J/A+A/602/A77 HOBYS: 46 MDCs found in NGC 6334 (Tige+, 2017)
The earliest phases of high-mass star formation, as seen in NGC 6334 by
Herschel-HOBYS.
Tige J., Motte F., Russeil D., Zavagno A., Hennemann M., Schneider N.,
Hill T., Nguyen Luong Q., Di Francesco J., Bontemps S., Louvet F.,
Didelon P., Konyves V., Andre P., Leuleu G., Bardagi J., Anderson L.D.,
Arzoumanian D., Benedettini M., Bernard J.-P., Elia D., Figueira M.,
Kirk J., Martin P.G., Minier V., Molinari S., Nony T., Persi P.,
Pezzuto S., Polychroni D., Rayner T., Rivera-Ingraham A., Roussel H.,
Rygl K., Spinoglio L., White G.J.
<Astron. Astrophys., 602, A77 (2017)>
=2017A&A...602A..77T 2017A&A...602A..77T (SIMBAD/NED BibCode)
ADC_Keywords: Molecular clouds ; Photometry, millimetric/submm
Keywords: dust, extinction - ISM: clouds - stars: formation -
submillimeter: ISM - stars: protostars -
ISM: individual: NGC 6334
Abstract:
To constrain models of high-mass star formation, the Herschel-HOBYS
key program aims at discovering massive dense cores (MDCs) able to
host the high-mass analogs of low-mass prestellar cores, which have
been searched for over the past decade. We here focus on NGC 6334, one
of the best-studied HOBYS molecular cloud complexes.
We used Herschel/PACS and SPIRE 70-500µm images of the NGC 6334
complex complemented with (sub)millimeter and mid-infrared data. We
built a complete procedure to extract ∼0.1pc dense cores with the
getsources software, which simultaneously measures their far-infrared
to millimeter fluxes. We carefully estimated the temperatures and
masses of these dense cores from their spectral energy distributions
(SEDs). We also identified the densest pc-scale cloud structures of
NGC 6334, one 2pcx1pc ridge and two 0.8pcx0.8pc hubs, with
volume-averaged densities of ∼105cm-3.
A cross-correlation with high-mass star formation signposts suggests a
mass threshold of 75M☉ for MDCs in NGC 6334. MDCs have
temperatures of 9.5-40K, masses of 75-1000M☉, and densities of
1x105-7x107cm-3. Their mid-infrared emission is used to separate
6 IR-bright and 10 IR-quiet protostellar MDCs while their 70µm
emission strength, with respect to fitted SEDs, helps identify 16
starless MDC candidates. The ability of the latter to host high-mass
prestellar cores is investigated here and remains questionable. An
increase in mass and density from the starless to the IR-quiet and
IR-bright phases suggests that the protostars and MDCs simultaneously
grow in mass. The statistical lifetimes of the high-mass prestellar
and protostellar core phases, estimated to be 1-7x104yr and at most
3x105yr respectively, suggest a dynamical scenario of high-mass star
formation.
The present study provides good mass estimates for a statistically
significant sample, covering the earliest phases of high-mass star
formation. High-mass prestellar cores may not exist in NGC 6334,
favoring a scenario presented here, which simultaneously forms clouds,
ridges, MDCs, and high-mass protostars.
