Princeton University Astroplasmas Seminar

Pulsar halos are extended gamma-ray structures formed by electrons and positrons that have escaped from the central pulsar wind nebulae (PWNe), interacting with photons of the interstellar radiation fields. Pulsar halos serve as unique probes for investigating CR propagation in specific regions of the Galaxy and can provide indirect information about the progenitor electrons and positrons from a region that is close to the source. The inferred cosmic-ray diffusion coefficient from pulsar halos is smaller than the average value in the Galaxy, leading to various proposed interpretations in recent years. In this presentation, I will review recent developments in pulsar halo studies, from the characteristics of these sources, to potential multiwavelength investigations, proposed mechanisms for slow diffusion or other possible explanations, and the crucial role of pulsar halos in understanding cosmic-ray propagation and electron injection from PWNe.