Self-similar Champagne Flows in H II Regions

  title={Self-similar Champagne Flows in H II Regions},
  author={Frank Hsia-San Shu and Susana Lizano and Daniele Galli and J. Cant{\'o} and Gregory P. Laughlin},
  journal={The Astrophysical Journal},
  pages={969 - 979}
We consider the idealized expansion of an initially self-gravitating, static, singular, isothermal cloud core. For t ≥ 0, the gas is ionized and heated to a higher uniform temperature by the formation of a luminous but massless star in its center. The approximation that the mass and gravity of the central star are negligible for the subsequent motion of the H II region holds for distances r much greater than ~100 AU and for the massive cloud cores that give rise to high-mass stars. If the… 
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