Towards a three-dimensional distribution of the molecular clouds in the Galactic Centre

We present a study of the three-dimensional structure of the molecular clouds in the Galactic Centre (GC) using CO emission and OH absorption lines. Two CO isotopologue lines, $^{12}$CO ($J$=1$\rightarrow$0) and $^{13}$CO ($J$=1$\rightarrow$0), and four OH ground-state transitions, surveyed by the S...

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Main Authors: Yan, Q., Walsh, A., Dawson, J., Macquart, Jean-Pierre, Blackwell, R., Burton, M., Rowell, G., Zhang, B., Xu, Y., Tang, Z., Hancock, Paul
Format: Journal Article
Published: Oxford University Press 2017
Online Access:http://hdl.handle.net/20.500.11937/57869
http://dx.doi.org/10.1093/mnras/stx1724
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author Yan, Q.
Walsh, A.
Dawson, J.
Macquart, Jean-Pierre
Blackwell, R.
Burton, M.
Rowell, G.
Zhang, B.
Xu, Y.
Tang, Z.
Hancock, Paul
author_facet Yan, Q.
Walsh, A.
Dawson, J.
Macquart, Jean-Pierre
Blackwell, R.
Burton, M.
Rowell, G.
Zhang, B.
Xu, Y.
Tang, Z.
Hancock, Paul
author_sort Yan, Q.
building Curtin Institutional Repository
collection Online Access
description We present a study of the three-dimensional structure of the molecular clouds in the Galactic Centre (GC) using CO emission and OH absorption lines. Two CO isotopologue lines, $^{12}$CO ($J$=1$\rightarrow$0) and $^{13}$CO ($J$=1$\rightarrow$0), and four OH ground-state transitions, surveyed by the Southern Parkes Large-Area Survey in Hydroxyl (SPLASH), contribute to this study. We develop a novel method to calculate the OH column density, excitation temperature, and optical depth precisely using all four OH lines, and we employ it to derive a three-dimensional model for the distribution of molecular clouds in the GC for six slices in Galactic latitude. The angular resolution of the data is 15.5 arcmin, which at the distance of the GC (8.34 kpc) is equivalent to 38 pc. We find that the total mass of OH in the GC is in the range 2400-5100 Solar mass . The face-on view at a Galactic latitude of b = 0{\deg} displays a bar-like structure with an inclination angle of 67.5 $\pm$ 2.1{\deg} with respect to the line of sight. No ring-like structure in the GC is evident in our data, likely due to the low spatial resolution of the CO and OH maps.
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spelling curtin-20.500.11937-578692019-02-19T05:35:55Z Towards a three-dimensional distribution of the molecular clouds in the Galactic Centre Yan, Q. Walsh, A. Dawson, J. Macquart, Jean-Pierre Blackwell, R. Burton, M. Rowell, G. Zhang, B. Xu, Y. Tang, Z. Hancock, Paul We present a study of the three-dimensional structure of the molecular clouds in the Galactic Centre (GC) using CO emission and OH absorption lines. Two CO isotopologue lines, $^{12}$CO ($J$=1$\rightarrow$0) and $^{13}$CO ($J$=1$\rightarrow$0), and four OH ground-state transitions, surveyed by the Southern Parkes Large-Area Survey in Hydroxyl (SPLASH), contribute to this study. We develop a novel method to calculate the OH column density, excitation temperature, and optical depth precisely using all four OH lines, and we employ it to derive a three-dimensional model for the distribution of molecular clouds in the GC for six slices in Galactic latitude. The angular resolution of the data is 15.5 arcmin, which at the distance of the GC (8.34 kpc) is equivalent to 38 pc. We find that the total mass of OH in the GC is in the range 2400-5100 Solar mass . The face-on view at a Galactic latitude of b = 0{\deg} displays a bar-like structure with an inclination angle of 67.5 $\pm$ 2.1{\deg} with respect to the line of sight. No ring-like structure in the GC is evident in our data, likely due to the low spatial resolution of the CO and OH maps. 2017 Journal Article http://hdl.handle.net/20.500.11937/57869 10.1093/mnras/stx1724 http://dx.doi.org/10.1093/mnras/stx1724 Oxford University Press restricted
spellingShingle Yan, Q.
Walsh, A.
Dawson, J.
Macquart, Jean-Pierre
Blackwell, R.
Burton, M.
Rowell, G.
Zhang, B.
Xu, Y.
Tang, Z.
Hancock, Paul
Towards a three-dimensional distribution of the molecular clouds in the Galactic Centre
title Towards a three-dimensional distribution of the molecular clouds in the Galactic Centre
title_full Towards a three-dimensional distribution of the molecular clouds in the Galactic Centre
title_fullStr Towards a three-dimensional distribution of the molecular clouds in the Galactic Centre
title_full_unstemmed Towards a three-dimensional distribution of the molecular clouds in the Galactic Centre
title_short Towards a three-dimensional distribution of the molecular clouds in the Galactic Centre
title_sort towards a three-dimensional distribution of the molecular clouds in the galactic centre
url http://hdl.handle.net/20.500.11937/57869
http://dx.doi.org/10.1093/mnras/stx1724