Laboratory absorption strengths and line shape parameters in the 4-0, 5-0, and 6-0 vibration bands of HD

Abstract

Uncertainties in the fundamental line profiles and absorption strengths in HD are among the most important sources of error in the analysis of the spectra of HD in the atmosphere of the outer planets. Measurements of the 4-0, 5-0, and 6-0 vibrational bands of HD, taken at room temperature and a range of densities from 0.3 to 1.7 amagat are reported. High S/N spectra have been obtained at a spectral resolution finer than the natural line widths, allowing analysis of spectral profiles, absorption strengths, and pressure shifts in the HD lines. Line profiles are interpreted in terms of the theoretical Galatry approximation, and the HD pressure-broadening and self-diffusion coefficients are determined as free parameters.