Cosmic-Ray Lithium Production at the Nova Eruptions Followed by a Type Ia Supernova

Recent measurements of cosmic-ray (CR) light nuclei by AMS-02 have shown that there is an unexpected component of CR lithium whose spectral index is harder than that expected from the secondary production scenario. We propose the nearby type Ia supernova following a nova eruption as the origin of lithium nuclei in the CRs. By fitting the data of CR protons, helium, and lithium fluxes provided by AMS-02 with our theoretical model we show that this scenario is consistent with the observations. The observational tests that can check our hypothesis are briefly discussed.

Figure 1

Schematic picture of a type Ia supernova occurring after a nova eruption from a white dwarf. Since the nova ejecta is rich in Li, the subsequent supernova blast wave can accelerate a significant amount of lithium nuclei.

Figure 2

Comparison of our model spectra of CR protons, helium, and lithium nuclei with AMS-02 data. The data points are given by AMS-02 (for protons [3], for helium [4], and for lithium [23]).