Unveiling the origins of the most energetic particles in the Universe

Data: 
06/06/2018 - 14:00 - 15:00
Local: 
Auditório "Prof. Dr. Paulo Benevides Soares", Bloco G

Unveiling the origins of the most energetic particles in the Universe

 

Rafael Alves Batista

IAG/USP

 

A long-standing puzzle in astrophysics relates to the origin of the most energetic particles in the Universe, the ultra-high-energy cosmic rays (UHECRs). During their propagation to Earth, they may interact with pervasive background photon fields such as the cosmic microwave background and extragalactic background light, generating copious amounts of very energetic photons and neutrinos. The multimessenger framework enabled by combining these three messengers is a powerful tool for understanding high-energy processes taking place in extreme astrophysical environments. Each one of these particles brings information that is complementary to the others. Neutrinos, for instance, are electrically neutral and travel straight from their source to Earth, whereas photons can be absorbed, and cosmic rays are deflected by intervening galactic and extragalactic magnetic fields. In this talk I will review the state of the art of the field in light of the latest experimental results as well as some key theoretical developments made in the last decade. I will focus on the modelling of UHECR propagation in the Universe, including interactions with photon fields and the ill-understood cosmic magnetic fields. Finally, I will discuss the prospects for identifying the elusive sources of the highest energy particles.