A 8.8-50 GHz Complete Spectral Line Survey Toward TMC-1 I. Survey Data

Abstract

We completed the first spectral line survey toward a cold, dark cloud TMC-1 (cyanopolyyne peak) in a frequency range between 8.8 and 50.0 GHz by the 45-m radio telescope of Nobeyama Radio Observatory. We detected 414 lines of 38 molecular species including 11 new molecules, such as C6H, CCO, C3O, CCS, C3S, HNCCC, HCCNC, HC3NH+, HCCCHO, CH2CN, and cyclic C3H (c-C2H), which were previously reported; only one significant line, U49536, remains unidentified. 177 out of 414 lines are reported for the first time. Some half of the detected molecules are linear carbon-chain species and their derivatives. We also discovered three new rarer isotopomers: CC34S, C 334S, and HDCS. Spectral charts are presented together with the observed line parameters of all detected lines. Improved molecular constants of several carbon-chain molecules obtained during the course of identification are also presented.