AMS-02 beryllium data and its implication for cosmic ray transport
arXiv:1910.04113 · doi:10.1103/PhysRevD.101.023013
Abstract
The flux of unstable secondary cosmic ray nuclei, produced by spallation processes in the interstellar medium, can be used to constrain the residence time of cosmic rays inside the Galaxy. Among them, Be is especially useful because of its relatively long half-life of 1.39 Myr. In the framework of the diffusive halo model we describe cosmic ray transport taking into account all relevant interaction channels and accounting for the decay of unstable secondary nuclei. We then compare our results with the data collected by the Alpha Magnetic Spectrometer (AMS-02) on board the International Space Station for the flux ratios Be/C, B/C, Be/O, B/O, C/O and Be/B as well as C, N and O absolute fluxes. These measurements, and especially the Be/B ratio, allow us to single out the flux of Be and infer a best fit propagation time of CRs in the Galaxy. Our results show that, if the cross sections for the production of secondary elements through spallation are taken at face value, AMS-02 measurements are compatible with the standard picture based on CR diffusion in a halo of size kpc. Taking into account the uncertainties in the cross sections, this conclusion becomes less reliable, although still compatible with the standard picture. Implications of our findings for alternative models of CR transport are discussed.
11 pages, 6 figures. Accepted for publication on Physical Review D
References in corpus (12)
- Observation of an anomalous positron abundance in the cosmic radiation
- A new measurement of the antiproton-to-proton flux ratio up to 100 GeV in the cosmic radiation
- Direct detection of a break in the teraelectronvolt cosmic-ray spectrum of electrons and positrons
- Extended gamma-ray sources around pulsars constrain the origin of the positron flux at Earth
- Spectral breaks as a signature of cosmic ray induced turbulence in the Galaxy
- Origin of the Cosmic Ray Spectral Hardening
- Galactic cosmic rays after the AMS-02 observations
- Cosmic Ray Electrons, Positrons and the Synchrotron emission of the Galaxy: consistent analysis and implications
- Detailed Investigation of the Gamma-Ray Emission in the Vicinity of SNR W28 with FERMI-LAT
- Interpretation of the cosmic ray positron and antiproton fluxes
- Non-linear diffusion of cosmic rays escaping from supernova remnants - II. Hot ionized media
- Effects of reacceleration and source grammage on secondary cosmic rays spectra