ON THE PULSAR VELOCITY-MAGNETIC FIELD CORRELATION

From a sample of 98 radio pulsars with reliable kinematic measurements, we reexamine the evidence for a correlation between the transverse speed V-t and the inferred dipole magnetic field strength B. We find the correlation to be only marginally significant and, most importantly, find no evidence for a correlation amongst the pulsars younger than 3 Myr. Since such pulsars are relatively unaffected by spatial selection effects, we conclude that there is no causal V-B correlation. The trend seen by previous authors amongst a smaller sample of predominantly older pulsars, and in the old pulsars of the new sample, can largely be explained by the relatively short time-scales on which pulsars of high magnetic field lose rotational kinetic energy, and hence radio luminosity, compared to those with weaker magnetic fields. It is also possible that some weak magnetic field, low-velocity pulsars in the sample have had a different evolutionary history from the bulk of the population.