J/MNRAS/456/2041 Fragmentation in filamentary molecular clouds (Contreras+ 2016)
Fragmentation in filamentary molecular clouds.
Contreras Y., Garay G., Rathborne J.M., Sanhueza P.
<Mon. Not. R. Astron. Soc., 456, 2041-2051 (2016)>
=2016MNRAS.456.2041C 2016MNRAS.456.2041C (SIMBAD/NED BibCode)
ADC_Keywords: Interstellar medium ; Molecular clouds
Keywords: stars: formation - stars: massive - ISM: clouds
Abstract:
Recent surveys of dust continuum emission at sub-mm wavelengths have
shown that filamentary molecular clouds are ubiquitous along the
Galactic plane. These structures are inhomogeneous, with overdensities
that are sometimes associated with infrared emission and active of
star formation. To investigate the connection between filaments and
star formation, requires an understanding of the processes that lead
to the fragmentation of filaments and a determination of the physical
properties of the overdensities (clumps). In this paper, we present a
multiwavelength study of five filamentary molecular clouds, containing
several clumps in different evolutionary stages of star formation. We
analyse the fragmentation of the filaments and derive the physical
properties of their clumps. We find that the clumps in all filaments
have a characteristic spacing consistent with the prediction of the
'sausage' instability theory, regardless of the complex morphology of
the filaments or their evolutionary stage. We also find that most
clumps have sufficient mass and density to form high-mass stars,
supporting the idea that high-mass stars and clusters form within
filaments.
Description:
We used the ATLASGAL (Schuller et al., 2009A&A...504..415S 2009A&A...504..415S) maps to
measure the dust thermal emission at 870um towards each filament.
We use data from the Millimetre Astronomy Legacy Team 90GHz survey
(MALT90; Foster et al., 2013PASA...30...38F 2013PASA...30...38F; Jackson et al.
2013PASA...30...57J 2013PASA...30...57J) to determine the dynamical state of the clumps
and to derive the properties of the dense gas within the clumps.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table4.dat 108 101 Summary of the properties of the clumps embedded
within the filaments
table3.dat 435 80 Velocity, peak temperature and line width for
the detected molecules in our sample
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See also:
J/ApJ/815/130 : High-mass molecular clumps from MALT90 (Guzman+, 2015)
Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 3 A3 --- Clump Clump designation
5- 23 A19 --- ATLASGAL ATLASGAL name (AGALLLL.lll+BB.bbb)
24- 54 A31 --- IRem Signatures detected in the IR images (1)
56- 68 A13 --- Class IR-based category assigned to each clump (for
more details see section 4.1)
70- 79 A10 --- IRAS IRAS sources that are located within 30 arcsec
from the clump
81- 84 F4.2 pc Size Size of the clump
86- 87 I2 K Tdust Assumed dust temperature (2)
89- 92 I4 Msun Mdust Mass derived from the dust emission
94- 97 I4 Msun Mvir ?=- Virial mass derived from the N2H+
line width
99-102 F4.2 --- alpha ?=- Ratio between the virial and dust mass
104-108 F5.1 10+4cm-3 n(H2) Molecular hydrogen volume density
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Note (1): 4.5um-e refers to extended 4.5um enhanced emission, and
24um-p refers to point-like emission in this table.
Note (2): Assumed dust temperature based on the work of Guzman et al.
(2015ApJ...815..130G 2015ApJ...815..130G, Cat. J/ApJ/815/130).
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Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 A3 --- Clump Clump designation
5- 10 F6.2 km/s N2H+vlsr ?=-99.99 Line velocity for N2H+
12- 15 F4.2 km/s e_N2H+vlsr ?=9.99 uncertainty on N2H+vlsr
17- 22 F6.2 K N2H+TA* ?=-99.99 Antenna temperature for N2H+
24- 27 F4.2 K e_N2H+TA* ?=9.99 uncertainty on N2H+TA*
29- 34 F6.2 km/s N2H+dv ?=-99.99 Line width for N2H+
