J/ApJ/838/49 CO large-field observations around l=150° (Xiong , 2017)
CO(J=1-0) observations of a filamentary molecular cloud in the Galactic region
centered at l=150°, b=3.5°.
Xiong F., Chen X., Yang J., Fang M., Zhang S., Zhang M., Du X., Long W.
<Astrophys. J., 838, 49-49 (2017)>
=2017ApJ...838...49X 2017ApJ...838...49X (SIMBAD/NED BibCode)
ADC_Keywords: Carbon monoxide ; Interstellar medium ; Photometry, infrared ;
YSOs ; Molecular clouds
Keywords: ISM: clouds; ISM: molecules; ISM: structure; stars: formation
Abstract:
We present large-field (4.25x3.75deg2) mapping observations toward
the Galactic region centered at l=150°,b=3.5° in the J=1-0
emission line of CO isotopologues (12CO, 13CO, and C18O), using
the 13.7m millimeter-wavelength telescope of the Purple Mountain
Observatory. Based on the 13CO observations, we reveal a filamentary
cloud in the Local Arm at a velocity range of -0.5 to 6.5km/s. This
molecular cloud contains 1 main filament and 11 sub-filaments, showing
the so-called "ridge-nest" structure. The main filament and three
sub-filaments are also detected in the C18O line. The velocity
structures of most identified filaments display continuous
distribution with slight velocity gradients. The measured median
excitation temperature, line width, length, width, and linear mass of
the filaments are ∼9.28K, 0.85km/s, 7.30pc, 0.79pc, and
17.92M☉/pc, respectively, assuming a distance of 400pc. We find
that the four filaments detected in the C18O line are thermally
supercritical, and two of them are in the virialized state, and thus
tend to be gravitationally bound. We identify in total 146 13CO
clumps in the cloud, about 77% of the clumps are distributed along the
filaments. About 56% of the virialized clumps are found to be
associated with the supercritical filaments. Three young stellar
object candidates are also identified in the supercritical filaments,
based on the complementary infrared data. These results indicate that
the supercritical filaments, especially the virialized filaments, may
contain star-forming activities.
Description:
Our observation of the G150 region was conducted by the 13.7m
millimeter-wavelength telescope of the Purple Mountain Observatory
(PMO) located in Delingha, China, from 2013 September to 2014
November. The whole observed region covered an area within
147.75°≤l≤152° and 1.5°≤b≤5.25°, and was observed
in 12CO(J=1-0), 13CO(J=1-0), and C18O(J=1-0) simultaneously with
the 9-beam Superconducting Spectroscopic Array Receiver. The half
power beam width of the telescope is about 52" at 115.2GHz, and 50" at
110.2GHz.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 45 12 Properties of filaments
table2.dat 60 146 Properties of clumps in the G150 region
table3.dat 99 57 Infrared photometric magnitudes of YSO candidates
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See also:
VIII/39 : Composite CO Survey of the Milky Way (Dame+ 1987)
VII/233 : The 2MASS Extended sources (IPAC/UMass, 2003-2006)
II/311 : WISE All-Sky Data Release (Cutri+ 2012)
J/A+A/440/151 : Observations at 850um in Perseus clusters (Hatchell+, 2005)
J/A+A/505/405 : A catalogue of Spitzer dark clouds (Peretto+, 2009)
J/A+A/533/A17 : Coalsack CO maps (Beuther+, 2011)
J/ApJ/783/130 : Parallaxes of high mass star forming regions (Reid+, 2014)
J/AJ/147/46 : Properties of clumps in the NAN complex (Zhang+, 2014)
J/A+A/584/A91 : Catalog of dense cores in Aquila from Herschel (Konyves+, 2015)
J/ApJ/828/59 : Molecular clouds in the Milky Way with CO obs. (Su+, 2016)
J/ApJS/224/7 : CO obs. of the outer arm in the 2nd quadrant (Du+, 2016)
J/ApJS/230/17 : CO obs. of MCs in the Extreme Outer Galaxy region (Sun+, 2017)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 3 A3 --- ID Filament identifier (F1 to F12)
5- 9 F5.2 K Tex [7.9/10.2] Excitation temperature
11-14 F4.2 km/s DelV [0.6/1.1] Line width Δv in
the 13CO emission
16-21 F6.2 Msun Mass [67.2/850] LTE mass traced by the 13CO emission
23-27 F5.2 pc Length [3.7/13.5] Length in the 13CO emission
29-32 F4.2 pc Width [0.4/1.8] Width in the 13CO emission
34-38 F5.2 Msun/pc M/l [10.2/63.4] Linear mass traced by
the 13CO emission
40-45 F6.2 Msun MC18O [16/200.3]? LTE mass traced by the C18O emission
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 5 A5 --- --- [MWISP] Milky Way Imaging Scroll Painting
(MWISP)
7- 21 A15 --- MWISP Clump identifier (GLLL.lll+BB.bbb)
23- 26 F4.2 km/s Vel [0.7/5.4] LSR velocity
28- 32 F5.3 pc Rad [0.01/0.2] Physical radius
34- 38 F5.2 K Tex [5.6/13.5] Excitation temperature
40- 43 F4.2 km/s DelV [0.1/1.1] Line width
45- 48 F4.2 Msun MLTE [0.03/1.8] LTE mass
50- 54 F5.2 Msun MVir [0.3/17.3] Virial mass
56- 60 F5.2 --- alpha [0.7/18.7] Virial parameter (1)
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Note (1): The ratio of virial mass to LTE mass of the clumps.
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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- 2 I2 --- Seq [1/57] YSO index number
4- 12 F9.5 deg GLON Galactic longitude
14- 20 F7.5 deg GLAT Galactic latitude
22- 26 F5.2 mag Jmag [12.7/19]? 2MASS J (1.25um) band magnitude (1)
28- 31 F4.2 mag e_Jmag [0.02/0.2]? Uncertainty in Jmag (1)
33- 37 F5.2 mag Hmag [11.6/16.2]? 2MASS H (1.65um) band magnitude (1)
39- 42 F4.2 mag e_Hmag [0.02/0.3]? Uncertainty in Hmag (1)
44- 48 F5.2 mag Ksmag [10.5/15.2]? 2MASS Ks (2.16um) band magnitude
50- 53 F4.2 mag e_Ksmag [0.02/0.2]? Uncertainty in Ksmag
55- 59 F5.2 mag 3.4mag [8.6/16] WISE W1 (3.4um) band magnitude
61- 64 F4.2 mag e_3.4mag [0.02/0.06] Uncertainty in 3.4mag
66- 70 F5.2 mag 4.6mag [7.8/13] WISE W2 (4.6um) band magnitude
72- 75 F4.2 mag e_4.6mag [0.02/0.03] Uncertainty in 4.6mag
77- 81 F5.2 mag 12mag [5/12.3] WISE W3 (12um) band magnitude (1)
83- 86 F4.2 mag e_12mag [0.01/0.2]? Uncertainty in 12mag (1)
88- 91 F4.2 mag 22mag [2.4/9.3] WISE W4 (22um) band magnitude (1)
93- 96 F4.2 mag e_22mag [0.02/0.5]? Uncertainty in 22mag (1)
98- 99 A2 --- Class YSO classification (42 sources "II";
15 sources "I")
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Note (1): For the photometric magnitudes without uncertainties, the values
presented here are the upper limits.
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History:
From electronic version of the journal
Acknowledgements:
Fang Xiong (pmo.ac.cn) who provided more accurate coordinates for table 3.
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 26-Oct-2017