Atomic Physics with the Goddard High Resolution Spectrograph on the Hubble Space Telescope. V. Oscillator Strengths for Neutral Carbon Lines below 1200 Angstrom

摘要

We analyzed high resolution spectra of interstellar neutral carbon absorptiontoward $\lambda$ Ori, 1 Sco, and $\delta$ Sco that were obtained with theGoddard High Resolution Spectrograph on the Hubble Space Telescope. Severalmultiplets were detected within the wavelength interval 1150 to 1200 A, wheremost neutral carbon lines have ill-defined oscillator strength; multiplets atlonger wavelengths with well-defined atomic parameters were also seen. Weextracted accurate column densities and Doppler parameters from lines withprecise laboratory-based f-values. These column densities and b-values wereused to obtain a self-consistent set of f-values for all the observed neutralcarbon lines. For many of the lines with wavelength below 1200 A, the derivedf-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 thosegiven in Zsargo et al. (1997), which were based on lower resolution data.