J/A+A/570/A65 ATLASGAL massive clumps CO depletion (Giannetti+, 2014)
ATLASGAL-selected massive clumps in the inner Galaxy.
I. CO depletion and isotopic ratios.
Giannetti A., Wyrowski F., Brand J., Csengeri T., Fontani F.,
Walmsley C.M., Nguyen Luong Q., Beuther H., Schuller F., Guesten R.,
Menten K.M.
<Astron. Astrophys., 570, A65-65 (2014)>
=2014A&A...570A..65G 2014A&A...570A..65G
ADC_Keywords: Molecular clouds ; Interstellar medium
Keywords: ISM: abundances - ISM: clouds - ISM: molecules
Abstract:
In the low-mass regime, molecular cores have spatially resolved
temperature and density profiles allowing a detailed study of their
chemical properties. It is found that the gas-phase abundances of
C-bearing molecules in cold starless cores rapidly decrease with
increasing density. Here the molecules tend to stick to the grains,
forming ice mantles. We study CO depletion in a large sample of
massive clumps, and investigate its correlation with evolutionary
stage and with the physical parameters of the sources. Moreover, we
study the gradients in [12C]/[13C] and [18O]/[17O] isotopic
ratios across the inner Galaxy, and the virial stability of the
clumps. From the ATLASGAL 870µm survey we selected 102 clumps,
which have masses in the range ∼102-3x104M☉, sampling
different evolutionary stages. We use low-J emission lines of CO
isotopologues and the dust continuum emission to infer the depletion
factor fD. RATRAN one-dimensional models were also used to determine
fD and to investigate the presence of depletion above a density
threshold. The isotopic ratios and optical depth were derived with a
Bayesian approach. We find a significant number of clumps with a high
degree of CO depletion, up to ∼20. Larger values are found for colder
clumps, thus for earlier evolutionary phases. For massive clumps in
the earliest stages of evolution we estimate the radius of the region
where CO depletion is important to be a few tenths of a pc. The value
of the [12C]/[13C] ratio is found to increase with distance from
the Galactic centre, with a value of ∼66±12 for the solar
neighbourhood. The [18O]/[17O] ratio is approximately constant
(∼4) across the inner Galaxy between 2kpc and 8kpc, albeit with a
large range (∼2-6). Clumps are found with total masses derived from
dust continuum emission up to ∼20 times higher than Mvir, especially
among the less evolved sources. These large values may in part be
explained by the presence of depletion: if the CO emission comes
mainly from the low-density outer layers, the molecules may be
subthermally excited, leading to an overestimate of the dust masses.
CO depletion in high-mass clumps seems to behave as in the low-mass
regime, with less evolved clumps showing larger values for the
depletion than their more evolved counterparts, and increasing for
denser sources. The ratios [12C]/[13C] and [18O]/[17O] are
consistent with previous determinations, and show a large intrinsic
scatter.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea1.dat 100 35 Distances and classification for the sources in
subsample S1, derived from C17O(3-2)
tablea2.dat 100 44 Distances and classification for the sources in
subsample S2, derived from C17O(3-2)
tablea3.dat 100 23 Distances and classification for the sources in
subsample S3, derived from C17O(3-2)
tablea4.dat 91 43 Line parameters of of C17O(1-0) and C17O(3-2)
for subsample S1
tablea5.dat 58 43 Line parameters of C18O(1-0) for subsample S1
tablea6.dat 58 43 Line parameters of 13CO(1-0) for subsample S1
tablea7.dat 58 43 Line parameters of 13C18O(1-0) for subsample S1
tablea8.dat 118 51 Line parameters of C18O(2-1) and C17O(3-2)
