Absolute line strengths for carbon and sulfur

Abstract

Absolute transition probabilities for 124 CI, SI, and SII lines in the range 3600-7400 \AA{}A are measured with a spectroscopic shock tube. Relative strengths of two CII lines are also determined. Mixtures of neon and ten different compounds of carbon and sulfur are heated to temperatures 8200-13000\ifmmode^\circ\else\textdegree\fi{}K at pressures (4.8-27.0) \ifmmode\times\else\texttimes\fi{} ${10}^{6}$ dyn ${\mathrm{cm}}^{\ensuremath{-}2}$. Thermodynamic and photometric variables are measured redundantly. Absolute $A$ values are determined in emission by two or more independent methods which in combination have much less than the traditional sensitivity to systematic errors in source temperature. Estimated accuracies for the more prominent visible lines are 13-30%. Results are compared with theoretical predictions, other experiments, and with quantum-mechanical sum rules.