Studying Particle Physics with Telescopes
LOFAR, a radio telescope comprised of antennae across Europe is used to observe the near and distant Universe; from processes around super massive black holes in the centre of galaxies to searching for the earliest clouds of ionised hydrogen. Recent simulations have shown there is another use closer to home, to understand air showers.
Air showers are cascades of particles in the Earth’s upper atmosphere. A high-energy cosmic ray hits an air molecule causing unstable particles like pions to form. Pions are a bit weird, they’re not like the particles we’re used to in everyday stuff in atoms, but are made up of two sub atomic particles (quarks) instead of the three in protons and neutrons. These pions are unstable so decay within moments or interact with other air molecules, sending out more pions and other particles like protons, neutrinos, electrons, and radio waves. This causes a chain reaction in the atmosphere detectable by LOFAR which looks a lot like a shower.
As the antennae of LOFAR are so spread out, the team believe it’s possible to find air showers in observations and will be able to calculate the location, the entry angle of the cosmic ray, energy and how deep into the atmosphere the shower got when reaching maximum. This will be useful information for astronomers and particle physicists alike!
Paper: Nelles et al 2014