Astronomical Applications Department, U.S. Naval Observatory thesis Page 8
6 Morphology of Massive Stars and Ionized Gas
74
6.1 Evolution of Young Star Formation Regions . . . . . . . . . . . . 74
6.2 Observations of Massive Stars Inside Ionized Structures . . . . . . 76
6.3 Propagating Star Formation . . . . . . . . . . . . . . . . . . . . . 78
6.3.1 Stochastic Self-Propagating Star Formation Model . . . . . 79
6.4 Observations of Sequential Star Formation . . . . . . . . . . . . . 80
7 Massive Star Formation and the Global Gas Distribution
90
7.1 Large-Scale Triggering in Giant Shells . . . . . . . . . . . . . . . . 91
7.2 Relative FUV and HI Morphologies . . . . . . . . . . . . . . . . . 93
7.2.1 Holmberg II . . . . . . . . . . . . . . . . . . . . . . . . . . 93
7.2.2 IC2574 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
7.2.3 Sextans A . . . . . . . . . . . . . . . . . . . . . . . . . . . 97
7.3 HI Hole Energetics . . . . . . . . . . . . . . . . . . . . . . . . . . 99
7.4 Characteristic Di erences in ISM . . . . . . . . . . . . . . . . . . 102
7.4.1 The Solid Body Regime . . . . . . . . . . . . . . . . . . . 102
7.4.2 Random Motions . . . . . . . . . . . . . . . . . . . . . . . 103
8 Summary
117
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