J/A+A/584/A92 Galactic Cold Cores. IV. Cold sub-mm sources (Montillaud+, 2015)
Galactic Cold Cores.
IV. Cold sub-millimetre sources: catalogue and statistical analysis.
Montillaud J., Juvela M., Rivera-Ingraham A., Malinen J., Pelkonen V.-M.,
Ristorcelli I., Montier L., Marshall D.J., Marton G., Pagani L., Toth L.V.,
Zahorecz S., Ysard N., McGehee P., Paladini R., Falgarone E.,
Bernard J.-P., Motte F., Zavagno A., Doi Y.
<Astron. Astrophys. 584, A92 (2015)>
=2015A&A...584A..92M 2015A&A...584A..92M (SIMBAD/NED BibCode)
ADC_Keywords: Millimetric/submm sources ; Interstellar medium ; Morphology
Keywords: catalogs - submillimetre: ISM - stars: formation - ISM: clouds
Abstract:
For the project Galactic cold cores, Herschel photometric observations
were carried out as a follow-up of cold regions of interstellar clouds
previously identified with the Planck satellite. The aim of the
project is to derive the physical properties of the population of cold
sources and to study its connection to ongoing and future star
formation.
We build a catalogue of cold sources within the clouds in 116 fields
observed with the Herschel PACS and SPIRE instruments. We wish to
determine the general physical characteristics of the cold sources and
to examine the correlations with their host cloud properties.
From Herschel data, we compute colour temperature and column density
maps of the fields. We estimate the distance to the target clouds and
provide both uncertainties and reliability flags for the distances.
The getsources multi-wavelength source extraction algorithm is
employed to build a catalogue of several thousands of cold sources.
Mid-infrared data are used along with a colour and position criteria
to separate starless and protostellar sources. We also propose another
classification method based on sub-millimetre temperature profiles. We
analyse the statistical distributions of the physical properties of
the source samples.
We provide a catalogue of ∼4000 cold sources within or near star
forming clouds, most of which are located either in nearby molecular
complexes (<1kpc) or in star forming regions of the nearby galactic
arms (∼2kpc). About 70% of the sources have a size compatible with an
individual core, and 35% of those sources are likely gravitationally
bound. Significant statistical differences in physical properties are
found between starless and protostellar sources, in column density -
dust temperature, mass - size, and mass - dust temperature diagrams.
The core mass functions are very similar to those previously reported
for other regions. On statistical grounds we find that gravitationally
bound sources have higher background column densities (median
Nbg(H2)∼5x1021cm-2) than unbound sources (median
Nbg(H2)∼3x1021cm-2). These values of Nbg(H2) are higher for
larger dust temperature of the external layers of the parent cloud.
However, only in few cases do we find clear Nbg(H2) thresholds for
the presence of cores. The dust temperature of cloud external layers
shows clear variations with galactic location, as possibly do the
source temperatures.
Our data support a more complex view of star formation than in the
simple idea of a column density threshold. They show a clear influence
of the surrounding UV-visible radiation on how cores distribute in
their host clouds, with possible variations on the Galactic scale.
Description:
The Galactic Cold Cores source catalogue contains the sub-millimetre
sources extracted from the Herschel maps of the Galactic Cold Cores
project using the extraction algorithm getsources. The source
coordinates, size and orientations are provided along with the fluxes
at 160, 250, 350 and 500 microns as computed by getsources. The
physical properties (e.g. temperature, column density, mass, ...)
derived from those observed properties are also provided. The table
also gives the results of the classifications discussed in the paper
(galactic or extragalactic source, starless or protostellar source).
