The smallest characteristic scales, at which electron dynamics determines the plasma behaviour, are the next frontier in space and astrophysical plasma research. The analysis of astrophysical processes at these scales lies at the heart of the research theme of electron-astrophysics. Electron scales are the ultimate bottleneck for dissipation of plasma turbulence, which is a fundamental process not understood in the electron-kinetic regime. In addition, plasma electrons often play an important role for the spatial transfer of thermal energy due to the high heat flux associated with their velocity distribution. The regulation of this electron heat flux is likewise not understood. By focussing on these and other fundamental electron processes, the research theme of electron-astrophysics links outstanding science questions of great importance to the fields of space physics, astrophysics, and laboratory plasma physics. In this White Paper, submitted to ESA in response to the Voyage 2050 call, we review a selection of these outstanding questions, discuss their importance, and present a roadmap for answering them through novel space-mission concepts.

电子动力学决定等离子体行为的最小特征尺度是空间和天体物理学等离子体研究的下一个前沿。在这些尺度上对天体物理过程的分析是电子天体物理学研究主题的核心。电子尺度是等离子体湍流消散的最终瓶颈，这是电子动力学体系中不被理解的基本过程。此外，由于与其速度分布相关的高热通量，等离子体电子通常在热能的空间传输中发挥重要作用。这种电子热通量的调节同样不为人所知。通过关注这些和其他基本电子过程，电子天体物理学的研究主题将对空间物理学、天体物理学和实验室等离子体物理学领域具有重要意义的突出科学问题联系起来。在这份响应 Voyage 2050 号召而提交给 ESA 的白皮书中，我们回顾了这些悬而未决的问题，讨论了它们的重要性，并提出了通过新颖的太空任务概念来回答这些问题的路线图。