Questions touching the field of elementary particle physics, which require high energies to be studied. Use this tag if you are asking about quarks, gluons, mesons, hadrons, leptons, etc.

High energy (astro)physics is also refered to as particle physics and devoted to the study of elementary particles. The bulk of the baryonic matter of the universe is a hot phase, and we observe emissions from cosmic sources in the high energy domain of the electromagnetic spectrum.