We present three-dimensional kinematic reconstructions of optically emittingmaterial in the young Galactic supernova remnant Cassiopeia A (Cas A). TheseDoppler maps have the highest spectral and spatial resolutions of any previoussurvey of Cas A and represent the most complete catalog of its opticallyemitting material to date. We confirm that the bulk of Cas A's optically brightejecta populate a torus-like geometry tilted approximately 30 degrees withrespect to the plane of the sky with a -4000 to +6000 km/s radial velocityasymmetry. Near-tangent viewing angle effects and an inhomogeneous surroundingCSM/ISM environment suggest that this geometry and velocity asymmetry may notbe faithfully representative of the remnant's true 3D structure or thekinematic properties of the original explosion. The majority of the opticalejecta are arranged in several well-defined and nearly circular ring-likestructures with diameters between approximately 30 arcsec (0.5 pc) and 2 arcmin(2 pc). These ejecta rings appear to be a common phenomenon of youngcore-collapse remnants and may be associated with post-explosion input ofenergy from plumes of radioactive 56Ni-rich ejecta that rise, expand, andcompress non-radioactive material. Our optical survey also encompassed Cas A'sfaint outlying ejecta knots and exceptionally high-velocity NE and SW streamsof S-rich debris often referred to as `jets'. These outer knots, which exhibita chemical make-up suggestive of an origin deep within the progenitor star,appear to be arranged in opposing and wide-angle outflows with openinghalf-angles of approximately 40 degrees.
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