12–23 Jul 2021
Online
Europe/Berlin timezone

A unified picture for three different cosmic-ray observables.

19 Jul 2021, 18:00
1h 30m
06

06

Talk CRD | Cosmic Ray Direct Discussion

Speaker

Daniele Gaggero (IFT)

Description

We present here a unified scenario that connects together 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-borne 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.

Keywords

cosmic-ray transport
cosmic-ray sources

Subcategory Theoretical Results

Primary authors

Ottavio Fornieri (DESY Zeuthen) Daniele Gaggero (IFT) Dr Daniel Guberman (INFN Pisa) Dr Loann Brahimi (Laboratoire Universe et Particules de Montpellier (LUPM) Un. Montpellier, CNRS IN2P3, CC72) Pedro De la Torre Luque (Stockholm University) Dr Alexandre Marcowith (LUPM)

Presentation materials