Collaborative Research: The Magellanic Clouds as a Laboratory for Star Formation at Low Metallicity

合作研究：麦哲伦星云作为低金属丰度恒星形成的实验室

• 批准号: 2009544
• 负责人: Margaret Meixner
• 金额: $ 26.19万
• 依托单位: Johns Hopkins University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-08-15 至 2020-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2009544&HistoricalAwards=false
• 关键词: Collaborative; Research; Magellanic; Clouds; Laboratory

These astronomers seek to understand what causes clouds of gas in space to collapse to form stars. The immediate cause is the force of gravity, but why gravity acts quickly on some clouds and slowly in others remains a puzzle. The investigators have a plan to solve this puzzle by using detailed observations of gas clouds located in two nearby satellite galaxies, the Magellanic Clouds. The observations, taken with NSF’s Atacama Large Millimeter/submillimeter Array’s (ALMA) observatory, will have the quality and detail needed to measure the properties of the gas. The investigators will compare measurements of the stellar environment with the locations and ages of young stars. The investigators are from three different universities, and each will contribute to training of next generation scientists. The students will get hands-on experience in the techniques of scientific data analysis and instrumentation. The team will develop of new virtual reality tools for improving the public understanding of science.With the ALMA’s unprecedented sensitivity and access to the southern sky, astronomers are beginning to resolve the clumpy, filamentary structure of molecular clouds in the Magellanic Clouds. Analysis has shown that the velocity dispersion of the molecular gas at a given scale increases with the overall star formation activity of the cloud, suggesting that energetic feedback from young stars plays a significant role in maintaining turbulent motions within the cloud. However, other lines of evidence, including our finding that clumps and filaments are typically marginally unstable to collapse, support the view that increased velocity dispersion and star formation can both be driven by gravitational instability. The investigators plan observations to reveal the conditions for star formation. They will use a broad, survey-based, approach which can identify regions deficient in one of the key ingredients (e.g., young stars or dense gas) and thus more accurately distinguish cause and effect. Combining ALMA imaging of the molecular gas on sub-parsec scales with infrared surveys of the young stellar populations in these galaxies will provide new insights into the roles of triggering, feedback, and cloud conditions in the star formation process.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.

这些天文学家试图了解是什么导致太空中的气体云塌缩形成恒星，其直接原因是重力，但为什么重力作用在某些云上很快，而在另一些云上却很慢，这仍然是一个谜团，研究人员有一个解决方案。通过使用美国国家科学基金会阿塔卡马大型毫米/亚毫米阵列（ALMA）天文台对位于两个附近卫星星系麦哲伦云的气体云的详细观测来解决这个难题。研究人员将测量气体特性所需的质量和细节，将恒星环境的测量结果与年轻恒星的位置和年龄进行比较。研究人员来自三所不同的大学，每一位都将为培养下一代科学家学生做出贡献。将获得科学数据分析和仪器技术方面的实践经验。该团队将开发新的虚拟现实工具，以提高公众对科学的理解。凭借 ALMA 前所未有的灵敏度和进入南方天空的机会，天文学家开始解决这一问题。块状丝状结构分析表明，给定尺度下分子气体的速度色散随着云的整体恒星形成活动而增加，这表明来自年轻恒星的能量反馈在维持内部湍流运动方面发挥着重要作用。然而，其他证据，包括我们的发现，团块和细丝通常不太不稳定，容易塌陷，都支持这样的观点：速度分散和恒星形成都可能是由引力不稳定驱动的。他们将使用一种基于调查的广泛方法来揭示恒星形成的条件，该方法可以识别缺乏关键成分（例如年轻恒星或致密气体）的区域，从而更准确地结合 ALMA 成像。通过对这些星系中年轻恒星群的红外调查，在亚秒差距尺度上对分子气体进行研究，将为了解触发、反馈和云条件在恒星形成过程中的作用提供新的见解。该奖项反映了 NSF 的法定使命，并已被视为值得通过使用基金会的智力优点和更广泛的影响审查标准进行评估来支持。