J/ApJ/756/60 A 3mm line survey in 37 IR dark clouds (Sanhueza+, 2012)
Chemistry in infrared dark cloud clumps: a molecular line survey at 3 mm.
Sanhueza P., Jackson J.M., Foster J.B., Garay G., Silva A., Finn S.C.
<Astrophys. J., 756, 60 (2012)>
=2012ApJ...756...60S 2012ApJ...756...60S
ADC_Keywords: Abundances ; Millimetric/submm sources ; Molecular clouds ;
Interstellar medium
Keywords: astrochemistry; ISM: abundances; ISM: clouds; ISM: molecules;
stars: formation
Abstract:
We have observed 37 Infrared Dark Clouds (IRDCs), containing a total
of 159 clumps, in high-density molecular tracers at 3mm using the 22m
ATNF Mopra Telescope located in Australia. After determining kinematic
distances, we eliminated clumps that are not located in IRDCs and
clumps with a separation between them of less than one Mopra beam. Our
final sample consists of 92 IRDC clumps. The most commonly detected
molecular lines are (detection rates higher than 8%) N2H+, HNC,
HN13C, HCO+, H13CO+, HCN, C2H, HC3N, HNCO, and SiO. We
investigate the behavior of the different molecular tracers and look
for chemical variations as a function of an evolutionary sequence
based on Spitzer IRAC and MIPS emission. Optical depth calculations
show that in IRDC clumps the N2H+ line is optically thin, the C2
H line is moderately optically thick, and HNC and HCO+ are optically
thick.
Description:
We made single-pointing observations of molecular lines at 3mm using
the ATNF Mopra 22m telescope located in Australia. The source list
comprises 37 IRDCs, containing a total of 159 clumps. This is a
sub-sample of the 38 IRDCs and 190 clumps identified by Rathborne et
al. (2006, Cat. J/ApJ/641/389) using 1.2mm dust continuum emission at
11" angular resolution.
The observations were carried out during 2008 July-August and 2010
September. They were performed with the 3mm Monolithic Microwave
Integrated Circuits (MMIC) receiver and the Mopra spectrometer (MOPS)
in the "broadband" mode, resulting in a total bandwidth of 8.3GHz
split over four overlapping sub-bands of 2.2GHz. The observed
frequencies range between 85.540 and 93.840GHz. This frequency range
allowed us to observe 15 molecular lines simultaneously.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 73 159 Clump properties
table3.dat 85 1156 Molecular line Gaussian parameters
table5.dat 105 92 Optical depths and column densities for
the 92 IRDC clumps
table10.dat 100 92 Continuum emission parameters and molecular
abundances for the 92 IRDC clumps
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See also:
J/A+A/530/A118 : G29.96-0.02 and G35.20-1.74 1mm and 3mm maps (Pillai+, 2011)
J/A+A/527/A88 : Chemistry in infrared dark clouds (Vasyunina+, 2011)
J/ApJS/197/25 : MALT90 pilot survey (Foster+, 2011)
J/ApJ/715/310 : Early stages of star formation in IRDCs (Rathborne+, 2010)
J/ApJ/710/150 : Molecular lines in EGOs (Chen+, 2010)
J/A+A/515/A42 : Catalog of high extinction clouds (Rygl+, 2010)
J/A+A/505/405 : A catalogue of Spitzer dark clouds (Peretto+, 2009)
J/MNRAS/399/1506 : IRDC cores in SCUBA Legacy Catalogue (Parsons+, 2009)
J/AJ/136/2391 : GLIMPSE Extended Green Objects catalog (Cyganowski+, 2008)
J/ApJ/680/349 : Galactic distribution of IRDCs (Jackson+, 2008)
J/PAZh/33/143 : Laboratory studies of HNCO (Lapinov+, 2007)
J/ApJ/653/1325 : Galactic distribution of infrared dark clouds (Simon+, 2006)
J/ApJ/641/389 : Millimetric observations of IRDC cores (Rathborne+, 2006)
J/ApJ/651/L125 : Water masers associated with IR dark cloud cores (Wang+, 2006)
J/ApJ/639/227 : MSX IRDC candidate catalog (Simon+, 2006)
J/A+A/432/369 : Leiden Atomic and Molecular Database (LAMDA) (Schoeier+, 2005)
J/A+A/426/97 : SIMBA survey. 1.2-mm/IRAS sources (Faundez+, 2004)
J/A+A/361/1079 : HNCO in massive galactic dense cores (Zinchenko, 2000)
J/A+A/321/293 : SiO production in interstellar shocks (Schilke+ 1997)
J/A+A/291/943 : Protostellar cores (Ossenkopf+, 1994)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 13 A13 --- MSXDC IRDC Name (GLLL.ll+BB.bb)
15- 18 A4 --- Clump Clump identifier
(<[RJS2006] MSXDC GLLL.ll+DD.dd MMNN> in Simbad)
20- 21 I2 h RAh Hour of right ascension (J2000)
23- 24 I2 min RAm Minute of right ascension (J2000)
26- 29 F4.1 s RAs Second of right ascension (J2000)
31 A1 --- DE- Sign of declination (J2000)
32- 33 I2 deg DEd Degree of declination (J2000)
35- 36 I2 arcmin DEm Arcminute of declination (J2000)
38- 39 I2 arcsec DEs Arcsecond of declination (J2000)
41- 45 F5.1 km/s Vlsr [2.6/119.2] LSR velocity from the N2H+
JF1F=123->012 transition
47 A1 --- f_Vlsr [cd] Note on the Vlsr origin (1)
49- 51 F3.1 kpc Dist [0.5/7.8] Distance
53 A1 --- f_Dist [cd] Note on the Dist origin (1)
55- 58 F4.1 K Tdust [16/52]? Dust temperature
60 A1 --- Cl Spitzer classification (2)
62- 73 A12 --- Comm Comment (3)
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Note (1): Flag as follows:
c = Velocity and distance determined from the HCO+ line.
d = Velocity and distance from Rathborne et al. (2010, Cat. J/ApJ/715/310).
