Studies on Cosmic-Ray Nuclei with Voyager, ACE, and AMS-02. I. Local Interstellar Spectra and Solar Modulation

Abstract

The acceleration of cosmic ray particles and their propagation in the Milky Way and the heliosphere tangle with each other, leading to complexity and degeneracy of the modeling of Galactic cosmic rays (GCRs). The recent measurements of the GCR spectra by Voyager-1 from outside of the heliosphere gave a first direct observation of GCRs in the local interstellar (LIS) environment. Together with the high-precision data near the Earth taken by ACE and AMS-02, we derive the LIS spectra of Helium, Lithium, Beryllium, Boron, Carbon, and Oxygen nuclei from a few MeV/n to TeV/n, using a non-parameterization method. These LIS spectra are helpful in further studying the injection and propagation parameters of GCRs. The nearly 20 years of data recorded by ACE are used to determine the solar modulation parameters over the solar cycles 23 and 24, based on the force-field approximation. We find general agreements of the modulation potential with the results inferred from neutron monitors and other cosmic ray data.

Bayesian Analysis of the Hardening in AMS-02 Nuclei Spectra

“…cellent opportunity to study the hardening of the CR nuclei spectra quantitatively. Some previous works have proposed different solutions to this problem: (i) adding a new break in high-energy region (∼ 300 GV) to the injection spectra (see, e.g., Korsmeier & Cuoco (2016); Boschini et al (2017b); Niu et al ( , 2017; Zhu et al (2018)); (ii) adding a new in high-rigidity break to the diffusion coefficient (see, e.g., Génolini et al (2017)); (iii) inhomogeneous diffusion (see, e.g., Blasi et al (2012); Tomassetti (2012Tomassetti ( , 2015a; Feng et al (2016); Guo & Yuan (2018)); (iv) the superposition of local and distant sources (see, e.g., Vladimirov et al (2012); Bernard et al (2013); Thoudam & Hörandel (2013); Tomassetti & Donato (2015); Kachelrieß et al (2015); Kawanaka & Yanagita (2018)).…”

Progresses of the Dark Matter Particle Explorer experiment

“…For energies higher than ∼ 10 GeV, the CRE fluxes become less affected by the solar modulation. A time delay between the solar activities and the impacts on the CRE fluxes [63,69] is not clearly seen because of the relatively short time coverage of the current analysis. On September 7, 2017, a big solar flare occured.…”

Time lag in cosmic-ray modulation and global properties of the Solar Cycle

“…In practice, the correlation coefficient can be calculated as function of the lag ∆T , so that a fine scan over ∆T will provide the best estimation of the time lag. A similar approaches were adopted in other works [37,3]. As an example, in Fig.…”