Rotational spectrum of the CCS radical studied by laboratory microwave spectroscopy and radio-astronomical observations

The rotational spectral lines of the CCS radical and its isotopic species, CC(S-34), (C-13)CS, and C(C-13)S, have been observed in the laboratory, and the J(N) = 4(3)-3(2), J(N) = 2(1)-1(0), and J(N) = 3(4)-2(3) transitions for CCS and that of J(N) = 4(3)-3(2) for CC(S-34) have been observed toward a cold dark cloud, L1498. The molecular constants of CCS, CC(S-34), (C-13)CS, and C(C-13)S have been determined from the observed transition frequencies, and the rest frequencies of CCS and CC(S-34) below 300 GHz are listed with their line strengths. The frequencies of the low-N transitions of (C-13)CS and C(C-13)S are calculated for future astronomical observations.