Spectral Line Survey toward Young Massive Protostar NGC 2264 CMM3 in the
  4 mm, 3 mm, and 0.8 mm Bands
  Spectral line survey observations are conducted toward the high-mass
protostar candidate NGC 2264 CMM3 in the 4 mm, 3 mm, and 0.8 mm bands with the
Nobeyama 45 m telescope and the Atacama Submillimeter Telescope Experiment
(ASTE) 10 m telescope. In total, 265 emission lines are detected in the 4 mm
and 3 mm bands, and 74 emission lines in the 0.8 mm band. As a result, 36
molecular species and 30 isotopologues are identified. In addition to the
fundamental molecular species, many emission lines of carbon-chain molecules
such as HC5N, C4H, CCS, and C3S are detected in the 4 mm and 3 mm bands.
Deuterated molecular species are also detected with relatively strong
intensities. On the other hand, emission lines of complex organic molecules
such as HCOOCH3, and CH3OCH3 are found to be weak. For the molecules for which
multiple transitions are detected, rotation temperatures are derived to be 7-33
K except for CH3OH. Emission lines with high upper-state energies (Eu > 150 K)
are detected for CH3OH, indicating existence of a hot core. In comparison with
the chemical composition of the Orion KL, carbon-chain molecules and deuterated
molecules are found to be abundant in NGC 2264 CMM3, while sulfur-bearing
species and complex organic molecules are deficient. These characteristics
indicate chemical youth of NGC 2264 CMM3 in spite of its location at the center
of the cluster forming core, NGC 2264 C.