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 265 116 General properties of Herschel fields
gccscat.dat 571 4466 The GCC source catalogue
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See also:
VI/139 : Herschel Observation Log (Herschel Science Centre, 2013)
J/A+A/584/A93 : Galactic cold cores. V. Dust opacity (Juvela+, 2015)
J/A+A/584/A94 : Galactic cold cores. VI. Herschel fields list (Juvela+, 2015)
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 13 A13 --- Field Field name
15- 19 F5.3 kpc Dist ?=- Adopted distance
21- 25 F5.3 kpc E_Dist ? Error on Dist (upper value)
27- 31 F5.3 kpc e_Dist ? Error on Dist (lower value)
33 A1 --- Flag [0/2] Reliability flag on Dist (1)
35- 39 F5.2 kpc RG ?=- Galactic radius (galactocentric distance)
41- 44 I4 pc AltG ?=- Galactic altitude
46- 49 F4.1 K T0.1 0.1th percentile dust temperature in the field
51- 54 F4.1 K T90 90th percentile dust temperature in the field
56- 62 E7.2 cm-2 Nh2 Median H2 column index in the field
65- 71 E7.2 Msun Mass ?=- Total mass in the field
73- 79 E7.2 Msun C90 ?=- Mass at 90% completeness
82- 88 E7.2 Msun C50 ?=- Mass at 90% completeness
90-265 A176 --- Assoc Associated clouds and masers (2)
--------------------------------------------------------------------------------
Note (1): Reliability flag as follows:
0 = weak
1 = medium
2 = high level of confidence
Note (2): the names of clouds from the LDN, MBM and TGU catalogues that lie
within 1.5 degrees of the field, in order of increasing distance from the
centre of the field. Known masers are also reported. We added horizontal lines
to mark the 90, 180 and 270 values of galactic longitude.
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Byte-by-byte Description of file: gccscat.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 I4 --- ID Source number in this catalogue
6- 18 A13 --- Field Name of the Herschel field where sources
were extracted (GLLL.l+BB.bb)
20- 24 F5.3 kpc Dist Adopted distance
26- 30 F5.3 kpc E_Dist Upper distance uncertainty
32- 36 F5.3 kpc e_Dist Lower distance uncertainty
38 A1 --- Dflag [0/2] Distance quality flag (1)
40- 51 F12.8 deg RAdeg Right ascension (J2000)
53- 64 F12.8 deg DEdeg Declination (J2000)
66- 77 F12.8 deg GLON Galactic longitude
79- 90 F12.8 deg GLAT Galactic latitude
92-100 E9.3 --- SIGGLO Global significance of the source
extraction (2)
102 A1 --- FG [0/3] getsources quality flag (2)(3)
104-107 F4.2 --- GOOD Goodness of the extraction (2)
109-117 E9.3 --- SIGMONO1 Monochromatic significance of the source
extraction at 160 microns (2)
119-121 I3 --- FM1 ? Monochromatic quality flag for the source
extraction at 160um (2) (4)
123-132 E10.3 Jy/beam FXPBEST1 ?=0 Peak flux value in the source at 160um
(Jansky/beam) (2) (5)
134-142 E9.3 Jy/beam e_FXPBEST1 ?=0 Uncertainty on the peak flux value in
the source at 160um (Jansky/beam) (2) (5)
144-153 E10.3 Jy FXTBEST1 ?=0 Total flux value in the source
at 160um (2)
155-163 E9.3 Jy e_FXTBEST1 ?=0 Uncertainty on the total flux value in
the source at 160um (2)
165-170 F6.2 arcsec AFWHM1 FWHM of the source major axis at 160um (2)
172-177 F6.2 arcsec BFWHM1 FWHM of the source minor axis at 160um (2)
179-184 F6.2 deg PA1 Position angle of the source major axis at
160um (2) (6)
186-194 E9.3 --- SIGMONO2 Monochromatic significance of the source
extraction at 250 microns (2)
196 A1 --- FM2 [0/2] Monochromatic quality flag for the
source extraction at 250um (2) (4)
198-206 E9.3 Jy/beam FXPBEST2 ?=0 Peak flux value in the source at 250um
(Jansky/beam) (2) (5)
208-216 E9.3 Jy/beam e_FXPBEST2 ?=0 Uncertainty on the peak flux value in
the source at 250um (Jansky/beam) (2) (5)
218-226 E9.3 Jy FXTBEST2 ?=0 Total flux value in the source at
250um (2)
228-236 E9.3 Jy e_FXTBEST2 ?=0 Uncertainty on the total flux value in
the source at 250um (2)
238-243 F6.2 arcsec AFWHM2 FWHM of the source major axis at 250um (2)
