1ST RESULTS FROM GODDARD HIGH-RESOLUTION SPECTROGRAPH - C-I, S-I, AND CO TOWARD ZETA-PERSEI AND THE PHYSICAL CONDITIONS IN DIFFUSE CLOUDS

Observations made by the Goddard High Resolution Spectrograph of the cool, neutral interstellar gas in the line of sight to zeta-Per are reported. Heliocentric velocities and equivalent widths were measured for absorption lines of C I and S I. Synthetic spectra were computed and fitted to the observed CO (2-0) and (3-0) bands in the A 1-PI-X 1-SIGMA+ system. Derived populations of the C I ground-state fine-structure levels and the CO ground-state rotational levels were used to derive densities of two of the three, and possibly four, detected cloud components. The velocity component displaying the strongest C I absorption reveals extraordinarily high pressure (P/k > 4.3 x 10(4) cm-3 K).