摘要
本文探讨用相对论喷流模型解释ＢＬＬａｃ天体０７１６＋７１从射电到γ射线的整个电磁波段的非热辐射。喷流的结构分两个区域描述：内区具有抛物线结构，喷流是加速的；外区具有圆锥形结构，喷流速度恒定。相对论电子的密度和最高能量，以及磁场等参数随距离向外按幂律下降。在此模型中，射电至紫外线起源于相对论电子的同步辐射，而高能的Ｘ射线和ｒ射线则起源于自康普顿散射。辐射的频率越高，产生区域越靠近中央能源机器。辐射频率≥１０２２Ｈｚ的γ射线是在喷流最致密的区域内产生的，它到喷流基底的距离≤１０１７ｃｍ．这个模型相当好地解释了１９９１年３月和１９９２年１月由射电，光学－紫外（ＩＵＥ），Ｘ射线（ＲＯＳＡＴ）和γ射线（ＥＧＲＥＴ）观测所确定的高活动态下的辐射光度和能谱分布。与Ｍａｒａｓｃｈｉ等为解释光学激变类星体（ＯＶＶ）３Ｃ２７９的γ辐射所提出的喷流模型相比较，本文对ＢＬＯ０７１６＋７１所提出的模型要求较弱的磁场和更高的电子能量。
The nonthermal radiations of BLO 0716+71 from radio to gamma-ray are consistently interpreted in terms of a relativistic jet model. It is assumed that the jet consists of two regions: in the inner region the jet has a parabolic structure and is accelerated, and in the outer region the jet has a conical structure and its speed keeps constant. The magnetic field, electron density and maximum electron energy etc. are assumed to decrease outwards in power-law form. In this model, the radiations from radio to UV are originated from synchrotron radiation of the relativistic electrons and the high energy radiations (X-ray and gamma-ray) are originated from inverse Compton scattering. It is shown that the proposed model can considerably well fit the“'high state”of 0716+71. In comparison with the jet model proposed by Maraschi et al. (1992) for interpreting the gamma-ray emission of 3C279, the model for 0716+71 requires a lower magnetic field (B0=2G) and a higher electron energy cutoff (γe,max(R0)=2.5 X104).
出处
《天文学报》
CSCD
北大核心
1995年第2期138-146,共9页
Acta Astronomica Sinica
基金
国家自然科学基金
关键词
河外射电源
喷流模型
Γ射线
BLO天体
Extragalactic radio source
Gamma-ray radiation
Relativistic jet model
BLO 0716+714
