X-rays from superbubbles in the Large Magellanic Cloud. VI. A sample of thirteen superbubbles

We present ROSAT observations and analysis of thirteen superbubbles in the Large Magellanic Cloud. Eleven of these observations have not been previously reported. We have studied the X-ray morphology of the superbubbles and have extracted and analyzed their X-ray spectra. Diffuse X-ray emission is detected from each of these superbubbles, and X-ray emission is brighter than that theoretically expected for a wind-blown bubble, suggesting that the X-ray emission from the superbubbles has been enhanced by interactions between the superbubble shell and interior supernova remnants. We have also found significant positive correlations between the X-ray luminosity of a superbubble and its Ha luminosity, expansion velocity, and OB star count. Further, we have found that a large fraction of the superbubbles in the sample show evidence of breakout regions, where hot X-ray-emitting gas extends beyond the H alpha shell.