Nearby source interpretation of differences among light and medium composition spectra in cosmic rays

• 作者: Qiang Yuan Bing-Qiang Qiao Yi-Qing Guo Yi-Zhong Fan Xiao-Jun Bi
• 来源期刊: 物理学前沿
• 年，卷（期）: 2021,（2）
• 所属期刊栏目: Particle,Nuclear Physics,Astrophysics & Cosmology
• 页码范围: 189-194
• 页数: 6页
• 语种: 英文

摘要

Recently the AMS-02 reported the precise measurements of the energy spectra of medium-mass com-positions(Neon,Magnesium,Silicon)of primary cosmic rays,which reveal different properties from those of light compositions(Helium,Carbon,Oxygen).Here we propose a nearby source scenario,together with the background source contribution,to explain the newly measured spectra of cosmic ray Ne,Mg,Si,and particularly their differences from that of He,C,O.Their differences at high en-ergies can be naturally accounted for by the element abundance of the nearby source.Specifically,the abundance ratio of the nearby source to the background of the Ne,Mg,Si elements is lower by a factor of～1.7 than that of the He,C,O elements.Such a difference could be due to the abundance difference of the stellar evolution of the progenitor star or the acceleration process/environment,of the nearby source.This scenario can simultaneously explain the high-energy spectral softening features of cos-mic ray spectra revealed recently by CREAM/NUCLEON/DAMPE,as well as the energy-dependent behaviors of the large-scale anisotropies.It is predicted that the dipole anisotropy amplitudes below PeV energies of the Ne,Mg,Si group are smaller than that of the He,C,O group,which can be tested with future measurements.