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arXiv · 1608.08694

A Multi-Line Ammonia Survey of the Galactic Center Region with the Tsukuba 32-m Telescope - I. Observations and Data

Hitoshi Arai·Makoto Nagai·Shinji Fujita·Naomasa Nakai·Masumichi Seta·Aya Yamauchi·Hiroyuki Kaneko·Kenzaburo Hagiwara·Koh-ichi Mamyoda·Yusuke Miyamoto·Masa-aki Horie·Shun Ishii·Yusuke Koide·Mitsutoshi Ogino·Masaki Maruyama·Katsuaki Hirai·Wataru Oshiro·Satoshi Nagai·Daiki Akiyama·Keita Konakawa·Hiroaki Nonogawa·Dragan Salak·Yuki Terabe·Yoshiki Nihonmatsu·Fumiyoshi Funahashi
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Abstract

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.

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Hitoshi Arai, Makoto Nagai, Shinji Fujita, Naomasa Nakai, Masumichi Seta, Aya Yamauchi, Hiroyuki Kaneko, Kenzaburo Hagiwara, Koh-ichi Mamyoda, Yusuke Miyamoto, Masa-aki Horie, Shun Ishii, Yusuke Koide, Mitsutoshi Ogino, Masaki Maruyama, Katsuaki Hirai, Wataru Oshiro, Satoshi Nagai, Daiki Akiyama, Keita Konakawa, Hiroaki Nonogawa, Dragan Salak, Yuki Terabe, Yoshiki Nihonmatsu, Fumiyoshi Funahashi. 2016-08-31. A Multi-Line Ammonia Survey of the Galactic Center Region with the Tsukuba 32-m Telescope - I. Observations and Data. https://doi.org/10.1093/pasj%2Fpsw072

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