从微波爆和X射线爆联合估算日冕磁场  

THE ESTIMATION OF CORONAL MAGNETIC FIELD FROM THE MICROWAVE AND X-RAY BURSTS

作　　者：姚金兴[1] 于兴凤[1] 

机构地区：[1]中国科学院紫金山天文台

出　　处：《天文学报》1994年第3期318-325,共8页Acta Astronomica Sinica

基　　金：天文基金委员会太阳分支学科

摘　　要：本文假定Ｘ射线爆和微波爆有共同的起源，用它们的爆发流量资料联合估算源中的磁场强度Ｂ、离子数密度ｎｉ和视线方向深度Ｌ．以１９８１年４月２７日０８００ＵＴ的由五个峰组成的延伸爆为例进行了计算。计算结果为：从厚靶模型和热模型得到的五个峰的磁场Ｂ分别为１８６５─６５９Ｇ和７７６─２３４Ｇ；而从薄靶模型算得的Ｂ为３５─１５３Ｇ，ｎｉ为１０８─６×１０９／ｃｍ３，最大的Ｌ为３．３×１０９ｃｍ．这个爆发的Ｘ射线主源的高度在光球上１．４×１０４ｋｍ，因此从薄靶模型得到的结果较为合理，这也与五个峰的“微波富有指数”随时增加相一致的。这似乎表明，五个峰的源位于同一冕环中，能量释放从环顶沿着磁力线向色球方向传播。传播的速度可能是离子声速，因为用上述数据得到的最小的阿尔芬速度超过１０４ｋｍ／ｓ。In this paper,supposing that X-ray bursts and microwavc bursts have common origin,we estimate the magnetic field B,the ion density ni and the depth L of the source along the direction of sight by the flux densities in the cm and X-ray ranges,with three different models.The results are as follows.1.B is 1865-659 G from the thick targed model.2.B is 776-234 G from the thermal model.3.B is 35-153G,ni is 108-5×109/cm3 and L is 5×109cm from the thin target model.The height of the source of X-ray burst is 1.4×104 km from the photosphere.It is concluded that the results from the thin target model is most reasonable.This conclussion is also consistent with increase of“microwave richness index”of 5 main peaks.It seems that the sources of 5 main peaks were located at the same coronal loop,the energy release propagated from the top to the feet in the chromosphere along the magnetic field line of the loop.The speed of propagation may be ionacoustic speed,because Alfven speed from the data mentioned above is over 104km/s.

关 键 词：太阳微波爆 射线爆 日冕磁场 

分 类 号：P182.62[天文地球—天文学]