论文标题
星形行星相互作用：波结构和翼翼相互作用
Star-Planet Interaction: Wave Structures and Wing-Wing Interaction
论文作者
论文摘要
当行星通过电磁力将行星伴侣与宿主恒星伴侣时，电磁星形行星相互作用（SPI）描述了现象。 Alfvén波可以通过形成AlfvénWings来建立这种耦合。 SPI允许我们从太阳系中不知道的现象。机翼互动就是一个例子，其中两个行星的alfvén翅膀合并并非线性相互作用。在本文中，我们关注SPI对其他行星和恒星风的影响。首先，我们分析与SPI相关的不同波结构。然后，第二部分研究机翼互动。我们的研究应用了磁性水力学模型来描述具有多个可能行星的恒星系统。例如，我们选择了Trappist-1及其两个最内向的行星。我们扩展了冥王星代码，以模拟大气中性颗粒和血浆离子之间的碰撞。中性气云模仿行星并穿过模拟域。这允许模拟完全依赖时间的恒星系统。我们分析了波结构，这是由于恒星风与trappist-1 b之间的相互作用所致。内向的波结构是Alfvén机翼。交互的外部部分由Alfvén机翼，慢速波浪，行星唤醒和缓慢的冲击组成。我们量化了外行星在外行星上的各个波扰动的强度，为热，磁性和动态压力的局部背景值的10 \％至40 \％。翼之间的相互作用是由于两个行星在连接过程中的相对位置而发生的，并显示了三个阶段。首先，当Planet C的Alfvén机翼穿过Planet B的波浪结构并具有另一个强度的磁通量的强度时，首先是$ 20 \％$的初始非线性强化，这是一个中间阶段，具有减少的通量，而第三相。
Electromagnetic Star-Planet Interaction (SPI) describes the phenomenon, when a planet couples to its host star via electromagnetic forces. Alfvén waves can establish such a coupling by forming Alfvén wings. SPI allows phenomena that we do not know from the Solar System. Wing-wing interaction is such an example, where the Alfvén wings of two planets merge and interact non-linearly. In this paper we focus on the effects that SPI has on other planets and the stellar wind. First, we analyse the different wave structures connected to SPI. The second part then investigates wing-wing interaction. Our study applies a magnetohydrodynamic model to describe a stellar system with multiple possible planets. As an example, we chose TRAPPIST-1 and its two innermost planets. We extended the PLUTO code to simulate collisions between atmospheric neutral particles and plasma ions. Neutral gas clouds imitate the planets and move through the simulation domain. That allows the simulation of fully time-dependent stellar systems. We analysed the wave structures, which result from the interaction between stellar wind and TRAPPIST-1 b. The inward going wave structure is an Alfvén wing. The outward going part of the interaction consists of an Alfvén wing, slow mode waves, the planetary wake and a slow shock. We quantified the strength of the respective wave perturbations at the outer planets to be on the order of 10\% to 40\% of the local background values of thermal, magnetic and dynamic pressure. Wing-wing interaction occurs due to the relative position of two planets during their conjunction and shows three phases. First there is an initial, non-linear intensification of the Poynting flux by $20\%$, an intermediate phase with reduced Poynting flux and a third phase when the Alfvén wing of planet c goes through planet b's wave structures with another intensification of the Poynting flux.
