J/ApJS/236/49 CO and 850um obs. of Planck Galactic cold clumps (Zhang+, 2018)
The TOP-SCOPE survey of PGCCs: PMO and SCUBA-2 observations of 64 PGCCs in the
second Galactic quadrant.
Zhang C.-P., Liu T., Yuan J., Sanhueza P., Traficante A., Li G.-X., Li D.,
Tatematsu K., Wang Ke, Lee C.W., Samal M.R., Eden D., Marston A., Liu X.-L.,
Zhou J.-J., Li P.S., Koch P.M., Xu J.-L., Wu Y., Juvela M., Zhang T.,
Alina D., Goldsmith P.F., Toth L.V., Wang J.-J., Kim K.-T.
<Astrophys. J. Suppl. Ser., 236, 49 (2018)>
=2018ApJS..236...49Z 2018ApJS..236...49Z
ADC_Keywords: Milky Way; Interstellar medium; Carbon monoxide;
Millimetric/submm sources; Infrared sources
Keywords: dust, extinction ; ISM: clouds ; ISM: structure ; stars: formation
Abstract:
In order to understand the initial conditions and early evolution of
star formation in a wide range of Galactic environments, we carried
out an investigation of 64 Planck Galactic cold clumps (PGCCs) in the
second quadrant of the Milky Way. Using the 13CO and C18O J=1-0
lines and 850µm continuum observations, we investigated cloud
fragmentation and evolution associated with star formation. We
extracted 468 clumps and 117 cores from the 13CO line and 850µm
continuum maps, respectively. We made use of the Bayesian distance
calculator and derived the distances of all 64 PGCCs. We found that in
general, the mass-size plane follows a relation of m∼r1.67. At a
given scale, the masses of our objects are around 1/10 of that of
typical Galactic massive star-forming regions. Analysis of the clump
and core masses, virial parameters, densities, and mass-size relation
suggests that the PGCCs in our sample have a low core formation
efficiency (∼3.0%), and most PGCCs are likely low-mass star-forming
candidates. Statistical study indicates that the 850µm cores are
more turbulent, more optically thick, and denser than the 13CO
clumps for star formation candidates, suggesting that the 850µm
cores are likely more appropriate future star formation candidates
than the 13CO clumps.
Description:
The CO observations were made during 2011 April-May and 2011
December-2012 January using the 13.7m millimeter telescope of Qinghai
Station at the Purple Mountain Observatory (PMO). The 13CO and
C18O data are used here. See section 2.1.
The majority of the SCUBA-2 850um observations were conducted as part
of the SCOPE project (Liu+ 2018ApJS..234...28L 2018ApJS..234...28L). The rest of the data
were collected from the James Clerk Maxwell Telescope (JCMT) data
archive of the Canadian Astronomy Data Centre (CADC). See section 2.2.
In this work, WISE 12 and 22um image data are used. See section 2.3.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 53 64 64 Planck Galactic Cold Clumps (PGCCs)
in the Second Quadrant
table2.dat 118 468 Observed parameters of extracted CO clumps
table3.dat 105 468 Derived parameters of extracted CO clumps
table4.dat 118 117 Observed parameters of extracted 850um cores
table5.dat 101 117 Derived parameters of extracted 850um cores
--------------------------------------------------------------------------------
See also:
II/328 : AllWISE Data Release (Cutri+ 2013)
VIII/39 : Composite CO Survey of the Milky Way (Dame+ 1987)
J/A+A/291/943 : Protostellar cores (Ossenkopf+, 1994)
J/PASJ/56/313 : 13CO survey of Mon & CMa molecular clouds (Kim+, 2004)
J/ApJ/649/759 : Bubbles in the galactic disk (Churchwell+, 2006)
J/ApJ/641/389 : Millimetric observations of IRDC cores (Rathborne+, 2006)
J/ApJ/670/428 : Bubbles in the galactic disk. II. (Churchwell+, 2007)
J/MNRAS/379/663 : 850um observations of W3 giant molecular cloud (Moore+, 2007)
J/MNRAS/374/1413 : SCUBA survey of Orion (Nutter+, 2007)
J/A+A/487/993 : MAMBO Mapping of c2d Clouds and Cores (Kauffmann+, 2008)
J/A+A/527/A145 : Chamaeleon I 870um sources (Belloche+, 2011)
J/A+A/530/A118 : G29.96-0.02 and G35.20-1.74 1mm and 3mm maps (Pillai+, 2011)
J/ApJ/756/60 : A 3mm line survey in 37 IR dark clouds (Sanhueza+, 2012)
J/MNRAS/422/3178 : Distances of 793 BGPS sources (Eden+, 2012)
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/MNRAS/431/1587 : GRS/BGPS sources in Galactic Plane (Eden+, 2013)
