Collaborative Proposal: Resolving Physical Conditions of Diffuse Ionized Gas throughout the Milky Way-Magellanic System

气体云是恒星诞生的地方，向我们展示了恒星对其周围环境的壮观影响。恒星的紫外线从原子中剥离电子，使它们电离。这些自由电子最终会再次与原子联合收割机结合，并发出明显的颜色。在过去的几十年里，威斯康星州的H-Alpha映射器（WHAM）发现，整个天空都在发出微弱的红光，这些红光是由弥漫在银河系中的电离氢原子发出的。WHAM小组一直在探索整个银河系及其邻近的卫星星系麦哲伦云的这种“弥漫的电离气体”。WHAM可以揭示比猎户座星云微弱近1亿倍的发射。 WHAM仍然是世界上最灵敏的仪器之一，用于研究我们天空中微弱的漫射光。该小组正在开发一个新的展览和教育活动，将有助于展示科学家如何使用光谱学来识别元素和探索遥远物体的属性。该展览将吸引公众和学生团体与WHAM使用相同的法布里-珀罗技术。 研究人员将继续为本科生和研究生提供极好的机会。在以前的NSF资助的研究中，WHAM研究人员制作了第一个追踪银河系和麦哲伦云中弥漫电离气体的调查。这些努力补充了对氢的无线电调查，追踪其较冷的中性相。中性和电离氢发射现在被检测到在每个方向从我们的位置在银河系内。有了这个奖项，研究人员使用WHAM开始一个多样化的观察计划。通过捕捉其他元素的辐射，他们正在追踪整个扩散气体的温度和电离度。这项新研究推进了我们对星际物质的理解，塑造它的过程，以及恒星如何影响我们的银河系。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Clouds of gas, where stars are born, show us the spectacular impact of stars on their immediate surroundings. The stars’ ultraviolet light strips electrons from atoms, ionizing them. These free electrons eventually combine again with atoms and emit telltale colors. Over the last few decades, the Wisconsin H-Alpha Mapper (WHAM) discovered that the entire sky is glowing faintly in red light emitted by ionized hydrogen atoms that pervade the Milky Way. The WHAM group has been exploring this "diffuse ionized gas" throughout the Milky Way and its neighboring satellite galaxies, the Magellanic Clouds. WHAM can reveal emission nearly a 100-million times fainter than the Orion Nebula. WHAM remains one of the most sensitive instruments in the world for studying faint, diffuse light in our sky. The Team is developing a new exhibit and educational activities that will help show how scientists use spectroscopy to identify elements and explore the properties of distant objects. The exhibit will engage the public and student groups with the same Fabry-Perot technology used by WHAM. The investigators will continue to provide excellent opportunities for undergraduate and graduate students.During previous NSF-funded studies, WHAM investigators produced the first surveys that traced diffuse ionized gas in the Milky Way and the Magellanic Clouds. These efforts complement radio surveys of hydrogen that trace its cooler, neutral phase. Neutral and ionized hydrogen emission are now detected in every direction from our location inside the Galaxy. With this award, the investigators use WHAM to embark on a diverse observational program. Capturing emission from other elements, they are tracing the temperature and degree of ionization throughout the diffuse gas. This new study advances our understanding of interstellar matter, the processes that shape it, and how stars affect our Galaxy.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.