辐射压对非同步转动双星系统洛希势函数的影响

The effect of the radiative pressure on the potential function in asynchronous rotational binary

辐射压是影响大质量恒星结构和演化不可忽视的重要物理因素.根据辐射压对非同步转动的洛希势函数的影响,数值计算了洛希瓣的大小和3个拉格朗日点的位置和相应的势函数,并与同步转动的洛希模型计算的结果做了对比.结果发现:辐射压可以整体地减小大质量恒星表面的重力加速度,而转动离心力能最大减少赤道附近的重力加速度.辐射压和非同步转动均可以明显地改变洛希瓣的大小和3个拉格朗日点的位置和势函数,影响双星系统物质交换的时间.因此,研究辐射压,非同步转动等物理因素对大质量双星系统洛希势函数的影响,对密近双星的演化具有重要意义.

Radiative pressure is an important physical factor and can affect the structure and evolution of the massive star. The Roche lobe, three Lagrangian points and the corresponding Roche potentials are calculated according to the asynchronous rotational Roche potential which includes the radiative pressure. They are compared with the corresponding synchronous rotational Roche potentials. It is found that the centrifugal force greatly reduces the gravitational acceleration at the equator while the radiative pressure can reduce the gravitational acceleration of the massive star. Both the asynchronous rotation and the radiative pressure have an obvious influence on the Roche lobe, the positions of three Lagrangian points, the Roche potentials and the time of mass overflow. Therefore, it is very important to calculate the asynchronous rotational Roche potential which includes the radiative pressure in the massive close binaries.