J/ApJ/559/307 Sub-mm mapping in Orion B molecular cloud (Johnstone+, 2001)
Large area mapping at 850 microns.
III. Analysis of the clump distribution in the Orion B molecular cloud.
Johnstone D., Fich M., Mitchell G.F., Moriarty-Schieven G.
<Astrophys. J. 559, 307 (2001)>
=2001ApJ...559..307J 2001ApJ...559..307J
ADC_Keywords: Interstellar medium ; Molecular clouds ; Infrared sources
Keywords: ISM: continuum - ISM: clouds -
ISM: individual (HH 25-26, L1630, NGC 2068, NGC 2071, Orion B) -
ISM: molecules - ISM: structure - stars: formation
Abstract:
We present results from a survey of a 900 arcmin2 region of the
Orion B molecular cloud, including NGC 2068, NGC 2071, and HH
24/25/26, at 850µm using the Submillimeter Common-User Bolometer
Array (SCUBA) on the James Clerk Maxwell Telescope. Following the
techniques developed by Johnstone et al. (2000ApJ...545..327J 2000ApJ...545..327J), we
identify 75 independent objects and compute size, flux, and degree of
central concentration. Comparison with isothermal, pressure-confined,
self-gravitating Bonnor-Ebert spheres implies that the clumps have
internal temperatures of 20-40K and surface pressures
5.5<log(P/k)[CGS]<6.5. The clump masses span 0.2-12.3M☉ assuming
typical dust temperatures and a dust emissivity
κ850=0.01cm2/g.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 79 75 850µm clump properties in Orion B North
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Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 12 A12 --- [JFM2001] The SMM J name (1)
14- 16 A3 --- OriBsmm The OriBN name (2)
18- 19 I2 h RAh Right Ascension (J2000) (3)
21- 22 I2 min RAm Right Ascension (J2000) (3)
24- 27 F4.1 s RAs Right Ascension (J2000) (3)
29 A1 --- DE- Sign of the Declination (J2000) (3)
30- 31 I2 deg DEd Declination (J2000) (3)
33- 34 I2 arcmin DEm Declination (J2000) (3)
36- 37 I2 arcsec DEs Declination (J2000) (3)
39- 43 F5.2 Jy S850 The total 850 micron (350GHz) flux density (4)
45- 48 F4.2 Jy P850 The peak 850 micron flux density in units
of Jy/beam (4)
50- 53 F4.1 10+3AU Reff Effective radius (4)
55- 58 F4.2 --- Conc Observed concentration of the clump (5)
60- 62 F3.0 K Tdust The dust temperature (6)
64- 66 F3.1 [K/cm3] logP/k Log of the central pressure (6)
68- 72 F5.2 solMass Mass1 Clump mass from Bonnor-Ebert (6)
74- 78 F5.2 solMass Mass2 Clump mass from total flux (7)
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Note (1): Name formed from J2000 positions (hhmm.mmdddmm.m).
[JFM2001] SMM JHHMMSS+DDMMm in Simbad.
Note (2): Name as given by Mitchell et al. (2001ApJ...556..215M 2001ApJ...556..215M).
OriBsmm NN in Simbad.
Note (3): Position of peak surface brightness within clump (accurate to 3').
Note (4): Derived from {clfind} (Williams et al. 1994).
Note (5): Where Conc=1-[1.13*B(arcsec)2*S850]/[π*Reff2*F850].
Derived from Bonnor-Ebert analysis (Bonnor, 1956MNRAS.116..351B 1956MNRAS.116..351B and
Ebert, 1955ZA.....37..217E 1955ZA.....37..217E, see text).
Note (6): Derived from Bonnor-Ebert analysis (see text).
Note (7): Derived from the total flux assuming Tdust=30K and
κ850=0.01cm2/g.
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History:
From electronic version of the journal
References:
Johnstone et al., Paper I 2000ApJS..131..505J 2000ApJS..131..505J
Johnstone et al., Paper II 2000ApJ...545..327J 2000ApJ...545..327J
(End) Greg Schwarz [AAS], Patricia Bauer [CDS] 14-Jan-2002