J/A+A/689/A140 13CO clump properties two 2 W5 bubble regions (Shen+, 2024)
Extended CO(1-0) survey and ammonia measurements towards two bubble regions
in W5. Feedback on molecular gas and clumps.
Shen H., Esimbek J., Henkel C., Xu Y., Zhou J., Li D., He Y., Tang X.,
Wu G., Komesh T., Tursun K., Zhou D., Imanaly E., Berdikhan D.
<Astron. Astrophys. 689, A140 (2024)>
=2024A&A...689A.140S 2024A&A...689A.140S (SIMBAD/NED BibCode)
ADC_Keywords: Molecular clouds ; Carbon monoxide ; Radio lines ; Morphology ;
Velocity dispersion
Keywords: methods: observational - techniques: image processing -
stars: winds, outflows - ISM: clouds - ISM: kinematics and dynamics -
submillimeter: ISM
Abstract:
The feedback effect of massive stars can either accelerate or inhibit
star formation activity within molecular clouds. Studying the
morphology of molecular clouds near W5 offers an excellent opportunity
to examine this feedback effect. We conducted a comprehensive survey
of the W5 complex using the Purple Mountain Observatory 13.7m
millimeter telescope. This survey includes 12CO, 13CO, and C18O
(J=1-0), with a sky coverage of 6.6deg2 (136.0°<l<138.75°,
0°<b<2.4°). Furthermore, we performed simultaneous
observations of the NH3 (1,1) and NH3 (2,2) lines in the four
densest star-forming regions of W5, using the 26m radio telescope of
the Xinjiang Astronomy Observatory (XAO). Our analysis of the
morphological distribution of the molecular clouds, distribution of
high-mass young stellar objects (HMYSOs), 13CO/C18O abundance
ratio, and the stacked average spectral line distribution at different
8um thresholds provide compelling evidence of triggering. Within the
mapped region, we identified a total of 212 molecular clumps in the
13CO cube data using the astrodendro algorithm. Remarkably,
approximately 26.4% (56) of these clumps demonstrate the potential to
form massive stars and 42.9% (91) of them are gravitationally bound.
Within clumps that are capable of forming high-mass stars, there is a
distribution of class I YSOs, all located in dense regions near the
boundaries of the Hii regions. The detection of NH3 near the most
prominent cores reveals moderate kinetic temperatures and densities
(as CO). Comparing the Tkin and Tex values reveals a reversal in
trends for AFGL 4029 (higher Tex and lower Tkin) and W5-w1, indicating
the inadequacy of optically thick CO for dense region parameter
calculations. Moreover, a comparison of the intensity distributions
between NH3 (1,1) and C18O (1-0) in the four densest region
reveals a notable depletion effect in AFGL 4029, characterised by a
low Tkin (9K) value and a relatively high NH3 column density,
2.5x1014cm-2. By classifying the 13CO clumps as: "feedback",
"non-feedback", "outflow", or "non-outflow" clumps, we observe that
the parameters of the "feedback" and "outflow" clumps exhibit
variations based on the intensity of the internal 8um flux and the
outflow energy, respectively. These changes demonstrate a clear linear
correlation, which distinctly separate them from the parameter
distributions of the "non-feedback" and "non-outflow" clumps, thus
providing robust evidence to support a triggering scenario.
Description:
Using CO data from the survey MWISP project, we studied the gas
structure distribution of the W5 molecular clouds complex and the
feedback effect of OB stars at the center of the two bubbles on
molecular cloud gas. To analyze the effects of feedback and outflow on
star formation in molecular clouds, we identified clumps on 13CO
cube data and performed a detailed analy sis of these clump
parameters.
212 identified 13CO clumps properties.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 99 212 13CO clump properies derived from 13CO
dendrogram leaves of W5
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Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- ID [0/328] Leaf number
5- 10 F6.2 deg GLON Galactic Longitude
12- 15 F4.2 deg GLAT Galactic Latitude
17- 21 F5.1 km/s Vmean Mean velocity of the structure
23- 25 F3.1 km/s FWHM FWHM line width
27- 30 F4.2 pc Radius Leaf radius
32- 35 F4.1 Lsun Lum Luminosity
37- 40 F4.2 10+22cm-2 N(H2) H2 column density
42- 47 F6.1 Msun M(LTE) LTE mass
49- 55 F7.1 Msun Mvir Virial mass
57- 61 F5.1 --- alphavir Virial parameter
63- 67 F5.2 10+4cm-3 n(H2) Volume density
69- 72 F4.2 Msun/pc2 Sigma Surface mass density
74- 79 F6.2 10-3Lsun/Msun L/M The ratio of luminosity to LTE mass
81- 84 F4.1 K Tex CO excitation temperature
86- 89 F4.2 km/s Vtherm Thermal velocity dispersion
91- 94 F4.2 km/s Vntherm Non-thermal velocity dispersion
96- 99 F4.1 --- Vntherm/Vtherm The ratio of Vnthermal/vthermal
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History:
From Hailiang Shen, shenhailiang(at)xao.ac.cn
Acknowledgements:
We would like to thank the staff of the Purple Mountain Observatory
for their assistance with the 13.7m millimeter telescope
observations. We also appreciate the support from the Xinjiang
Astronomy Observatory for the NH3 line observations using the 26m
radio telescope. This work was supported by the National Key R&D
Program of China (Grant No. 2022YFA1603103). We are grateful to Dr.
Christian Henkel for his valuable comments and suggestions. Special
thanks to the VizieR team for their guidance on data submission.
(End) Patricia Vannier [CDS] 26-Aug-2024