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Non-equilibrium Microwave Plasma for Efficient High Temperature Chemistry
Published on: August 1, 2017
High-Temperature Rotational Transitions of Water in Sunspot and Laboratory Spectra
1Department of Physics and Astronomy, University College London, Gower Street, London, WC1E 6BT, United Kingdom
Journal of Molecular Spectroscopy
|February 3, 1998
Summary
This study assigns spectral lines for hot water (H2O) in sunspots and laboratories using advanced computational methods. The research successfully identifies most observed transitions, significantly enhancing our understanding of water
Area of Science:
- Spectroscopy
- Computational Chemistry
- Astrophysics
Background:
- Hot water spectra are crucial for understanding atmospheric conditions in sunspots and laboratory plasmas.
- Previous spectral assignments for water have been incomplete, particularly for high-lying rotational and vibrational states.
Purpose of the Study:
- To assign spectral transitions of hot water observed in sunspot absorption and laboratory emission.
- To improve the understanding of water molecule behavior under extreme temperature conditions.
Main Methods:
- Variational nuclear motion calculations were employed, utilizing a high-level ab initio electronic surface.
- Both adiabatic and nonadiabatic corrections to the Born-Oppenheimer approximation were included.
- Assignments were made for spectra obtained in sunspot absorption (approx. 3000°C) and laboratory emission (approx. 1550°C).
Main Results:
- Assignments were made for approximately 3000 of 4700 laboratory transitions and 1687 sunspot transitions.
- All strong lines in the sunspot spectrum were assigned, involving high-lying rotational levels within key vibrational states.
- The range of Ka values was significantly extended, and Coriolis interactions causing level splitting were identified.
Conclusions:
- The study provides comprehensive spectral assignments for hot water, validating computational methods.
- This work significantly advances the interpretation of water spectra in astrophysical and laboratory contexts.
- Comparisons with existing line lists confirm the accuracy and completeness of the new assignments.
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