A review of observational results on very high energy gamma-ray emission from pulsars

Abstract

Radio pulsars have played a very important part in the growth of VHE (Very High Energy) gamma-ray astronomy. Apart from their ability to accelerate particles to very high energies, the modest sensitivity of the first generation atmospheric Cerenkov telescopes could be increased with the time signature of the pulsars. The main inference from the telescopes of the '80s was that the time-averaged emission spectra from the lower energies had to steepen in the GeV-TeV energy region. This conclusion has been reinforced in the 90s from experiments with much better sensitivities. However, results from several experiments from the past and the more sensitive experiments at present (for eg, the PACT) can be reconciled by invoking a possibly different component arising in the TeV region. This possible 'Last Hurrah' of the pulsar needs further study from the ground based experiments.