CONSECUTIVE BRIGHT PULSES IN THE VELA PULSAR

Abstract

We report on the discovery of consecutive bright radio pulses from the Vela pulsar, a new phenomenon that may lead to a greater understanding of the pulsar emission mechanism. This results from a total of 345 hours worth of observations of the Vela pulsar using the University of Tasmania's 26 m radio telescope to study the frequency and statistics of abnormally bright pulses and sub-pulses. The bright pulses show a tendency to appear consecutively. The observations found two groups of six consecutive bright pulses and many groups of two to five bright pulses in a row. The strong radio emission process that produces the six bright pulses lasts between 0.4 and 0.6 seconds. The numbers of bright pulses in sequence far exceed what would be expected if individual bright pulses were independent random events. Consecutive bright pulses must be generated by an emission process that is long-lived relative to the rotation period of the neutron star. We also confirm the existence of giant micro pulses previously observed in Vela, and also the apparent change in bright pulse occurrences after a glitch.