Circumbinary disk, an efficient medium extracting orbital angular momentum in close binaries  

作　　者：CHEN WenCong ZENG QingGuo 

机构地区：[1]Department of Physics and Information Engineering, Shangqiu Normal University, Shangqiu 476000, China [2]Department of Astronomy, Nanjing University, Nanjing 210093, China

出　　处：《Chinese Science Bulletin》2009年第5期711-718,共8页

基　　金：Supported by the National Natural Science Foundation of China (Grant Nos. 10873011, 10573009, 10573010);Program for Science & Technology Innovation Talents in Universities of Henan Province, China

摘　　要：The loss of orbital angular momentum plays an important role in the mass transfer and orbital evolution of close binaries. The traditional mechanisms of orbital angular momentum loss consist of gravitational wave radiation, mass loss and magnetic braking. However, a small fraction of the mass outflow may form a thin circumbinary disk (CB disk) located in the orbital plane of the binary during mass exchange. The tide torques caused by the gravitational interaction between a CB disk and a binary system brake binary effectively, and extract the orbital angular momentum from the binary system. In this study, numerical calculations for the evolution of the white dwarf binary show that a CB disk is an efficient medium extracting orbital angular momentum even if the mass loss is very small. Finally, some theo-retical research and observational progress on CB disks are presented.The loss of orbital angular momentum plays an important role in the mass transfer and orbital evolution of close binaries. The traditional mechanisms of orbital angular momentum loss consist of gravitational wave radiation, mass loss and magnetic braking. However, a small fraction of the mass outflow may form a thin circumbinary disk （CB disk） located in the orbital plane of the binary during mass exchange. The tide torques caused by the gravitational interaction between a CB disk and a binary system brake binary effectively, and extract the orbital angular momentum from the binary system. In this study, numerical calculations for the evolution of the white dwarf binary show that a CB disk is an efficient medium extracting orbital angular momentum even if the mass loss is very small. Finally, some theoretical research and observational progress on CB disks are presented.

关 键 词：绕双星盘 轨角动量 质量亏损 磁力制动 CB磁盘模型 

分 类 号：P1[天文地球—天文学]