潮汐转矩对转动恒星结构和演化的影响研究

发布时间：2018-10-24 19:21

【摘要】：潮汐效应是影响恒星结构和演化非常重要的物理因素.本文研究了影响潮汐转矩系数E_2的三个理论模型.根据转动恒星中的角动量传输和元素扩散方程,给出了潮汐转矩系数E_2对转动恒星内部结构和元素混合的影响.结果表明:潮汐转矩系数E_2与恒星质量、金属丰度、演化时间有密切关系.潮汐转矩系数E_2越大,双星系统轨道角动量转化为子星自转角动量和自转角动量在恒星内部传输的效率越高.强潮汐转矩造成恒星表面有较大的氦和氮元素的超丰和对流核质量,使恒星具有较高的光度.然而,对比模型M1和M3,充分的转动混合效应可以降低元素的不透明度和辐射温度梯度,压制转动动力学效应造成的辐射温度梯度的增加,使恒星中心对流核减少.强潮汐产生的转动混合效应使氢元素丰度和数密度增加,增强氢燃烧效率,提高中心核温度,使恒星膨胀,具有较大的转动惯量.因此,研究潮汐效应对元素混合效应的影响,对密近双星的演化具有重要意义.
[Abstract]:Tidal effect is a very important physical factor affecting star structure and evolution. In this paper, three theoretical models affecting tidal torque coefficient EW _ 2 are studied. Based on the equations of angular momentum transfer and element diffusion in rotating stars, the influence of tidal torque coefficient E _ (2) on the internal structure and element mixing of rotating stars is given. The results show that the tidal torque coefficient E _ 2 is closely related to star mass, metal abundance and evolution time. The higher the tidal torque coefficient E _ 2 is, the higher the efficiency of the orbital angular momentum transformation from orbital angular momentum to substar rotation angular momentum and rotation angular momentum is. The strong tidal torque results in a high mass of helium and nitrogen elements on the surface of the star, which makes the star have a higher luminosity. However, compared with model M1 and M3, the sufficient rotation mixing effect can reduce the opacity and radiation temperature gradient of elements, suppress the increase of radiation temperature gradient caused by rotational dynamics effect, and reduce the convection nucleus in the center of the star. The rotational mixing effect caused by the strong tide increases the abundance and density of hydrogen element, enhances the efficiency of hydrogen combustion, increases the central core temperature, and makes the star expand, which has a large moment of inertia. Therefore, it is of great significance to study the effect of tidal effect on the element mixing effect in the evolution of dense binaries.
【作者单位】：贵州大学理学院;瑞士日内瓦大学天文系;中国科学院天体结构与演化重点实验室;
【基金】：国家自然科学基金(编号:11463002) 中国科学院天体结构与演化重点实验室开放课题(编号:OP201405) 国家公派留学西部访学项目基金(编号:留金法[2015]5103)资助
【分类号】：P152

【相似文献】