Revealing the most energetic light from pulsars and their nebulae

Abstract

The observation of Very-High-Energy (vhe, >100 GeV) gamma rays is key in studying the non-thermal sources of radiation in our Universe. Pulsars and Pulsar Wind Nebulae (pwne) are two source classes that are known to emit vhe gamma rays. While pulsar wind nebulae are the dominant vhe gamma-ray source class in our galaxy, only two pulsars have been detected above 100 GeV so far. Most pulsar models explain gamma-ray emission via synchro-curvature radiation in the radiation-reaction limited regime, which leads to a sharp cut-off in the pulsar spectrum at energies of a few GeV. However, the detection of pulsed emission from the Crab pulsar up to hundreds of GeVby magic and veritas, suggests that classical pulsar models do not provide a full picture of the emission mechanisms at work. TeV pulsar wind nebulae, on the other hand, are observed via their inverse Compton radiation and are primarily found around young and energetic pulsars located towards the inner Milky Way. Detections of TeV pwne in the outer part of our galaxy are scarce, but could provide valuable input for the connection between the interstellar radiation field and the pwn luminosity...