J/A+A/655/A12 LMC N113 and N159W ALMA para-H2CO datacubes (Tang+, 2021)
Kinetic temperature of massive star-forming molecular clumps measured with
formaldehyde. IV. The ALMA view of N113 and N159W in the LMC.
Tang X.D., Henkel C., Menten K.M., Gong Y., Chen C.-H.R., Li D.L.,
Lee M.-Y., Mangum J.G., Ao Y.P., Muehle S., Aalto S., Garcia-Burillo S.,
Martin S., Viti S., Muller S., Costagliola F., Asiri H., Levshakov S.A.,
Spaans M., Ott J., Impellizzeri C.M.V., Fukui Y., He Y.X., Esimbek J.,
Zhou J.J., Zheng X.W., Zhao X., Li J.S.
<Astron. Astrophys. 655, A12 (2021)>
=2021A&A...655A..12T 2021A&A...655A..12T (SIMBAD/NED BibCode)
ADC_Keywords: Magellanic Clouds ; Star Forming Region ; Radio lines
Keywords: stars: formation - ISM: clouds - ISM: molecules - radio lines: ISM
Abstract:
We mapped the kinetic temperature structure of two massive
star-forming regions, N113 and N159W, in the Large Magellanic Cloud
(LMC). We have used ∼1.6" (∼0.4pc) resolution measurements of the
para-H2CO JKaKc=303-202, 322-221, and 321-220
transitions near 218.5GHz to constrain RADEX non local thermodynamic
equilibrium models of the physical conditions. The gas kinetic
temperatures derived from the para-H2CO line ratios
322-221/303-202 and 321-220/303-202 range from
28 to 105K in N113 and 29 to 68K in N159W. Distributions of the dense
gas traced by para-H2CO agree with those of the 1.3mm dust and
Spitzer 8.0um emission, but they do not significantly correlate with
the H emission. The high kinetic temperatures (Tkin≳50K) of the dense
gas traced by para-H2CO appear to be correlated with the embedded
infrared sources inside the clouds and/or young stellar objects in the
N113 and N159W regions. The lower temperatures (Tkin<50K) were
measured at the outskirts of the H2CO-bearing distributions of both
N113 and N159W. It seems that the kinetic temperatures of the dense
gas traced by para-H2CO are weakly affected by the external sources
of the Hα emission. The non thermal velocity dispersions of
para-H2CO are well correlated with the gas kinetic temperatures in the
N113 region, implying that the higher kinetic temperature traced by
para-H2CO is related to turbulence on a ∼0.4pc scale. The dense gas
heating appears to be dominated by internal star formation activity,
radiation, and/or turbulence. It seems that the mechanism heating the
dense gas of the star-forming regions in the LMC is consistent with
that in Galactic massive star-forming regions located in the Galactic
plane.
Description:
Our observations were carried out with the 12m array of the Atacama
Large Millimeter/submillimeter Array (ALMA) at Band 6 (Project:
2013.1.01136.S). Two Execution Blocks were conducted using 35 and 38
antennas in January 17 and April 8, 2015, respectively. The projected
baseline lengths ranged from 15 to 349m.
Three spectral windows were centered on SiO (5-4),
H2CO(322-221), and CO(2-1), respectively, with a ∼937.5MHz
bandwidth and 960 channels for each band, yielding a channel width of
976.562kHz, corresponding to 1.27-1.35km/s.
The surveyed areas of N113 and N159W are centered on
RA=05:13:18.2, DE=-69:22:25.0 (2000) and
RA=05:39:36.0, DE=-69:45:25.0 (2000), respectively.
Objects:
---------------------------------------------------
RA (2000) DE Designation(s)
---------------------------------------------------
05 13 21.7 -69 21 33 N113 = LHA 120-N113
05 39 32.51 -69 46 02.7 N159W = LHA 120-N159W
---------------------------------------------------
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
list.dat 115 6 List of fits datacubes
fits/* . 6 Individual fits datacubes
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See also:
J/A+A/598/A30 : Massive star forming molecular clumps Tkin (Tang+, 2017)
J/A+A/600/A16 : Six LMC star forming region spectra (Tang+, 2017)
J/A+A/609/A16 : OMC 1 reduced H2CO(3-2) datacubes (Tang+, 2018)
Byte-by-byte Description of file: list.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
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1- 9 F9.5 deg RAdeg Right Ascension of center (J2000)
10- 18 F9.5 deg DEdeg Declination of center (J2000)
20- 22 I3 --- Nx Number of pixels along X-axis
24- 26 I3 --- Ny Number of pixels along Y-axis
28- 29 I2 --- Nz Number of slices
31- 37 F7.3 GHz bFreq Lower value of frequency interval
39- 45 F7.3 GHz BFreq Upper value of frequency interval
47- 52 I6 Hz dFreq Frequency resolution
54- 57 I4 Kibyte size Size of FITS file
59- 80 A22 --- FileName Name of FITS file, in subdirectory fits
82-115 A34 --- Title Title of the FITS file
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Acknowledgements:
Xindi Tang, tangxindi(at)xao.ac.cn
References:
Tang et al., Paper I 2017A&A...598A..30T 2017A&A...598A..30T, Cat. J/A+A/598/A30
Tang et al., Paper II 2017A&A...600A..16T 2017A&A...600A..16T, Cat. J/A+A/600/A16
Tang et al., Paper III 2018A&A...609A..16T 2018A&A...609A..16T, Cat. J/A+A/609/A16
(End) Patricia Vannier [CDS] 22-Oct-2021