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. =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) 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; Jackson et al. 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: -------------------------------------------------------------------------------- FileName Lrecl Records Explanations -------------------------------------------------------------------------------- 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 -------------------------------------------------------------------------------- See also: J/ApJ/815/130 : High-mass molecular clumps from MALT90 (Guzman+, 2015) Byte-by-byte Description of file: table4.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 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 N_2_H^+^ 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 -------------------------------------------------------------------------------- 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, Cat. J/ApJ/815/130). -------------------------------------------------------------------------------- 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 N_2_H^+^ 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 N_2_H^+^ 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 N_2_H^+^ 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 HC_3_N 156-159 F4.2 km/s e_HC3Nvlsr ?=9.99 uncertainty on HC3Nvlsr 161-166 F6.2 K HC3NTA* ?=-99.99 Antenna temperature for HC_3_N 168-171 F4.2 K e_HC3NTA* ?=9.99 uncertainty on HC3NTA* 173-178 F6.2 km/s HC3Ndv ?=-99.99 Line width for HC_3_N 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 C_2_H 192-195 F4.2 km/s e_C2Hvlsr ?=9.99 uncertainty on C2Hvlsr 197-202 F6.2 K C2HTA* ?=-99.99 Antenna temperature for C_2_H 204-207 F4.2 K e_C2HTA* ?=9.99 uncertainty on C2HTA* 209-214 F6.2 km/s C2Hdv ?=-99.99 Line width for C_2_H 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 H^13^CO^+^ 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 H^13^CO^+^ 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 H^13^CO^+^ 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 ^13^CS 264-267 F4.2 km/s e_13CSvlsr ?=9.99 uncertainty on 13CSvlsr 269-274 F6.2 K 13CSTA* ?=-99.99 Antenna temperature for ^13^CS 276-279 F4.2 K e_13CSTA* ?=9.99 uncertainty on 13CSTA* 281-286 F6.2 km/s 13CSdv ?=-99.99 Line width for ^13^CS 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 HN^13^C 300-303 F4.2 km/s e_HN13Cvlsr ?=9.99 uncertainty on HN13Cvlsr 305-310 F6.2 K HN13CTA* ?=-99.99 Antenna temperature for HN^13^C 312-315 F4.2 K e_HN13CTA* ?=9.99 uncertainty on HN13CTA* 317-322 F6.2 km/s HN13Cdv ?=-99.99 Line width for HN^13^C 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 CH_3_CN 408-411 F4.2 km/s e_CH3CNvlsr ?=9.99 uncertainty on CH3CNvlsr 413-418 F6.2 K CH3CNTA* ?=-99.99 Antenna temperature for CH_3_CN 420-423 F4.2 K e_CH3CNTA* ?=9.99 uncertainty on CH3CNTA* 425-430 F6.2 km/s CH3CNdv ?=-99.99 Line width for CH_3_CN 432-435 F4.2 km/s e_CH3CNdv ?=9.99 uncertainty on CH3CNdv -------------------------------------------------------------------------------- History: From electronic version of the journal ================================================================================ (End) Patricia Vannier [CDS] 20-Sep-2016