Note (2): Denotes the classification based on Spitzer/IRAC colors and the
presence or absence of Spitzer/MIPS 24um emission.
Classification code as follows:
B = blue
I = intermediate
R = red
A = active
Q = quiescent
Note (3): Comment as follows:
IRDC = the clump is located in an IRDC (the 92 sources of this study).
Non-IRDC = the clump is not associated with an IRDC.
No Detection = no molecular line was detected in this survey.
Bright Blue = objects with bright 3.6um emission that are predominantly
unextincted stars.
Blended = the angular separation between two sources is less than one
Mopra beam.
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 13 A13 --- MSXDC IRDC name (GLLL.ll+BB.bb)
15- 18 A4 --- Clump Clump identifier (MMNN)
20- 47 A28 --- Mol Molecule identifier
49- 52 F4.2 K rms The rms noise
54- 57 F4.2 K TA ? Antenna temperature
59- 62 F4.2 K e_TA ? Uncertainty in TA
64- 69 F6.2 km/s Vlsr ? Local standard of rest velocity
71- 74 F4.2 km/s e_Vlsr ? Uncertainty in Vlsr
76- 80 F5.2 km/s DelV ? Line width
82- 85 F4.2 km/s e_DelV ? Uncertainty in DelV
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Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
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1- 7 A7 --- IRDCt IRDC truncated name (GLLL.ll)
9- 12 A4 --- Clump Clump identifier (MMNN)
14- 17 F4.2 --- tauN [0.04/5]? N2H+ optical depth
19- 22 F4.1 --- tauHC [7/75]? HCO+ optical depth
24- 27 F4.1 --- tauHN [4.5/74]? HNC optical depth
29- 31 F3.1 --- tauC [0.2/6]? C2H optical depth
33- 37 F5.2 10+13cm-2 NN2H [0.3/14]? N2H+ column density
39- 42 F4.2 10+13cm-2 e_NN2H [0.08/6.2]? NN2H uncertainty
44- 48 F5.2 10+14cm-2 NHCO [0.5/10.1]? HCO+ column density
50- 53 F4.2 10+14cm-2 e_NHCO [0.1/7]? NHCO uncertainty
55- 59 F5.2 10+14cm-2 NHNC [0.5/14]? HNC column density
61- 64 F4.2 10+14cm-2 e_NHNC [0.2/4]? NHNC uncertainty
66- 69 F4.2 10+14cm-2 NC2H [0.6/8]? C2H column density
71- 74 F4.2 10+14cm-2 e_NC2H [0.2/7]? NC2H uncertainty
76- 79 F4.2 10+13cm-2 NHC3N [0.1/3.4]? HC3N column density
81- 84 F4.2 10+13cm-2 e_NHC3N [0.1/0.3]? NHC3N uncertainty
86- 89 F4.2 10+13cm-2 NHNCO [0.9/10]? HNCO column density
91- 94 F4.2 10+13cm-2 e_NHNCO [0.5/1.5]? NHNCO uncertainty
96-100 F5.2 10+12cm-2 NSiO [1/35]? SiO column density
102-105 F4.2 10+12cm-2 e_NSiO [0.7/2.1]? NSiO uncertainty
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Byte-by-byte Description of file: table10.dat
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Bytes Format Units Label Explanations
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1- 7 A7 --- IRDCt IRDC truncated name (GLLL.ll)
9- 12 A4 --- Clump Clump identifier (MMNN)
14- 16 I3 mJy F1.2mm [14/548] 1.2mm flux in mJy/beam
18- 21 F4.2 10+22/cm2 N(H2) [0.1/6] H2 column density
23- 27 F5.2 10-9 N2H [0.1/17]? N2H+ abundance
29- 33 F5.2 10-9 e_N2H [0.02/17]? N2H uncertainty
35- 39 F5.2 10-8 HCO [0.3/28]? HCO+ abundance
41- 45 F5.2 10-8 e_HCO [0.09/15]? HCO uncertainty
47- 51 F5.2 10-8 HNC [0.5/19]? HNC abundance
53- 57 F5.2 10-8 e_HNC [0.1/11]? HNC uncertainty
59- 63 F5.2 10-8 C2H [0.7/16.2]? C2H abundance
65- 69 F5.2 10-8 e_C2H [0.2/26.1]? C2H uncertainty
71- 75 F5.2 10-10 HC3N [1.4/13.8]? HC3N abundance
77- 80 F4.2 10-10 e_HC3N [0.3/3.6]? HC3N uncertainty
82- 85 F4.2 10-9 HNCO [0.2/8.1]? HNCO abundance
87- 90 F4.2 10-9 e_HNCO [0.1/2]? HNCO uncertainty
92- 95 F4.2 10-10 SiO [2.7/9.2]? SiO abundance
97-100 F4.2 10-10 e_SiO [0.3/4.5]? SiO uncertainty
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 24-Mar-2014