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 previous ly reported. We have studied the X-ray morphology of the superbubbles and h ave extracted and analyzed their X-ray spectra. Diffuse X-ray emission is d etected from each of these superbubbles, and X-ray emission is brighter tha n that theoretically expected for a wind-blown bubble, suggesting that the X-ray emission from the superbubbles has been enhanced by interactions betw een the superbubble shell and interior supernova remnants. We have also fou nd significant positive correlations between the X-ray luminosity of a supe rbubble and its Ha luminosity, expansion velocity, and OB star count. Furth er, we have found that a large fraction of the superbubbles in the sample s how evidence of breakout regions, where hot X-ray-emitting gas extends beyo nd the H alpha shell.