论文标题
运输建模对银河宇宙射线内部$^{60} $ fe丰度的影响
Impact of transport modelling on the $^{60}$Fe abundance inside Galactic cosmic ray sources
论文作者
论文摘要
Ace-Cris的合作最近发布了银河宇宙射线中放射性$^{60} $ fe核的测量，在能量范围$ \ sim 195-500 $ MEV的每个核中。我们对宇宙射线传播进行建模，并从此测量中得出$^{60} $ fe/$^{56} $ fe比率，该比率在银河系宇宙射线的来源中预期。我们描述了磁盘/光晕扩散模型框架内的宇宙射线起源和传输，即一种场景，在这种情况下，我们银河系中物质和宇宙射线源局限于薄磁盘，而宇宙射线传播在较大的晕圈中发生，具有微不足道的物质密度。我们解决了宇宙射线传输方程，该方程考虑了散布反应，衰减和电离损失以及对流。我们发现，$^{60} $ fe/$^{56} $ fe比率必须非常接近地球本地宇宙射线频谱中检测到的值，这是因为散布反应比$^{56} $ fe更有效，而不是$^{60} $ fe。这样的结果可以帮助识别银河宇宙射线的来源。
The ACE-CRIS collaboration has recently released the measurement of radioactive $^{60}$Fe nuclei abundance in Galactic Cosmic Rays, in the energy range $\sim 195-500$ MeV per nucleon. We model Cosmic Ray propagation and derive from this measurement the $^{60}$Fe/$^{56}$Fe ratio that is expected in the sources of Galactic Cosmic Rays. We describe Cosmic Ray origin and transport within the framework of the disk/halo diffusion model, namely a scenario in which the matter and the Cosmic Ray sources in our Galaxy are confined to a thin disk, while Cosmic Ray propagation occurs in a much larger halo with negligible matter density. We solve the Cosmic Ray transport equation accounting for spallation reactions, decay and ionization losses as well as advection. We find that the $^{60}$Fe/$^{56}$Fe ratio at the source must be very close to the value detected in the local Cosmic Ray spectrum at Earth, due to the fact that spallation reactions are more effective for $^{56}$Fe than for $^{60}$Fe. Such a result could help identify the sources of Galactic Cosmic Rays.
