Electron heat flux instability in the near-Sun solar wind

How the solar wind heat flux is constrained and how strahl electrons are scattered are two fundamental problems in the study of the electron dynamics in the solar wind. Recently, much attention has been paid to the role of the electron heat flux instability on these two problems. We have performed the instability analyses for the electron heat flux instability in the near-Sun solar wind where the plasma beta is much lower than one. We found that lower-hybrid waves and oblique Alfvén waves can be primarily triggered by the electron heat flux in the low-beta plasma environment, and we also explored the wave-particle interactions in each type instability through the energy transfer rate method. Moreover, using PSP observations, we will show the possible observation signature for the lower-hybrid waves in the near-Sun solar wind.