Over the last decade , considerable effort has been made to measure the proper motions of the pulsars B1757 - 24 and B1951 + 32 in order to establish or refute associations with nearby supernova remnants and to understand better the complicated geometries of their surrounding nebulae .
We present proper motion measurements of both pulsars with the Very Large Array , increasing the time baselines of the measurements from 3.9 yr to 6.5 yr and from 12.0 yr to 14.5 yr , respectively , compared to previous observations .
We confirm the nondetection of proper motion of PSR B1757 - 24 , and our measurement of ( \mu _ { \alpha } , \mu _ { \delta } ) = ( -11 \pm 9 , -1 \pm 15 ) mas yr ^ { -1 } confirms that the association of PSR B1757 -24 with SNR G5.4 - 1.2 is unlikely for the pulsar characteristic age of 15.5 kyr , although an association can not be excluded for a significantly larger age .
For PSR B1951 + 32 , we measure a proper motion of ( \mu _ { \alpha } , \mu _ { \delta } ) = ( -28.8 \pm 0.9 , -14.7 \pm 0.9 ) mas yr ^ { -1 } , reducing the uncertainty in the proper motion by a factor of 2 compared to previous results .
After correcting to the local standard of rest , the proper motion indicates a kinetic age of \sim 51 kyr for the pulsar , assuming it was born near the geometric center of the supernova remnant .
The radio-bright arc of emission along the pulsar proper motion vector shows time-variable structure , but moves with the pulsar at an approximately constant separation \sim 2.5″ , lending weight to its interpretation as a shock structure driven by the pulsar .