Charge exchange emission from solar wind helium ions

D. Bodewits, R.A. Hoekstra, B. Seredyuk, R.W. McCullouqh, G.H. Jones, A.G.G.M. Tielens

Research output: Contribution to journalArticleAcademicpeer-review

47 Citations (Scopus)

Abstract

Charge exchange X-ray and far-ultraviolet (FUV) aurorae can provide detailed insight into the interaction between solar system plasmas. Using the two complementary experimental techniques of photon emission spectroscopy and translation energy spectroscopy, we have studied state-selective charge exchange in collisions between fully ionized helium and target gasses characteristic of cometary and planetary atmospheres (H(2)O, CO(2), CO, and CH(4)). The experiments were performed at velocities typical for the solar wind (200-1500 km s(-1)). Data sets are produced that can be used for modeling the interaction of solar wind alpha particles with cometary and planetary atmospheres. These data sets are used to demonstrate the diagnostic potential of helium line emission. Existing Extreme Ultraviolet Explorer (EUVE) observations of comets Hyakutake and Hale-Bopp are analyzed in terms of solar wind and coma characteristics. The case of Hale-Bopp illustrates well the dependence of the helium line emission to the collision velocity. For Hale-Bopp, our model requires low velocities in the interaction zone. We interpret this as the effect of severe post-bow shock cooling in this extraordinary large comet.

Original languageEnglish
Pages (from-to)593-605
Number of pages13
JournalAstrophysical Journal
Volume642
Issue number1
Publication statusPublished - 1-May-2006

Keywords

  • atomic data
  • comets : general
  • solar wind
  • ultraviolet : solar system
  • X-RAY-EMISSION
  • SELECTIVE ELECTRON-CAPTURE
  • FAR-ULTRAVIOLET EMISSION
  • SLOW HE2+ IONS
  • CROSS-SECTIONS
  • COMET HYAKUTAKE
  • COLLISIONS
  • IONIZATION
  • GASES
  • ATMOSPHERES

Cite this