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

Ultra-high energy cosmic rays from radio galaxies

Oct 9, 2018, 3:20 PM
20m
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
ORAL Sessions

Speaker

James Matthews (University of Oxford)

Description

The origin of ultra-high energy cosmic rays (UHECRs) is an open question, but radio galaxies offer one of the best candidate acceleration sites. Acceleration at the termination shocks of relativistic jets is problematic because relativistic shocks are poor accelerators to high energy. Using hydrodynamic simulations and general physical arguments, I will show that shocks with non- or mildly relativistic shock velocities can be formed as plasma flows from the termination shock into the radio lobe and that these shocks have suitable characteristics for acceleration to 10-100EeV. I will discuss a model in which giant-lobed radio galaxies such as Centaurus A and Fornax A act as slowly-leaking UHECR reservoirs, with the UHECRs being accelerated during a more powerful past episode. I will also show that Centaurus A, Fornax A and other radio galaxies may explain the observed hotspots in the Auger and TA data at ultra-high energies.

Primary authors

James Matthews (University of Oxford) Prof. Tony Bell (University of Oxford) Prof. Katherine Blundell Dr Anabella Araudo (Astronomical Institute, Czech Academy of Sciences)

Presentation materials