X-rays from superbubbles in the Large Magellanic Cloud

Abstract

We find diffuse X-ray emission not associated with known SNRs in seven LMC HII complexes. All, except 30 Dor, have simple ring morphologies, indicating shell structures. Assuming these are superbubbles, we find the X-ray luminosity expected from their hot interiors to be an order of magnitude lower than the observed value. SNRs close to the center of a superbubble add very little emission, but we calculate that off-center SNRs hitting the ionized shell could explain the observed emission.