36- 39 F4.2 km/s e_N2H+dv ?=9.99 uncertainty on N2H+dv
41- 46 F6.2 km/s HNCvlsr ?=-99.99 Line velocity for HNC
48- 51 F4.2 km/s e_HNCvlsr ?=9.99 uncertainty on HNCvlsr
53- 58 F6.2 K HNCTA* ?=-99.99 Antenna temperature for HNC
60- 63 F4.2 K e_HNCTA* ?=9.99 uncertainty on HNCTA*
65- 70 F6.2 km/s HNCdv ?=-99.99 Line width for HNC
72- 75 F4.2 km/s e_HNCdv ?=9.99 uncertainty on HNCdv
77- 82 F6.2 km/s HCNvlsr ?=-99.99 Line velocity for HCN
84- 87 F4.2 km/s e_HCNvlsr ?=9.99 uncertainty on HCNvlsr
89- 94 F6.2 K HCNTA* ?=-99.99 Antenna temperature for HCN
96- 99 F4.2 K e_HCNTA* ?=9.99 uncertainty on HCNTA*
101-106 F6.2 km/s HCNdv ?=-99.99 Line width for HCN
108-111 F4.2 km/s e_HCNdv ?=9.99 uncertainty on HCNdv
113-118 F6.2 km/s HCO+vlsr ?=-99.99 Line velocity for HCO+
120-123 F4.2 km/s e_HCO+vlsr ?=9.99 uncertainty on HCO+vlsr
125-130 F6.2 K HCO+TA* ?=-99.99 Antenna temperature for HCO+
132-135 F4.2 K e_HCO+TA* ?=9.99 uncertainty on HCO+TA*
137-142 F6.2 km/s HCO+dv ?=-99.99 Line width for HCO+
144-147 F4.2 km/s e_HCO+dv ?=9.99 uncertainty on HCO+dv
149-154 F6.2 km/s HC3Nvlsr ?=-99.99 Line velocity for HC3N
156-159 F4.2 km/s e_HC3Nvlsr ?=9.99 uncertainty on HC3Nvlsr
161-166 F6.2 K HC3NTA* ?=-99.99 Antenna temperature for HC3N
168-171 F4.2 K e_HC3NTA* ?=9.99 uncertainty on HC3NTA*
173-178 F6.2 km/s HC3Ndv ?=-99.99 Line width for HC3N
180-183 F4.2 km/s e_HC3Ndv ?=9.99 uncertainty on HC3Ndv
185-190 F6.2 km/s C2Hvlsr ?=-99.99 Line velocity for C2H
192-195 F4.2 km/s e_C2Hvlsr ?=9.99 uncertainty on C2Hvlsr
197-202 F6.2 K C2HTA* ?=-99.99 Antenna temperature for C2H
204-207 F4.2 K e_C2HTA* ?=9.99 uncertainty on C2HTA*
209-214 F6.2 km/s C2Hdv ?=-99.99 Line width for C2H
216-219 F4.2 km/s e_C2Hdv ?=9.99 uncertainty on C2Hdv
221-226 F6.2 km/s H13CO+vlsr ?=-99.99 Line velocity for H13CO+
228-231 F4.2 km/s e_H13CO+vlsr ?=9.99 uncertainty on H13CO+vlsr
233-238 F6.2 K H13CO+TA* ?=-99.99 Antenna temperature for H13CO+
240-243 F4.2 K e_H13CO+TA* ?=9.99 uncertainty on H13CO+TA*
245-250 F6.2 km/s H13CO+dv ?=-99.99 Line width for H13CO+
252-255 F4.2 km/s e_H13CO+dv ?=9.99 uncertainty on H13CO+dv
257-262 F6.2 km/s 13CSvlsr ?=-99.99 Line velocity for 13CS
264-267 F4.2 km/s e_13CSvlsr ?=9.99 uncertainty on 13CSvlsr
269-274 F6.2 K 13CSTA* ?=-99.99 Antenna temperature for 13CS
276-279 F4.2 K e_13CSTA* ?=9.99 uncertainty on 13CSTA*
281-286 F6.2 km/s 13CSdv ?=-99.99 Line width for 13CS
288-291 F4.2 km/s e_13CSdv ?=9.99 uncertainty on 13CSdv
293-298 F6.2 km/s HN13Cvlsr ?=-99.99 Line velocity for HN13C
300-303 F4.2 km/s e_HN13Cvlsr ?=9.99 uncertainty on HN13Cvlsr
305-310 F6.2 K HN13CTA* ?=-99.99 Antenna temperature for HN13C
312-315 F4.2 K e_HN13CTA* ?=9.99 uncertainty on HN13CTA*
317-322 F6.2 km/s HN13Cdv ?=-99.99 Line width for HN13C
324-327 F4.2 km/s e_HN13Cdv ?=9.99 uncertainty on HN13Cdv
329-334 F6.2 km/s SiOvlsr ?=-99.99 Line velocity for SiO
336-339 F4.2 km/s e_SiOvlsr ?=9.99 uncertainty on SiOvlsr
341-346 F6.2 K SiOTA* ?=-99.99 Antenna temperature for SiO
348-351 F4.2 K e_SiOTA* ?=9.99 uncertainty on SiOTA*
353-358 F6.2 km/s SiOdv ?=-99.99 Line width for SiO
360-363 F4.2 km/s e_SiOdv ?=9.99 uncertainty on SiOdv
365-370 F6.2 km/s HNCOvlsr ?=-99.99 Line velocity for HNCO
372-375 F4.2 km/s e_HNCOvlsr ?=9.99 uncertainty on HNCOvlsr
377-382 F6.2 K HNCOTA* ?=-99.99 Antenna temperature for HNCO
384-387 F4.2 K e_HNCOTA* ?=9.99 uncertainty on HNCOTA*
389-394 F6.2 km/s HNCOdv ?=-99.99 Line width for HNCO
396-399 F4.2 km/s e_HNCOdv ?=9.99 uncertainty on HNCOdv
401-406 F6.2 km/s CH3CNvlsr ?=-99.99 Line velocity for CH3CN
408-411 F4.2 km/s e_CH3CNvlsr ?=9.99 uncertainty on CH3CNvlsr
413-418 F6.2 K CH3CNTA* ?=-99.99 Antenna temperature for CH3CN
420-423 F4.2 K e_CH3CNTA* ?=9.99 uncertainty on CH3CNTA*
425-430 F6.2 km/s CH3CNdv ?=-99.99 Line width for CH3CN
432-435 F4.2 km/s e_CH3CNdv ?=9.99 uncertainty on CH3CNdv
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 20-Sep-2016