Pulsars in a Bubble? Following Electron Diffusion in the Galaxy with TeV Gamma Rays

Understand

TeV Halos, extended regions of TeV gamma-ray emission around middle-aged pulsars, have recently been established as a new source class in gamma-ray astronomy.

• These halos have been attributed to relativistic electrons and positrons that have left the acceleration region close to the pulsar and are diffusing in the surrounding medium.
• Measuring the morphology of TeV Halos enables for the first time a direct measurement of the electron diffusion on scales of tens of parsecs.
• There are hints that the presence of relativistic particles affects the diffusion rate in the pulsars' surroundings.