for subsample S2
tablea9.dat 118 23 Line parameters of C17O(3-2) for subsample S3
tablea10.dat 41 43 Excitation temperature for subsample S1
tablea11.dat 41 51 Excitation temperature for subsample S2
tablea12.dat 97 43 Optical depths and isotopic ratios for subsample S1
tablea13.dat 103 43 Molecular column densities for subsample S1
(12C18O, 12C17O,1-0, 12C17O,3-2,
13C18O, N2)
tablea14.dat 68 51 Molecular column densities for subsample S2
(12C18O, 12C17O, H2)
tablea15.dat 51 23 Molecular column densities for subsample S3
(12C17O, H2)
tablea16.dat 60 35 Masses from 870um dust emission and virial masses
for subsample S1
tablea17.dat 60 44 Masses from 870um dust emission and virial masses
for subsample S2
tablea18.dat 60 23 Masses from 870um dust emission and virial masses
for subsample S3
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See also:
J/MNRAS/443/1555 : ATLASGAL massive star forming clumps sample (Urquhart+ 2014)
Byte-by-byte Description of file: tablea1.dat tablea2.dat tablea3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 A4 --- --- [AGAL]
5- 18 A14 --- AGAL AGAL source name (LLLL.lll+BB.bbb)
20- 21 I2 h RAh Right ascension (J2000)
23- 24 I2 min RAm Right ascension (J2000)
26- 30 F5.2 s RAs Right ascension (J2000)
32 A1 --- DE- Declination sign (J2000)
33- 34 I2 deg DEd Declination (J2000)
36- 37 I2 arcmin DEm Declination (J2000)
39- 43 F5.2 arcsec DEs Declination (J2000)
44- 50 F7.2 km/s VLSR LSR velocity
52- 55 F4.1 kpc Dnear Near distance
57- 62 F6.1 pc znear Height above the Galactic plane for the
near distance
64- 67 F4.1 kpc Dfar ?=- Far distance
69- 74 F6.1 pc zfar ?=- Height above the Galactic plane for the
far distance
76 A1 --- HI [TNF-] Distance ambiguity resolution from
Wienen et al., in prep: T=tangent, N=near, F=far
78- 81 F4.1 kpc Dlit ?=- Literature values for the distance
83- 84 I2 --- r_Dlit ? Reference for Dlit (2)
86- 87 A2 --- Met Method Method with which the distance Dlit
was determined (3)
89- 92 F4.1 kpc Dist Adopted distance
94- 96 F3.1 kpc DGC Resulting Galactocentric distance
98-100 A3 --- Group Source classification (G1)
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Note (2): References as follows:
1 = Caswell et al., (1975A&A....45..239C 1975A&A....45..239C)
2 = Green & McClure-Griffith (2011MNRAS.417.2500G 2011MNRAS.417.2500G)
3 = Moises et al. (2011MNRAS.411..705M 2011MNRAS.411..705M, Cat. J/MNRAS/411/705)
4 = Bik et al. (2005A&A...440..121B 2005A&A...440..121B, Cat. J/A+A/440/121)
5 = Sato et al. (2010PASJ...62..287S 2010PASJ...62..287S)
6 = Gwinn et al. (1992ApJ...393..149G 1992ApJ...393..149G, Cat. J/ApJ/393/149)
7 = Immer et al. (2012A&A...548A.120I 2012A&A...548A.120I)
8 = Xu et al. (2011ApJ...733...25X 2011ApJ...733...25X)
9 = Kurayama et al. (2011PASJ...63..513K 2011PASJ...63..513K)
10 = Pandian et al. (2008A&A...489.1175P 2008A&A...489.1175P)
11 = Sewilo et al. (2004ApJS..154..553S 2004ApJS..154..553S, Cat. J/ApJS/154/553)
12 = Bica et al. (2004MNRAS.352..226B 2004MNRAS.352..226B)
13 = Busfield et al. (2006MNRAS.366.1096B 2006MNRAS.366.1096B, Cat. J/MNRAS/366/1096)
14 = Urquhart et al. (2011MNRAS.410.1237U 2011MNRAS.410.1237U, Cat. J/MNRAS/410/1237)
15 = Figueredo et al. (2005AJ....129.1523F 2005AJ....129.1523F)
16 = Zhang et al. (2009ApJ...693..419Z 2009ApJ...693..419Z)
17 = Xu et al. (2009A&A...507.1117X 2009A&A...507.1117X)
Note (3): Methods as follows:
PA = Direct parallax measurement
SP = Spectrophotometric measurement
Hi = Hi self-absorption
FR = Formaldehyde self-absorption
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Byte-by-byte Description of file: tablea4.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 A4 --- --- [AGAL]
