A statistical study of 233 pulsar proper motions

Abstract

We present and analyse a catalogue of 233 pulsars with proper motion measurements. The sample contains a wide variety of pulsars including recycled objects and those associated with globular clusters or supernova remnants. After taking the most precise proper motions for those pulsars for which multiple measurements are available, the majority of the proper motions (58 per cent) are derived from pulsar timing methods, 41 per cent using interferometers and the remaining 1 per cent using optical telescopes. Many of the one-dimensional (1D) and two-dimensional (2D) speeds (referring to speeds measured in one coordinate only and the magnitudes of the transverse velocities, respectively) derived from these measurements are somewhat lower than earlier estimates because of the use of the most recent electron density model in determining pulsar distances. The mean 1D speeds for the normal and recycled pulsars are 152(10) and 54(6) km s−1, respectively. The corresponding mean 2D speeds are 246(22) and 87(13) km s−1. PSRs B2011+38 and B2224+64 have the highest inferred 2D speeds of ~1600 km s−1. We study the mean speeds for different subsamples and find that, in general, they agree with previous results. Applying a novel deconvolution technique to the sample of 73 pulsars with characteristic ages less than 3 Myr, we find the mean three-dimensional (3D) pulsar birth velocity to be 400(40) km s−1. The distribution of velocities is well described by a Maxwellian distribution with 1D rms σ = 265 km s−1. There is no evidence for a bimodal velocity distribution. The proper motions for PSRs B1830-08 and B2334+61 are consistent with their proposed associations with the supernova remnants W41 and G114.3+0.3, respectively.