J/A+A/699/A355 G333 complex and the G331 giant MC datacube (Zhou+, 2025)
High-resolution APEX/LAsMA 12CO and 13CO (3-2) observation of the G333
giant molecular cloud complex.
III. Decomposition of molecular clouds into multi-scale hub-filament structures.
Zhou J.W., Urquhart J.S., Wyrowski F., Neupane S., Liu T., Juvela M.
<Astron. Astrophys. 699, A355 (2025)>
=2025A&A...699A.355Z 2025A&A...699A.355Z (SIMBAD/NED BibCode)
ADC_Keywords: Molecular clouds ; Carbon monoxide ; Radio lines
Keywords: stars: formation - ISM: clouds - ISM: kinematics and dynamics -
ISM: structure
Abstract:
We decomposed the G333 complex and the G331 giant molecular cloud into
multi-scale hub-filament systems (HFs) using the high-resolution
13CO (3-2) data from LAsMA observations. We employed the filfinder
algorithm to identify and characterize filaments within HFs. Compared
with non-HFs, HFs have a significantly higher density contrast, higher
masses, and lower virial ratios. Velocity gradient measurements around
intensity peaks provide evidence of gas inflow within these
structures. There may be an evolutionary sequence from non-HFs to HFs.
There is currently no distinct gravitational focusing process for
non-HFs that would result in a significant density contrast. The
density contrast can effectively measure the extent of gravitational
collapse and the strength of the gravitational center of the
structure, which definitively shape the hub-filament morphology. Based
on the results from this study and the kinematic evidence from our
previous studies, we suggest that molecular clouds are network
structures formed by the gravitational coupling of multi-scale
hub-filament structures. The knots in the networks are the hubs: they
are the local gravitational centers and the main star-forming sites.
Clumps in molecular clouds are equivalent to the hubs. The network
structure of molecular clouds can naturally explain why feedback from
protoclusters does not significantly change the
kinematic properties of the surrounding embedded dense gas structures,
as concluded in our previous studies.
Description:
The analysis of this work based on the 13CO (3-2) fits cube.
We mapped a 3.4°x1.2° area centered on
(l, b) = (332.33°, -0.29°). The observations were conducted
between March and August 2022 using the APEX telescope.
Objects:
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RA (2000) DE Designation(s)
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16 22 10.93 -50 05 38.4 G333 = GAL 333.6-00.2
16 12 09.79 -51 27 06.0 G331 = GAL 331.5-00.1
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
list.dat 95 1 Information of fits data cube
fits/* . 1 fits data cube
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See also:
J/A+A/676/A69 : G333 giant molecular cloud complex moment maps (Zhou+, 2023)
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- 32 I3 --- Nz Number of pixels along Z-axis
34- 40 I7 m/s bVRAD Lower value of VRAD interval
42- 48 F7.1 m/s BVRAD Lower value of VRAD interval
50- 52 I3 m/s dVRAD VRAD resolution
54- 60 I7 Kibyte size Size of FITS file
62- 72 A11 --- FileName Name of FITS file, in subdirectory fits
74- 95 A22 --- Title Title of the FITS file
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Acknowledgements:
Jian-wen Zhou, jwzhou(at)mpifr-bonn.mpg.de
History:
Zhou et al., Paper I 2023A&A...676A..69Z 2023A&A...676A..69Z, Cat. J/A+A/676/A69
Zhou et al., Paper II 2024A&A...682A.128Z 2024A&A...682A.128Z
(End) Patricia Vannier [CDS] 03-Jul-2025