How does stellar feedback drive interstellar turbulence and molecular hydrogen formation?

恒星是在密集和寒冷的星际介质(ISM)中形成的，这些区域富含不同类型的分子。要了解恒星和行星是如何形成的，就必须了解它们的分子是如何从弥漫的中性ISM气体中形成的。一旦形成，恒星就会向ISM注入能量，引起湍流，从而震动和搅动未来的恒星诞生地。天文学家使用21厘米的氢原子线(HI)来研究中性的ISM。威斯康星大学麦迪逊分校的研究人员将研究星际湍流如何影响扩散气体。他们将使用澳大利亚的一台新射电望远镜来获得麦哲伦星云的HI观测。该项目团队还将继续为中学生制作连环画，题为《银河童子军：与斯特拉和莱利的太空事件》。该连环画以日常生活中科学的刺激和产品为特色，主要目标是提高社会科学素养。这些材料将向公众开放。通过制作连环画和三本活动书，该小组将为中小学生提供独特的STEM学科介绍。这个项目有以下目标。首先，为了量化不同天文来源对星际湍流的影响，该项目将使用一种新的统计方法来量化麦哲伦星云上HI湍流特性的空间变化水平。其次，为了给恒星形成的数值模拟提供直接的约束，我们将绘制麦哲伦星云上的湍流运动的精确模式和操作尺度图。这将限制抖动而不是搅动HI气体的湍流能量的比例。第三，由于分子氢由受湍流运动影响的原子氢结构形成，该项目将测试在分子氢形成过程中包含湍流的理论。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Stars are formed in the interstellar medium (ISM) in dense and cold regions that are rich in different types of molecules. To understand how stars and planets form, it is essential to understand how their molecules form out of diffuse, neutral ISM gas. Once formed, stars inject energy into the ISM causing turbulence, which shakes and stirs the future stellar birthplaces. Astronomers study the neutral ISM using the 21-cm emission line of atomic hydrogen (HI). The researchers at the University of Wisconsin-Madison will investigate how interstellar turbulence affects the diffuse gas. They will use a new radio telescope in Australia to obtain HI observations of the Magellanic Clouds. The project team will also continue with the development of a comic strip for middle school students, entitled “Galaxy scouts: Spaceventures with Stella and Riley”. This strip features excitement and products of science in daily life, with the key goal of enhancing societal scientific literacy. These materials will be publicly available. By developing the comic strip and three activity books, the group will provide a unique introduction to STEM disciplines for elementary and middle school students.This project has the following objectives. First, to quantify the influence of different astronomical sources on interstellar turbulence, the project will quantify the level of spatial variations of HI turbulent properties across the Magellanic Clouds by using a novel statistical method. Second, to provide direct constraints for numerical simulations of star formation, the exact modes of turbulent motions and scales of operations will be mapped across the Magellanic Clouds. This will constrain the fraction of turbulent energy that shakes, as opposed to stirs, the HI gas. Third, as molecular hydrogen forms from the atomic hydrogen structures affected by turbulent motions, the project will test theories that incorporate turbulence in the molecular hydrogen 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.