A Multi-Line Ammonia Survey of the Galactic Center Region with the
  Tsukuba 32-m Telescope - I. Observations and Data
  We present survey data of the NH3 (J, K) = (1, 1)--(6, 6) lines,
simultaneously observed with the Tsukuba 32-m telescope, in the main part of
the central molecular zone of the Galaxy. The total number of on-source
positions was 2655. The lowest three transitions were detected with S/N > 3 at
2323 positions (93% of all the on-source positions). Among 2323, the S/N of (J,
K ) = (4, 4), (5, 5), and (6, 6) exceeded 3.0 at 1426 (54%), 1150 (43%), and
1359 (51%) positions, respectively. Simultaneous observations of the lines
enabled us to accurately derive intensity ratios with less systematic errors.
Boltzmann plots indicate there are two temperature components: cold ($\sim$ 20
K) and warm ($\sim$ 100 K). Typical intensity ratios of Tmb(2,2)/Tmb(1,1),
Tmb(4,4)/Tmb(2,2), Tmb(5,5)/Tmb(4,4), and Tmb(6,6)/Tmb(3,3) were 0.71, 0.45,
0.65, and 0.17, respectively. These line ratios correspond to diversity of
rotational temperature, which results from mixing of the two temperature
components.
