J/ApJS/249/33 Nobeyama molecular line survey of SCUBA-2 cores (Kim+, 2020)
Molecular cloud cores with a high deuterium fraction: Nobeyama single-pointing
survey.
Kim G., Tatematsu K., Liu T., Yi H.-W., He J., Hirano N., Liu S.-Y.,
Choi M., Sanhueza P., Toth L.V., Evans Ii N.J., Feng S., Juvela M.,
Kim K.-T., Vastel C., Lee J.-E., Nguyen Lu'o'ng Q., Kang M.,
Ristorcelli I., Feher O., Wu Y., Ohashi S., Wang K., Kandori R., Hirota T.,
Sakai T., Lu X., Thompson M.A., Fuller G.A., Li D., Shinnaga H., Kim J.
<Astrophys. J. Suppl. Ser., 249, 33-33 (2020)>
=2020ApJS..249...33K 2020ApJS..249...33K (SIMBAD/NED BibCode)
ADC_Keywords: Molecular data; Molecular clouds; Interstellar medium; YSOs;
Star Forming Region; Surveys; Millimetric/submm sources
Keywords: Clouds; Interstellar molecules; Astrochemistry; Star formation
Abstract:
We present the results of a single-pointing survey of 207 dense cores
embedded in Planck Galactic Cold Clumps distributed in five different
environments (λ Orionis, Orion A, Orion B, the Galactic plane,
and high latitudes) to identify dense cores on the verge of star
formation for the study of the initial conditions of star formation.
We observed these cores in eight molecular lines at 76-94GHz using the
Nobeyama 45m telescope. We find that early-type molecules (e.g., CCS)
have low detection rates and that late-type molecules (e.g., N2H+
and c-C3H2) and deuterated molecules (e.g., N2D+ and DNC) have
high detection rates, suggesting that most of the cores are chemically
evolved. The deuterium fraction (D/H) is found to decrease with
increasing distance, indicating that it suffers from differential beam
dilution between the D/H pair of lines for distant cores (>1kpc). For
λ Orionis, Orion A, and Orion B located at similar distances,
D/H is not significantly different, suggesting that there is no
systematic difference in the observed chemical properties among these
three regions. We identify at least eight high-D/H cores in the Orion
region and two at high latitudes, which are most likely to be close to
the onset of star formation. There is no clear evidence of the
evolutionary change in turbulence during the starless phase,
suggesting that the dissipation of turbulence is not a major mechanism
for the beginning of star formation as judged from observations with a
beam size of 0.04pc.
Description:
The "SCUBA-2 Continuum Observations of Pre-protostellar Evolution
(SCOPE)" survey discovered more than 3000 Planck Galactic Cold Clumps
(PGCC) cores across the Galaxy at 850um with SCUBA-2 (Submillimetre
Common-User Bolometer Array 2) on board the James Clerk Maxwell
telescope (JCMT) (e.g., Yi+ 2018, J/ApJS/236/51 ;
Eden+ 2019, J/MNRAS/485/2895). As a pilot study, we selected a total of
207 targets that are located at different Galactic positions (local
Giant Molecular Clouds, high latitude, and Galactic plane).
We carried out single-pointing observations toward the 850um intensity
peak position of 207 SCUBA-2 cores with the 45m single-dish radio
telescope of the Nobeyama Radio Observatory from 2017-February to
2018-May (CG161004, LP177001; P.I.: K. Tatematsu).
The T70 receiver was adopted for observations toward all 207 SCUBA-2
cores in the c-C3H2 JKaKc=212-101 (85.34GHz),
DNC J=1-0 (76.31GHz), HN13C J=1-0 (87.09GHz),
and N2D+ J=1-0 (77.11GHz) molecular emission lines.
The TZ receiver was used for observations toward 111 SCUBA-2 cores in
the Orion region in the CCS JN=76-65 (CCS-L; 81.51GHz),
CCS JN=87-76 (CCS-H; 93.87GHz), HC3N J=9-8 (81.88GHz), and
N2H+ J=1-0 (93.17GHz) lines.