5- 18 A14 --- AGAL AGAL source name (LLLL.lll+BB.bbb)
19 A1 --- --- [-]
20 I1 --- m_AGAL [1/3]? Multiplicity index on Source
22- 26 F5.2 K.km/s T.dV1 C17O(1-0) integrated flux
28- 31 F4.2 K Tmb1 C17O(1-0) main beam temperature
33- 36 F4.2 K e_Tmb1 C17O(1-0) rms noise
38- 43 F6.2 km/s VLSR1 C17O(1-0) LSR velocity
45- 48 F4.2 km/s e_VLSR1 rms uncertainty on VLSR1
50- 52 F3.1 km/s DV1 C17O(1-0) δV
54- 56 F3.1 km/s e_DV1 rms uncertainty on DV1
58- 61 F4.1 K.km/s T.dV2 ?=- C17O(3-2) integrated flux
63- 66 F4.1 K Tmb2 ?=- C17O(3-2) main beam temperature
68- 71 F4.2 K e_Tmb2 C17O(3-2) rms noise
73- 78 F6.2 km/s VLSR2 ?=- C17O(3-2) LSR velocity
80- 83 F4.2 km/s e_VLSR2 ?=- rms uncertainty on VLSR2
85- 87 F3.1 km/s DV2 ?=- C17O(3-2) δV
89- 91 F3.1 km/s e_DV2 ?=- rms uncertainty on DV2
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Byte-by-byte Description of file: tablea5.dat tablea6.dat tablea7.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 A4 --- --- [AGAL]
5- 18 A14 --- AGAL AGAL source name (LLLL.lll+BB.bbb)
19 A1 --- --- [-]
20 I1 --- m_AGAL [1/3]? Multiplicity index on Source
22- 27 F6.2 K.km/s T.dV ?=- CO(1-0) isotope integrated flux
29- 33 F5.2 K Tmb ?=- CO(1-0) isotope main beam temperature
35- 38 F4.2 K e_Tmb CO(1-0) isotope rms noise
40- 45 F6.2 km/s VLSR ?=- CO(1-0) isotope LSR velocity
47- 50 F4.2 km/s e_VLSR ?=- rms uncertainty on VLSR
52- 54 F3.1 km/s DV ?=- CO(1-0) isotope δV
56- 58 F3.1 km/s e_DV ?=- rms uncertainty on DV
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Byte-by-byte Description of file: tablea8.dat tablea9.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 A4 --- --- [AGAL]
5- 18 A14 --- AGAL AGAL source name (LLLL.lll+BB.bbb)
19 A1 --- --- [-]
20 I1 --- m_AGAL [1/4]? Multiplicity index on Source
22- 27 F6.2 K.km/s T.dV1 ? C18O(2-1) integrated flux
29- 33 F5.2 K Tmb1 ? C18O(2-1) main beam temperature
35- 38 F4.2 K rms1 ? C18O(2-1) rms noise
40- 46 F7.2 km/s VLSR1 ? C18O(2-1) LSR velocity
48- 51 F4.2 km/s e_VLSR1 ? rms uncertainty on VLSR1
53- 56 F4.1 km/s DV1 ? C18O(2-1) δV
58- 60 F3.1 km/s e_DV1 ? rms uncertainty on DV1
62- 64 F3.1 --- tau1 ? C18O(2-1) optical depth
66- 68 F3.1 --- b_tau2 ? Lower value of 68% confidence level of
C18O(2-1) optical depth
69 A1 --- --- [-]
70- 72 F3.1 --- B_tau2 ? Upper value of 68% confidence level of
C18O(2-1) optical depth
74- 78 F5.2 K.km/s T.dV2 ?=- C17O(3-2) integrated flux
80- 84 F5.2 K Tmb2 ?=- C17O(3-2) main beam temperature
86- 89 F4.2 K e_Tmb2 C17O(3-2) rms noise
91- 97 F7.2 km/s VLSR2 ?=- C17O(3-2) LSR velocity
99-102 F4.2 km/s e_VLSR2 ?=- rms uncertainty on VLSR2
104-106 F3.1 km/s DV2 ?=- C17O(3-2) δV
108-110 F3.1 km/s e_DV2 ?=- rms uncertainty on DV2
112-114 F3.1 --- tau2 ?=- C17O(3-2) Optical depth
116-118 F3.1 --- e_tau2 ?=- rms uncertainty on tau2
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Byte-by-byte Description of file: tablea10.dat tablea11.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 A4 --- --- [AGAL]
5- 18 A14 --- AGAL AGAL source name (LLLL.lll+BB.bbb)
19 A1 --- --- [-]
20 I1 --- m_AGAL [1/4]? Multiplicity index on Source
23- 26 F4.1 K Tex Excitation temperature
28- 31 F4.1 K b_Tex Lower value of 68% confidence level of Tex
32 A1 --- --- [-]
33- 36 F4.1 K B_Tex Upper value of 68% confidence level of Tex
37 A1 --- n_Tex [*] Note on Tex (1)
38- 40 A3 --- Group Group (G1)
41 A1 --- n_Group [)] ')' indicates classification of the main
component
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Note (1): For source AGAL015.029-00.669-2, the published value was a typo
and the corrected value is tabulated, from the author.
