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Scintillometry of the Crab: evidence for ultrarelativistic plasma

November 6, 2024
4:05 PM - 5:05 PM
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Pupin 1402

Colloquium by Marten van Kerkwijk, University of Toronto

The Crab Pulsar is the prime example of an emitter of giant pulses, with durations of about a microsecond but structure down to the nanosecond level, and brightness temperatures of up to 1037 K. The pulsar’s location inside the Crab Nebula offers an unusual opportunity to study the emission regions in detail, using the nebula, which scatters radio waves, as a lens. I will present observations of scattered pulses that show that they are resolved by the nebula, implying the emission originates from regions of about 1000 km in size as projected on the sky. Given the micro-second pulse durations, this implies the emission is produced over about 10 Mm along the line of sight, which is most easily understood if the plasma blobs that emit radio pulses move ultrarelativistically, with γ~104.

Followed by wine and cheese.

Host: Yuri Levin