[ITAL]Hubble Space Telescope[/ITAL] and [ITAL]Chandra[/ITAL] Monitoring of the Crab Synchrotron Nebula

Abstract

We report the results of coordinated Hubble Space Telescope and Chandra observations of the Crab synchrotron nebula. Similar dynamical structures, including equatorial wisps moving outward at ~0.5c, are seen in both passbands. The inner X-ray ring is a variable, irregular structure from which wisps and diffuse emission emerge. The X-ray/visible jet to the southeast of the pulsar is a true jet. The data support the interpretation that the inner ring and a highly dynamical feature at the base of the jet are unstable quasi-stationary shocks in the "cold" equatorial wind and polar jet from the pulsar.