Radio Recombination Line Emission from Ultracompact HII Regions

  • E. Churchwell
  • C. M. Walmsley
  • D. O. S. Wood
  • H. Steppe
Part of the Astrophysics and Space Science Library book series (ASSL, volume 163)


We report observations of H30α, H42α, and H76α line emission toward a selection of 12 ultracompact (UC) HII regions. These same UC HII regions have also been imaged with the VLA. Continuum and radio recombination line (RRL) models have been calculated and compared. For the highest density nebulae, single component models do not seem to be consistent with both the continuum and RRL observations. Possisble correlations of line velocities and line widths are considered. Evidence for electron impact broadening is shown.


Principal Quantum Number Flux Density Scale Molecular Line Line Velocity Very Large Array 
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Copyright information

© Kluwer Academic Publishers 1990

Authors and Affiliations

  • E. Churchwell
    • 1
  • C. M. Walmsley
    • 2
  • D. O. S. Wood
    • 3
  • H. Steppe
    • 4
  1. 1.Astronomy Dept.MadisonUSA
  2. 2.Max-Planck-Inst.Bonn 1West Germany
  3. 3.Center for AstrophysicsCambridgeUSA
  4. 4.IRAMGranadaSpain

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