Supersonic gas motion in giant extragalactic H II regions

We present high signal-to-noise ratio, long-slit spectra of the central reg ion of the 30 Doradus nebula taken with unprecedented spatial (similar to 0 .1 pc) and spectral (similar to 3 km s(-1)) resolution. We use these observ ations to investigate the dominant line-broadening mechanisms for the globa l nebula. We find no evidence for significant gravitational broadening of t he lines. Thus, broadening appears to be dominated by stellar winds and the rmal motions. However, we identify a new broad component to the lines that explains the integrated profile wings identified in previous observations. The broad component appears at all positions observed, and is possibly rela ted to the disruption through photo-evaporation of high-density condensatio ns within the nebula.