O VI Emission from Superbubbles in the Large Magellanic Cloud
Abstract
Observations of interstellar regions in the Large Magellanic Cloud (LMC) obtained serendipitously by the Far Ultraviolet Spectroscopic Explorer (FUSE) have revealed O VI λ1032 emission from several superbubbles and from one region not associated with any nebula. In every case, the O VI emission is centered at or around the LMC velocity of +275 km s-1. The O VI surface brightnesses (8900-21,800 LU [line unit; 1 photon s-1 cm -2 sr-1]) toward superbubbles are significantly higher than the value (6400 LU) in the one LMC diffuse-gas spectrum, and also higher than in spectra of the diffuse hot gas emission in our Galaxy (Dixon et al.). The superbubble O VI brightnesses are lower than those of supernova remnants, but their values are consistent with the emission arising in supernova-driven shocks. However, other emission mechanisms, such as conductive interfaces and turbulent mixing layers, are not excluded by our data.
Based on observations made with the NASA-CNES-CSA Far Ultraviolet Spectroscopic Explorer. FUSE is operated for NASA by the Johns Hopkins University under NASA contract NAS 5-32985.- Publication:
-
Publications of the Astronomical Society of the Pacific
- Pub Date:
- March 2007
- DOI:
- 10.1086/513288
- Bibcode:
- 2007PASP..119..284S
- Keywords:
-
- ISM: Structure;
- galaxies: individual (LMC);
- Ultraviolet: ISM