An Interferometric Spectral-Line and Imaging Survey of VY Canis Majoris
  in the 345 GHz Band
  A spectral line survey of the oxygen-rich red supergiant VY Canis Majoris was
made between 279 and 355 GHz with the Submillimeter Array. Two hundred twenty
three spectral features from 19 molecules (not counting isotopic species of
some of them) were observed, including the rotational spectra of TiO, TiO2, and
AlCl for the first time in this source. The parameters and an atlas of all
spectral features is presented. Observations of each line with a synthesized
beam of ~0.9 arcsec, reveal the complex kinematics and morphology of the nebula
surrounding VY CMa. Many of the molecules are observed in high lying rotational
levels or in excited vibrational levels. From these, it was established that
the main source of the submillimeter-wave continuum (dust) and the high
excitation molecular gas (the star) are separated by about 0.15 arcsec.
Apparent coincidences between the molecular gas observed with the SMA, and some
of the arcs and knots observed at infrared wavelengths and in the optical
scattered light by the Hubble Space Telescope are identified. The observations
presented here provide important constraints on the molecular chemistry in
oxygen-dominated circumstellar environments and a deeper picture of the complex
circumstellar environment of VY CMa.
