Measuring interstellar temperature and ionization variations using observations of faint diffuse [OII] emission

该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。星际介质（ISM）在恒星诞生和死亡的持续循环以及星系演化中起着至关重要的作用。然而，星际物质的作用，从它的性质如何受到恒星的影响，到它的性质反过来如何影响恒星的形成，人们知之甚少。Edwin Mierkiewicz博士和他的团队将执行一个[OII]观测计划，该计划将(1)提供唯一的机会，将我们银河系的热电离介质（WIM）中温度的变化与电离条件的变化区分开来；(2)确认h - α， [NII]和[SII]数据是否可以提供可靠的关于我们自己和其他星系中扩散电离气体的温度信息。这项研究使用创新的光谱技术来解决由威斯康星h - α映射器（WHAM）观测提出的加热、温度和电离变化的突出问题，但WHAM和其他可用的天文仪器不适合解决这些问题。除了其内在的兴趣之外，对WIM的透彻理解对于理解星际介质的组成和性质，以及我们银河系盘状和光晕内电离和加热的主要来源也很重要。Mierkiewicz和他的团队在天体物理仪器和观测技术方面对学生进行了长期的培训。研究生和本科生将参与这项工作的所有阶段。研究生的参与将导致一篇博士论文。Mierkiewicz博士是美国国家科学基金会资助的威斯康星大学本科生天文学研究经历（REU）项目的负责人。该项目重视参与者的多样性，并致力于让来自代表性不足的群体和小型学院的学生参与天体物理学研究。REU的暑期学生将参与这项工作。

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). The interstellar medium (ISM) plays a vital role in the ongoing cycle of stellar birth and death, and galactic evolution. However the role of interstellar matter, from how its properties are influenced by stars to how, in turn, its properties influence star formation is poorly understood. Dr. Edwin Mierkiewicz and his team will carry out a program of [OII] observations which will (1) provide the only opportunity to separate unambiguously variations in temperature from variations in ionization conditions in the warm ionized medium (WIM) of our Galaxy and (2) confirm whether H-alpha, [NII], and [SII] data can provide reliable temperature information about diffuse ionized gas in our own and other galaxies. This research uses innovative spectroscopic techniques to address outstanding questions of heating, and of temperature and ionization variations in the WIM raised by Wisconsin H-Alpha Mapper (WHAM) observations, but which WHAM and other available astronomical instruments are not suited to address. Beyond its intrinsic interest, a thorough understanding of the WIM is important for understanding the composition and nature of the interstellar medium, and the primary sources of ionization and heating within the disk and halo of our Galaxy.Dr. Mierkiewicz and his team have a long history of student training in astrophysics instrumentation and observational techniques. Graduate and undergraduate students will participate in all phases of this work. The graduate student involvement will lead to a Ph.D. thesis. Dr. Mierkiewicz is the director of the separately NSF-funded University of Wisconsin Astronomy Research Experiences for Undergraduates (REU) program. This program values diversity among its participants and works to involve students from underrepresented groups and small colleges in astrophysics research. Summer REU students will participate in this work.