Wind-driven rotational agitation of the pulsar PSR B0540-69

Pulsars can accelerate particles in their magnetospheres and form a relativistic stellar wind. These winds are one of the few possible sources of galactic cosmic rays. The acceleration mechanism and its efficiency are poorly understood, but it could be that a near-by pulsar was responsible for the positron excess that has been reported by several satellite missions. PSR B0540-69 is a young and energetic pulsar that has experienced very unique rotational transitions in the past. We present an analysis of this and other new anomalous episodes and demonstrate that the observed rotation irregularities in this pulsar can be interpreted as torque transitions caused by a variable energetic wind. This hypothesis is consistent with observations that show that the X-ray nebula around this pulsar is also variable.