Pulsar Wind Nebula

A pulsar magnetosphere is a plasma-rich region outside a rapidly rotating, highly magnetised neutron star. The magnetosphere acts as a mediator through which the rotational energy of the pulsar is converted into the acceleration of charged particles and produces VHE gamma-ray emission. What are the underlying mechanisms responsible for the particle accelerations in the magnetosphere of pulsars? How exactly do pulsars produce pulsed VHE radiation? How the future CTAO observations can constrain the competing models to explain the gamma-ray pulse radiation?

Pulsar magnetospheres are efficient accelerators, involving general relativistic electrodynamics with a strong magnetic field. Particles that can escape the magnetosphere, streaming away, creating the so-called pulsar wind. Emissions from the pulsars themselves have also been detected at TeV energies indicating two components:

• (i) pulsed radiation with pulsar period - produced by particle acceleration in the pulsar magnetosphere
   
• (ii) non-pulsed (steady profile with possible flares and slow variations as seen in observations at GeV energies of the Crab pulsar) produced by the Pulsar wind nebula. Focusing on the pulsed gamma-ray emission allows to separate the processes occurring in the magnetosphere from the emission of the surrounding nebula. Competing models predict characteristic cut-off features in the spectra of pulsed gamma rays in the low-energy range of CTAO. By exploring these spectral characteristics, CTAO can help constrain and refine existing models, ultimately advancing our understanding of particle acceleration mechanisms in the magnetosphere of pulsars.