EXPLANATION OF THE LOCAL GALACTIC COSMIC RAY ENERGY SPECTRA MEASURED BY VOYAGER 1. I. PROTONS
EXPLANATION OF THE LOCAL GALACTIC COSMIC RAY ENERGY SPECTRA MEASURED BY VOYAGER 1. I. PROTONS
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航行者 1 号测量的本地银河宇宙线能量谱的解释。 I. 质子
DOI：
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发表时间：
2014
期刊：
影响因子：
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通讯作者：
A. Kempf
中科院分区：
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作者：
R. Schlickeiser;W. R. Webber;A. Kempf
在最初发现宇宙射线之后几乎整整 100 年，V1 航天器在 2012 年 8 月 25 日离开日光层调制区域后，首次观测到非相对论动能的宇宙射线 H、He、C/O 核的局部星际介质能谱。我们通过使用更新的稳态空间扩散模型（包括所有粒子动量损失）对这些粒子在局部银河环境中的传播进行建模来解释这些观测结果局部星际气体（库仑/电离、介子产生、绝热减速和碎裂相互作用）。如果太阳系位于空间均匀的分布宇宙射线源层内，并且注入相同的动量幂律∝p−s（其中 s = 2.24 ± 0.12），则与 V1 宇宙射线 H 观测结果非常一致。 V1 H 观测的最佳拟合还提供了对特征断裂动能 TC = 116 ± 27 MeV 的估计，表示从低能量下的电离/库仑能量损失到高能量下银河风中的介子产生和绝热减速损失的转变。由于在没有绝热减速的情况下，确定的值远小于217 MeV，因此我们的结果证明了当地银河环境中存在银河风。
Almost exactly 100 yr after the original discovery of cosmic rays, the V1 spacecraft has observed, for the first time, the local interstellar medium energy spectra of cosmic ray H, He, C/O nuclei at nonrelativistic kinetic energies, after leaving the heliosphere modulation region on 2012 August 25. We explain these observations by modeling the propagation of these particles in the local Galactic environment with an updated steady-state spatial diffusion model including all particle momentum losses with the local interstellar gas (Coulomb/ionization, pion production, adiabatic deceleration, and fragmentation interactions). Excellent agreement with the V1 cosmic ray H observations is obtained if the solar system resides within a spatially homogeneous layer of distributed cosmic ray sources injecting the same momentum power law ∝p−s with s = 2.24 ± 0.12. The best fit to the V1 H observations also provides an estimate of the characteristic break kinetic energy TC = 116 ± 27 MeV, representing the transition from ionization/Coulomb energy losses at low energies to pion production and adiabatic deceleration losses in a Galactic wind at high energies. As the determined value is substantially smaller than 217 MeV in the absence of adiabatic deceleration, our results prove the existence of a Galactic wind in the local Galactic environment.