The H2O Southern Galactic Plane Survey: NH3 (1,1) and (2,2) catalogues
Article
Article Title | The H2O Southern Galactic Plane Survey: NH3 (1,1) and (2,2) catalogues |
---|---|
ERA Journal ID | 1074 |
Article Category | Article |
Authors | Purcell, C.R., Longmore, S.N., Walsh, A.J., Whiting, M.T., Breen, S.L., Britton, T., Brooks, K.J., Burton, M.G., Cunningham, M.R., Green, J.A., Harvey-Smith, L., Hindson, L., Hoare, M.G., Indermuehle, B., Jones, P.A., Lo, N., Lowe, V., Phillips, C.J., Thompson, M.A., Urquhart, J.S., Voronkov, M.A. and White G. L. |
Journal Title | Monthly Notices of the Royal Astronomical Society |
Journal Citation | 426 (3), pp. 1972-1991 |
Number of Pages | 20 |
Year | 2012 |
Publisher | Oxford University Press |
Place of Publication | United Kingdom |
ISSN | 0035-8711 |
1365-2966 | |
Digital Object Identifier (DOI) | https://doi.org/10.1111/j.1365-2966.2012.21800.x |
Web Address (URL) | https://academic.oup.com/mnras/article/426/3/1972/988583 |
Abstract | The H2O Southern Galactic Plane Survey (HOPS) has mapped a 100° strip of the Galactic plane (-70° > l > 30°, |b| < 0.°5) using the 22 m Mopra antenna at 12 mm wavelengths. Observations were conducted in on-the-fly mode using the Mopra spectrometer (MOPS), targeting water masers, thermal molecular emission and radio-recombination lines. Foremost among the thermal lines are the 23 GHz transitions of NH3 J, K = (1,1) and (2,2), which trace the densest parts of molecular clouds (n > 104 cm-3). In this paper, we present the NH3 (1,1) and (2,2) data, which have a resolution of 2 arcmin and cover a velocity range of ±200 km s-1. The median sensitivity of the NH3 data cubes is σTmb = 0.20 ± 0.06 K. For the (1,1) transition, this sensitivity equates to a 3.2 kpc distance limit for detecting a 20 K, 400M⊙ cloud at the 5σ level. Similar clouds of mass 5000M⊙ would be detected as far as the Galactic Centre, while 30 000M⊙ clouds would be seen across the Galaxy. We have developed an automatic emission finding procedure based on the Australian Telescope National Facility (ATNF) DUCHAMP software and have used it to create a new catalogue of 669 dense molecular clouds. The catalogue is 100 per cent complete at the 5σ detection limit (Tmb = 1.0K). A preliminary analysis of the ensemble cloud properties suggests that the near-kinematic distances are favoured. The cloud positions are consistent with current models of the Galaxy containing a long bar. Combined with other Galactic plane surveys this new molecular-line data set constitutes a key tool for examining Galactic structure and evolution. Data cubes, spectra and catalogues are available to the community via the HOPS website. |
Keywords | Galaxy:structure; ISM:evolution; Radio lines:ISM; Stars:early-type; Stars:formation; Surveys |
Public Notes | This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society ©: 2012 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved. |
Funder | Science and Technology Facilities Council |
Byline Affiliations | University of Sydney |
University of Leeds, United Kingdom | |
University of Manchester, United Kingdom | |
European Southern Observatory (ESO), Germany | |
Center for Astrophysics Harvard and Smithsonian, United States | |
James Cook University | |
Commonwealth Scientific and Industrial Research Organisation (CSIRO), Australia | |
Macquarie University | |
University of New South Wales | |
University of Hertfordshire, United Kingdom | |
University of Chile, Chile | |
Paris Diderot University, France | |
Max Planck Society, Germany |
https://research.usq.edu.au/item/yy593/the-h2o-southern-galactic-plane-survey-nh3-1-1-and-2-2-catalogues
Download files
28
total views22
total downloads1
views this month1
downloads this month