The Vela supernova remnant and the Gum nebula: new perspectives at 2.4 GHz

Sensitive, polarimetric observations are presented for the region of the Galactic plane 276°≥l≥238°, with a latitude coverage of +5°≥b≥-8° over most of this range. These observations were made using the Parkes 64-m radio telescope, at a frequency of 2.4 GHz. Both total-power and polarized emission are detected from the Vela supernova remnant, over an area exceeding 8° in diameter. Additionally, a number of features are identified beyond the shell of Vela, which correspond with what appear to be ejecta accelerated by the supernova explosion. Radio emission containing a significant polarized component is detected from the Gum nebula. To account for our observations, both a thermal and a non-thermal component of this emission are therefore required. The discrete SNR G 240.9-0.9 is reinterpreted as a section of this emission from the Gum nebula.