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 165 207 Information of 207 SCUBA-2 cores embedded in
Planck Galactic Cold Clumps
table3.dat 137 121 Properties of 82GHz CCS, 94GHz CCS, HC3N,
and N2H+ lines
table4.dat 139 229 Properties of c-C3H2, DNC, HN13C,
and N2D+ lines
table5.dat 187 229 Column density, column density ratio, Mach number,
and integrated intensity ratio of N2D+,
N2H+, DNC, HN13C, CCS, and HC3N molecules
--------------------------------------------------------------------------------
See also:
II/328 : AllWISE Data Release (Cutri+ 2013)
II/360 : Gaia DR2 x AllWISE catalogue (Marton+, 2019)
J/ApJS/123/233 : Catalog of Optically selected cores (Lee+, 1999)
J/ApJ/639/227 : MSX IRDC candidate catalog (Simon+, 2006)
J/PASJ/59/1185 : Water maser in galactic IRAS sources (Sunada+, 2007)
J/A+A/505/405 : A catalogue of Spitzer dark clouds (Peretto+, 2009)
J/PASJ/63/S1 : Atlas of dark clouds based on 2MASS (Dobashi+, 2011)
J/ApJ/756/60 : A 3mm line survey in 37 IR dark clouds (Sanhueza+, 2012)
J/AJ/144/192 : Spitzer survey of Orion A & B. I. YSO cat. (Megeath+, 2012)
J/ApJS/209/31 : The MYStIX IR-Excess Source catalog (MIRES) (Povich+, 2013)
J/MNRAS/438/1848 : NGC 7129 Vilnius photometry (Straizys+, 2014)
J/A+A/579/A80 : Star-forming regions deuteration (Gerner+, 2015)
J/ApJS/220/11 : SEDs of Spitzer YSOs in the Gould Belt (Dunham+, 2015)
J/MNRAS/458/3479 : SVM selection of WISE YSO Candidates (Marton+, 2016)
J/MNRAS/460/3179 : APOGEE stars distance and extinction (Wang+, 2016)
J/A+A/594/A28 : Planck Cat. of Galactic cold clumps (PGCC) (Planck+, 2016)
J/ApJ/834/142 : Gould's Belt Distances Survey. II. OMC (Kounkel+, 2017)
J/A+A/610/A30 : B stars in 4 open clusters (Aidelman+, 2018)
J/A+A/611/A9 : LDN 183 and LDN 169 Vilnius photometry (Straizys+, 2018)
J/ApJ/859/33 : GOBELINS. IV. VLBA obs. of Taurus (Galli+, 2018)
J/ApJS/236/51 : PGCCs in lambda Orionis complex. II. 850um cores (Yi+, 2018)
J/AJ/156/18 : APOGEE:Binary comp. of evolved stars (Price-Whelan+, 2018)
J/ApJ/865/73 : GOBELINS. V. Kinematics of Perseus (Ortiz-Leon+, 2018)
J/ApJ/886/102 : ALMA obs. of 70um dark high-mass clumps (Sanhueza+, 2019)
J/MNRAS/485/2895 : The SCOPE 850um compact source catalogue (Eden+, 2019)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 20 A20 --- Name SCUBA-2 core name (1)
22- 23 I2 h RAh Hour of right ascension (J2000) (1)
25- 26 I2 min RAm Minute of right ascension (J2000)
28- 32 F5.2 s RAs Second of right ascension (J2000)
34 A1 --- DE- Sign of declination (J2000) (1)
35- 36 I2 deg DEd Degree of declination (J2000) (1)
38- 39 I2 arcmin DEm Arcminute of declination (J2000)
41- 44 F4.1 arcsec DEs Arcsecond of declination (J2000)
46- 57 A12 --- Assoc YSO association (2)
59- 62 F4.2 kpc Dist [0.11/9.21] Distance from this work
64- 65 I2 --- Ref [1/18] Reference for the adopted distance (3)
67- 70 F4.1 K Td [9.2/22.4] Dust temperature from PGCC
from Eden+ (2019, J/MNRAS/485/2895)
72- 74 F3.1 K e_Td [0.4/8.6] Td uncertainty
76- 79 F4.1 10+23cm-2 NH2 [0.2/11.7] Hydrogen column density
from Eden+ (2019, J/MNRAS/485/2895) (4)
81- 83 F3.1 10+23cm-2 e_NH2 [0.1/3.1] NH2 uncertainty
85- 86 A2 --- Env Environment surrounding the SCUBA-2 core (5)
88- 119 A32 --- YSO Source name of YSO
121- 124 A4 --- --- [PGCC]
126- 138 A13 --- PGCC Name of Planck Galactic Cold Clump
(PGCC; GLLL.ll+BB.bb)
140- 165 A26 --- Cloud Name(s) of parent cloud(s)
--------------------------------------------------------------------------------
Note (1): Name and coordinates from Yi+ (2018, J/ApJS/236/51) or
Eden+ (2019, J/MNRAS/485/2895).
