J/MNRAS/470/1462 HOPS. III. Dense molecular gas properties (Longmore+, 2017)
H2O Southern Galactic Plane Survey (HOPS):
Paper III. Properties of dense molecular gas across the inner Milky Way.
Longmore S.N., Walsh A.J., Purcell C.R., Burke D.J., Henshaw J., Walker D.,
Urquhart J., Barnes A.T., Whiting M., Burton M.G., Breen S.L., Britton T.,
Brooks K.J., Cunningham M.R., Green J.A., Harvey-smith L., Hindson L.,
Hoare M.G., Indermuehle B., Jones P.A., Lo N., Lowe V., Moore T.J.T.,
Thompson M.A., Voronkov M.A.
<Mon. Not. R. Astron. Soc., 470, 1462-1490 (2017)>
=2017MNRAS.470.1462L 2017MNRAS.470.1462L (SIMBAD/NED BibCode)
ADC_Keywords: Galactic plane ; Masers ; Radio lines ; Line Profiles
Keywords: line: profiles - masers - stars: formation - ISM: evolution -
radio lines: ISM
Abstract:
The H2O Southern Galactic Plane Survey (HOPS) has mapped 100deg2
of the Galactic plane for water masers and thermal molecular line
emission using the 22m Mopra telescope. We describe the automated
spectral-line fitting pipelines used to determine the properties of
emission detected in HOPS data cubes, and use these to derive the
physical and kinematic properties of gas in the survey. A combination
of the angular resolution, sensitivity, velocity resolution and high
critical density of lines targeted make the HOPS data cubes ideally
suited to finding precursor clouds to the most massive and dense
stellar clusters in the Galaxy. We compile a list of the most massive
HOPS ammonia regions and investigate whether any may be young massive
cluster progenitor gas clouds. HOPS is also ideally suited to trace
the flows of dense gas in the Galactic Centre. We find the kinematic
structure of gas within the inner 500pc of the Galaxy is consistent
with recent predictions for the dynamical evolution of gas flows in
the centre of the Milky Way. We confirm a recent finding that the
dense gas in the inner 100pc has an oscillatory kinematic structure
with characteristic length-scale of 20pc, and also identify similar
oscillatory kinematic structure in the gas at radii larger than 100pc.
Finally, we make all of the above fits and the remaining HOPS data
cubes across the 100deg2 of the survey available to the community.
Description:
We have described the automated spectral-line fitting pipelines
developed to determine the properties of spectral-line emission for
HOPS data cubes. We then used this to determine the characteristic
molecular gas properties in the HOPS sample from the NH3 emission.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tableb1.dat 114 687 Output from the automated spectral line fitting
procedure
tableb2.dat 39 64 Derived gas properties for sources with robust
NH3 (1,1) and NH3 (2,2) detections
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See also:
J/MNRAS/416/1764 : H2O Southern Galactic Plane Survey (HOPS) (Walsh+, 2011)
J/MNRAS/426/1972 : H2O Southern Galactic Plane Survey. II (Purcell+, 2012)
Byte-by-byte Description of file: tableb1.dat
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Bytes Format Units Label Explanations
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1- 7 F7.3 deg GLON Galactic longitude (1)
9- 14 F6.3 deg GLAT Galactic latitude (1)
16- 20 F5.2 K T11Bm ? Best fit NH3(1,1) peak brightness
temperature of the main component
22- 25 F4.2 K e_T11Bm ? rms uncertainty on T11Bm
27- 33 F7.2 km/s V11lsr ? Best fit NH3(1,1) line-centre velocity
35- 38 F4.2 km/s e_V11lsr ? rms uncertainty on V11lsr
40- 44 F5.2 km/s DV11 ? Best fit NH3(1,1) line width
46- 50 F5.2 km/s e_DV11 ? rms uncertainty on DV11
52- 56 F5.2 --- taum11 ? Opacity of the NH3(1,1) transition
58- 62 F5.2 --- e_taum11 ? rms uncertainty on taum11
64- 68 F5.2 K T11ex ? Excitation temperature of the NH3(1,1)
transition
70- 75 F6.2 K.km/s IntT22BdV ? NH3(2,2) integrated intensity
77- 81 F5.2 K.km/s e_IntT22BdV ? rms uncertainty on IntT22BdV
83- 89 F7.2 km/s V22lsr ? Best fit NH3(2,2) line-centre velocity
91- 95 F5.2 km/s e_V22lsr ? rms uncertainty on V22lsr
97-101 F5.2 km/s DV22 ? Best fit NH3(2,2) line width
103-107 F5.2 km/s e_DV22 ? rms uncertainty on DV22
109-114 F6.2 K T22B ? Best fit NH3(2,2) peak brightness
temperature
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Note (1): Galactic positions of the region taken from the source name in
Paper II.
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Byte-by-byte Description of file: tableb2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 9 F9.5 deg GLON Galactic longitude
11- 18 F8.5 deg GLAT Galactic latitude
20- 21 I2 K Trot Rotational temperature,
for the peak NH3 (1,1) pixel
23- 26 F4.2 10+14cm-3 NH3 Total NH3 column density,
for the peak NH3 (1,1) pixel
28- 29 I2 K Tkin Kinetic temperature,
for the peak NH3 (1,1) pixel
31- 34 F4.2 km/s DVnt Non-thermal contributions to the line width,
for the peak NH3 (1,1) pixel
36- 39 F4.2 km/s DVth Thermal contributions to the line width,
for the peak NH3 (1,1) pixel
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History:
From electronic version of the journal
References:
Walsh et al., Paper I 2011MNRAS.416.1764W 2011MNRAS.416.1764W, Cat. J/MNRAS/416/1764
Purcell et al., Paper II 2012MNRAS.426.1972P 2012MNRAS.426.1972P, Cat. J/MNRAS/426/1972
(End) Patricia Vannier [CDS] 23-Apr-2020