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Byte-by-byte Description of file: tablea12.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 A4 --- --- [AGAL]
5- 18 A14 --- AGAL AGAL source name (LLLL.lll+BB.bbb)
19 A1 --- --- [-]
20 I1 --- m_AGAL [1/3]? Multiplicity index on Source
23 A1 --- l_tau1 Limit flag on tau1
24- 27 F4.2 --- tau1 C18O(1-0) optical depth
29- 32 F4.2 --- b_tau1 ? Lower value of 68% confidence level of tau1
33 A1 --- --- [-]
34- 37 F4.2 --- B_tau1 ? Upper value of 68% confidence level of tau1
39 A1 --- l_tau2 Limit flag on tau2
40- 43 F4.2 --- tau2 C17O(1-0) optical depth
45- 48 F4.2 --- b_tau2 ? Lower value of 68% confidence level of tau2
49 A1 --- --- [-]
50- 53 F4.2 --- B_tau2 ? Upper value of 68% confidence level of tau2
55- 57 F3.1 --- 18/17O Isotopic ratio [18O]/[17O]
59- 61 F3.1 --- b_18/17O Lower value of 68% confidence level of
isotopic ratio [18O]/[17O]
62 A1 --- --- [-]
63- 65 F3.1 --- B_18/17O Upper value of 68% confidence level of
isotopic ratio [18O]/[17O]
67- 71 F5.1 --- 12/13C Isotopic ratio [12C]/[13C]
73- 76 F4.1 --- b_12/13C Lower value of 68% confidence level of
isotopic ratio [12C]/[13C]
77 A1 --- --- [-]
78- 82 F5.1 --- B_12/13C Upper value of 68% confidence level of
isotopic ratio [12C]/[13C]
84- 87 F4.1 --- 1217/1318 Isotopic ratio [12C17O]/[13C18O]
89- 92 F4.1 --- b_1217/1318 Lower value of 68% confidence level of
isotopic ratio [12C17O]/[13C18O]
93 A1 --- --- [-]
94- 97 F4.1 --- B_1217/1318 Upper value of 68% confidence level of
isotopic ratio [12C17O]/[13C18O]
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Byte-by-byte Description of file: tablea13.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 A4 --- --- [AGAL]
5- 18 A14 --- AGAL AGAL source name (LLLL.lll+BB.bbb)
19 A1 --- --- [-]
20 I1 --- m_AGAL [1/3]? Multiplicity index on Source
22- 25 F4.1 10+16cm-2 N(CO) 12C18O molecular column density
27- 30 F4.1 10+16cm-2 b_N(CO) Lower value of 68% confidence level of
N(12C18O)
31 A1 --- --- [-]
32- 35 F4.1 10+16cm-2 B_N(CO) Upper value of 68% confidence level of
N(12C18O)
37- 40 F4.1 10+15cm-2 N(1-0) 12C17O molecular column density
42- 45 F4.1 10+15cm-2 b_N(1-0) Lower value of 68% confidence level of
N(12C17O,1-0)
46 A1 --- --- [-]
47- 50 F4.1 10+15cm-2 B_N(1-0) Upper value of 68% confidence level of
N(12C17O,1-0)
52 A1 --- l_N(3-2) Limit flag on N(12C17O3-2)
53- 56 F4.1 10+15cm-2 N(3-2) 12C17O molecular column density
58- 61 F4.1 10+15cm-2 b_N(3-2) ? Lower value of 68% confidence level of
N(12C17O,3-2)
62 A1 --- --- [-]
63- 66 F4.1 10+15cm-2 B_N(3-2) ? Upper value of 68% confidence level of
N(12C17O,3-2)
68 A1 --- l_N(1318) Limit flag on N(13C18O)
69- 73 F5.1 10+13cm-2 N(1318) 13C18O molecular column density
75- 79 F5.1 10+13cm-2 b_N(1318) ? Lower value of 68% confidence level of
N(13C18O)
80 A1 --- --- [-]
81- 85 F5.1 10+13cm-2 B_N(1318) ? Upper value of 68% confidence level of
N(13C18O)
87- 89 F3.1 10+23cm-2 N(H2) ? H2 molecular column density
91- 93 F3.1 10+23cm-2 b_N(H2) ? Lower value of 68% confidence level of
N(H2)
94 A1 --- --- [-]
95- 98 F4.1 10+23cm-2 B_N(H2) ? Upper value of 68% confidence level of
N(H2)
100-102 A3 --- Group Group (G1)
103 A1 --- n_Group [)] ')' indicates classification of the
main component
