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arXiv 1109.0618astro-ph.HEastro-ph.CO
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活动星系核弯曲喷流的宽带谱模拟

Broadband spectral modelling of bent jets of Active Galactic Nuclei

B. Sunder Sahayanathan

摘要:

本文建立了活动星系核喷流结和耀变体喷流的辐射发射过程的模型。本文建立了一个连续注入等离子体模型,用来研究1136-135、1150+497、1354+195和3C 371等源的X射线辐射。然后在内部冲击模型的框架内研究了结动力学。在这种情况下,由于活动星系核中央发动机偶尔发射的两个连续的物质团的碰撞,形成了结。在这种碰撞中产生的冲击将电子加速到相对论能量。这些电子随后通过同步加速器和/或逆康普顿过程在无线电到X射线能量范围内发射辐射。M87结的研究涉及两个区域模型,其中具有幂律分布的电子被进一步加速。这些高能电子的同步辐射被用来解释观测到的光谱。本文研究了BL Lac天体MKN 501射电图中观测到的边缘增亮特征,考虑了喷流边界处电子的剪切加速。这种解释不需要像早期模型所要求的那样需要大的射流视角,并且与从非常高的能量研究中获得的约束一致。在MKN 421的情况下,辐射发射的时间行为的粒子加速机制的依赖性已在两区模型的框架内进行了研究。

英文摘要:

In this thesis, models have been developed to study the radiation emission processes from the knots of AGN jets as well as for blazar jets. A continuous injection plasma model is developed to study the X-ray emission from the knots of sources 1136-135, 1150+497, 1354+195 and 3C 371. The knot dynamics is then studied within the framework of internal shock model. In such a scenario, knots are formed due to the collision of two successive matter blobs emitted sporadically from the central engine of AGN. Shocks, generated in such collisions, accelerate electrons to relativistic energies. These electrons subsequently emit radiation via synchrotron and/or inverse Compton processes in the radio-to-X-ray energy range. The study of M87 knots involves a two zone model where the electrons with a power-law distribution are further accelerated. The synchrotron emission from these energetic electrons is then used to explain the observed spectrum. The limb-brightening feature observed in the radio maps of the BL Lac object MKN501 is studied considering shear acceleration of electrons at the boundary of the jet. This interpretation does not require a large viewing angle of the jet as demanded by the earlier models and is consistent with the constraints obtained from very high energy studies. In case of MKN421, the dependence of temporal behaviour of radiation emission on the particle acceleration mechanism has been studied within the framework of two zone model.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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