Probing the pulsar wind nebula of PSR B0355+54

We present XMM-Newton and Chandra X-ray observations of the middle-aged radio pulsar PSR B0355+54. Our X-ray observations reveal emission not only from the pulsar itself, but also from a compact diffuse component extending ∼50″ in the opposite direction to the pulsar's proper motion. There is also evidence for the presence of fainter diffuse emission extending ∼5′ from the point source. The compact diffuse feature is well fitted with a power law, the index of which is consistent with the values found for other pulsar wind nebulae. The morphology of the diffuse component is similar to the ram-pressure-confined pulsar wind nebulae detected for other sources. The X-ray emission from the pulsar itself is well described by a thermal plus power-law fit, with the thermal emission most likely originating in a hot polar cap.