Studies of Interstellar Processes

这项赠款支持Dr. Draine在几个主题上的研究， 扩散星际理论天体物理学领域 所谓了 主要内容包括：（一）星际物质的激发 氢分子，目的是能够计算 准确地说，非局部热力学平衡激发 以及在各种条件下从分子氢发射;（B） 非稳态光解前沿的结构，包括 静止和传播的锋面，目的是能够 预测详细的发射光谱;和（C）星际磁- 扩散云和稠密云中的水动力冲击波， 包括研究不稳定性的非线性发展， 磁流体动力冲击 (A)作为星际介质中最丰富的分子， 分子氢是一个关键的诊断， 分子气体，如光离解区和激波前沿。 必须有精确的理论计算， 碰撞激发的氢分子的光谱。 (B)它有 最近变得清楚，时间依赖的光解前沿 是非常重要的。 忽略气体流过这样一个 前面是当前模型的一个主要限制，Dr. Draine将 试图纠正这一缺陷。 (C)的亮点之一 星际天体物理学的最后十年，确定 分子气体中冲击波的光谱， 观察。 德雷恩博士的研究应该有助于 消除这种差异。

This grant supports Dr. Draine's research on several topics within the area of theoretical astrophysics of diffuse interstellar matter. The topics include: (A) excitation of interstellar molecular hydrogen, with the aim of being able to calculate accurately the non-local thermodynamic equilibrium excitation of and emission from molecular hydrogen under various conditions; (B) structure of non-stationary photodissociation fronts, including both stationary and propagating fronts, with the aim of being able to predict detailed emission spectra; and (C) interstellar magneto- hydrodynamic shock waves in both diffuse and dense clouds, including study of the non-linear development of instabilities in magneto-hydrodynamic shocks. (A) As the most abundant molecule in the interstellar medium, molecular hydrogen is a critical diagnostic for regions of warm molecular gas such as photodissociation regions and shock fronts. It is essential to have accurate theoretical calculations of the spectrum of collisionally excited molecular hydrogen. (B) It has recently become clear that time-dependent photodissociation fronts are of major importance. The neglect of gas flow through such a front is a major limitation of current models, and Dr. Draine will attempt to rectify this defect. (C) One of the highlights of interstellar astrophysics of the last decade, the determination of the spectra of shocks in molecular gas, is in gross disagreement with observation. Dr. Draine's course of study should help to eliminate this discrepancy.