J/A+A/692/A114 NGC 6334 12^CO and 13CO J=3--2 maps (Neupane+, 2024)
High-resolution observations of 12CO and 13CO J = 3 --> 2 towards the
NGC 6334 extended filament. I. Emission morphology and velocity structure.
Neupane S., Wyrowski F., Menten K.M., Urquhart J., Colombo D., Lin L.-H.,
Garay G.
<Astron. Astrophys. 692, A114 (2024)>
=2024A&A...692A.114N 2024A&A...692A.114N (SIMBAD/NED BibCode)
ADC_Keywords: Molecular clouds ; Carbon monoxide ; Radio lines
Keywords: ISM: bubbles - ISM: clouds - evolution - HII regions -
ISM: kinematics and dynamics - ISM: structure
Abstract:
NGC 6334 is a giant molecular cloud (GMC) complex that exhibits
elongated filamentary structure and harbours numerous OB-stars, HII
regions, and star-forming clumps. To study the emission morphology and
velocity structure of the gas in the extended NGC 6334 region using
high-resolution molecular line data, we made observations of the
12CO and 13CO J=3 --> 2 lines with the LAsMA instrument at the
APEX telescope . The LAsMA data provided a spatial resolution of 20"
(∼0.16pc) and sensitivity of ∼0.4K at a spectral resolution of
0.25km/s. Our observations revealed that gas in the extended NGC 6334
region exhibits connected velocity coherent structure over ∼80pc
parallel to the Galactic plane. The NGC 6334 complex has its main
velocity component at ~-3.9km/s with two connected velocity structures
at velocities ~-9.2km/s (the `bridge' features) and ~-20km/s (the
northern filament, NGC 6334-NF). We observed local velocity
fluctuations at smaller spatial scales along the filament that are
likely tracing local density enhancement and infall, while the broader
V-shaped velocity fluctuations observed towards the NGC 6334 central
ridge and G352.1 region located in the eastern filament EF1 indicate
globally collapsing gas onto the filament. We investigated the 13CO
emission and velocity structure around 42 WISE HII regions located in
the extended NGC 6334 region and found that most HII regions show
signs of molecular gas dispersal from the centre (36 of 42) and
intensity enhancement at their outer radii (34 of 42). Furthermore
most HII regions (26 of 42) are associated with least one ATLASGAL
clump within or just outside of their radii, the formation of which
may have been triggered by HII bubble expansion. Typically towards
larger HII regions we found visually clear signatures of bubble
shells emanating from the filamentary structure. Overall the NGC 6334
filamentary complex exhibits sequential star formation from west to
east. Located in the west, the GM-24 region exhibits bubbles within
bubbles and is at a relatively evolved stage of star formation. The
NGC 6334 central ridge is undergoing global gas infall and exhibits
two gas bridge features possibly connected to the cloud-cloud
collision scenario of the NGC 6334-NF and the NGC 6334 main gas
component. The relatively quiescent eastern filament (EF1 - G352.1) is
a hub-filament in formation, which shows the kinematic signature of
global gas infall onto the filament. Our observations highlight the
important role of HII regions in shaping the molecular gas emission
and velocity structure as well as the overall evolution of the
molecular filaments in the NGC 6334 complex.
Description:
We mapped the NGC 6334 star-forming complex in the 12CO J=3-2 and
13CO J=3-2 lines, using the Large APEX sub-Millimetre Array (LAsMA),
a 7 pixel heterodyne array receiver installed on the Atacama
Pathfinder Experiment (APEX) 12m sub-millimetre telescope located on
the Llano de Chajnantor (elevation of ∼5100m) in the Atacama desert,
Chile.
The observations were made from June to September 2021 under good
atmospheric conditions of ≤1.5mm precipitable water vapour (PWV)
content. The mapped region was divided into sub-maps (called tiles)
10'x10' in size that were observed in on-the-fly (OTF) mode in both l
and b directions. The 12CO J=3-2 and 13CO J=3-2 lines were
observed simultaneously using a local oscillator frequency of
338.3GHz. The 13CO (νrest=330.587GHz) line is observed in the
lower side band and 12CO (νrest=345.796GHz) line in the upper
side band.
Moment0 maps of 12CO and 13CO J = 3--2 lines toward NGC 6334
extended region.
Objects:
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RA (2000) DE Designation(s)
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17 20 52.66 -36 07 52.4 NGC 6334 = NAME Cat's Paw Nebula
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
list.dat 117 2 List of fits maps
fits/* . 2 Individual fits maps
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See also:
J/A+A/587/A135 : Halpha images of NGC 6334 and NGC 6357 (Russeil+, 2016)
J/A+A/592/A54 : Combined ArTeMiS+SPIRE 350um image of NGC6334 (Andre+, 2016)
J/A+A/593/A37 : Spectral cube toward NGC 6334 I & I(N) (van der Wiel+, 2016)
J/A+A/660/A56 : NGC 6334 maps and CO velocity cubes (Arzoumanian+, 2022)
Byte-by-byte Description of file: list.dat
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Bytes Format Units Label Explanations
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1 A1 --- --- [G]
2- 10 F9.5 deg GLON Galactic longitude
11- 19 F9.5 deg GLAT Galactic latitude
21- 24 I4 --- Nx Number of pixels along X-axis
26- 28 I3 --- Ny Number of pixels along Y-axis
30- 33 I4 Kibyte size Size of FITS file
35- 48 A14 --- FileName Name of FITS file, in subdirectory fits
50-117 A68 --- Title Title of the FITS file
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Acknowledgements:
Sudeep Neupane, sudeepneupane(at)gmail.com
(End) Patricia Vannier [CDS] 29-Nov-2024