标题： LS 5039中轨道调制的超高能光子的产生 显示英文标题

标题： The production of orbitally modulated UHE photons in LS 5039

摘要： 伽马射线双星表现出可变的辐射，可以达到超高能。 产生这种极高能辐射的粒子加速过程尚不清楚。 我们研究了伽马射线双星LS 5039中的粒子加速器和超高能光子发射器的特性。 从双星系统的特性以及HAWC探测到的超高能辐射出发，我们使用分析工具来研究这些特性如何限制辐射和加速区域，即同步辐射损失、粒子约束和加速粒子谱的作用，并提出一种可以缓解所推导约束的加速场景。 对强子过程的适度目标密度和整体伽马射线轨道变化有利于由高度相对论性电子散射大质量伴星的紫外光子的逆康普顿散射。 最高能量电子的加速意味着加速区域中同步辐射冷却的约束，这可以设定其磁场的上限。 此外，检测到的变化要求加速和辐射区域都有非常强的粒子约束，这设定了它们磁场的下限，该下限与加速区域的同步辐射冷却约束勉强一致。 如果辐射区域与加速器分离，同步辐射损失可能更高，但这需要一个非常硬的粒子注入谱。 由Derishev及其合作者提出的LS 5039场景，其中超相对论性磁化喷流通过γγ吸收在喷流内注入的轻子加速，提供了一种加速极高能电子的可行机制。 这种机制通过减少同步辐射冷却的影响来缓解加速和约束要求，并可以生成所需的粒子谱。 显示英文摘要

摘要： Gamma-ray binaries present emission that is variable and can reach UHE. The processes behind the acceleration of the particles that produce this very energetic radiation are yet to be understood. We probe the properties of the particle accelerator and the UHE photon emitter in the gamma-ray binary LS 5039. From the properties of the binary system and the UHE radiation detected by HAWC, we used analytical tools to investigate how these properties constrain the emission and acceleration regions, namely the role of synchrotron losses, particle confinement, and the accelerated particle spectrum, and propose an acceleration scenario that can relax the derived constraints. The modest target densities for hadronic processes and the overall gamma-ray orbital variability favor inverse Compton scattering of ultraviolet photons from the massive companion star by highly relativistic electrons. The acceleration of the highest energy electrons implies a constraint on synchrotron cooling in the acceleration region, which can set an upper limit on its magnetic field. Moreover, the detected variability requires very strong particle confinement in both the acceleration and emission regions, which sets a lower limit on their magnetic fields that is barely consistent with the synchrotron cooling constraint from acceleration. Synchrotron losses may be higher in the emitting region if it is separated from the accelerator, but this requires a very hard particle injection spectrum. A scenario for LS 5039 of the kind proposed by Derishev and collaborators, in which an ultrarelativistic magnetized outflow accelerates leptons injected within the outflow by gammagamma absorption, provides a viable mechanism to accelerate very energetic electrons. This mechanism relaxes the acceleration and confinement requirements by reducing the impact of synchrotron cooling, and can generate the required particle spectrum.