X-rays from superbubbles in the large magellanic cloud .4. The blowout structure of N44

We have used optical echelle spectra along with ROSAT and ASCA X-ray spectra to test the hypothesis that the southern portion of the N44 X-ray bright region is the result of a blowout structure. Three pieces of evidence now support this conclusion. First, the filamentary optical morphology corresponding with the location of the X-ray bright South Bar suggests the blowout description (Chu et al. 1993). Second, optical echelle spectra show evidence of high-velocity (approximate to 90 km s(-1)) gas in the region of the blowout. Third, X-ray spectral fits show a lower temperature for the South Bar than the main superbubble region of shell 1. Such a blowout can affect the evolution of the superbubble and explain some of the discrepancy discussed by Oey & Massey (1995) between the observed shell diameter and the diameter predicted on the basis of the stellar content and the pressure-driven bubble model of Weaver et al. (1977).