Radio Studies of Stellar Coronae, Winds, and Circumstellar Environments

AST-0206367 PI Brownstone对恒星射电辐射的研究提供了对恒星日冕、风、磁层和星周环境中发生的物理过程的补充和独特的见解。 射电观测的独特之处在于，它能够揭示恒星大气中非热过程的存在，以及磁场强度和磁能释放点或附近的结构。在这里进行的调查将使与以下方面有关的现象学和物理过程的研究取得重大进展：演化巨星和超巨星的质量损失过程，包括风加速过程和风驱动机制;活动双星的日冕结构和大双星的脉冲和冷却阶段发生的物理过程是这些系统中的事件;不同质量的主序星的热和非热射电辐射，以及这些性质如何随着恒星的演化而变化;控制射电辐射水平和恒星活动的基本过程，一般作为基本恒星参数和演化状态的函数;最后，恒星X射线日冕中的热过程与射电观测到的非热日冕过程之间的物理和几何关系。

AST-0206367PI BrownThe study of stellar radio emission provides complementary and often unique insightsinto physical processes occurring in stellar coronae, winds, magnetospheres, and circumstellar environments. Radio observations are unique in their ability to reveal the presence of nonthermal processes in stellar atmospheres, as well as the magnetic field strength and structure at or close to the site of magnetic energy release.The investigations to be carried out here will allow significant advances in the study ofthe phenomenolgy and physical processes related to: the mass loss process from evolved giant and supergiant stars, including the wind acceleration process and the wind driving mechanism(s); the coronal structure of active binary stars and the physical processes occurring during the impulsive and cooling phases of the large are events in these systems; the thermal and nonthermal radio emission of main sequence stars of differing mass and how these properties change as such stars evolve; the fundamental processes controlling the level of radio emission and stellar activity in general as a function of basic stellar parameters and evolutionary state; and finally, the physical and geometrical relationship between thermal processes in stellar X-ray coronae and nonthermal coronal processes observed in the radio.***