Collaborative Research: Studying Magnetic Fields in the Interstellar Medium

天文学家将填补恒星之间空间空隙的气体和尘埃称为星际介质，或称ISM。磁场是银河系ISM的重要组成部分。它们影响气体运动的方式，以及气体在自身重量下坍塌形成恒星的方式。因此，能够衡量这些领域的实力是非常重要的。该团队开发了他们自己的技术，使用气体速度来测量磁场的强度。通过观测气体中原子和分子的无线电发射，研究人员可以研究ISM中的不同区域，探测到不同的深度。测量磁场所需的许多无线电观测已经存在。像NSF资助的绿岸望远镜和NSF支持的阿雷西博天文台这样的望远镜已经探测了ISM的大部分地区。该团队将展示磁场如何在密度较高的区域发生变化，它们如何影响恒星的诞生，以及它们如何在整个ISM中发生变化。这个项目也代表了专门开发星际介质复杂模型的天文学家和有观察ISM经验的天文学家之间的合作。两所大学(威斯康星大学麦迪逊分校和伊利诺伊大学香槟分校)的研究生和本科生将参与这项合作。事实上，交换学生是该项目的重要组成部分。首席调查员还将组织一次年度讲习班，并将教授与这项研究有关的课程，向外本科生开放。这两位PI还在威斯康星州外联中心和太空广场以及当地高中向公众展示。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。

Astronomers refer to the gas and dust that fills the void in space between the stars as the Interstellar Medium, or ISM. Magnetic fields are an important component of the ISM in the Milky Way Galaxy. They affect the way the gas moves and the way the gas collapses under its own weight to form stars. Being able to measure the strength of these fields is therefore very important. The team has developed their own technique, which uses gas velocities, to measure the strength of the magnetic field. By observing radio emission from atoms and molecules in the gas, the researchers can study different regions in the ISM, probing to different depths. Many of the radio observations needed for the magnetic field measurements already exist. Telescopes like the NSF-funded Green Bank telescope and the NSF-supported Arecibo Observatory have surveyed much of the ISM. The team will show how magnetic fields change in denser regions, how they affect the birth of stars, and how they change across the ISM. This project also represents a collaboration between astronomers who specialize in developing complex models of the Interstellar Medium, and astronomers with experience observing the ISM. Students at graduate and undergraduate levels from both institutions (University of Wisconsin-Madison and University of Illinois at Urbana-Champaign) will be involved in this collaboration. Indeed, student exchange is an important part of the project. The Principal Investigators (PIs) will also organize an annual workshop and will teach classes related to this research that are open to external undergraduate students. Both PIs also present to public audiences at the Wisconsin Outreach Center and Space Place, and in local high schools.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.