Very-High-Energy Gamma Ray Emission from Blazar Jets

从耀变体中发射伽马射线的确切起源仍然难以捉摸。相互竞争的模型提出，发射区域可能非常靠近中心黑洞，或者它可能位于喷流的上游，局部高能事件是伽马射线的来源。提出的机制从自康普顿到外部康普顿，甚至是射流中携带的高能质子的强子路线。一种观测趋势极有可能与发射机制有关，但尚未被清楚地理解，即所谓的耀变体序列。这是耀变体在高能量（即在GeV范围内，小于VHE）下的峰值伽马射线能量与其光度的明显反相关。在这个项目中，我们将基于具有高磁化基底的喷流开发新的模型，以确定VHE发射是否沿耀变体序列显示出有用的诊断特征。该项目将是理论/计算，与MHD建模，然后与现有数据集进行比较。

The precise origin of gamma-ray emission form blazars remains elusive. Competing models propose that the emitting region might lie very close to the central black hole, or that it might lie upstream in the jet with localized high-energy events being the source of the gamma rays. The mechanisms proposed vary from self-Compton to external Compton, and even hadronic routes from high-energy protons entrained in the jet. One observational trend which is highly likely to be related to the emissions mechanisms, but which is not yet clearly understood, is the so-called blazar sequence. This is the apparent anti-correlation of peak gamma-ray energy at high energies (i.e. in the GeV range, less than VHE) from blazars with their luminosities. In this project we will develop new models, based on jets with a highly magnetised base, to determine if the VHE emission shows useful diagnostic signatures along the blazar sequence. The project will be theoretical/computational, with MHD modelling, and later comparison with existing data sets.