A Jet Deceleration Model on TeV BL Lacertae Objects
A Jet Deceleration Model on TeV BL Lacertae Objects
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DOI：
10.1086/425354
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发表时间：
2004-12
期刊：
影响因子：
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通讯作者：
Jian-cheng Wang;Huiquan Li;L. Xue
中科院分区：
文献类型：
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作者：
Jian-cheng Wang;Huiquan Li;L. Xue
目前对TeV BL Lac天体喷流动力学的理解是，它们从具有大洛伦兹因子的亚秒差距尺度大幅减速，发射TeV辐射到秒差距尺度，其中观测到的射电成分主要是亚光速或温和的相对论性。提出了TeV BL Lac天体的减速喷流模型，包括喷流动力学和粒子注入。射流等离子体被假定为连续地注入在射流的底部，并在距离中心核一定距离处消散。结果发现，射流的减速轮廓取决于外部介质的密度分布，显示出在外部介质中具有快速下降的密度轮廓的较慢的变化。喷流耗散的动能被假定为转移到电子加速。相对论电子沿着喷流注入，产生同步辐射和逆康普顿辐射。讨论了射流物理量的一般特征。结果表明，所产生的光谱能量分布（SED）主要取决于在耗散区，磁结构，和射流的视角的注入电子的能量分布。该模型描述了底层的未受干扰的射流，并适用于适合的静态红外X射线光谱的几个TeV BL紫胶对象。在这种情况下，TeV BL Lac天体的耗散体动能可以提供相对论电子辐射，其初始磁场与发射电子均分。
The current understanding of the kinetics of known TeV BL Lac objects' jets is that they substantially decelerate from a subparsec scale with a large Lorentz factor, emitting TeV radiation to a parsec scale, where the observed radio component is predominantly subluminal or mildly relativistic. A decelerating jet model of TeV BL Lac objects including jet dynamics and particle injection is proposed. The jet plasma is assumed to be continuously injected at the base of the jet and to dissipate at some distance from the central core. It is found that the deceleration profile of the jet depends on the density distribution of the external medium, showing slower variation in an external medium with a fast-falling density profile. The dissipated kinetic energy of the jet is assumed to be transferred to electron acceleration. The relativistic electrons are injected along the jet and then produce synchrotron and inverse Compton emission. The general characteristics of the physical quantities of the jet are discussed. It is shown that the resulting spectral energy distributions (SEDs) mainly depend on the energy distribution of injected electrons in the dissipation region, the magnetic structure, and the viewing angle of the jet. The model describes the underlying undisturbed jet and is applied to fit the quiescent infrared to X-ray spectra of several TeV BL Lac objects. In this scenario, the dissipated bulk kinetic energy of TeV BL Lac objects can provide relativistic electrons for radiation, and their initial magnetic fields are under equipartition with the emitting electrons.