J/A+AS/124/385 Dense molecular cores. V. (Zinchenko+ 1997)
Studies of dense molecular cores in regions of massive star formation.
V. Structure and kinematics of dense cores from ammonia observations
Zinchenko I., Henning T., Schreyer K.
<Astron. Astrophys. Suppl. Ser. 124, 385 (1997)>
=1997A&AS..124..385Z 1997A&AS..124..385Z (SIMBAD/NED BibCode)
ADC_Keywords: Masers ; Radio lines ; Radial velocities
Keywords: stars: formation - ISM: clouds - ISM: molecules -
radio lines: interstellar
Abstract:
We present results of the observations of 17 molecular clouds
associated with bright FIR sources in the NH3 (1, 1) and (2, 2)
lines with the 100-m radio telescope in Effelsberg. The lines were
detected in 11 clouds and 10 of them have been mapped in these lines.
The kinetic temperatures, sizes, masses and mean densities of the
ammonia cores have been derived. For most of the detected clouds the
masses derived under the assumption of a relative ammonia abundance of
χ(NH3)=3x10-8 are close to virial masses. However, in S 88 B
the ratio M/Mvir is only ∼0.1 and in a few other cases this ratio is
significantly lower than unity which may indicate ammonia
underabundance. Almost all objects with the signs of underabundance
are among the most luminous IR sources in our sample. Most of the
mapped cores are elongated with noticeable velocity gradients along
the major axis. The most prominent example is S 255. S 87 has a
two-component structure with 2 distinct velocity components which
overlap partly spatially. In about half of the mapped sources the
NH3 line widths increase near the peaks of the ammonia emission. The
kinetic temperatures are centrally peaked. They reach 20-28K in the
centre and drop to 15-20K at the edges of the ammonia emitting
regions. In S 76 E a weak extended emission in the (1, 1) line at the
velocity blue-shifted by
∼5km/s relative to the core emission was detected. Hyperfine intensity
anomalies in the (1, 1) transition were found in S 199 in addition to
the known case of these anomalies in S 87.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1 85 17 Source list
table5 69 20 NH3 mapping data for S76E
table6 69 15 NH3 mapping data for S86
table7 75 42 NH3 mapping data for S87
table8 72 15 NH3 mapping data for S88B
table9 57 10 NH3 mapping data for S145
table10 72 22 NH3 mapping data for S199
table11 72 25 NH3 mapping data for S231
table12 72 29 NH3 mapping data for S255
table13 72 32 NH3 mapping data for RNO1B
table14 75 15 NH3 mapping data for BFS48
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See also:
J/A+A/288/601 : Dense molecular cores. I. (Zinchenko+ 1994)
J/A+AS/111/95 : Dense molecular cores. II. (Zinchenko+, 1995)
J/A+AS/118/191 : Dense molecular cores. IV. (Juvela, 1996)
J/A+AS/133/337 : Dense molecular cores. VII. (Zinchenko+ 1998)
J/ApJS/125/161 : A database of dense cores mapped in ammonia (Jijina+, 1999)
Byte-by-byte Description of file: table1
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Bytes Format Units Label Explanations
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1- 6 A6 --- Name Source name
8- 9 I2 h RAh Right ascension (1950)
11- 12 I2 min RAm Right ascension (1950)
14- 17 F4.1 s RAs Right ascension (1950)
19- 20 I2 deg DEd Declination (1950)
22- 23 I2 arcmin DEm Declination (1950)
25- 26 I2 arcsec DEs Declination (1950)
28- 33 F6.2 deg GLON Galactic longitude
35- 39 F5.2 deg GLAT Galactic latitude
41- 44 F4.1 kpc RG Galacto-centric distance of the source
46- 49 F4.2 kpc Dist Distance from the Earth
50 A1 --- r_Dist Distance reference (1)
52- 54 I3 pc z Height above the Galactic plane
56- 65 A10 --- IRAS IRAS PSC (Cat. II/125) name
66 A1 --- m_IRAS Multiplicity index on IRAS
68- 73 E6.1 solLum L(IR) IRAS luminosity
75 A1 --- Detec [oh] Source detection (2)
77- 85 A9 --- Rem Remark
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Note (1): a: Brand & Blitz (1993, Cat. J/A+A/275/67))
b: Plume et al. (1992ApJS...78..505P 1992ApJS...78..505P)
c: Blitz et al. (1982ApJS...49..183B 1982ApJS...49..183B, Cat. VII/50)
d: Henning et al. (1992A&AS...93..525H 1992A&AS...93..525H)
e: Avedisova & Palous (1989BAICz..40...42A 1989BAICz..40...42A)
f: Yang et al. (1991ApJ...373..137Y 1991ApJ...373..137Y)
g: Fich & Blitz (1984ApJ...279..125F 1984ApJ...279..125F)
i: assumed
Note (2): h: Outflow detected as given by Mattila et al. (1996, in prep.)
o: Outflow detected as given by Wu et al.
(1976, Cat. J/A+AS/115/283)
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Byte-by-byte Description of file: table*
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Bytes Format Units Label Explanations
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3- 6 I4 arcsec Dalpha Offset in R.A. (multiplied by cosδ)
9- 12 I4 arcsec Ddelta Offset in Dec.
15 I1 --- N Velocity component
18- 23 F6.2 km/s Vlsr ? LSR velocity
26- 29 F4.2 km/s e_Vlsr ? rms uncertainty on Vlsr
33- 37 F5.2 km/s DeltaV ? Line width
40- 43 F4.2 km/s e_DeltaV ? rms uncertainty on DeltaV
46 A1 --- l_logNH3 limit flag on logNH3
47- 51 F5.2 [cm-2] logNH3 Ammonia NH_3(1,1) column density
54- 57 F4.2 [cm-2] e_logNH3 ? rms uncertainty on logNH3
60- 63 F4.1 K Tkin ? Kinetic temperature
66- 69 F4.1 K e_Tkin ? rms uncertainty on Tkin
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Acknowledgements: Igor Zinchenko
References:
Zinchenko I., Paper III 1995A&A...303..554Z 1995A&A...303..554Z
Lapinov et al., Paper VI 1998A&A...336.1007L 1998A&A...336.1007L
(End) Patricia Bauer [CDS] 03-Dec-1996