First results from the UHRF : ultra-high-resolution observations of interstellar CH, CH+, CN towards dzeta Ophiuchi.
We present ultra-high-resolution observations (R> 700000) of interstellar CH, CH+ and CN towards ζ Oph obtained with the newly commissioned Ultra-High- Resolution Facility (UHRF) at the AAT. The molecular lines have all been fully resolved, and we discuss their implications for this well-studied molecular sightline. The CH and CN lines each consist of two narrow (b ≍ 0.5 km s-1) components separated by 1.13±0.10 km s-1; an additional broad (b = 1.8 km s-1) component is present in CH. We show that the very broad (b =2.1 km s-11) CH+ line profile is consistent with the formation of this molecule in warm haloes surrounding the cold cores responsible for the narrow CH and CN components.