论文标题
惠斯勒波和电子特性：Helios观测值
Whistler Waves and Electron Properties in the Inner Heliosphere: Helios Observations
论文作者
论文摘要
我们介绍了在内层内观察到的窄带惠斯勒波特征的分析（0.3-1 au）。这些签名是通过在Helios1航天器上的搜索线圈磁力计测量的AC磁场的10-200 Hz频率范围内的光谱密度的颠簸。我们表明，在慢性太阳风（<500 km/s）中观察到大多数惠斯勒签名，并且它们的发生随径向距离（R）的增加，从0.3 au的〜3％到0.9 au时的〜10％。在快速太阳风（> 600 km/s）中，惠斯勒活动明显降低。惠斯勒的签名开始出现，以r> 0.6 au出现，其数量从0.65 au的〜0.03％增加到0.9 au时的〜1％。我们已经研究了电子核心和光环各向异性的变化，以及电子归一化热通量随R和太阳风速的函数。我们发现，在缓慢的风中，电子核心和光晕核心比在快速速度中高，并且这些各向异性在两种类型的风中都径向增加，这与惠斯勒特征的发生相一致。我们假设存在反馈机制，以解释吹口哨与卤各向异性有关的观察到的径向变化。
We present the analysis of narrowband whistler wave signatures observed in the inner heliosphere (0.3-1 au). These signatures are bumps in the spectral density in the 10-200 Hz frequency range of the AC magnetic field as measured by the search coil magnetometer on board the Helios1 spacecraft. We show that the majority of whistler signatures are observed in the slow solar wind (<500 km/s) and their occurrence increases with the radial distance (R), from ~3% at 0.3 au to ~10% at 0.9 au. In the fast solar wind (>600 km/s), whistler activity is significantly lower; whistler signatures start to appear for R > 0.6 au and their number increases from ~0.03% at 0.65 au to ~1% at 0.9 au. We have studied the variation of the electron core and halo anisotropy, as well as the electron normalized heat flux as a function of R and of the solar wind speed. We find that, in the slow wind electron core and halo anisotropy is higher than in fast one, and also that these anisotropies increase radially in both types of winds, which is in line with the occurrence of whistler signatures. We hypothesize the existence of a feedback mechanism to explain the observed radial variations of the occurrence of whistlers in relation with the halo anisotropy.