Note (2): Young stellar object (YSO) association inferred by visual inspection
with YSO information of SIMBAD data and protostar catalogs of WISE,
Spitzer, Herschel, and GAIA ("Protostellar"=149 occurrences or
"Starless"=58 occurrences).
Note (3): Reference as follows:
1 = Aidelman et al. 2018, J/A+A/610/A30
2 = Camargo et al. 2012MNRAS.423.1940C 2012MNRAS.423.1940C
3 = Fischera & Martin 2012A&A...547A..86F 2012A&A...547A..86F
4 = Galli et al. 2018, J/ApJ/859/33
5 = Hirota et al. 2008PASJ...60..961H 2008PASJ...60..961H
6 = Humphreys 1978ApJS...38..309H 1978ApJS...38..309H
7 = Kounkel et al. 2017, J/ApJ/834/142
8 = Lada et al. 2009ApJ...703...52L 2009ApJ...703...52L
9 = Lombardi et al. 2008A&A...480..785L 2008A&A...480..785L
10 = Ortiz-Leon et al. 2018, J/ApJ/865/73
11 = Perryman et al. 1997, I/239
12 = Pidopryhora et al. 2015ApJS..219...16P 2015ApJS..219...16P
13 = Reid et al. 2016ApJ...823...77R 2016ApJ...823...77R
14 = Straizys et al. 2010BaltA..19..169S 2010BaltA..19..169S
15 = Straizys et al. 2014, J/MNRAS/438/1848
16 = Straizys et al. 2018, J/A+A/611/A9
17 = Sunada et al. 2007, J/PASJ/59/1185
18 = Wang et al. 2016, J/MNRAS/460/3179
Note (4): H2 column density is derived from the 850um peak intensity of the
core and the dust temperature of PGCC (Yi+ 2018, J/ApJS/236/51 and
Eden+ 2019, J/MNRAS/485/2895).
Note (5): Environment as follows:
OL = λ Orionis; 15 occurrences
OA = Orion A; 70 occurrences
OB = Orion B of the Orion region; 28 occurrences
G = Galactic plane (|b|<2°); 52 occurrences
H = high latitudes (|b|≥2°); 42 occurrences
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 20 A20 --- Name SCUBA-2 core name
22- 23 A2 --- l_Tpk82 [≤ ] Limit flag on Tpk82 (1)
25- 28 F4.2 K Tpk82 [0.14/1.3]? 82GHz CCS peak temperature at
the TA* scale
30- 34 F5.2 km/s Vlsr82 [1.71/10.69]? 82GHz CCS Local Standard of
Rest systemic velocity
36- 39 F4.2 km/s DelV82 [0.1/1.17]? 82GHz CCS full width at
half maximum
41- 42 A2 --- l_Tpk94 [≤ ] Limit flag on Tpk94 (1)
44- 47 F4.2 K Tpk94 [0.14/0.94]? 94GHz CCS peak temperature at
the TA* scale
49- 53 F5.2 km/s Vlsr94 [1.56/11.4]? 94GHz CCS Local Standard of
Rest systemic velocity
55- 58 F4.2 km/s DelV94 [0.1/0.9]? 94GHz CCS full width at
half maximum
60- 61 A2 --- l_TpkHC3N [≤ ] Limit flag on TpkHC3N (1)
63- 66 F4.2 K TpkHC3N [0.15/2.06]? HC3N peak temperature at
the TA* scale
68- 72 F5.2 km/s VlsrHC3N [1.44/13.63]? HC3N Local Standard of
Rest systemic velocity
74- 77 F4.2 km/s DelVHC3N [0.1/1.78]? HC3N full width at
half maximum
79- 80 A2 --- l_TpkN2H [≤ ] Limit flag on TpkN2H (1)
82- 85 F4.2 K TpkN2H [0.16/4.9]? N2H+ peak temperature at
the TA* scale (2)
87- 91 F5.2 km/s VlsrN2Hga [1.12/13.6]? N2H+ Local Standard of
Rest systemic velocity (2)
93- 96 F4.2 km/s DelVN2Hga [0.19/1.48]? N2H+ full width at
half maximum (2)
98- 102 F5.2 km/s VlsrN2H [1.35/13.6]? N2H+ systemic velocity (3)
104- 107 F4.2 km/s DelVN2H [0.22/1.42]? N2H+ FWHM (3)
109- 112 F4.1 K Tex [4/21.8]? Excitation temperature (3)
114- 116 F3.1 K e_Tex [0.1/4.3]? Tex uncertainty
118 A1 --- f_Tex d = value derived from dust temperature
120- 123 F4.1 --- tau [0.5/12.7]? Total line optical depth (3)
125- 127 F3.1 --- e_tau [0.1/4]? Tau uncertainty
129- 133 F5.1 K Tant [1.2/109]? Tantτ value (3)
135- 137 F3.1 K e_Tant [0.1/3.3]? Tant uncertainty
--------------------------------------------------------------------------------
Note (1): All values are measured in a spectrum whose peak temperature is
higher than 3σ. In the case of a peak temperature below
3σ, the 3σ level is listed as an upper limit.
