Millimeter-wave Spectral Line Surveys toward the Galactic Circumnuclear
  Disk and Sgr A*
  We have performed unbiased spectral line surveys at 3 mm band toward the
Galactic circumnuclear disk (CND) and Sgr A* using the Nobeyama Radio
Observatory (NRO) 45 m radio telescope. The target positions are two tangential
points of the CND and the direction of Sgr A*. We have obtained three wide-band
spectra which cover the frequency range from 81.3 GHz to 115.8 GHz, detecting
46 molecular lines from 30 species including 10 rare isotopomers and four
hydrogen recombination lines. Each line profile consists of multiple velocity
components which arise from the CND, +50 km/s and +20 km/s clouds (GMCs), and
the foreground spiral arms. We define the specific velocity ranges which
represent the CND and the GMCs toward each direction, and classify the detected
lines into three categories: the CND-/GMC-/HBD-types, based on the line
intensities integrated over the defined velocity ranges. The CND- and GMC-types
are the lines which mainly trace the CND and the GMCs, respectively. The
HBD-type possesses the both characteristics of the CND-/GMC-types. We also
present the lists of line intensities and other parameters, as well as
intensity ratios, which must be useful to investigate the difference between
nuclear environments of our Galaxy and of others.
