1ST RESULTS FROM THE GODDARD HIGH-RESOLUTION SPECTROGRAPH - ELEMENT ABUNDANCES AS A FUNCTION OF VELOCITY IN THE NEUTRAL GAS TOWARD ZETA-PERSEI

Observations of ultraviolet interstellar absorption lines toward zeta-Persei (HD 24912) obtained with the echelle mode of the Goddard High-Resolution Spectrograph (GHRS) aboard the Hubble Space Telescope at a resolution of 3.5 km s-1 are presented. The data for O I, C II, Mg II, S II, Fe II, Si II, Mn II, and Zn II are converted into representations of apparent column density per unit velocity, N(a)(epsilon), over the velocity range from -30 to +40 km s-1. The profiles for ions that are the dominant state of ionization in neutral clouds permit a study of the variation of element abundance with velocity caused by changes in the gas phase depletion in the different absorbing regions situated toward zeta-Per. In the denser portions of the diffuse clouds with upsilon approximately +5 to 15 km s-1, heavy element depletions are very large. However, in absorbing components near -5 and +25 km s-1, the depletions are less severe, with a nearly solar gas phase abundance ratio being found for the gas in the +25 km s-1 component. The measurements confirm that the GHRS is well suited for diagnostic spectroscopy of interstellar gas.