A unified picture for three different cosmic-ray observables.
Résumé
We present here a unified scenario that connects three peculiar spectral features recently reported in the spectra of charged cosmic rays (CRs).The spectral hardening measured by AMS-02 in the hadronic spectra above $\sim 250 \, \mathrm{GeV}$ is here interpreted as a diffusion imprint, and modeled by means of a transport coefficient that smoothly hardens with rigidity. We implement such propagation framework to solve the transport equation with the {\tt DRAGON2} numerical code in order to determine the large-scale contribution to the CR fluxes. On top of this solution we explore the hypothesis of a nearby, hidden Supernova Remnant (SNR) to be responsible for the high-energy (above $\sim 100 \, \mathrm{GeV}$) all-lepton flux, in particular for the spectral break consistently measured by all the space- and ground-based detectors around $1 \, \mathrm{TeV}$. We compute such contribution analytically adopting the same propagation setup implemented for the large-scale background.Simultaneously, we find the signature of the same source in the peculiar \textit{bump} structure observed by the DAMPE Collaboration in the proton spectrum, consisting of a strong hardening at $\sim 500 \, \mathrm{GeV}$ and a softening at $13 \, \mathrm{TeV}$. We validate our hypothesis with the CR dipole-anisotropy (DA) amplitude and phase. In particular, we interpret the high-energy data (above $10 \, \mathrm{TeV}$) pointing towards the Galactic Center as the convolution of the directional fluxes of the large-scale-background sources, whereas the DA amplitude below that energy is compatible with the predictions of our model and is therefore considered as a signature of the nearby SNR that we invoke.