的性质。这些问题的答案将有助于我们在形成重原子之前就了解早期宇宙中的恒星形成。研究者领导了洛厄尔天文台的美国原住民天文学外展计划，该计划与天文学家与纳瓦霍和霍皮国家的4至8年级教师配对。 该计划举办了三年教师讲习班，向教师介绍课堂活动，以增强他们对天文学的理解。 合作者创建了具有文化响应的课程，使土著学生能够将自己视为科学家，并解决了部落和教育标准。该奖项反映了NSF的法定任务，并被认为是值得通过基金会的知识分子评估来获得支持的，并具有更广泛的影响。

项目成果

The Environments of CO Cores and Star Formation in the Dwarf Irregular Galaxy WLM

矮不规则星系 WLM 中 CO 核心的环境和恒星形成

• DOI: 10.3847/1538-3881/ac4e88
• 发表时间: 2022
• 期刊: The Astronomical Journal
• 作者: Archer, Haylee N.;Hunter, Deidre A.;Elmegreen, Bruce G.;Cigan, Phil;Jansen, Rolf A.;Windhorst, Rogier A.;Hunt, Leslie K.;Rubio, Monica
• 通讯作者: Rubio, Monica

Relationships between the Stellar, Gaseous, and Star Formation Disks in LITTLE THINGS Dwarf Irregular Galaxies: Indirect Evidence for Substantial Fractions of Dark Molecular Gas

• DOI: 10.3847/1538-3881/abd089
• 发表时间: 2020-11
• 期刊: The Astronomical Journal
• 作者: D. Hunter;B. Elmegreen;Esther Goldberger;Hannah Taylor;A. Ermakov;K. Herrmann;Se-Heon Oh;B. Malko;B. Barandi;Ryan Jundt