VLBI astrometry of two millisecond pulsars

We present astrometric results on two millisecond pulsars, PSR B1257+12 and PSR J1022+1001, as carried out through VLBI. For PSR B1257+12, a model-independent distance of 710_-38 ⁺⁴³ pc and proper motion of (μ_α = 46.44 ± 0.08 mas/yr, μ_δ=-84.87 ± 0.32 mas/yr) were obtained from 5 epochs of VLBA and 4 epochs of EVN observations, spanning about 2 years. The two dimensional proper motion of PSR J1022+1001 (μ_α~-10.13 mas/yr, μ_δ~16.89 mas/yr) was also estimated, using 3 epochs of EVN observations. Based on our results, the X-ray efficiency of PSR B1257+12 should be in the same range as other millisecond pulsars, and not as low as previously thought.