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Byte-by-byte Description of file: tablea14.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 A4 --- --- [AGAL]
5- 18 A14 --- AGAL AGAL source name (LLLL.lll+BB.bbb)
19 A1 --- --- [-]
20 I1 --- m_AGAL [1/4]? Multiplicity index on Source
22- 25 F4.1 10+16cm-2 N(CO) 12C18O molecular column density
27- 30 F4.1 10+16cm-2 b_N(CO) Lower value of 68% confidence level of
N(12C18O)
31 A1 --- --- [-]
32- 35 F4.1 10+16cm-2 B_N(CO) Upper value of 68% confidence level of
N(12C18O)
37 A1 --- l_N(1217) Limit flag on N(12C17O)
38- 41 F4.1 10+15cm-2 N(1217) 12C18O molecular column density
43- 46 F4.1 10+15cm-2 b_N(1217) ? Lower value of 68% confidence level of
N(12C17O)
47 A1 --- --- [-]
48- 51 F4.1 10+15cm-2 B_N(1217) ? Upper value of 68% confidence level of
N(12C17O)
53- 55 F3.1 10+23cm-2 N(H2) ? H2 molecular column density
57- 59 F3.1 10+23cm-2 b_N(H2) ? Lower value of 68% confidence level of
N(H2)
60 A1 --- --- [-]
61- 63 F3.1 10+23cm-2 B_N(H2) ? Upper value of 68% confidence level of
N(H2)
65- 67 A3 --- Group Group (G1)
68 A1 --- n_Group [)] ')' indicates classification of the main
component
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Byte-by-byte Description of file: tablea15.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 A4 --- --- [AGAL]
5- 18 A14 --- AGAL AGAL source name (LLLL.lll+BB.bbb)
20- 23 F4.1 10+15cm-2 N(1217) 12C17O molecular column density
25- 28 F4.1 10+15cm-2 b_N(1217) Lower value of 68% confidence level of
N(12C17O)
29 A1 --- --- [-]
30- 33 F4.1 10+15cm-2 B_N(1217) Upper value of 68% confidence level of
N(12C17O)
35- 38 F4.1 10+23cm-2 N(H2) H2 molecular column density
40- 42 F3.1 10+23cm-2 b_N(H2) Lower value of 68% confidence level of
N(H2)
43 A1 --- --- [-]
44- 47 F4.1 10+23cm-2 B_N(H2) Upper value of 68% confidence level of
N(H2)
49- 51 A3 --- Group Group (G1)
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Byte-by-byte Description of file: tablea16.dat tablea17.dat tablea18.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 A4 --- --- [AGAL]
5- 18 A14 --- AGAL AGAL source name (LLLL.lll+BB.bbb)
19 A1 --- --- [-]
20 I1 --- m_AGAL [1/3]? Multiplicity index on Source
22- 26 F5.2 10+3Msun Mass Mass
28- 32 F5.2 10+3Msun b_Mass Lower value of 68% confidence level of Mass
33 A1 --- --- [-]
34- 38 F5.2 10+3Msun B_Mass Upper value of 68% confidence level of Mass
40- 44 F5.2 10+3Msun Mvir Viral mass
46- 50 F5.2 10+3Msun b_Mvir Lower value of 68% confidence level of Mvir
51 A1 --- --- [-]
52- 56 F5.2 10+3Msun B_Mvir Upper value of 68% confidence level of Mvir
58- 60 A3 --- Group Group (G1)
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Global notes:
Note (G1): Groups as follows:
D24 = 22 brightest sources that are dark at 24um
D8 = 23 brightest objects dark at 8um
IRB = 32 brightest sources of the whole survey, ex-cluding the Central
Molecular Zone (i.e. the central few x102pc)
RMS = 25 brightest sources, that are classified as a Massive Young Stellar
Object (MYSO) in the Red MSX Sources survey (Urquhart et al.,
2008A&A...487..253U 2008A&A...487..253U. J/A+A/487/253)
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History:
From electronic version of the journal
Acknowledgements:
Andrea Giannetti, agianne(at)ira.inaf.it
(End) Patricia Vannier [CDS] 02-Dec-2014