February 2012 – DIAS astronomer provides explanation for radiation detected from the Crab Pulsar
An explanation for recently detected radiation from the Crab Pulsar – one of the brightest persistent gamma-ray sources in the sky – is proposed in Nature this week. The pulses of very high-energy gamma-ray emission are ascribed to a cold wind originating near to the site of emission. Pulsars are neutron stars that are thought to eject electron-positron winds. Initially the winds are dominated by electromagnetic energy but as they move away from the pulsar their energy becomes more kinetic. Constraining where this acceleration takes place has been difficult, but Felix Aharonian and colleagues estimate the point where this transition occurs. They suggest that the recent observations of pulsed, very high-energy gamma-ray emission from the Crab pulsar are produced by this accelerating wind.