S. Muller, A. Beelen, M. Guélin, S. Aalto, J. H. Black, F. Combes,
S. J. Curran, P. Theule, and S. N. Longmore
used the Australia Telescope Compact Array (ATCA) to study the molecular content of a foreground galaxy at z = 0.89 (FG0.89 consisting of two subsources, FG0.89SW and FG0.89NO) in absorption toward the quasar PKS 1830-211:
Molecules at z = 0.89: A 4-mm-Rest-Frame Absorption-Line Survey toward PKS 1830-211
Astron. Astrophys. 535, (2011) Art. No. A103.
Propadienylidene, l-C3H2, was identified by three Ka = 1 ortho transitions (2 with J" = 2 and the lower J" = 3) and one with Ka = 0 (para) and J" = 3. The OPR is compatible with the high temperature limit of 3. The abundance ratio c-C3H2 to l-C3H2 is about 25, between 35 in diffuse clouds, and 70 found in the dark cloud TMC-1.