NEW OBSERVATIONS WITH THE HST GODDARD HIGH-RESOLUTION SPECTROGRAPH OF THE LOW-REDSHIFT LYMAN-ALPHA CLOUDS IN THE 3C-273 LINE-OF-SIGHT

We present spectra of 3C 273 between 1216 and 1250 Angstrom obtained in the (pre-COSTAR [Corrective Optics Space Telescope Axial Replacement instrument]) configuration of the GHRS, taken with the G160M grating, with a resolution of approximate to 20 km s(-1). The two strong Ly alpha lines at velocities of similar to 1000 and similar to 1600 km s(-1) are well fitted with Voigt profiles and yield column densities, Doppler parameters and redshifts of log N(H I) = 14.19 +/- 0.04, V-Dop = 40.7 +/- 3.0 km s(-1), V = 1012.4 +/- 2.0 km s(-1), and log N(H I) = 14.22 +/- 0.07, V-Dop 34.2 +/- 3.3 km s(-1) and V = 1582.0 +/- 2.0 km s(-1), respectively. Motivated by the initial announcement by Williams and Schommer of detectable Ha emission associated with the similar to 1600 km s(-1) cloud, we discuss the difficulty of finding models which can account for emission of that magnitude given the observed neutral hydrogen column density, though a recent reobservation by these authors has shown the initial detection to be spurious. The C/H abundance ratio is probably less than about one-fourth of the solar abundance in these clouds, although this result is very uncertain and model dependent.