THE MAGNETIC-FIELD OF THE CRAB-NEBULA AND THE NATURE OF ITS JET

We present the results of multifrequency, polarimetric VLA observations of the Crab Nebula which allow us to correct for Faraday rotation and map the projected magnetic field with unprecedented 1″.8 resolution. The field is generally well ordered on a scale size of about 10″. A striking result is that, along most of the periphery where our high sensitivity detects the magnetic field orientation for the first time, the field is aligned radially with an apparent high degree of order. The observed Faraday rotation is constant over most of the Crab and has the same value over the "jet," suggesting that, apart from certain filaments and other small areas, it is of interstellar origin. The field in the "jet " is aligned along its length. We discuss the nature of the "jet," concluding that it is most likely the result of a high-velocity beam formed inside the nebula - although this interpretation is not without its problems.