Note (2): Peak temperature at the TA* scale, systemic velocity, and
FWHM inferred by Gaussian fitting to the brightest hyperfine component
of the N2H+ line, respectively.
Note (3): Systemic velocity, FWHM, excitation temperature, total line optical
depth of all the hyperfine components (τ), and
Tantτ(=(Tex-Tbg)τ) estimated through the hyperfine structure
fitting to seven components of the N2H+ line, respectively.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 20 A20 --- Name SCUBA-2 core name
22- 23 A2 --- l_Tpkc [≤ ] Limit flag on Tpkc
25- 28 F4.2 K Tpkc [0.08/2.34] Peak temperature at the TA*
scale of the c-C3H2 line
30- 35 F6.2 km/s Vlsrc [-31.72/106]? c-C3H2 systemic velocity
37- 40 F4.2 km/s DelVc [0.22/3.76]? c-C3H2 FWHM
42- 43 A2 --- l_TpkDNC [≤ ] Limit flag on TpkDNC
45- 48 F4.2 K TpkDNC [0.08/2.58] Peak temperature at the TA*
scale of the DNC line
50- 55 F6.2 km/s VlsrDNC [-21/106]? DNC systemic velocity
57- 60 F4.2 km/s DelVDNC [0.2/3.65]? DNC FWHM
62- 63 A2 --- l_TpkHN13C [≤ ] Limit flag on TpkHN13C
65- 68 F4.2 K TpkHN13C [0.08/0.93] Peak temperature at the TA*
scale of the HN13C line
70- 75 F6.2 km/s VlsrHN13C [-19.32/106.07]? HN13C systemic velocity
77- 80 F4.2 km/s DelVHN13C [0.27/3.32]? HN13C FWHM
82- 83 A2 --- l_TpkN2D [≤ ] Limit flag on TpkN2D
85- 88 F4.2 K TpkN2D [0.08/1.2] Peak temperature at the TA*
scale of the N2D+ line from brightest
hyperfine component
90- 95 F6.2 km/s VlsrN2Dga [-19.27/45.77]? N2D+ systemic velocity
from the brightest hyperfine component
97- 100 F4.2 km/s DelVN2Dga [0.19/2]? N2D+ FWHM from the brightest
hyperfine component
102- 107 F6.2 km/s VlsrN2D [-17.4/45.7]? N2D+ systemic velocity (1)
109- 112 F4.2 km/s DelVN2D [0.27/1.8]? N2D+ FWHM (1)
114- 116 F3.1 K Tex [4/9.8]? Excitation temperature (1)
118- 120 F3.1 K e_Tex [0.1/5]? Tex uncertainty
122 A1 --- f_Tex d=value is derived from dust temperature
124- 126 F3.1 --- tau [0.2/4.3]? Total line optical depth of
all the hyperfine components (1)
128- 131 F4.1 --- e_tau [0.1/12.1]? Tau uncertainty
133- 135 F3.1 K Tant [0.3/9.5]? Tantτ(=(Tex-Tbg)τ) (1)
137- 139 F3.1 K e_Tant [0.1/1.2]? Tant uncertainty
--------------------------------------------------------------------------------
Note (1): Systemic velocity, FWHM, excitation temperature, total line optical
depth of all the hyperfine components, and Tant estimated through the
hyperfine structure fitting to seven components of the N2D+ line,
respectively.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 20 A20 --- Name SCUBA-2 core name
