椭圆星系中扩散和对流cosmic ray输运的分析观点
Analytical view of diffusive and convective cosmic ray transport in elliptical galaxies
摘要：
内容：本文导出了广义扩散和对流输运方程的解析解，用以解释宇宙线质子在椭圆星系中的输运。目的：椭圆星系内的宇宙线输运是理解地球上测量的高能粒子起源的一个有趣的元素。作为这些高能粒子的可能来源，椭圆星系显示出致密的星际介质，这是星系核活动或星系间合并事件的结果。因此，对宇宙线输运的适当描述必须考虑稠密星际环境中的扩散和对流过程。在这里，我们表明，运输方程可以解决解析相对于给定的几何形状和边界条件的位置空间，以及在动量空间。结果：给出了广义宇宙射线源的空间解。此外，一个喷流样源的特殊情况下进行了说明。我们提出的解决方案在动量空间中的逃逸项宇宙射线质子依赖于星系的空间形状。对于一个三角形注入函数，动量的解决方案得到解析。我们发现，在地球上测量的光谱指数可以通过适当地选择费米I和费米II过程的强度来获得。从这些结果中，我们计算的伽玛射线通量从π衰变由于质子-质子相互作用，以连接到观测。此外，我们还测定了宇宙射线的逃逸谱。结果表明，这两种谱都比椭圆星系中宇宙射线的内禀幂律谱硬。
英文摘要：
Context: An analytical solution of the generalized diffusive and convective transport equation is derived to explain the transport of cosmic ray protons within elliptical galaxies. Aims: Cosmic ray transport within elliptical galaxies is an interesting element in understanding the origin of high energetic particles measured on Earth. As probable sources of those high energetic particles, elliptical galaxies show a dense interstellar medium as a consequence of activity in the galactic nucleus or merging events between galaxies. Thus it is necessary for an appropriate description of cosmic ray transport to take the diffusive and convective processes in a dense interstellar environment into account. Here we show that the transport equations can be solved analytically with respect to the given geometry and boundary conditions in position space, as well as in momentum space. Results: The spatial solution is shown using a generalized source of cosmic rays. Additionally, the special case of a jet-like source is illustrated. We present the solution in momentum space with respect to an escape term for cosmic ray protons depending on the spatial shape of the galaxy. For a delta-shape injection function, the momentum solution is obtained analytically. We find that the spectral index measured on Earth can be obtained by appropriately choosing of the strength of Fermi I and Fermi II processes. From these results we calculate the gamma-ray flux from pion decay due to proton-proton interaction to give connection to observations. Additionally we determine the escape-spectrum of cosmic rays. The results show that both spectra are harder than the intrinsic power-law spectrum for cosmic rays in elliptical galaxies.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