Description:
Fluxes and information for the 46 MDCs found in NGC 6334
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
catalog.dat 555 46 Information and fluxes of the 46 MDCs
(tables A1-A12)
table3.dat 51 46 Physical parameters of the 46 MDCs found in
NGC 6334
list.dat 145 11 List of FITS images
fits/* . 11 Individual FITS images
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See also:
J/ApJS/69/99 : NGC 6334 centers of star formation JHK photom. (Straw+ 1989)
J/A+A/316/102 : JHK Photometry in NGC 6334 (Tapia+, 1996)
J/A+A/357/1020 : JHK photometry in NGC 6334. IV (Persi+, 2000)
J/ApJ/668/906 : Massive clumps in NGC 6334 (Munoz+, 2007)
J/A+A/481/169 : ATCA 3mm obs. of NGC 6334I and NGC 6334I(N) (Beuther+, 2008)
J/AJ/136/2083 : NGC 6334 clumps from 450/850um observations (Matthews+, 2009)
J/AJ/138/227 : Stellar clusters in NGC 6334 complex (Feigelson+, 2009)
J/ApJ/707/1 : Water and Methanol masers in NGC 6334I(N) (Brogan+, 2009)
J/A+A/515/A55 : NGC 6334-NGC 6357 complex (Russeil+, 2010)
J/A+A/538/A142 : OB stars in NGC 6334 and NGC 6357 (Russeil+, 2012)
J/ApJ/778/96 : Spitzer and NEWFIRM observations of NGC 6334 (Willis+, 2013)
J/A+A/587/A135 : Halpha images of NGC 6334 and NGC 6357 (Russeil+, 2016)
J/A+A/592/A54 : Combined ArTeMiS+SPIRE 350um image of NGC6334 (Andre+, 2016)
J/A+A/593/A37 : Spectral cube toward NGC 6334 I and I(N) (van der Wiel+, 2016)
Byte-by-byte Description of file: catalog.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- Number [1/46] getsources number
4- 18 A15 --- Name HOBYS_J name (HHMMSS.s+DDMMSS)
20- 21 I2 h RAh Right ascension (J2000.0)
23- 24 I2 min RAm Right ascension (J2000.0)
26- 30 F5.2 s RAs Right ascension (J2000.0)
32 A1 --- DE- Declination sign (J2000.0)
33- 34 I2 deg DEd Declination (J2000.0)
36- 37 I2 arcmin DEm Declination (J2000.0)
39- 42 F4.1 arcsec DEs Declination (J2000.0)
44 A1 --- Flag70 Fluxes reliability and upper limit flag (1)
46- 51 F6.1 Jy/beam Sp70 ? Peak intensity at 70um
53- 56 F4.1 Jy/beam e_Sp70 ? Peak intensity uncertainty
58- 64 F7.1 Jy Si70 ? Integrated flux at 70um
66- 69 F4.1 Jy e_Si70 ? Integrated flux uncertainty
71- 74 F4.1 arcsec AMAJ70 ? FWHM major axis
76- 79 F4.1 arcsec AMIN70 ? FWHM minor axis
81- 83 I3 deg PA70 ? Position angle
85 A1 --- Flag160 Fluxes reliability and upper limit flag (1)
87- 92 F6.1 Jy/beam Sp160 ? Peak intensity at 160um
94- 97 F4.1 Jy/beam e_Sp160 ? Peak intensity uncertainty
99-104 F6.1 Jy Si160 ? Integrated flux at 160um
106-110 F5.1 Jy e_Si160 ? Integrated flux uncertainty
112-115 F4.1 arcsec AMAJ160 ? FWHM major axis
117-120 F4.1 arcsec AMIN160 ? FWHM minor axis
122-124 I3 deg PA160 ? Position angle
126 A1 --- Flag250 Fluxes reliability and upper limit flag (1)
128-133 F6.1 Jy/beam Sp250 Peak intensity at 250um
135-138 F4.1 Jy/beam e_Sp250 Peak intensity uncertainty
140-145 F6.1 Jy Si250 Integrated flux at 250um
147-150 F4.1 Jy e_Si250 Integrated flux uncertainty
152-155 F4.1 arcsec AMAJ250 FWHM major axis
157-160 F4.1 arcsec AMIN250 FWHM minor axis
162-164 I3 deg PA250 Position angle
166 A1 --- Flag350 Fluxes reliability and upper limit flag (1)
168-173 F6.1 Jy/beam Sp350 Peak intensity at 350um
175-178 F4.1 Jy/beam e_Sp350 Peak intensity uncertainty
180-185 F6.1 Jy Si350 Integrated flux at 350um
