A Morphological Study of the Supernova Remnant Rx J0852.0-4622 (Vela Jr.)

We conduct a multiwavelength morphological study of the Galactic supernova remnant (SNR) RX J0852.0-4622 (also known as Vela Jr., Vela Z, and G266.2-1.2). RX J0852.0-4622 is coincident with the edge of the larger Vela SNR causing confusion in the attribution of some filamentary structures to either RX J0852.0-4622 or its larger sibling. We find that the RX J0852.0-4622 radio-continuum emission can be characterized by a two-dimensional shell with a radius of 0.°90 ± 0.°01 (or 11.8 ± 0.6 pc at an assumed distance of 750 pc) centered at (l, b) = (133.°08 ± 0.°01,-46.°34 ± 0.°01) (or R.A. = 8^h52^m19.ˢ2, decl. = -46°20‧24.″0, J2000), consistent with X-ray and gamma-ray emission. Although [O III] emission features are generally associated with the Vela SNR, one particular [O III] emission feature, which we denote as “the Vela Claw,” morphologically matches a molecular clump that is thought to have been stripped by the stellar progenitor of the RX J0852.0-4622 SNR. We argue that the Vela Claw feature is possibly associated with RX J0852.0-4622. Toward the northwestern edge of RX J0852.0-4622 , we find a flattening of the radio spectral index toward another molecular clump also thought to be associated with RX J0852.0-4622 . It is currently unclear whether this feature and the Vela Claw result from interactions between the RX J0852.0-4622 shock and interstellar medium gas.