科研之友
微信
新浪微博
Facebook
分享链接
摘要
Observations by the Hinode satellite show in great detail the dynamics of rising plumes, dark in chromospheric lines, in quiescent prominences that propagate from large (similar to 10 Mm) bubbles that form at the base of the prominences. These plumes present a very interesting opportunity to study magnetohydrodynamic (MHD) phenomena in quiescent prominences, but obstacles still remain. One of the biggest issues is that of the magnetic field strength, which is not easily measurable in prominences. In this paper we present a method that may be used to determine a prominence's plasma beta when rising plumes are observed. Using the classic fluid dynamic solution for flow around a circular cylinder with an MHD correction, the compression of the prominence material can be estimated. This has been successfully confirmed through simulations; application to a prominence gave an estimate of the plasma beta as beta = 0.47 +/- 0.079 to 1.13 +/- 0.080 for the range gamma = 1.4-1.7. Using this method it may be possible to estimate the plasma beta of observed prominences, therefore helping our understanding of a prominence's dynamics in terms of MHD phenomena.
- 出版日期2012-12-20
