Astrophysics and Space Science

, Volume 10, Issue 3, pp 383–392 | Cite as

On the spectrum of a gaseous nebula of pure hydrogen

III: The Balmer decrement
  • H. Gerola
  • M. Salem
  • N. Panagia
Article

Abstract

The Balmer decrement was calculated for a homogeneous, spherical, pure hydrogen nebula, ionised and excited both by radiative and collisional processes. Reabsorption in the Balmer series from sublevels 2s and 2p was taken into account. Calculations were carried out for electron temperatures of 104 K and 2×104 K, electron densities from 103 to 106 cm−3, and radii from 1015 to 1017 cm. The results define allowed and forbidden regions in the log(Hβ/Hγ) vs log(Hα/Hβ) diagram different from those of previous results obtained assuming purely radiative or purely collisional ionisation and excitation. A brief comparison with observations is presented and discussed.

Keywords

Hydrogen Electron Temperature Pure Hydrogen Collisional Process Balmer Series 

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Copyright information

© D. Reidel Publishing Company 1971

Authors and Affiliations

  • H. Gerola
    • 1
  • M. Salem
    • 1
  • N. Panagia
    • 2
  1. 1.Departmento de Física, Facultad de Ciencias Exactas y NaturalesUniversidad de Buenos AiresBuenos AiresArgentine
  2. 2.Laboratorio di AstrofisicaFrascatiItaly

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