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J. Hester (ASU), D. Burrows (PSU), Crab Nebula Dynamics Collaboration
We report the results of coordinated HST and Chandra observations of the Crab synchrotron nebula. HST/WFPC2 was used during 2001/2002 to observe the Crab synchrotron nebula for 8 months with 10 day sampling. Seven Chandra ACIS observations were obtained on 20 day centers, coordinated with the HST observations.
The observations show wisps moving outward from the pulsar at space velocities in excess of 0.5c into a zone located within +/- 5 degrees of the equatorial plane of the system. Differences in wisp morphology and motion between the front and back of the torus are due to time delay effects resulting from relativistic motions along the line of sight.
The same wisps seen in visible light are also seen in X-ray emission. Wisps brighten and fade in the same general volume as the X-ray torus, suggesting that wisp evolution is associated with energy loss by high energy particles. We are currently working to model the wisps as the result of a cooling instability in the synchrotron plasma.
In addition to the wisps, we also confirm the earlier identification by Hester et al. (1995 ApJ, 448, 240) of a high latitude "halo" around the axis of the system. The knot reported by Hester et al., located 0.5" from the pulsar along the axis of symmetry, is also still present.
The data confirm that the X-ray/visible jet to the southeast of the pulsar is a true dynamical jet. Material is seen to move along the jet at speeds of about 0.5c. The highly dynamical bow shock at the head of the jet, as well as the jet itself, are more centrally concentrated in X-rays and somewhat more spread out in visible emission.
We would like to acknowledge and thank sincerely the support staff at both the STScI and the CXC.
The author(s) of this abstract have provided an email address for comments about the abstract: jhester@asu.edu
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Bulletin of the American Astronomical Society, 34
© 2002. The American Astronomical Soceity.