Interstellar absorption lines of CH and CH(+) have been detected toward the star HD 210121, which is located behind a previously unknown high-latitude cloud. The CH observations and the measured... Show moreInterstellar absorption lines of CH and CH(+) have been detected toward the star HD 210121, which is located behind a previously unknown high-latitude cloud. The CH observations and the measured extinction toward the star provide independent measures of the H2 column density along the line of sight, which are compared with that deduced from CO mm observations. The inferred CH(+) column density is comparatively small, suggesting that shocks do not play a dominant role in the chemistry in the cloud. Show less
