论文标题
在模拟的M-warf恒星中纵向调制的发电机作用
Longitudinally Modulated Dynamo Action in Simulated M-Dwarf Stars
论文作者
论文摘要
M-dwarf恒星以其许多表现出的强烈磁性活性而闻名。在具有近表面对流区域的酷星中，这种磁性活动被认为主要是由对流的相互作用以及其建立的大规模差异旋转和循环驱动的。这些流的高度非线性性质产生了一个有趣的敏感和多样的参数空间，并具有广泛的动态范围。我们在这里报告了三个全球MHD模拟，迅速旋转M2（0.4 $ M_ \ odot $）星星。这三个模型中的每一个都建立了剧烈对流的巢穴，在低纬度下经度高度调节。它们的磁参数的轻微差异使每个模型都达到了分散的发电机状态，但是对流巢的效果是统一的特征。在每种情况下，纵向调节对流的作用导致环形磁场的局部（全球）逆转，以及积极经度的形成，具有增强的poloidal场幅度幅度和磁带出现。
M-dwarf stars are well known for the intense magnetic activity that many of them exhibit. In cool stars with near-surface convection zones, this magnetic activity is thought to be driven largely by the interplay of convection and the large scale differential rotation and circulations it establishes. The highly nonlinear nature of these flows yields a fascinatingly sensitive and diverse parameter space, with a wide range of possible dynamics. We report here on a set of three global MHD simulations of rapidly rotating M2 (0.4 $M_\odot$) stars. Each of these three models established nests of vigorous convection that were highly modulated in longitude at low latitudes. Slight differences in their magnetic parameters led each model to disparate dynamo states, but the effect of the convective nest was a unifying feature. In each case, the action of longitudinally modulated convection led to localized (and in one case, global) reversals of the toroidal magnetic field, as well as the formation of an active longitude, with enhanced poloidal field amplitudes and flux emergence.
