Collaborative Research: Dust, Gas, and Star Formation: Synthesizing 20 Years of Radio, Millimeter, and Infrared Surveys

合作研究：尘埃、气体和恒星形成：综合 20 年的无线电、毫米波和红外勘测

• 批准号: 1615728
• 负责人: Karin Sandstrom
• 金额: $ 37.96万
• 依托单位: University of California-San Diego
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-09-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1615728&HistoricalAwards=false
• 关键词: Collaborative; Research; Dust; Gas; Star

Galaxies grow by converting interstellar gas into new generations of stars. A main step in that process is the conversion of low-density, atomic gas into cold, dense, star-forming clouds. Interstellar dust controls this process by shielding gas from destructive ultraviolet radiation and promoting chemical reactions. The abundance of both dust and cold gas depend on local environment in a galaxy, but the nature of this dependence is still debated at a very basic level. This project will test competing hypotheses for what sets the amount of dust and cold gas in galaxies by mapping dust, neutral interstellar gas (diffuse atomic gas and cold, dense molecular gas), and local conditions in a sample of nearby galaxies ten times larger than those used in previous studies. The investigators will use these observations database to answer two questions about gas and star formation in galaxies. The first question is what sets the amount of cold, star-forming gas? The second question is what determines the abundance of dust? These two intertwined questions are critical to understand how galaxies grow and change over time.The investigators will assemble the next generation database of dust and gas distributions in galaxies. To do this, they will combine new and archival observations of atomic hydrogen (HI) from the NSF-funded Very Large Array with Herschel spacecraft measurements of the distribution and properties of interstellar dust. They will increase, by an order of magnitude, the sample of galaxies with such observations. An order of magnitude increase in the set of galaxies studied in this way will advance the field into a new regime of statistical hypothesis testing, a potentially transformative step in understanding the physics of gas in galaxies.The observing database will be shared on the internet with other astronomers and also the public. The investigators will build on the Zooniverse project to share their observations with the public. Zooniverse is an internet tool that allows the public to view and classify scientific observations. With this tool, the public can both appreciate the observations and aid in the research. The investigators plan to create 'the HI Holes Project', in which volunteer citizen scientists will identify giant holes in the gaseous interstellar medium of real and simulated galaxies.

星系通过将星际气体转化为新一代恒星而生长。该过程的主要步骤是将低密度，原子气体转化为寒冷，致密的恒星形成云。星际尘埃通过保护气体免受破坏性紫外线辐射并促进化学反应来控制这一过程。灰尘和冷气的丰度取决于银河系中的当地环境，但是这种依赖性的性质仍在非常基本的水平上进行了争论。该项目将通过绘制灰尘，中性的星体气体（弥漫性原子气和冷，密集的分子气）和附近星系样本中的局部条件来测试星系中尘埃和冷气数的量的竞争假设，这是先前研究中使用的十倍。研究人员将使用这些观察数据库回答有关星系中气体和恒星形成的两个问题。 第一个问题是什么设置了冷，星形的气体？ 第二个问题是什么决定了尘土的丰度？这两个交织在一起的问题对于了解星系如何随着时间而变化至关重要。研究人员将组装星系中灰尘和气体分布的下一代数据库。为此，他们将结合NSF资助的非常大阵列的原子氢（HI）的新的和档案观测，以及赫歇尔航天器的分布和特性的星际灰尘的分布和特性。 它们将通过一个数量级来增加带有此类观察结果的星系样本。 以这种方式研究的一组星系的数量级增加将使该领域成为统计假设检验的新制度，这是理解星系中气体物理学的潜在变革步骤。观察数据库将在Internet上与其他天文学家以及公众共享。 调查人员将基于“动物”项目，以与公众分享他们的观察结果。 Zooniverse是一种互联网工具，允许公众查看和对科学观察进行分类。 借助此工具，公众可以欣赏观察结果，又可以帮助研究。调查人员计划创建“ hi洞项目”，其中志愿者公民科学家将在真实和模拟星系的气态星际媒介中识别出巨大的孔。