245-250 F6.2 arcsec BFWHM2 FWHM of the source minor axis at 250um (2)
252-257 F6.2 deg PA2 Position angle of the source major axis
at 250um (2) (6)
259-267 E9.3 --- SIGMONO3 Monochromatic significance of the source
extraction at 350 microns (2)
269 A1 --- FM3 [0/1] Monochromatic quality flag for the
source extraction at 350um (2) (4)
271-279 E9.3 Jy/beam FXPBEST3 ?=0 Peak flux value in the source at 350um
(Jansky/beam) (2) (5)
281-289 E9.3 Jy/beam e_FXPBEST3 ?=0 Uncertainty on the peak flux value in
the source at 350um (Jansky/beam) (2) (5)
291-299 E9.3 Jy FXTBEST3 ?=0 Total flux value in the source
at 350um (2)
301-309 E9.3 Jy e_FXTBEST3 ?=0 Uncertainty on the total flux value in
the source at 350um (2)
311-316 F6.2 arcsec AFWHM3 FWHM of the source major axis at 350um (2)
318-323 F6.2 arcsec BFWHM3 FWHM of the source minor axis at 350um (2)
325-330 F6.2 deg PA3 Position angle of the source major axis
at 350um (2) (6)
332-340 E9.3 --- SIGMONO4 Monochromatic significance of the source
extraction at 500 microns (2)
342 A1 --- FM4 [0/1] Monochromatic quality flag for the
source extraction at 500um (2) (4)
344-352 E9.3 Jy/beam FXPBEST4 ?=0 Peak flux value in the source at 500um
(Jansky/beam) (2) (5)
354-362 E9.3 Jy/beam e_FXPBEST4 ?=0 Uncertainty on the peak flux value in
the source at 500um (Jansky/beam) (2) (5)
364-372 E9.3 Jy FXTBEST4 ?=0 Total flux value in the source
at 500um (2)
374-382 E9.3 Jy e_FXTBEST4 ?=0 Uncertainty on the total flux value in
the source at 500um (2)
384-389 F6.2 arcsec AFWHM4 FWHM of the source major axis at 500um (2)
391-396 F6.2 arcsec BFWHM4 FWHM of the source minor axis at 500um (2)
398-403 F6.2 deg PA4 Position angle of the source major axis at
500um (2) (6)
405-413 E9.3 --- SIGMONO5 Monochromatic significance of the source
extraction in the opacity map (tau_200) (2)
415 A1 --- FM5 [0/2] Monochromatic quality flag for the
source extraction in the opacity map
(tau_200) (2) (4)
417-425 E9.3 beam-1 FXPBEST5 ?=0 Peak flux value in the source in the
opacity map (tau_200) (beam-1) (2) (5)
427-435 E9.3 beam-1 e_FXPBEST5 ?=0 Uncertainty on the peak flux value in
the source in the opacity map (tau_200)
(beam-1) (2) (5)
437-445 E9.3 --- FXTBEST5 ?=0 Total flux value in the source in the
opacity map (tau_200) (2)
447-455 E9.3 --- e_FXTBEST5 ?=0 Uncertainty on the total flux value in
the source in the opacity map
(tau_200) (2)
457-462 F6.2 arcsec AFWHM5 FWHM of the source major axis in the opacity
map (tau_200) (2)
464-469 F6.2 arcsec BFWHM5 FWHM of the source minor axis in the opacity
map (tau_200) (2)
471-476 F6.2 deg PA5 Position angle of the source major axis in
the opacity map (tau_200) (2) (6)
478-488 E11.5 deg I200 Calculated surface brightness at 200um (7)
490-494 F5.2 K Tdust Dust temperature (7)
496-506 E11.5 cm-2 NH2 Column density (7)
508-518 E11.5 Lsun Lbol Bolometric luminosity (7)
520-530 E11.5 Msun Mass Source mass (7)
532-538 F7.5 --- Chi2 Chi2 of the SED fit (7)
540-550 E11.5 cm-2 NH2bg Background column density (7)
552-559 F8.2 --- aBE Ratio of Bonnor-Ebert mass to estimated
mass (7)
561 A1 --- WKGalFlag [0/3] Galactic/extragalactic flag using WISE
data and Koenig et al.
(2012AAS...21932007K) method (8)
563 A1 --- XgalFlag [0/1] Galactic/extragalactic flag after
combining all methods (9)
565 A1 --- StateNIR [0/4] State of evolution derived from
near-IR data (10)
567 A1 --- Class [0/9] Class of the embedded YSO (11)
569 A1 --- StateFIR [0/2] State of evolution derived from
mid-IR data (12)
571 A1 --- State [0/4] Final state of evolution (13)
--------------------------------------------------------------------------------
Note (1): Distance quality flag as follows:
0 = unreliable
1 = reliable estimate from only one method. Needs to be compared with an
independent method
2 = reliable estimates from several independent methods
Note (2): getsources output are described in Men'shchikov et al.,
2012A&A...542A..81M 2012A&A...542A..81M.
