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BLO0716+71非热辐射的喷流模型:从射电到γ射线
A JET MODEL FOR THE NONTHERMAL RADIATIONS OF BLO 0716+71: FROM RADIO TO GAMMA-RAY
【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。
【Abstract】 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).
【Key words】 Extragalactic radio source; Gamma-ray radiation; Relativistic jet model; BLO 0716+714;
- 【文献出处】 天文学报 ,ACTA ASTRONOMICA SINICA , 编辑部邮箱 ,1995年02期
- 【分类号】P157.7
- 【下载频次】26