论文标题
极端TEV BL LACS:一个自一致的随机加速模型
Extreme TeV BL Lacs: a self-consistent stochastic acceleration model
论文作者
论文摘要
最近,一种特定的大麻吸引了伽玛射线天文学界的注意力:极端的Tev Bl lacs,在非常高能量的情况下表现出极具活力和硬发射。解释他们的特征仍然是一个开放的挑战,实际上,最常用的现象学模型很难令人满意地繁殖他们的SED。基于我们最近提出的情况,我们假设非热颗粒首先是通过射流回归冲击加速的,这会引起其余射流中的湍流。非热颗粒通过湍流进一步加速,这会使粒子光谱和辐射发射变硬。鉴于血浆的物理特性,如发射模型所推断的那样,我们期望加速颗粒对湍流产生强烈的影响。假设各向同性和同质性,非热颗粒与湍流及其光谱之间的相互作用是建模的,以求解一个由两个非线性的,耦合的Fokker-Planck方程组成的系统,而辐射发射是通过同步体自我Compton模型计算的。然后将我们的模型预测的发射与原型的Extreme Tev bl lac对象1ES 0229+200进行比较,并且获得的复制其SED的参数与期望一致。
Lately a specific kind of blazars drew the attention of the gamma-ray astronomy community: the extreme TeV BL Lacs, blazars that present an extremely energetic and hard emission at very high-energy. Explaining their features is still an open challenge, in fact the most used phenomenological models have difficulties to satisfactorily reproduce their SED. Based on a scenario we have recently proposed, we suppose that the non-thermal particles are firstly accelerated by a jet recollimation shock, which induces turbulence in the rest of the jet. Non-thermal particles are further accelerated by the turbulence, which hardens the particle spectra and accordingly the radiative emission. Given the physical properties of the plasma, as inferred by emission models, we expect a strong impact of the accelerating particles on the turbulence. Assuming isotropy and homogeneity, the interaction between non-thermal particles and turbulence and their spectra is modeled solving a system of two non-linear, coupled Fokker-Planck equations, while the radiative emission is calculated through the Synchrotron Self Compton model. The emission predicted by our model is then compared with the prototype extreme TeV BL Lac object 1ES 0229+200 and the parameters obtained to reproduce its SED are in line with the expectations.