0 v 1 1 4 M ar 2 00 1 Atomic Physics with the Goddard High Resolution Spectrograph on the Hubble Space Telescope . V . Oscillator Strengths for Neutral Carbon Lines

We analyzed high resolution spectra of interstellar C I absorption toward λ Ori, 1 Sco, and δ Sco that were obtained with the Goddard High Resolution Spectrograph on the Hubble Space T elescope. Several multiplets were detected within the wavelength interval 1150 to 1200Å, where most C I lines have ill-defined oscillator strength; multiplets at longer wavelengths with well-defined atomic parameters were also seen. We extracted accurate column densities and Doppler parameters from lines with precise laboratory-based f-values. These column densities and b-values were used to obtain a self-consistent set of f-values for all the observed C I lines. For many of the lines with wavelength below 1200Å, the derived f-values differ appreciably from the values quoted in the compilation by Morton (1991). The present set of f-values extends and in some cases supersedes those given in Zsargó et al. (1997), which were based on lower resolution data.