In the Universe, various environments are characterized by shocks capable of converting the kinetic energy of gas and particle flows into heat, turbulence, magnetic energy, and, ultimately, accelerating particles to relativistic energies, producing cosmic rays. The sizes of these systems can vary by many orders of magnitude, ranging from the typical dimensions of the interplanetary environment to the enormous galaxy
Our planet is constantly bombarded by highly energetic particles known as ‘cosmic rays‘. The spectrum of cosmic rays up to energies of 1015 electronvolts (eV) is formed by the sources in our Galaxy, while particles with observed energies up to 1021 eV should have extra-galactic origin. The cosmic ray spectrum follows a power law, meaning that the flux of particles with a given
Energetic particles, called “cosmic rays”, constantly rain down on our planet. Thanks to several years of theoretical studies and observations, we know that these particles can be accelerated by shocks propagating in certain astrophysical environments. The classical example of such environment are the supernovae remnants, which are expanding clouds created by supernova explosions, which are often interacting with surrounding material.
Gli shock sono onde d’urto che viaggiano a velocità supersonica e sono molto importanti in astrofisica perché vengono osservati su diverse scale spaziali ed in diversi contesti, dal nostro “piccolo” sistema solare, fino a scale extragalattiche e cosmologiche. Gli shock astrofisici differiscono da quelli osservabili sulla Terra perché si manifestano in condizioni estreme, non riproducibili sul nostro pianeta. Mentre nell’atmosfera
What remains after a supernova explosion, which is among the most energetic phenomena in the Universe, is an expanding cloud interacting with the surrounding interstellar medium (the “supernova remnants”) and a compact object produced by the contraction of the nucleus of the progenitor star. Given its proximity to the Sun (“only” 945 light years), the Vela supernova remnant is one
