High accuracy measurements of the interstellar magnetic field in the direction of pulsars with a new method

Low error measurements at the Arecibo Observatory (at 318MHz) of the weighted average interstellar magnetic field projected on the line of sight [B-parallel to] and of the Rotation Measure in the direction of several pulsars were done using a new method. This method is based on the measurement of the period of the temporal modulation in the linearly polarized component of the pulsar pulse observed in a wide receiver bandpass. The error in the measurement of [B-parallel to] and RM is about one order of magnitude smaller than previously published measurements. Because of its high accuracy this method will continue to be used for the monitoring of the interstellar magnetic field in the directions to pulsars.