SIMPLIFIED MODELS FOR PHOTOHADRONIC INTERACTIONS IN COSMIC ACCELERATORS
SIMPLIFIED MODELS FOR PHOTOHADRONIC INTERACTIONS IN COSMIC ACCELERATORS
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DOI：
10.1088/0004-637x/721/1/630
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发表时间：
2010-02
期刊：
影响因子：
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通讯作者：
Svenja Hummer;M. Ruger;F. Spanier;W. Winter
中科院分区：
文献类型：
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作者：
Svenja Hummer;M. Ruger;F. Spanier;W. Winter
我们讨论宇宙加速器中光介子产生的简化模型，例如活动星系核（AGN）和伽马射线爆发（GRB）。我们的自洽模型直接基于 SOPHIA 软件中使用的底层物理原理，如果包含新数据，可以轻松调整。它们允许有效计算中微子和光子光谱（来自 π0 衰变），这是现代天体物理源和参数研究的瞬态模拟的主要要求。此外，还明确生成了次级粒子（π 介子和 μ 介子），如果要包括冷却过程，则这是必需的。对于中微子的产生，我们包括了 μ 子衰变的螺旋度依赖性，这实际上导致比相互作用模型的细节更大的校正。例如，对 π0、π+ 和 π− 通量的单独计算允许对源处的中微子风味比进行预测，这是使用天体物理源进行中微子特性的许多测试的要求。我们确认，对于带电π介子的产生，经常使用的Δ（1232）共振产生通常不是活动星系核和伽玛射线暴中的主要过程，并且我们表明，对于任意输入光谱，如果中微子的数量是从中性与带电π介子的比率获得的，则中微子的数量至少被低估了两倍。我们使用各向同性同步加速器和热谱比较了几个简化级别的结果，并证明它们与 SOPHIA 软件足够接近。
We discuss simplified models for photo-meson production in cosmic accelerators, such as active galactic nuclei (AGNs) and gamma-ray bursts (GRBs). Our self-consistent models are directly based on the underlying physics used in the SOPHIA software and can be easily adapted if new data are included. They allow for the efficient computation of neutrino and photon spectra (from π0 decays) as a major requirement of modern time-dependent simulations of the astrophysical sources and parameter studies. In addition, the secondaries (pions and muons) are explicitly generated, a necessity if cooling processes are to be included. For the neutrino production, we include the helicity dependence of the muon decays which in fact leads to larger corrections than the details of the interaction model. The separate computation of the π0, π+, and π− fluxes allows, for instance, for flavor ratio predictions of the neutrinos at the source, which are a requirement of many tests of neutrino properties using astrophysical sources. We confirm that for charged pion generation, the often used production by the Δ(1232)-resonance is typically not the dominant process in AGNs and GRBs, and we show, for arbitrary input spectra, that the number of neutrinos are underestimated by at least a factor of two if they are obtained from the neutral-to-charged pion ratio. We compare our results for several levels of simplification using isotropic synchrotron and thermal spectra and demonstrate that they are sufficiently close to the SOPHIA software.