The Detection of X-Ray Emission from the OB Associations of the Large Magellanic Cloud

A systematic study of the X-ray properties of OB associations in the Large Magellanic Cloud has been carried out using data from the Einstein Observatory. No! unexpectedly, we find an excess of young, X-ray-bright supernova remnants in the vicinity of the associations. In addition, however, we detect diffuse X-ray emission from over two dozen other associations; luminosities in the 0.16-3.5 keV band range from ~ 2 x 10^34^ (the detection threshold) to ~ 10^36^ ergs s^-1^. For several of the more luminous examples, we show that emission from interstellar bubbles created by the OB stellar winds alone is insufficient to explain the emission. We conclude that transient heating of the bubble cavities by recent supernovae may be required to explain the observed X-rays and that such a scenario is consistent with the number of X-ray-bright associations and the expected supernova rate from the young stars they contain, The mean X-ray luminosity of the ~ 50 undetected associations is ~ 10^34^ ergs s^-1^, and the emission from all associations contributes ~ 4% to the total diffuse X-ray emission from the galaxy.