J/ApJ/772/45 : Hi-GAL obs.: star formation in the 3rd quadrant (Elia+, 2013)
J/MNRAS/435/2003 : G305 star-forming complex in 13CO (Hindson+, 2013)
J/ApJS/209/37 : Planck cold clumps in 12CO, 13CO and C18O (Meng+, 2013)
J/ApJ/780/173 : Masses of giant molecular clouds in MW (Battisti+, 2014)
J/A+A/565/A75 : ATLASGAL. Dust condensations in Gal. plane (Csengeri+, 2014)
J/A+A/561/A148 : Mass Distribution of Infrared Dark Clouds (Gomez+, 2014)
J/MNRAS/443/1555 : ATLASGAL massive star forming clumps (Urquhart+, 2014)
J/A+A/584/A91 : Dense cores in Aquila from Herschel (Konyves+, 2015)
J/MNRAS/453/4264 : JCMT Plane Survey: l=30° field (Moore+, 2015)
J/MNRAS/448/1551 : JCMT Gould Belt Survey: Serpens MWC 297 (Rumble+, 2015)
J/A+A/579/A91 : ATLASGAL inner Galaxy cold dust clumps (Wienen+, 2015)
J/MNRAS/459/342 : Dense cores in Taurus L1495 cloud (Marsh+, 2016)
J/A+A/594/A28 : Planck Catalog of Galactic cold clumps (PGCC) (Planck+, 2016)
J/ApJ/820/37 : HCO+ & HCN obs. toward Planck Gal. Cold Clumps (Yuan+, 2016)
J/A+A/585/A117 : N131 bubble CO integrated intensity maps (Zhang+, 2016)
J/ApJS/224/43 : Planck cold clumps & cores in the 2nd quadrant (Zhang+, 2016)
J/A+A/601/A60 : ATLASGAL: Massive cluster progenitors (Csengeri+, 2017)
J/A+A/600/L10 : Massive cluster progenitors from ATLASGAL (Csengeri+, 2017)
J/A+A/599/A139 : ATLASGAL massive clumps dust characterization (Koenig+, 2017)
J/ApJS/231/11 : High-mass starless clump cand. from ATLASGAL (Yuan+, 2017)
J/A+A/598/A76 : Six infrared dark clouds multi-wavelength obs. (Zhang+, 2017)
J/MNRAS/473/1059 : Complete sample of Galactic clumps (Urquhart+, 2018)
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 13 A13 --- PLCKECC Planck Early Cold Cores Catalog Name,
GLLL.ll-BBB.bb (Cat. VIII/88)
15- 16 I2 h RAh [0/23] Hour of Right Ascension (J2000)
18- 19 I2 min RAm Minute of Right Ascension (J2000)
21- 25 F5.2 s RAs Second of Right Ascension (J2000)
27- 27 A1 --- DE- [+] Sign of the Declination (J2000)
28- 29 I2 deg DEd [30/71] Degree of Declination (J2000)
31- 32 I2 arcmin DEm Arcminute of Declination (J2000)
34- 38 F5.2 arcsec DEs Arcsecond of Declination (J2000)
40- 43 F4.2 kpc Dist [0.4/5] Distance (1)
45- 48 F4.2 kpc e_Dist [0.02/0.7] Uncertainty in Dist (1)
50- 53 F4.2 --- Prob [0.3/1] Distance probability (1)
--------------------------------------------------------------------------------
Note (1): The distances, uncertainties and probabilities derived by the
Bayesian Distance Calculator, http://bessel.vlbi-astrometry.org/bayesian
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table[24].dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 13 A13 --- PLCKECC Planck Early Cold Cores Catalog Name,
GLLL.ll-BBB.bb (Cat. VIII/88)
15- 16 I2 --- Seq [1/18] 13CO clump (table 2) or SCUBA 850um
core (table 4) number in the PLCKECC
18- 24 F7.2 arcsec OffRA [-423/417] Offset from PLCKECC center (in
Table 1)
26- 32 F7.2 arcsec OffDE [-428/413] Offset from PLCKECC center (in
Table 1)
34- 39 F6.2 km/s V13CO [-51.1/5.7]? 13CO LSR velocity
41- 44 F4.2 km/s e_V13CO [0/0.3]? Uncertainty in V13CO
46- 49 F4.2 km/s W13CO [0.3/6]? 13CO Gaussian line-width
51- 54 F4.2 km/s e_W13CO [0.01/0.7]? Uncertainty in W13CO
56- 59 F4.2 K P13CO [0.5/8.3]? 13CO main beam brightness
temperature
61- 64 F4.2 K e_P13CO [0.07/0.8]? Uncertainty in P13CO
66- 71 F6.2 km/s VC18O [-51.1/6]? C18O LSR velocity
73- 76 F4.2 km/s e_VC18O [0.01/0.4]? Uncertainty in VC18O
78- 81 F4.2 km/s WC18O [0.3/4.2]? C18O Gaussian line-width (1)
83- 86 F4.2 km/s e_WC18O [0.02/0.7]? Uncertainty in WC18O
88- 91 F4.2 K PC18O [0.2/2.3]? C18O main beam brightness
temperature
93- 96 F4.2 K e_PC18O [0.04/0.4]? Uncertainty in PC18O
98-101 F4.2 --- tau13CO [0.2/8]? 13CO optical depth (2)
103-106 F4.2 --- e_tau13CO [0.05/3]? Uncertainty in tau13CO
108-112 F5.2 K Tex13CO [2/50]? Excitation temperature, 13CO (3)
114-118 F5.2 K e_Tex13CO [0.2/15]? Uncertainty in Tex13CO
--------------------------------------------------------------------------------
Note (1): If the linewidth of C18O is less than two velocity channels (or
two times velocity resolution), the Gaussian fitting will produce a
linewidth of 0.33±0.07kms/s.
