We present high-precision timing of five millisecond pulsars ( MSPs ) carried out for more than seven years ; four pulsars are in binary systems and one is isolated .
We are able to measure the pulsars ’ proper motions and derive an estimate for their space velocities .
The measured two-dimensional velocities are in the range 70–210 km s ^ { -1 } , consistent with those measured for other MSPs .
We also use all the available proper motion information for isolated and binary MSPs to update the known velocity distribution for these populations .
As found by earlier works , we find that the velocity distribution of binary and isolated MSPs are indistinguishable with the current data .
Four of the pulsars in our observing program are highly recycled with low-mass white dwarf companions and we are able to derive accurate binary parameters for these systems .
For three of these binary systems we are able to place initial constraints on the pulsar masses with best-fit values in the range 1.0–1.6 M _ { \odot } .
The implications of the results presented here to our understanding of binary pulsar evolution are discussed .
The updated parameters for the binary systems studied here , together with recently discovered similar systems , allowed us to update previous limits on the the violation of the strong equivalence principle through the parameter | \Delta| to 4.6 \times 10 ^ { -3 } ( 95 % confidence ) and the violation of Lorentz-invariance/momentum-conservation through the parameter | \hat { \alpha } _ { 3 } | to 5.5 \times 10 ^ { -20 } ( 95 % confidence ) .