Open AccessMolecular line mapping of the giant molecular cloud associated with RCW 106 – I. 13 CO
Author(s) -
Bains I.,
Wong T.,
Cunningham M.,
Sparks P.,
Brisbin D.,
Calisse P.,
Dempsey J. T.,
Deragopian G.,
Ellingsen S.,
Fulton B.,
Herpin F.,
Jones P.,
Kouba Y.,
Kramer C.,
Ladd E. F.,
Longmore S. N.,
McEvoy J.,
Maller M.,
Minier V.,
Mookerjea B.,
Phillips C.,
Purcell C. R.,
Walsh A.,
Voronkov M. A.,
Burton M. G.
Publication year - 2006
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1111/j.1365-2966.2006.10055.x
Subject(s) - physics , astrophysics , molecular cloud , telescope , line (geometry) , observatory , full width at half maximum , astronomy , galactic center , optics , galaxy , stars , geometry , mathematics
We present the first paper in a series detailing the results of 13 CO observations of a ∼1 deg 2 region of the giant molecular cloud (GMC) complex associated with the H ii region RCW 106. The 13 CO observations are also the first stage of a multimolecular line study of the same region. These observations were amongst the first made using the new on‐the‐fly mapping capability of the Australia Telescope National Facility Mopra Telescope. In the configuration used, the instrument provided a full width at half‐maximum (FWHM) beam size of 33 arcsec and a velocity resolution of 0.17 km s −1 . The gas emission takes the form of a string of knots, oriented along an axis that extends from the north‐west (NW) to the south‐east (SE) of the field of the observations, and which is surrounded by a more extended, diffuse emission. We analyse the 2D integrated 13 CO emission using the clumpfind algorithm and identify 61 clumps. We compare the gas data in the GMC with the dust data provided by 21‐μm Midcourse Space Experiment ( MSX ) and 1.2‐mm Swedish European Southern Observatory Submillimetre Telescope (SEST) images that we both regridded to the cell spacing of the Mopra data and smoothed to the same resolution. The 13 CO emission is more diffuse and extended than the dust emission revealed at the latter two wavebands, which both have a much higher contrast between the peaks and the extended emission. From comparison of their centre positions, we find that only ∼50 per cent of the 13 CO clump fits to the data are associated with any dust clumps. Using the clump fits, the total local thermodynamic equilibrium gas mass above the 3σ level measured from the molecular data is 2.7 × 10 5 M ⊙ , whereas that measured from the smoothed 1.2‐mm SEST dust data is 2.2 × 10 5 M ⊙ .