22- 23 A2 --- l_NN2D [≤> ] 3σ limit flag on NN2D
25- 29 F5.1 10+11cm-2 NN2D [3.7/140] N2D+ column density
31- 34 F4.1 10+11cm-2 e_NN2D [0.6/26]? NN2D uncertainty
36 A1 --- f_NN2D Flag on NN2D (1)
38- 39 A2 --- l_NN2H [≤> ] 3σ limit flag on NN2H
41- 44 F4.1 10+12cm-2 NN2H [0.7/67]? N2H+ column density
46- 48 F3.1 10+12cm-2 e_NN2H [0.1/7]? NN2H uncertainty
50 A1 --- f_NN2H Flag on NN2H (1)
52- 53 A2 --- l_NDNC [≤> ] 3σ limit flag on NDNC
55- 59 F5.1 10+11cm-2 NDNC [1.8/670] DNC column density
61- 65 F5.1 10+11cm-2 e_NDNC [1.3/340]? NDNC uncertainty
67 A1 --- f_NDNC Flag on NDNC (1)
69- 70 A2 --- l_NHN13C [≤> ] 3σ limit flag on NHN13C
72- 75 F4.1 10+11cm-2 NHN13C [1.9/64] HN13C column density
77- 80 F4.1 10+11cm-2 e_NHN13C [1.5/32]? NHN13C uncertainty
82 A1 --- f_NHN13C Flag on NHN13C (1)
84- 85 A2 --- l_NCCS [≤> ] 3σ limit flag on NCCS
87- 91 F5.1 10+11cm-2 NCCS [6.6/200]? 82GHz CCS column density
93- 97 F5.1 10+11cm-2 e_NCCS [4.2/100]? NCCS uncertainty
99 A1 --- f_NCCS Flag on NCCS (1)
101- 102 A2 --- l_NHC3N [≤> ] 3σ limit flag on NHC3N
104- 109 F6.1 10+11cm-2 NHC3N [5.2/1100]? HC3N column density
111- 115 F5.1 10+11cm-2 e_NHC3N [6/550]? NHC3N uncertainty
117 A1 --- f_NHC3N Flag on NHC3N (1)
119- 120 A2 --- l_N2D/N2H [≤> ] 3σ limit flag on N2D/N2H
122- 125 F4.2 --- N2D/N2H [0.04/1.71]? NN2D to NN2H ratio
127- 130 F4.2 --- e_N2D/N2H [0.01/0.14]? N2D/N2H uncertainty
132- 133 A2 --- l_DNC/HNC [≤> ] 3σ limit flag on DNC/HNC
135- 138 F4.1 --- DNC/HNC [0.1/14.6]? NDNC to NHN13C ratio
140- 143 F4.1 --- e_DNC/HNC [0.1/10.3]? DNC/HNC uncertainty
145- 146 A2 --- l_N2H/CCS [≤> ] 3σ limit flag on N2H/CCS
148- 151 F4.1 --- N2H/CCS [0.2/44.7]? NN2H to NCCS ratio
153- 156 F4.1 --- e_N2H/CCS [0.4/11.7]? N2H/CCS uncertainty
158- 159 A2 --- l_N2H/HCN [≤> ] 3σ limit flag on N2H/HCN
161- 164 F4.1 --- N2H/HCN [0.1/11.3]? NN2H to NHC3N ratio
166- 168 F3.1 --- e_N2H/HCN [0.1/5.6]? N2H/HCN uncertainty
170- 172 F3.1 --- M [0.3/2.4]? Mach number of the N2H+ line
174- 176 F3.1 --- e_M [0.1/0.4]? M uncertainty
178- 179 A2 --- l_Ratio [≤> ] 3σ limit flag on Ratio
181- 183 F3.1 --- Ratio [0.1/5.4]? Integrated intensity ratio
of DNC to HN13C lines
185- 187 F3.1 --- e_Ratio [0.1/1.1]? Ratio uncertainty
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Note (1): Flag as follows:
d = the column density is derived from dust temperature
D = lower limit when the assumed Tex is too low to constrain the upper bound
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History:
From electronic version of the journal
(End) Emmanuelle Perret [CDS] 24-Jan-2022