Note (2): The optical depth with tau13CO<0.20 is unreliable, therefore we
set them as tau13CO=0.20±0.05.
Note (3): The excitation temperature with Tex13CO>50.00K is unreliable,
therefore we set them as Tex13CO=50.00±5.00K.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 13 A13 --- PLCKECC Planck Early Cold Cores Catalog Name,
GLLL.ll-BBB.bb (Cat. VIII/88)
15- 16 I2 --- Seq [1/14] 13CO Clump number in the PLCKECC
18- 22 F5.1 arcsec FWHM [52/385] Extracted clump size (G1)
24- 27 F4.2 pc Reff [0.09/3.3] Clump effective radius (G2)
29- 32 F4.2 km/s sigC18O [0.1/1.8]? 1 dimensional linewidth, C18O
34- 37 F4.2 km/s e_sigC18O [0.01/0.3]? Uncertainty in sigC18O
39- 42 F4.1 10+21cm-2 NH2 [2.3/68.3]? Molecular hydrogen
column density from 13CO
44- 47 F4.1 10+21cm-2 e_NH2 [0.2/12.6]? Uncertainty in nH2
49- 53 F5.1 10+3cm-3 n [0.5/116.2]? Number density from 13CO
55- 58 F4.1 10+3cm-3 e_n [0.1/25.8]? Uncertainty in n
60- 64 F5.3 g/cm2 D [0.01/0.8]? Mass column density from 13CO
66- 70 F5.3 g/cm2 e_D [0.001/0.2]? Uncertainty in D
72- 77 F6.1 Msun MH2 [5.6/6132]? Mass in molecular hydrogen
from 13CO
79- 83 F5.1 Msun e_MH2 [0.5/961]? Uncertainty in MH2
85- 89 F5.1 Msun Mvir [4.4/899]? Virial Mass
91- 95 F5.1 Msun e_Mvir [0.6/115.4]? Uncertainty in Mvir
97-100 F4.2 --- aVir [0.04/3.1]? Virial parameter
102-105 F4.2 --- e_aVir [0.01/1]? Uncertainty in aVir
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table5.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 13 A13 --- PLCKECC Planck Early Cold Cores Catalog Name,
GLLL.ll-BBB.bb (Cat. VIII/88)
15- 16 I2 --- Seq [1/18] SCUBA 850um core number
in the PLCKECC
18- 21 F4.1 arcsec FWHM [14/39.2] Extracted core size (G1)
23- 26 F4.2 pc Reff [0.02/0.5] Core effective radius (G2)
28- 31 F4.2 km/s sigC18O [0.1/1.6]? 1 dimensional linewidth, C18O
33- 36 F4.2 km/s e_sigC18O [0.03/0.3]? Uncertainty in sigC18O
38- 42 F5.2 Jy S850 [0.1/10.5] Peak 850um Flux Density
44- 47 F4.1 10+22cm-2 NH2 [0.1/31.3] Molecular hydrogen
column density from S850um
49- 51 F3.1 10+22cm-2 e_NH2 [0/2.3] Uncertainty in NH2
53- 57 F5.1 10+4cm-3 n [1.8/408.2] Number density from S850um
59- 63 F5.1 10+4cm-3 e_n [0.2/137] Uncertainty in n
65- 69 F5.3 g/cm2 D [0.03/2.3] Mass column density
from S850um
71- 75 F5.3 g/cm2 e_D [0.004/0.8] Uncertainty in D
77- 81 F5.1 Msun MH2 [0.1/311] Mass in molecular hydrogen
from S850um
83- 86 F4.1 Msun e_MH2 [0/36] Uncertainty in MH2
88- 92 F5.2 --- aVir [0.1/17]? Virial parameter
94- 97 F4.2 --- e_aVir [0.02/8]? Uncertainty in aVir
99-101 A3 --- IR? [yes/no ] IR Source in the ALLWISE data
(cat. II/328)
--------------------------------------------------------------------------------
Global Notes:
Note (G1): The extracted clump sizes with Gaussclumps procedure; see Section3.2.
Note (G2): The clump effective radius Reff=FWHM/(2*sqrt(ln2)). The
uncertainties of Reff are ∼10%, which will cause additional uncertainty
of around 21% in the derived masses.
--------------------------------------------------------------------------------
History:
From electronic version of the journal
References:
Liu et al. TOP-SCOPE survey overview. 2018ApJS..234...28L 2018ApJS..234...28L
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 03-Sep-2018