J/ApJ/691/1560 Dense core survey in the Orion B cloud (Ikeda+, 2009)
A survey of dense cores in the Orion B cloud.
Ikeda N., Kitamura Y., Sunada K.
<Astrophys. J., 691, 1560-1582 (2009)>
=2009ApJ...691.1560I 2009ApJ...691.1560I
ADC_Keywords: Surveys ; Molecular clouds ; Radio lines ;
Millimetric/submm sources ; Interstellar medium
Keywords: ISM: clouds - ISM: individual (Orion B) - stars: formation
Abstract:
We have carried out an H13CO+(J=1-0 at 86.75433GHz) core survey
in a large area of 1deg2, covering most of the dense region in the
Orion B molecular cloud, using the Nobeyama 45m radio telescope with
the 25-BEam Array Receiver System. We cataloged 151 dense cores using
the clumpfind method. The cores have mean radius, velocity width, and
mass of 0.10±0.02pc, 0.53±0.15km/s, and 8.1±6.4M☉,
respectively, which are very similar to those in the Orion A cloud. We
examined the spatial relation between our H13CO+ cores and the
850um cores observed by Johnstone and colleagues in 2001 (Cat.
J/ApJ/559/307) and 2006 (Cat. J/ApJ/639/259), and found that there are
two types of spatial relationships: H13CO+ cores with and without
the 850um cores. Since the mean density of the 850um cores is higher
than that of the H13CO+ cores, we can interpret the H13CO+
cores with 850um cores as being more centrally concentrated and hence
more evolved, compared with those without.
Description:
All of our observations have been carried out with the Nobeyama 45m
radio telescope in the period from 2004 December to 2006 May.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 72 151 Physical properties of the H13CO+ cores in
the Orion B cloud
table4.dat 45 64 How the 850um cores are associated with the
H13CO+ cores in the Orion B cloud
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See also:
J/ApJ/665/1194 : Dense cores in the Orion A cloud survey (Ikeda+, 2007)
J/ApJ/639/259 : Sub-mm clumps in Orion B South molecular cloud (Johnstone+,
2006)
J/ApJ/559/307 : Sub-mm mapping in Orion B molecular cloud (Johnstone+, 2001)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- ID H13CO+ (86.754GHz) core identification
(<[IKS2009] H13CO+ NNN> in Simbad)
5 I1 h RAh Hour of right ascension (J2000)
7- 8 I2 min RAm Minute of right ascension (J2000)
10- 11 I2 s RAs Second of right ascension (J2000)
13 A1 --- DE- Declination sign (J2000)
14 I1 deg DEd Degree of declination (J2000)
16- 17 I2 arcmin DEm Arcminute of declination (J2000)
19- 22 F4.1 arcsec DEs Arcsecond of declination (J2000)
24- 27 F4.1 km/s VLSR LSR velocity of H13CO+ core (86.754GHz)
29- 31 F3.1 K Tpk Peak T*A temperature
33- 36 F4.1 arcsec Rad Core radius in arcsec (1)
38- 41 F4.2 pc Radp Core radius in parsec (1)
43- 46 F4.2 km/s dV Core velocity width (1)
48- 51 F4.1 Msun MLTE LTE core mass (1)(2)
53- 56 F4.1 K Tex Excitation temperature
58- 61 F4.1 Msun Mvir Virial mass (1)
63- 66 F4.2 10+4cm-3 n Mean number density of the core (1)
68- 72 F5.3 10pc2.m/s Vol Observed volume of the core (Ωobs) in
10-2pc2.km/s unit (1)
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Note (1): The typical uncertainty of each quantity is:
Rad = 0.04pc, derived from the uncertainty in the estimation of the
core projected area
dV = 0.13km/s, corresponding to the velocity resolution
MLTE = a factor of 3 (see text)
Mvir = a factor of 3, derived from the uncertainties in Rad and dv
n = a factor of 4, derived from the uncertainties in Rad and MLTE
Vol = 0.5x10-2pc2km/s, derived from the uncertainties in Rad and dv
Note (2): MLTE as in equation (5) of Paper I (Ikeda et al., 2007,
Cat. J/ApJ/665/1194)
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- ID Core identification (<[IKS2009] H13CO+ NNN>
in Simbad)
5- 6 A2 --- Type [AB' ] Type of H13CO+ core (1)
8- 19 A12 --- LocPk Name of the 850um core located at the
H13CO+ peak (HHMMmm+DDMMm) (2)
21- 32 A12 --- NotPk1 Name of the 850um core not at the H13CO+
peak (HHMMmm+DDMMm) (2)
34- 45 A12 --- NotPk2 Name of the second 850um core not at the
H13CO+ peak (HHMMmm+DDMMm) (2)
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Note (1): Types as follows:
A = cores whose H13CO+ emission peak coincides with a peak of the 850um
continuum emission. There are 35 Type A cores.
A' = cores whose peak coincides with a 850um peak, where one or more 850um
cores are located within the projected extent of the H13CO+ core.
There are 12 Type A' cores.
B = H13CO+ cores do not contain any 850um counterparts. There are 45
Type B cores.
B' = cores whose H13CO+ emission peak does not coincide with any 850um
peak, but where one or more 850um peaks are found within the H13CO+
core. There are 17 Type B' cores.
Note (2): The 850um cores are <[IKS2009] SMM JHHMMmm+DDMMm> in Simbad and
come from Johnstone et al. (2001, Cat. J/ApJ/559/307 -
<[JFM2001] SMM JHHMMmm+DDMMm> in Simbad- and 2006, Cat. J/ApJ/639/259,
<[JMM2006] SMM JHHMMmm+DDMMm> in Simbad).
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History:
From electronic version of the journal
References:
Ikeda et al. Paper I. 2007ApJ...665.1194I 2007ApJ...665.1194I Cat. J/ApJ/665/1194
(End) Emmanuelle Perret [CDS] 24-Feb-2011