Producing the "Jets" of the Cassiopeia A SNR with a Spherical Supernova
Abstract
Observing with the Chandra Observe of the X-ray emitting gas in the SNR Cassiopeia A have led some to the conclusion that the "jet(s)" seen in this SNR were produced by a strongly asymmetric supernova explosion and that the supernova itself may have been "jet-induces." Here we show that the morphology of Cas A is consistent with a spherically-symmetric explosion evolving into a slightly axisymmetric circumstellar medium as well as a mildly asymmetric explosion enveloping into a spherical CSM.
Following up on the original models of Blondin, Lundqvist and Chavalier (1996), we use a 2D and 3D hydro-dynamical simulations to show that young, ejecta-driven SNRs with relatively mild axisymmetry (density contrast between pole and equator of order a few in either the ejecta or CSM) can produce the extended features similar to the observe "jets" in Cas A. We use these models to show that shocked ejecta can be reaccelerated in the vicinity of the "jets" to produce local velocities that exceed R/t, i.e., gas that appears to be un-decelerated was in fact slowed down by the reverse shock and then reaccelerated. This has the added result that material originating deep in the SN ejecta can end up at very large distances along the "jets" as compared to the locations in the remnant.- Publication:
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American Astronomical Society Meeting Abstracts #207
- Pub Date:
- June 2006
- Bibcode:
- 2006AAS...20720904R