2016/07/29 by Hitoshi Arai, Makoto Nagai, M. Nagai +28 · 1 citation
Chemistry · Physics and Astronomy · #Astronomy #Astrophysics #Astrophysics and Star Formation Studies #Galaxy #Geometry #Intensity (physics) #Line (geometry) #Molecular Spectroscopy and Structure #Optics #Physics #Spectroscopy and Laser Applications #Telescope #astro-ph.GA
paper · pdf · doi:10.1093/pasj/psw072
19 pages, 11 figures
openalex publication_date 2016/07/29 · openalex created_date 2016/08/23 · arxiv created 2016/08/31 · arxiv updated 2016/09/07 · openalex updated_date 2026/08/05
Abstract We present survey data of six NH3 (J, K) = (1, 1), (2, 2), (3, 3), (4, 4), (5, 5), and (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 three lower transitions were detected with S/N > 3 at 2323 positions (93% of all the on-source positions). Among 2323, the S/N 's 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 that there are two temperature components: cold (∼20 K) and warm (∼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 the diversity of the rotational temperature, which results from mixing of the two temperature components.