Note (3): We report here the definition given in the output file of getsources,
FG: Flag identifying global properties over all wavelengths, as follows:
0 = isolated source (not blended with any other source in any waveband)
1 = blended source (footprints intersect by more than 20% in at least
one waveband)
2 = sub-structured source (the inner 25% area of its footprint contains
an entire footprint of at least one source)
3 = sub-structuring source (causing a larger source to be flagged as
sub-structured)
Note (4): We report here the definition given in the output file of getsources,
FM: Flag identifying monochromatic properties, as follows:
0 = no problems identified for the source at this wavelength
1 = substantially larger than its characteristic size:
AFWHMN>sqrt(2)*SCALEN
2 = larger than the desired maximum of [93 120 163 202 184] arcsec:
AFWHMN>sqrt(2)*max(SRCMAXSIZEN,APERTUREN)
3 = larger than both the characteristic size and the desired
maximum size or aperture
10 = peak intensity is not measurable: FXPBESTN/FXPERRON<1.0
20 = total flux is not measurable: FXTBESTN/FXTERRON<1.0
30 = both total flux and peak intensity are not measurable
100 = sub-structured (the inner 25% area of its footprint
contains an entire footprint of at least one source)
200 = significance is low: SIG_MONON<3.5
Note (5): The beam FWHM are 38.5 arcsec for all 160, 250, 350, and 500 microns
maps, and 40.0 arcsec for the opacity maps.
Note (6): East from North
Note (7): Derived from the modified blackbody fit of the getsources total fluxes
FXTBEST2, FXTBEST3, FXTBEST4, with a fixed spectral index beta=2.
Note (8): classification of galactic vs extragalactic sources using only WISE
data and Koenig et al. (2012AAS...21932007K)'s method (see Sect. 4.3)
as follows:
0 = galactic source
1 = source contaminated by galaxies
2 = the source is a group of galaxies
3 = extragalactic source
Note (9): final classification of galactic vs extragalactic sources as follows:
0 = galactic source
1 = extragalactic source
Note (10): classification of starless vs protostellar sources, using only WISE
data and Koenig et al. (2012AAS...21932007K)'s method (see Sect. 4.4.2)
as follows:
0 = irrelevant (because the source is extragalactic)
1 = undetermined (the method is not conclusive)
2 = starless
3 = protostellar
4 = protostellar, but one WISE source within the Herschel source was
originally classified as extragalactic (WKGalFlag>1 but XgalFlag=0)
Note (11): Class (I or II) of the embedded YSO derived using WISE data and
Koenig et al. (2012AAS...21932007K)'s method.
Class 0 objects are also reported on the basis of WISE 22 microns and
AKARI 65 microns observations (Sect. 4.4.2). If several NIR objects are
classified in the Herschel source, or if the object is eligible to
several classes, the most advanced class is reported.
0 = Class 0
1 = Class I
2 = Class II
9 = undetermined or irrelevant
Note (12): Classification of starless vs protostellar sources, using only
Herschel data (see Sect. 4.4.1) as follows:
0 = undetermined or irrelevant
1 = starless
2 = protostellar
Note (13): Final classification of starless vs protostellar sources, combining
both methods as follows:
0 = undetermined or irrelevant
1 = probable starless source (flag 1 in Sect. 4.4.3)
2 = reliable starless source (flag 2 in Sect. 4.4.3)
3 = probable protostellar source (flag 1 Sect. 4.4.3)
4 = reliable protostellar source (flag 2 Sect. 4.4.3)
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Acknowledgements:
Julien Montillaud, julien(at)obs-besancon.fr
References:
Juvela et al., Paper I 2010A&A...518L..93J 2010A&A...518L..93J
Juvela et al., Paper II 2011A&A...527A.111J 2011A&A...527A.111J
Juvela et al., Paper III 2012A&A...541A..12J 2012A&A...541A..12J
History:
* 26-Nov-2015: First on-line data
* 29-Jan-2016: table1 added, from electronic version
(End) Patricia Vannier [CDS] 21-Sep-2015