摘要
射电Ⅳ型运动爆发同日冕物质抛射（ＣＭＥｓ）关系极为密切。本文基于对Ⅳ型运动爆发的研究以及ＣＭＥｓ开放场的物理条件，探讨了ＣＭＥｓ形成及抛射的物理条件。由于磁通量突然喷发，能量大量释放，在ＣＭＥ闭合场中的等离子体被加速，导致高能质子和高能电子被大磁环捕获。随着磁环内的热压Ｐ和磁压Ｐｍ的升高，当β＞βＴ时磁环将炸裂，从而产生ＣＭＥｓ。抛射出的未离化的等离子体团将产生等离子体基波与谐波辐射。随着等离子体的不断离化，高能相对论电子绕开放磁场线作螺旋飞行，这时等离体辐射降到次要地位，回旋同步加速辐射上升到主导地位，这就是射电Ⅳ型运动爆发。如果离化的早，则在微波波段也能看到Ⅳ型运动爆发。这就是微波Ⅳ型爆发，也是微波Ⅳ型爆发罕见的原因。射电运动Ⅳ型爆发源就是日冕抛射的物质。
There are very close relations between the radio moving type Ⅳbursts and coronal mass ejections.On the basis of the studies of radio moving type Ⅳ burst and of the physical condition of open magnetic field of CMEs,the physical conditions on the generation and ejection of CMEs are studied in this paper.When the magnetic flux is sudden injected and a large number of magnetic energy is released,the plasma in closed magnetic field of CMEs is accelerated.For this reason,the accelerated energetic protons and electrons are trapped in a large magnetic loop.With the growths of the heat pressure P,the magnetic pressure P m and β≥β T the magnetic loop breaks as open one, and the CME produces.The ejected plasmoids which are not ionized will generate fundamental and harmonic emissions of the plasma.With the plasmoids are ionized,when energetic relativistic electrons travel in spirals round the open field line,the plasma emission becoms less important,the gyrosynchrotron emission is in the first order.This is the radio moving type Ⅳ burst.If the plasmoids are ionized ahead of time,the moving type Ⅳ burst can appear on microwave band. This is microwave type Ⅳ burst,and also is a reason that the microwave type Ⅳ burst is rare.The radio moving type Ⅳburst source is just the coronal ejection mass.
出处
《云南天文台台刊》
CSCD
1999年第2期24-29,共6页
Publications of the Yunnan Observatoty