187-190 F4.1 Jy e_Si350 Integrated flux uncertainty
192-195 F4.1 arcsec AMAJ350 FWHM major axis
197-200 F4.1 arcsec AMIN350 FWHM minor axis
202-206 F5.1 deg PA350 Position angle
208 A1 --- Flag500 Fluxes reliability and upper limit flag (1)
210-214 F5.1 Jy/beam Sp500 Peak intensity at 500um
216-219 F4.1 Jy/beam e_Sp500 Peak intensity uncertainty
221-225 F5.1 Jy Si500 Integrated flux at 500um
227-230 F4.1 Jy e_Si500 Integrated flux uncertainty
232-235 F4.1 arcsec AMAJ500 FWHM major axis
237-240 F4.1 arcsec AMIN500 FWHM minor axis
242-244 I3 deg PA500 Position angle
246-282 A37 --- GName GLIMPSE identification
285-290 F6.4 Jy Si3.6 ? Integrated flux at 3.6 mic
291 A1 --- f_Si3.6 [*] * indicate it is an aperture photometry
293-298 F6.4 Jy Si4.5 ? Integrated flux at 4.5 mic
299 A1 --- f_Si4.5 [*] * indicate it is an aperture photometry
301-305 F5.3 Jy Si5.8 ? Integrated flux at 5.8 mic
306 A1 --- f_Si5.8 [*] * indicate it is an aperture photometry
308-313 F6.3 Jy Si8.0 ? Integrated flux at 8.0 mic
314 A1 --- f_Si8.0 [*] * indicate it is an aperture photometry
316-333 A18 --- nameMG MIPSGAL identification
337-341 F5.3 Jy Si24 ? Integrated flux at 24 mic
342 A1 --- f_Si24 [*] * indicate it is an aperture photometry
348-370 A23 --- nameMSX MSX identification
372-376 F5.1 Jy Si21 ? Integrated flux at 21 mic
377-395 A19 --- nameW WISE identification
397-400 F4.1 Jy Si22 ? Integrated flux at 22 mic
402 A1 --- Flag450 Fluxes reliability and upper limit flag (1)
404-408 F5.2 Jy/beam Sp450 ? Peak intensity at 450um
410-412 F3.1 Jy/beam e_Sp450 ? Peak intensity uncertainty
414-418 F5.1 Jy Si450 ? Integrated flux at 450um
420-423 F4.1 Jy e_Si450 ? Integrated flux uncertainty
425-428 F4.1 arcsec AMAJ450 ? FWHM major axis
430-433 F4.1 arcsec AMIN450 ? FWHM minor axis
435-437 I3 deg PA450 ? Position angle
439 A1 --- Flag850 Fluxes reliability and upper limit flag (1)
441-445 F5.2 Jy/beam Sp850 ? Peak intensity at 850um
447-450 F4.2 Jy/beam e_Sp850 ? Peak intensity uncertainty
452-456 F5.2 Jy Si850 ? Integrated flux at 850um
458-461 F4.2 Jy e_Si850 ? Integrated flux uncertainty
463-466 F4.1 arcsec AMAJ850 ? FWHM major axis
468-471 F4.1 arcsec AMIN850 ? FWHM minor axis
473-475 I3 deg PA850 ? Position angle
477 A1 --- Flag870 Fluxes reliability and upper limit flag (1)
479-483 F5.2 Jy/beam Sp870 ? Peak intensity at 870um
485-488 F4.2 Jy/beam e_Sp870 ? Peak intensity uncertainty
490-494 F5.2 Jy Si870 ? Integrated flux at 870um
495-499 F5.2 Jy e_Si870 ? Integrated flux uncertainty
501-504 F4.1 arcsec AMAJ870 ? FWHM major axis
506-509 F4.1 arcsec AMIN870 ? FWHM minor axis
511-513 I3 deg PA870 ? Position angle
515 A1 --- Flag1200 Fluxes reliability and upper limit flag (1)
517-522 F6.3 Jy/beam Sp1200 ? Peak intensity at 1200um
524-528 F5.3 Jy/beam e_Sp1200 ? Peak intensity uncertainty
530-535 F6.3 Jy Si1200 ? Integrated flux at 1200um
536-541 F6.3 Jy e_Si1200 ? Integrated flux uncertainty
543-546 F4.1 arcsec AMAJ1200 ? FWHM major axis
548-551 F4.1 arcsec AMIN1200 ? FWHM minor axis
553-555 I3 deg PA1200 ? Position angle
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Note (1): Flags as follows:
0 = unreliable flux because the source is too weak
1 = reliable flux
