Parallax and kinematics of PSR B0919+06 from VLBA astrometry and interstellar scintillometry

Results are presented from a long-term astrometry program on PSR B0919+06 using the NRAO Very Long Baseline Array. With 10 observations (seven epochs) between 1994 and 2000, we measure a proper motion mu (alpha) = 18.35 +/- 0.06 mas yr(-1), mu (delta) = 86.56 +/- 0.12 mas yr(-1) and a parallax pi = 0.83 +/- 0.13 mas (68% confidence intervals). This yields a pulsar distance of 1.21 +/- 0.19 kpc, making PSR B0919+06 the farthest pulsar for which a trigonometric parallax has been obtained, and the implied pulsar transverse speed is 505 +/- 80 km s(-1). Combining the distance estimate with interstellar scintillation data spanning 20 yr, we infer the existence of a patchy or clumpy scattering screen along the line of sight in addition to the distributed electron density predicted by models for the Galaxy and constrain the location of this scattering region to within similar to 250 pc of the Sun. Comparison with the lines of sight toward other pulsars in the same quadrant of the Galaxy permits refinement of our knowledge of the local interstellar medium in this direction.