Astrophysics and Space Science

, Volume 274, Issue 1–2, pp 71–76 | Cite as

Hot Neutral H in the Heliosphere: Elastic H-H, H-p Collisions

  • Vladislav V. Izmodenov
  • Yury G. Malama
  • Alexandr P. Kalinin
  • Mike Gruntman
  • Rosine Lallement
  • Irina P. Rodionova
Article

Abstract

Williams et al. (1997) have suggested that a population of hot hydrogen atoms is created in the heliosphere through elastic H-H collisions between energetic `solar' atoms (neutralized solar wind) and interstellar atoms. They used a BGK-like approximation (Bhatnagar et al., 1954) for the Boltzmann collision term and the collision cross sections suggested by Dalgarno (1960). We show that both assumptions result in a significant overestimation of the the H-H collision effect. On the basis of calculated momentum transfer cross-sections for elastic H-H collisions, we argue that elastic H-H and H-p collisions cannot produce hot H atoms in the heliosphere.

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References

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Copyright information

© Kluwer Academic Publishers 2000

Authors and Affiliations

  • Vladislav V. Izmodenov
    • 1
  • Yury G. Malama
    • 2
  • Alexandr P. Kalinin
    • 2
  • Mike Gruntman
    • 3
  • Rosine Lallement
    • 4
  • Irina P. Rodionova
    • 5
  1. 1.Lomonosov Moscow State UniversityRussia
  2. 2.Institute for Problems in MechanicsMoscowRussia
  3. 3.Depart. Aerospace Engin.Univ. Southern California
  4. 4.Service d'Aeronomie, CRNSFrance
  5. 5.Semenov Institute for Chemical PhysicsMoscowRussia

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