Millisecond pulsar velocities

We present improved timing parameters for 13 millisecond pulsars (MSPs), in cluding nine new proper motion measurements. These new proper motions bring to 23 the number of MSPs with measured transverse velocities. In light of these new results we present and compare the kinematic properties of MSPs w ith those of ordinary pulsars, The mean transverse velocity of MSPs was fou nd to be 85 +/- 13 km s(-1), a value consistent with most models for the or igin and evolution of MSP's and approximately a factor of 4 lower than that of ordinary pulsars. We also find that, in contrast to young ordinary puls ars, the vast majority of which are moving away from the Galactic plane, al most half of the MSPs are moving towards the plane. This near-isotropy woul d be expected of a population that has reached dynamic equilibrium. Accurat e measurements of MSP velocities have allowed us to correct their measured spin-down rates for Doppler acceleration effects, and thereby derive their intrinsic magnetic field strengths and characteristic ages. We find that cl ose to half of our sample of MSPs have a characteristic age comparable to o r greater than the age of the Galactic disc.