J/A+A/606/A102 Herschel cold clumps CO survey (Feher+, 2017)
A CO survey on a sample of Herschel cold clumps.
Feher O., Juvela M., Lunttila T., Montillaud J., Ristorcelli I.,
Zahorecz S., Toth L.V.
<Astron. Astrophys. 606, A102 (2017)>
=2017A&A...606A.102F 2017A&A...606A.102F (SIMBAD/NED BibCode)
ADC_Keywords: Molecular clouds ; Spectra, millimetric/submm
Keywords: molecular data - ISM: clouds - dust, extinction - ISM: molecules
Abstract:
The physical state of cold cloud clumps has a great impact on the
process and efficiency of star formation and the masses of the
forming stars inside these objects. The sub-millimetre survey of the
Planck space observatory and the far-infrared follow-up mapping of the
Herschel space telescope provide an unbiased, large sample of these
cold objects.
We have observed 12CO(1-0) and 13CO(1-0) emission in 35
high-density clumps in 26 Herschel fields sampling different
environments in the Galaxy. We derive the physical properties of the
objects and estimate their gravitational stability.
The densities and temperatures of the clumps were calculated from both
the dust continuum and the molecular line data. Kinematic distances
were derived using 13CO(1-0) line velocities to verify previous
distance estimates and the sizes and masses of the objects were
calculated by fitting 2D Gaussian functions to their optical depth
distribution maps on 250um. The masses and virial masses were
estimated assuming an upper and lower limit on the kinetic
temperatures and considering uncertainties due to distance
limitations.
Description:
We present 12CO(1-0) and 13CO(1-0) spectra of 35 cold clumps based
on the infrared mapping of Herschel. The observations were performed
with the Onsala 20m telescope. The clumps are located between -30 and
10 degree Galactic latitudes, no closer than ∼2 degrees to the
Galactic plane and show AV>1.4. The data were taken with the Fast
Fourier Transform spectrometer of the telescope with a bandwidth of
100MHz and spectral resolution of 12.2kHz, in frequency throwing mode.
The pointing accuracy was around 3 arcseconds. The antenna temperature
rms noise is lower than 0.3K in the 12CO spectra and lower than 0.3K
in the 13CO spectra. 35 clumps have 13CO data towards the
Herschel-derived column density peak and from the 35 clumps, 28 have
12CO data in a five-point cross (with a step size of 33") towards
and around the peak. Each 12CO file contains the spectra of the
5-point cross in the next order: 1 = east of the peak, 2 = south of
the peak, 3 = peak position, 4 = north of the peak, 5 = west of the
peak.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 76 35 The observed clumps
sp/* . 63 Individual fits spectra
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See also:
J/A+A/544/A146 : ATLASGAL cold high-mass clumps with NH3 (Wienen+, 2012)
J/A+A/579/A91 : ATLASGAL inner Galaxy massive cold dust clumps (Wienen+, 2015)
J/ApJS/202/4 : Planck cold clumps survey in the Orion complex (Liu+, 2012)
J/ApJ/756/76 : Planck cold dust clumps CO survey (Wu+, 2012)
J/ApJS/209/37 : Planck cold clumps in 12CO, 13CO and C18O (Meng+, 2013)
J/A+A/594/A28 : Planck Catalogue of Galactic cold clumps, PGCC (Planck+, 2016)
J/ApJ/820/37 : HCO+ and HCN toward Planck Galactic Cold Clumps (Yuan+, 2016)
J/ApJS/224/43 : Planck cold clumps & cores in the 2nd quadrant (Zhang+, 2016)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 15 A15 --- GCC Herschel field ID (GLLL.ll+bbb.bb)
17 A1 --- Clump [ABC] Clump (column density peaks) ID on
the Herschel field (1)
19- 20 I2 h RAh Clump right ascension (J2000)
22- 23 I2 min RAm Clump right ascension (J2000)
25- 28 F4.1 s RAs Clump right ascension (J2000)
30 A1 --- DE- Clump declination sign (J2000)
31- 32 I2 deg DEd Clump declination (J2000)
34- 35 I2 arcmin DEm Clump declination (J2000)
37- 40 F4.1 arcsec DEs Clump declination (J2000)
42- 58 A17 --- FileName1 Name of the 12CO spectrum file in
subdirectory sp
60- 76 A17 --- FileName2 Name of the 13CO spectrum file in
subdirectory sp
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Note (1): Clumps are classified from the highest column density (A) to
the lowest (C).
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Acknowledgements:
Orsolya Feher, feher.orsolya(at)csfk.mta.hu
(End) Patricia Vannier [CDS] 05-Sep-2017