The Gum Nebula was observed by the A-21 LED proportional counters on the HEAO-1 satellite as part of the all-sky survey. We report the first detection of X-ray emission associated with the Gum Nebula. Soft X-ray spectra were constructed from the A-2 LED PHA data. Single temperature Raymond-Smith models were fitted to the observed spectra to yield temperature, column density and emission measure. The temperature is ≈6 × 105 K, the column density ≈4 x 1020 cm-2, and the emission measure ≪5 cm-6 pc. The X-ray and optical properties of the Gum Nebula are consistent with a supernova remnant in the shell stage of evolution, which was the product of an energetic (3 × 1051 ergs) supernova explosion which occurred about 2 × 106 yr ago.
All Science Journal Classification (ASJC) codes
- Astronomy and Astrophysics
- Space and Planetary Science