The Role of Magnetic Fields in the Evolution of Molecular Clouds

磁场在分子云演化中的作用

• 批准号: 8817651
• 负责人: Richard Crutcher
• 金额: $ 10.89万
• 依托单位: University of Illinois at Urbana-Champaign
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1989
• 资助国家: 美国
• 起止时间: 1989-03-01 至 1992-02-29
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8817651&HistoricalAwards=false
• 关键词: Role; Magnetic; Fields; Evolution; Molecular

Theoretical research has provided compelling arguments that magnetic fields play an important and perhaps essential role in the formation of stars out of clouds of material in the interstellar medium. Empirical tests of these theoretical results are very important. Possible tests are: (1) the measurement and mapping of the strengths of the magnetic fields in dense clouds by observations of the Zeeman effect on spectral lines of neutral atomic hydrogen, hydroxyl, and other molecules; (2) determination of cloud masses, sizes, kinematics, and densities by observation and mapping of millimeter-wave lines of selected molecules in order to assess the dynamical importance of magnetic fields; (3) measurement of the variation of the fractional ionization of molecular species in clouds in order to estimate the conditions for freezing the magnetic field flux; and (4) determination of the mass-to-magnetic flux ratio and its variation within a cloud. This grant supports an observational research project conducted by Dr. Richard Crutcher, at the University of Illinois, in collaboration with Dr. Thomas Troland, at the University of Kentucky, to test the current theoretical ideas in all of the areas outlined above.

理论研究提供了令人信服的论据， 磁场在这方面起着重要的，也许是必不可少的作用， 恒星的形成是由 星际介质 这些理论的实证检验 结果非常重要。 可能的测试有：（1） 磁场强度的测量和绘图 通过观测塞曼效应对光谱的影响， 中性原子氢、羟基和其他分子的线; (2)确定云的质量、大小、运动学， 通过观测和测绘的毫米波线密度 选择的分子，以评估动态的重要性， （3）测量磁场的变化; 云中分子种类的部分电离， 估计用于冻结所述磁场通量的条件;以及 (4)质磁比的测定及其 云的变化。 这项拨款支持一个观察性研究项目， 理查德·克鲁彻博士在伊利诺伊大学， 与托马斯特罗兰博士的合作， 肯塔基州，以测试目前的理论思想，在所有的 上述领域。