摘要
Radiative energy losses are very important in regulating the cosmic ray electron and/or positron(CRE) spectrum during their propagation in the Milky Way. Particularly, the Klein–Nishina(KN) effect of the inverse Compton scattering(ICS) results in less efficient energy losses of high-energy electrons, which is expected to leave imprints on the propagated electron spectrum. It has been proposed that the hardening of CRE spectra around 50 GeV observed by Fermi-LAT, AMS-02, and DAMPE could be due to the KN effect. We show in this work that the transition from the Thomson regime to the KN regime of the ICS is actually quite smooth compared with the approximate treatment adopted in some previous works. As a result, the observed spectral hardening of CREs cannot be explained by the KN effect. It means that an additional hardening of the primary electrons spectrum is needed. We also provide a parameterized form for the accurate calculation of the ICS energy-loss rate in a wide energy range.
作者
Kun Fang
Xiao-Jun Bi
Su-Jie Lin
Qiang Yuan
方堃;毕效军;林苏杰;袁强(Key Laboratory of Particle Astrophysics,Institute of High Energy Physics,Chinese Academy of Sciences,Beijing 100049,China;University of Chinese Academy of Sciences,Beijing 100049,China;School of Physics and Astronomy,Sun Yat-Sen University,Zhuhai 519082,China;Key Laboratory of Dark Matter and Space Astronomy,Purple Mountain Observatory,Chinese Academy of Sciences,Nanjing 210023,China;School of Astronomy and Space Science,University of Science and Technology of China,Hefei 230026,China;Center for High Energy Physics,Peking University,Beijing 100871,China)
基金
Supported by the National Key Research and Development Program of China(Grant No.2016YFA0400203 and 2016YFA0400204)
the National Natural Science Foundation of China(Grant Nos.11722328,U1738205,U1738203,11851303 and 11851305)
the Program for Innovative Talents and Entrepreneur in Jiangsu。
