Cloud structure and physical conditions in star-forming regions from optical observations. I. Data and component structure

We present high-resolution optical spectra (at similar to0.6-1.8 km s(-1)) of interstellar CN, CH, CH+, Ca I, K I, and Ca II absorption toward 29 lines of sight in three star-forming regions, rho Oph, Cep OB2, and Cep OB3. The observations and data reduction are described. The agreement between earlier measurements of the total equivalent widths and our results is quite good. However, our higher resolution spectra reveal complex structure and closely blended components in most lines of sight. The velocity component structure of each species is obtained by analyzing the spectra of the six species for a given sight line together. The tabulated column densities and Doppler parameters of individual components are determined by using the method of profile fitting. Total column densities along lines of sight are computed by summing results from profile fitting for individual components and are compared with column densities from the apparent optical depth method. A more detailed analysis of these data and their implications will be presented in a companion paper.