# Ultra High Energy Cosmic Rays 2018

Oct 8 – 12, 2018
Ecole Supérieure de Chimie, Paris
Europe/Paris timezone

## Transition from Galactic to Extragalactic Cosmic Rays

Oct 9, 2018, 5:50 PM
30m
Friedel Amphitheater (Ecole Supérieure de Chimie, Paris)

### Friedel Amphitheater

#### Ecole Supérieure de Chimie, Paris

Chimie ParisTech École Nationale Supérieure de Chimie de Paris 11, rue Pierre et Marie Curie 75231 PARIS Cedex 05
INVITED

### Speaker

Michael Kachelriess (Department of Physics, NTNU)

### Description

Additionally to the all-particle cosmic ray (CR) spectrum, data on the
primary composition and anisotropy have become available from the knee region up to few $\times 10^{19}$ eV. These data point to an early Galactic-extragalactic transition and the presence of Peter's cycle, i.e. a rigidity-dependent maximal energy. Theoretical models have to explain therefore the ankle as a feature in the extragalactic CR spectrum. Moreover, the Galactic CR spectrum has to explain the knee, and has to extend to sufficiently high energies. I review the experimental data and their interpretation, as well as models aiming to reproduce them.

### Primary author

Michael Kachelriess (Department of Physics, NTNU)