黑洞双星的B型QPO频率与幂律通量的相关性的解释  

An Explanation for the Correlation between Type-B QPO Frequency and the Power-law Flux in Black-hole Binaries

作　　者：黄昌印 张子升 HUANG Chang-yin;ZHANG Zi-sheng(School of Physics and Optoelectronic Engineering,Yangtze University,Jingzhou 434023)

机构地区：[1]长江大学物理与光电工程学院,荆州434023

出　　处：《天文学报》2023年第4期138-147,共10页Acta Astronomica Sinica

摘　　要：观测表明,黑洞双星的B型准周期振荡(Quasi-Periodic Oscillation,QPO)频率与幂律通量之间存在正相关性.试图基于阿尔文波振荡模型定量解释该相关性.标准薄吸积盘辐射通量极大值处的阿尔文波振荡产生QPO.标准薄盘上的软光子与冕或喷流基部的热电子介质发生逆康普顿散射产生幂律通量.通过吸积率的连续变化,得到QPO频率与幂律通量关系的分析解和数值解.模拟得到的相关性在合理的参数范围内与观测值相吻合.QPO频率与幂律通量的正相关性可以理解为,较强的磁场导致较高的阿尔文波频率和较高的电子温度从而得到较高的幂律通量.结果表明B型QPO可能与吸积盘或喷流中的环向磁场的活动有关.A positive correlation between the frequency of type-B quasi-periodic oscillations(QPOs)and the associated hard power-law flux has been discovered in a few black hole binaries.The correlation is explained quantitatively based on the Alfven wave oscillation model.The QPO is assumed to be generated by the Alfven wave oscillation in the standard thin Shakura-Sunyaev disk(SSD)at radius with the maximum radiation flux.The power-law flux is calculated based on inverse Compton scattering of soft photons from SSD by a medium of hot electrons in the corona or the base of jet.Both the explicit solutions and numerical results of the correlation between the QPO frequency and the power-law flux with the changing accretion rate are obtained.The modelled correlation fits well into the observed one within reasonable parameter range.The positive correlation could be interpreted by the hypothesis that a stronger magnetic field leads to a higher Alfven wave frequency and a higher electron temperature and therefore a stronger power-law flux.The results suggest that type-B QPOs may be related to the toroidal magnetic activities in the accretion disk or the jet.

关 键 词：吸积 吸积盘 磁场 黑洞物理 恒星:黑洞 X射线:双星 

分 类 号：P153[天文地球—天文学] P145.8