Constraining the Vela Pulsar's Radio Emission Region Using Nyquist-Limited Scintillation Statistics

TL;DR

This paper introduces a novel scintillation-based technique to measure the Vela pulsar's radio emission region with approximately 100 picoarcsecond resolution, constraining its size to less than 4 km and emission altitude to under 340 km.

Contribution

The study presents a new method leveraging scintillation statistics to precisely constrain the size and altitude of pulsar radio emission regions.

Findings

Emission region size less than 4 km

Emission altitude below 340 km

Achieved ~100 picoarcsecond resolution

Abstract

Using a novel technique, we achieve ~100 picoarcsecond resolution and set an upper bound of less than 4 km for the characteristic size of the Vela pulsar's emission region. Specifically, we analyze flux-density statistics of the Vela pulsar at 760 MHz. Because the pulsar exhibits strong diffractive scintillation, these statistics convey information about the spatial extent of the radio emission region. We measure both a characteristic size of the emission region and the emission sizes for individual pulses. Our results imply that the radio emission altitude for the Vela pulsar at this frequency is less than 340 km.