With the coincident detection of a gamma-ray flare and a neutrino from the blazar TXS 0506+056, Active Galactic Nuclei (AGN) have been put into focus as possible sources of the diffuse neutrino flux. We present a space and time-resolved model of the high-energy particle emission of a plasmoid assumed to travel along the axis of an AGN jet at relativistic speed. This was achieved by modifying the publicly available CRPropa (version 3.1+) propagation framework which in our work is capable of being applied to source physics on sub-kpc scales. The propagation of a population of primary protons is modelled in a purely turbulent magnetic field and we take into account interactions of these protons with photons scattered from the accretion disc, synchrotron radiation emitted by ambient relativistic electrons, as well with themselves and with other ambient matter. Our model produces a PeV-neutrino flare caused mainly by photo-hadronic interactions of primaries with the accretion disc field. Secondary high-energy gamma-rays partly attenuate with the ambient photon fields whose combined optical depths achieve their minimal opacity for photons of around 10 TeV. Thus, our model is well capable of producing neutrino flares with a significantly reduced emission of gamma-rays in jets with a hadronic jet component which in the future can be fit to specific AGN flare scenarios.
A Comprehensive Hadronic Code Comparison for Active Galactic Nuclei
Niels Bohr Institute, University of Copenhagen（哥本哈根大学尼尔斯·玻尔研究所）；National and Kapodistrian University of Athens（雅典国立卡波季斯特里亚斯大学）；North-West University（西北大学）；Bunkyo University（文教大学）；RIKEN（理化学研究所）；Penn State University（宾夕法尼亚州立大学）；Yukawa Institute for Theoretical Physics（京都大学汤川理论物理研究所）
Hadronic origin of multi-TeV gamma rays and neutrinos from low-luminosity active galactic nuclei: implications of past activities of the Galactic center
低光度活动星系核（LLAGNs）中的辐射低效吸积流（RIAFs）被认为是宇宙射线和中微子源，可能对观测到的漫射中微子强度有很大贡献。我们表明，这种情况下自然预测强子多TeV的伽马射线过剩银河系中心周围。在人马座A $^*$（Sgr A $^*$）的RIAF中加速的质子逃逸并与Sgr A $^*$周围的致密分子气体相互作用，这被称为中心分子区（CMZ），并产生伽马射线和中微子。基于与IceCube数据兼容的理论模型，我们计算了CMZ的伽马射线谱，发现如果Sgr A $^*$在过去比现在更活跃，那么高能立体系统可能已经探测到了具有$\gtrsim 1$ TeV的伽马射线。我们的模型预测中微子应该来自CMZ，其光谱与伽马射线光谱相似。我们还表明，这样的伽马射线过剩，预计一些附近的星系托管LLAGN。
A roadmap to hadronic supercriticalities: a comprehensive study of the parameter space for high-energy astrophysical sources
强子超临界是辐射不稳定性，当大量能量储存在相对论质子中时出现。当质子能量密度超过某个临界值时，开始失控过程，导致质子能量爆炸性地转移到电子-正电子对和辐射中。逃逸也导致辐射效率的增加，即光子亮度与注入质子亮度的比值。我们进行了一个全面的研究参数空间，通过调查的发病强子超临界的广泛的源参数（即，磁场强度为1 G $- 100$ kG，半径为$10^{11}$ cm $-10^{16}$ cm）和最大质子洛伦兹因子（$10^3-10^9$）。我们表明，超临界是可能的整个范围内的源参数相关的紧凑的天体物理源，如伽马射线爆发，核心和活动星系核的射流。我们还提供了一个深入的研究强子超临界的物理机制，并表明磁化相对论等离子体是高能天体物理学中的非线性动力系统的很好的例子。
