J/A+A/476/1243 Millimeter continuum mapping of Cygnus X (Motte+, 2007)
The earliest phases of high-mass star formation:
a 3 square degree millimeter continuum mapping of Cygnus X.
Motte F., Bontemps S., Schilke P., Schneider N., Menten K.M., Broguiere D.
<Astron. Astrophys. 476, 1243 (2007)>
=2007A&A...476.1243M 2007A&A...476.1243M
ADC_Keywords: Molecular clouds ; Photometry, infrared ; Radio continuum
Keywords: dust, extinction - HII regions - ISM: structure - stars: formation -
submillimeter
Description:
We report on a millimeter continuum survey of the entire Cygnus X
molecular complex. We used the MAMBO and MAMBO-2 bolometer arrays on
the IRAM 30m telescope to map a 3deg2 area at 1.2mm (see fits files
of Figures 2, kept to 11" resolution). Our MAMBO-2 imaging gives
a complete view of the cloud structures ranging from 0.03pc to 5pc,
i.e. from dense cores to clumps. We perform a multi-resolution
analysis to extract 129 compact dense cores (∼0.1pc, see Table 1) and
identify 40 massive large-scale clumps (∼0.7pc, see Table 2). The 21um
fluxes arising from dense cores are taken from the MSX point source
catalog (MSX C6, Cat. V/114).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 166 129 Dense cores (compact cloud fragments) identified
in Cygnus X
refs.dat 66 13 References
table2.dat 94 40 Clumps (large-scale cloud structures) identified
in Cygnus X
figs.dat 38 10 List of FITS files containing the 1.2mm observations
fits/* . 10 FITS files of the images
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See also:
V/114 : MSX6C Infrared Point Source Catalog (Egan+ 2003)
J/ApJS/74/181 : Small-diameter radiosources catalogue (Zoonematkermani+, 1990)
J/A+A/241/551 : Radio continuum in Cygnus X region (Wendker+ 1991)
J/ApJS/91/659 : Ultracompact HII regions radio images (Kurtz+ 1994)
J/A+A/336/339 : VLA observations of ultracompact HII regions (Molinari+ 1998)
J/A+A/375/539 : JHK photometry of compact HII regions in Cyg X (Comeron+, 2001)
J/A+A/432/737 : General Catalogue of 6.7GHz Methanol Masers (Pestalozzi+, 2005)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 5 A5 --- --- [CygX-]
6- 9 A4 --- CygX Dense core number (Nnn, NWnn, or Snn)
11- 26 A16 --- Name Name (JHHMMSS.s+DDMMSS)
28- 31 I4 mJy Speak Peak flux at 1.2mm, in mJy/beam (1)
33- 36 F4.2 pc FWHMa Dense core FWHM size, major axis (1)
37 A1 --- --- [x]
38- 41 F4.2 pc FWHMb Dense core FWHM size, minor axis (1)
43- 47 I5 mJy Sint Integrated flux at 1.2mm (1)
49 A1 --- l_M(40K) Limit flag on M(40K)
50- 52 I3 solMass M(40K) ? Dense core mass with Tdust=40K (2)
54- 56 I3 solMass M(20K) Dense core mass with Tdust=20K (2)
58 A1 --- l_nH2(40K) Limit flag on nH240K
59- 64 E6.2 cm-3 nH2(40K) ? Volume-averaged H2 density, number with
Tdust=40K (3)
66- 71 E6.2 cm-3 nH2(20K) Volume-averaged H2 density, number with
Tdust=20K (3)
73- 79 F7.2 Jy S21um ?=- MSX flux at 21 microns (4)
80 A1 --- n_S21um [A] A: sources are seen in absorption at 8um
82 A1 --- n_CygX [*] Individual note (5)
84- 88 A5 --- ref(1) ? Reference for cm free-free, if exists,
in refs.dat file (6)
90-109 A20 --- Maser Maser molecule, if exists (6)
111-115 A5 --- r_Maser Reference for Maser, in refs.dat file
117-166 A50 --- Note Names and comments
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Note (1): Peak flux, deconvolved FWHM size, and integrated flux derived
from a 2D-Gaussian fit to the 1.2mm map after background subtraction
(cf. Sect. 3.2 and Appendix B). An upper limit FWHM of 0.03pc was
assumed for unresolved fragments.
Note (2): Mass derived from Col. 5 using Eq. (1) and assuming
Kappa1.2mm=0.01cm2/g and Tdust=20K. A second estimate with
Tdust=40K is made for HII regions and the brightest infrared
protostars of Cygnus X.
Note (3): Volume-averaged density derived from size and mass using Eq. (2).
Note (4): The 21 microns fluxes are those given in the MSX point source
catalog (MSX C6, Cat. V/114), except for CygX-N30, N43, N46, N47,
N65 and S41, for which an aperture flux is measured on the MSX map.
The MSX flux of two extended HII regions is equally distributed
between CygX-N46 and N47, and between CygX-S18, S19, S20. All
fragments detected at 21 microns are also detected at 8um with the
exception of CygX-N30, N46, N47, and N65. "-" means that sources are
undetected down to a flux of about 3Jy (completion level of the MSX 6C
catalog in Cygnus X).
Note (5): (*) observations of high-density tracers toward CygX-N4 suggest
that this 1.2mm source does not correspond to a dense cloud fragment.
Its nature is yet unclear but it is probably not a site for future or
ongoing star formation.
Note (6): Coincidence with stellar activity signatures
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Byte-by-byte Description of file: refs.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- Ref Reference number
4- 22 A19 --- BibCode BibCode
24- 45 A22 --- Aut Author's name
47- 66 A20 --- Com Comments
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 3 A3 --- --- [Cl-]
4- 6 A3 --- Clump Clump number (Nnn, NWnn or Snn)
8- 23 A16 --- Name Name (JHHMMSS.s+DDMMSS)
25- 28 F4.2 pc FWHMa Clump FWHM size, major axis (1)
29 A1 --- --- [x]
30- 33 F4.2 pc FWHMb Clump FWHM size, minor axis (1)
35- 39 I5 mJy Sint Integrated flux at 1.2mm (1)
41- 44 I4 solMass Mass Clump mass (2)
46- 51 E6.2 cm-3 nH2 Volume-averaged density number (3)
53- 94 A42 --- Com Comments
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Note (1): Deconvolved FWHM size and integrated flux derived from a
2D-Gaussian fit to the 1.2 mm map smoothed to a 55'' beam.
Note (2): Mass derived from Col. 4 using Eq. (1) and assuming
Kappa1.2mm=0.01cm2/g and Tdust=15K.
Note (3): Volume-averaged density derived from size and mass, using Eq. (2).
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Byte-by-byte Description of file: figs.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- FITSfile Name of FITS file, in the "fits" subdirectory
12- 19 F8.4 deg RAdeg Image center, in decimal degrees (J2000)
21- 28 F8.4 deg DEdeg Image center, in decimal degrees (J2000)
30- 33 I4 pix Xdim Dimension (E-W) (1pix=4arcsec)
34 A1 --- --- [x]
35- 38 I4 pix Ydim Dimension (N-S) (1pix=4arcsec)
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Acknowledgements:
Frederique Motte, frederique.motte(at)cea.fr
(End) Frederique Motte [AIM/SAp], Patricia Vannier [CDS] 13-Sep-2007