Parallax of PSR J1744-1134 and the local interstellar medium

Abstract

We present the annual trigonometric parallax of PSR J1744-1134 derived from an analysis of pulse times of arrival. The measured parallax, π = 2.8 ± 0.3 mas, ranks among the most precisely determined distances to any pulsar. The parallax distance of 357+43-35 Pc is over twice that derived from the dispersion measure using the Taylor & Cordes model for the Galactic electron distribution. The mean electron density in the path to the pulsar, ne = (8.8 ± 0.9) × 10-3 cm-3, is the lowest for any disk pulsar. We have compared the nc for PSR J1744-1134 with those for another 11 nearby pulsars with independent distance estimates. We conclude that there is a striking asymmetry in the distribution of el..