论文标题
电子热通量在近似环境中
Electron heat flux in the near-Sun environment
论文作者
论文摘要
我们调查了Parker太阳能探针（PSP）在近阳性环境中观察到的电子热通量，以0.125-0.25 au为中心的距离。我们利用了太阳能电气和质子和田间实验的测量值来计算太阳能电气热通量及其组件，并将其放置在上下文中。 PSP观测结果揭示了太阳附近的电子热通量特征的许多趋势。热通量的幅度与太阳风速抗相关，这可能是由于高速风中饱和热通量较低的结果。当除以饱和热通量时，所得的归一化净热通量与所有PSP轨道上的等离子体beta反相关，这与无碰撞热通量调节机制的运行一致。在高层电流板附近，在很高的beta区域中，净热通量也会降低，但是在大多数情况下，全向外的上磁通通量仍处于可比的水平甚至增加的水平，似乎与与太阳的脱节似乎不一致。测得的热通量值似乎主要与太阳附近的碰撞机制不一致。取而代之的是，观察到的热通量对等离子体β的依赖性和外电子参数的分布都与与斜惠斯勒和磁性模式相关的理论不稳定性阈值一致。
We survey the electron heat flux observed by the Parker Solar Probe (PSP) in the near-Sun environment at heliocentric distances of 0.125-0.25 AU. We utilized measurements from the Solar Wind Electrons Alphas and Protons and FIELDS experiments to compute the solar wind electron heat flux and its components and to place these in context. The PSP observations reveal a number of trends in the electron heat flux signatures near the Sun. The magnitude of the heat flux is anticorrelated with solar wind speed, likely as a result of the lower saturation heat flux in the higher-speed wind. When divided by the saturation heat flux, the resulting normalized net heat flux is anticorrelated with plasma beta on all PSP orbits, which is consistent with the operation of collisionless heat flux regulation mechanisms. The net heat flux also decreases in very high beta regions in the vicinity of the heliospheric current sheet, but in most cases of this type the omnidirectional suprathermal electron flux remains at a comparable level or even increases, seemingly inconsistent with disconnection from the Sun. The measured heat flux values appear inconsistent with regulation primarily by collisional mechanisms near the Sun. Instead, the observed heat flux dependence on plasma beta and the distribution of suprathermal electron parameters are both consistent with theoretical instability thresholds associated with oblique whistler and magnetosonic modes.
