Angular Momentum Evolution and the Origin of Rotation in Stars

近年来，人们对低质量恒星的角动量演化进行了大量的观测和理论研究。原恒星旋转速率的初始分布可以为恒星形成过程以及金牛座T星与其星周吸积盘的相互作用提供线索。旋转与恒星磁场的产生密切相关，恒星的自旋可以用来研究磁化恒星风的角动量损失。物质的内部输运和角动量的内部输运有几个来源（流体力学的、磁性的和由重力波引起的）；这种传输产生的混合可以强烈地改变恒星表面的丰度。与恒星旋转相关的各种物理效应使主题变得复杂。幸运的是，角动量演化的理论模型有许多观测约束，最近的工作已经建立了解释这些数据的理论框架。这项研究是对恒星旋转的理论和观测相结合的项目。本工作的目的是改进角动量演化模型的物理性质，并为模型提供新的标定数据。＊＊＊

PI PinsonneaultThere has been extensive recent observational and theoretical work on the angularmomentum evolution of low mass stars. The initial distribution of protostellar rotation rates can provide clues about the star formation process and the interaction of T Tauri stars with their circumstellar accretion disks. Rotation is intimately connected with the generation of stellar magnetic fields, and the spindown of stars can be used to study angular momentum loss from a magnetized stellar wind. Internal transport of material and of angular momentum has several sources (hydrodynamic, magnetic, and induced by gravity waves); this transport produces mixing that can strongly modify the surface abundances of stars. The sheer variety of physical effects associated with stellar rotation makes the subject complex. Fortunately, there are numerous observational constraints on theoretical models of angular momentum evolution, and recent work has established a theoretical framework for interpreting these data. This study is a combined theoretical and observational program on stellar rotation. The goals of this work are to improve the physics in models of angular momentum evolution and to provide new calibrating data for the models. ***