2 = unreliable flux because the source is too large and/or too elliptical
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 3 A3 --- Sample Sample (1)
5- 6 I2 --- Number getsources number
8- 9 A2 --- l_FWHM [≤ ] Limit flag on FWHM
10- 13 F4.2 pc FWHM Deconvolved FWHM
15- 18 F4.1 K Tdust Mean dust temperature
20- 22 F3.1 K e_Tdust mrs uncertainty on Tdust
24- 27 I4 Msun Mass Mass
29- 31 I3 Msun e_Mass rms uncertainty on Mass
33- 37 I5 Lsun Lbol Bolometric luminosity
39- 40 A2 --- n_nH2 [≥ ] Limit flag on nH2
41- 46 E6.2 cm-2 nH2 Mean molecular hydrogen column density
48- 51 F4.1 --- chi2 chi2 value
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Note (1): Sample as follows:
IRb = IR-bright protostellar MDC
IRq = IR-quiet protostellar MDC
S = Starless MDC candidate
U = Undefined cloud structure
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Byte-by-byte Description of file: list.dat
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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- 23 I4 --- Nx Number of pixels along X-axis
25- 28 I4 --- Ny Number of pixels along Y-axis
30- 33 I4 um lambda ? Observed wavelength
35- 41 A7 --- Unit Image unit
43- 47 I5 Kibyte size Size of FITS file
49- 87 A39 --- FileName Name of FITS file, in subdirectory fits
89-145 A57 --- Title Title of the FITS file
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Acknowledgements:
We are grateful to Alexander Men'shchikov for his help and
discussions on getsources. SPIRE has been developed by a consortium of
institutes led by Cardiff Univ. (UK) and including Univ. Lethbridge
(Canada); NAOC (China); CEA, LAM (France); IFSI, Univ. Padua (Italy);
IAC (Spain); Stockholm Observatory (Sweden); Imperial College London,
RAL, UCL-MSSL, UKATC, Univ. Sussex (UK); and Caltech, JPL, NHSC, Univ.
Colorado (USA). This development has been supported by national
funding agencies: CSA (Canada); NAOC (China); CEA, CNES, CNRS
(France); ASI (Italy); MCINN (Spain); SNSB (Sweden); STFC, UKSA (UK);
and NASA (USA). PACS has been developed by a consortium of institutes
led by MPE (Germany) and including UVIE (Austria); KU Leuven, CSL,
IMEC (Belgium); CEA, LAM (France); MPIA (Germany); INAFIFSI/
OAA/OAP/OAT, LENS, SISSA (Italy); IAC (Spain). This development has
been supported by the funding agencies BMVIT (Austria), ESA-PRODEX
(Belgium), CEA/CNES (France), DLR (Germany), ASI/INAF (Italy), and
CICYT/MCYT (Spain). This research has made use of the SIMBAD database,
operated at CDS, Strasbourg, France. Part of this work was supported
by the ANR (Agence Nationale pour la Recherche) project PROBeS, number
ANR-08-BLAN-0241. We acknowledge financial support from "Programme
National de Physique Stellaire (PNPS) and program 'Physique et Chime
du Milieu Interstellaire' (PCMI) of CNRS/INSU, France. GJW gratefully
acknowledges the receipt of a Leverhulme Emeritus Professorial
Fellowship.
Delphine Russeil, delphine.russeil(at)lam.fr
References:
Motte et al., 2010A&A...518L..77M 2010A&A...518L..77M,
Initial highlights of the HOBYS key program, the Herschel imaging
survey of OB young stellar objects.
History:
* 28-Aug-2017: online version
* 26-Nov-2018: columns "nameW Si22" and "nameMSX Si21" interverted in
original file, now corrected.
(End) Patricia Vannier [CDS] 28-Aug-2017