权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Observational Study of the Role of Magnetic Fields in Star Formation

磁场在恒星形成中的作用的观测研究

基本信息

批准号：
0205810
负责人：
Richard Crutcher
金额：
$ 23.18万
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：
2002
资助国家：
美国
起止时间：
2002-07-01 至 2006-06-30
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=0205810&HistoricalAwards=false
关键词：
Observational Study Role Magnetic Fields

项目摘要

AST-0205810PI CrutcherThe theoretical effort to understand star formation and the role of magnetic fields in the formation and evolution of interstellar clouds is extensive and accelerating. However, in spite of significant progress in recent years, there remain fundamental unanswered questions about the basic physics of star formation. If dense molecular clouds have lifetimes significantly longer than their free-fall collapse times, they must be supported against gravitational collapse. One view is that magnetic fields provide this support. This hypothesis can be tested by measurement of the mass to magnetic flux ratio in dense clouds. The other extreme is that magnetic fields are weak and that molecular clouds are intermittent phenomena, and that the problem of cloud support for long time periods is irrelevant. This project will measure, directly or indirectly, magnetic field strengths in a large, statistically meaningful sample of molecular clouds in order to help answer the above questions. Because the requisite measurements are of weakly polarized continuum and spectral-line emission from molecular clouds, measurements of interstellar magnetic fields remain among the most difficult of astronomical observations, and information about magnetic fields remains very sparse. It is crucial to our understanding of the fundamental physical process of star formation that measurements of interstellar magnetic fields continue to progress.***

AST-0205810 PI Crutcher理解星星形成和磁场在星际云形成和演化中的作用的理论努力是广泛和加速的。然而，尽管近年来取得了重大进展，但关于星星形成的基本物理学仍然存在根本性的未解之谜。如果稠密分子云的寿命比自由落体坍缩时间长得多，那么它们必须得到支持以抵抗引力坍缩。一种观点认为，磁场提供了这种支持。这一假设可以通过测量稠密云层中的质量与磁通量之比来检验。另一个极端是磁场很弱，分子云是间歇性的现象，长时间的云支持问题是无关紧要的。该项目将直接或间接地测量分子云的大样本中的磁场强度，以帮助回答上述问题。由于所需的测量是弱偏振连续谱和分子云的谱线发射，星际磁场的测量仍然是天文观测中最困难的，有关磁场的信息仍然非常稀少。对星际磁场的测量继续取得进展，对我们理解星星形成的基本物理过程至关重要。*