BL Lac天体的γ射线和X射线辐射研究  

Study of γ-ray and X-ray Emission from BL LAC Objects

作　　者：张皓晶[1,2] 张雄[3] 

机构地区：[1]中国科学院国家天文台,北京100012 [2]中国科学院研究生院,北京100049 [3]云南师范大学物理系,昆明650092

出　　处：《天文学报》2008年第3期273-281,共9页Acta Astronomica Sinica

基　　金：国家自然科学基金(批准号:10521001;10433010;10663002;10763002)资助项目

摘　　要：收集了18个γ射线噪BL Lac天体的X射线流量密度和γ射线流量密度,以及X射线波段(1keV)和γ射线波段(>100 MeV)的平均光谱指数,研究了它们之间的相关性.结果表明:1)X射线流量密度与γ射线流量密度在高态、低态和平均态均有较强的相关性.2)X射线波段和γ射线波段的平均光谱指数之间有较强的负相关性.3)X射线和γ射线波段的平均光谱指数与X射线和γ射线辐射流量密度在高态和平均态时均无显著的相关性.4)γ射线波段的平均光谱指数与X射线辐射流量密度的低态有较强的负相关性.X射线波段的平均光谱指数与γ射线波段的流量密度的低态之间也存在弱相关性.分析结果支持BL Lac天体的X射线和γ射线辐射可能来自同一相对论电子分布的同步辐射和同步自康普顿(SSC)辐射.This paper collects 18γ-ray-loud BL Lacertae(BL Lac)objects with the observed X-ray andγ-ray flux densities(maximum,minimum,average)as well as the X-ray(1 keV)andγ-ray(above 100 MeV)average spectral indices.These flux den- sities and average spectral indices data came from 33 literatures.To analysis the charac- ter between X-ray andγ-ray flux densities in the maximum(F_(X max),F_(γmax)),minimum( F_(X min),F_(γmin))and average(F_(X aver),F_(γaver))value and those average spectral indices(α_X,α_γ),we employed the correlation analysis.We studied their correlations in detail,and our results show that:1)there is a strong correlation between F_X and F_γin the high,av- erage and low state.This result affirmed Stickel et al.model which supposed a few dust around the black hole.2)there is a strong correlations betweenα_X andα_γin the av- erage state.3)there is not a significant correlation between the average spectral indices and the flux densities in high and average state.4)there is a strong anti-correlation be- tween the averageγ-ray spectral indices and the X-ray flux densities in the low state, and also there is a weak correlation between the average X-ray spectral indices and theγ-ray flux densities in the low state.Our results are in agreement with the scenario that the X-ray andγ-ray emission from BL Lac objects are likely produced by the same popu- lation of relativistic electrons through synchrotron and synchrotron Self-Compton model (SSC)process,respectively.

关 键 词：星系 活动 蝎虎天体 普通 γ射线 理论 X-射线 星系 方法 数据分析 

分 类 号：P158[天文地球—天文学]