An Excess of Positivity

An Excess of Positivity

The Fermi Large Area Telescope used a clever method of splitting electrons and positrons via the Earth’s magnetic field to show that there’s a significant excess of cosmic ray positrons at high energies – much more than can be explained using known cosmic ray processes.

Surprises from the Crab Nebula

Surprises from the Crab Nebula

The Crab Nebula has long been used as a standard candle in order to calibrate high-energy instruments … but it turns out it’s had us fooled all along! This paper gives an overview of what we’ve been missing from the Crab Nebula, and what this could mean for our understanding of high-energy astrophysics.