In a growing number of galaxy clusters diffuse extended radio sources have been found.
These sources are not directly associated with individual cluster galaxies. The radio …

Understanding the physical mechanisms that control galaxy formation is a fundamental
challenge in contemporary astrophysics. Recent advances in the field of astrophysical …

The Crab Nebula is a bright source of gamma rays powered by the Crab Pulsar's rotational
energy through the formation and termination of a relativistic electron-positron wind. We …

Galactic cosmic rays reach energies of at least a few petaelectronvolts (of the order of 1015
electronvolts). This implies that our Galaxy contains petaelectronvolt accelerators …

Numerical simulations have become a major tool for understanding galaxy formation and
evolution. Over the decades the field has made significant progress. It is now possible to …

Radio observations prove the existence of relativistic particles and magnetic field associated
with the intra-cluster-medium (ICM) through the presence of extended synchrotron emission …

Recurrent novae are repeating thermonuclear explosions in the outer layers of white dwarfs,
due to the accretion of fresh material from a binary companion. The shock generated when …

We use two-dimensional and three-dimensional hybrid (kinetic ions–fluid electrons)
simulations to investigate particle acceleration and magnetic field amplification at non …

Protons and helium nuclei are the most abundant components of the cosmic radiation.
Precise measurements of their fluxes are needed to understand the acceleration and …

Abstract One century ago Viktor Hess carried out several balloon flights that led him to
conclude that the penetrating radiation responsible for the discharge of electroscopes was of …