一个边缘耀斑(后)环系速度场的近似计算  

An Approximate Calculation on Velocity Field of a Limb Post-Flare Loop System

作　　者：顾啸马[1] 敦金平[1] 钟树华[1] 

机构地区：[1]中国科学院云南天文台

出　　处：《天体物理学报》2000年第4期414-422,共9页

基　　金：国家自然科学基金

摘　　要：利用“多云模型”方法，从云南天文台二维多波段太阳光谱仪观测到的Ｈβ光谱资料中导出１９８９年８月１７日太阳西边缘的一个大的耀斑环系不同时间的视向速度场．为了解释观测速度场的主要特征，本文采用如下假设和近似：环内物质在太阳重力、磁场应力和环内气压梯度力联合作用下由环足沿螺旋磁力线上升运动．应用ＭＨＤ理论计算了它的理论速度场．通过两者的比较发现，计算出的速度场与第一时段的观测速度场基本相似，这似乎对耀斑物质蒸发模型提供了支持．The observed line-of-sight velocity field at different times of a large post-flare loop (PFL) system which occurred on the solar western limb on 1989 August 17 is derived based on a 'multi-cloud model' (MCM) method from Hβ spectral data obtained with the twodimensional multi-waveband spectra- spectroheliograph (MW- SSHG) at t he Yunnan Observatory. In order to explain the fundamental features of the velocity fields observed, an assumption and approximation to be taken into account that the matter within a loop system rises up from the loop foot to the loop top along the loop leg in a belieal magnetic line under the combined action of solar gravity, magnetic stress and a gradient of atmospheric pressure in the loop system, and a theoretical velocity field of the loop system is calculated with the aid of MHD theory. From a comparison of both velocity fields, it is found that the competed velocity field is basically similar with that Observed in the first duration. It seems a support to material evaporation model of solar flares.

关 键 词：太阳耀斑 速度场 计算 

分 类 号：P155[天文地球—天文学]