We have now detected HCN 4-3 at the positions of fragments C, F, G, H.
We have searched for it, but not detected it from B and L. The site of
fragment G impact produced the strongest line yet observed: peak antenna
temperature 1.2 K, near Gaussian profile with width = 5.3 km/s, integrated
intensity 6.2 K km/s.
We are monitoring the impact sites of F, G and H to examine the change in the lines over time. The strong line at G measured 21 hours after impact seems to have disappeared 35 hrs after impact. Emission is also no longer observed from C. But F and/or H are still showing emission (they are 6" apart and so not unambiguously resolved by our 14" beam).
We have also carried out long (0.5 hour in bad weather) integrations on the sites of fragments F and C at CO 3-2 (345 GHz), but did not detect anything. Combining the integrations on both sites gives an rms noise level of 150 mK (at 0.7 km/s resolution). We also integrated down to a 1-sigma noise of 420 mK (0.5 km/s resolution) on the site of fragment H without seeing anything.