Phenomenology of CR-scattering on pre-existing MHD modes - CNRS - Centre national de la recherche scientifique Accéder directement au contenu
Communication Dans Un Congrès Année : 2021

Phenomenology of CR-scattering on pre-existing MHD modes

Ottavio Fornieri
  • Fonction : Auteur
Daniele Gaggero
  • Fonction : Auteur
Silvio Sergio Cerri
Pedro de la Torre Luque
  • Fonction : Auteur

Résumé

We present the phenomenological implications of the micro-physics of CR diffusion as resulting from particle scattering onto the three modes in which \textit{Magneto-Hydro-Dynamics} (MHD) cascades are decomposed. We calculate the diffusion coefficients from first principles based on reasonable choices of the physical quantities characterizing the different environments of our Galaxy, namely the \textit{Halo} and the \textit{Warm Ionized Medium}, and implement for the first time these coefficients in the {\tt DRAGON2} numerical code. Remarkably, we obtain the correct propagated slope and normalization for all the charged species taken into account, without any \textit{ad-hoc} tuning of the transport coefficients. We show that fast magnetosonic modes dominate CR confinement up to $\sim 100 \, \mathrm{TeV}$; Alfv\'enic modes are strongly subdominant due to the anistropy of the cascade (in agreement with previous findings) up to rigidities in the sub-PeV domain, where their contribution may show up as a spectral feature, potentially observable in the upcoming years. We also find that such framework cannot be responsible for CR confinement below $\sim 200 \, \mathrm{GeV}$, possibly leaving room for an additional confinement mechanism, and that the Kolmogorov-like scaling of the $B/C$ ratio cannot be reproduced. Therefore this scaling might not be the imprint of the pre-exisiting turbulence spectrum.

Dates et versions

hal-03373061 , version 1 (11-10-2021)

Identifiants

Citer

Ottavio Fornieri, Daniele Gaggero, Silvio Sergio Cerri, Pedro de la Torre Luque, Stefano Gabici. Phenomenology of CR-scattering on pre-existing MHD modes. 37th International Cosmic Ray Conference, Jul 2021, Berlin, Germany. pp.426, ⟨10.22323/1.395.0426⟩. ⟨hal-03373061⟩
21 Consultations
0 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More