Revisiting the Spatially Dependent Propagation Model with the Latest Observations of Cosmic-Ray Nuclei

Abstract

Abstract Recently the AMS-02 collaboration published detections of light cosmic-ray nuclei, including lithium, beryllium, boron, carbon, and oxygen. Combined with the released energy spectra of proton and helium, both primary and secondary spectra have a prominent hardening above ∼200 GV. In particular, the spectral variation of secondary cosmic rays is greater than the primary ones. One of the plausible interpretations for the above anomalies is the spatial-dependent diffusion model. It has successfully described various observational phenomena, e.g., hardening of primary nuclei, diffuse gamma-ray distribution and cosmic-ray anisotropy, etc. In this work, we apply the spatial-dependent propagation model to the latest observations, including both primary and secondary nuclei. Apart from the primary components, the spectra of secondary nuclei can be properly reproduced as well, especially the upturn above 200 GV. We also calculate the ratios of both secondary-to-primary and secondary-to-secondary. We find that except for the Be/B ratio, the computations of the spatial-dependent propagation model are in good agreement with the current data.