J/A+AS/118/191 Multitransition CS-study towards H2O masers (Juvela, 1996)
Studies of dense molecular cores in regions of massive star formation.
IV. Multitransition CS-study towards southern H2O masers in the longitude
range l=308-360deg
Juvela M.
<Astron. Astrophys. Suppl. Ser. 118, 191 (1996)>
=1996A&AS..118..191J 1996A&AS..118..191J (SIMBAD/NED BibCode)
ADC_Keywords: Masers ; Radio lines ; Radial velocities
Keywords: masers - stars: formation - ISM: clouds - ISM: molecules -
radio lines: ISM
Abstract:
We have observed CS and C34S emission towards 33 H2O maser
positions in the southern sky (δ←28deg) using the SEST
telescope. Most of the sources were selected also for their
association with strong IRAS sources. CS(2-1) was detected in all
sources, with the possible exception of two. Most sources were also
mapped in the transitions CS(5-4) and C34S(2-1) and half of the
sample also in CS(2-1). CS and C34S transitions J=2-1, J=3-2 J=5-4
were measured towards the centres of the clouds as determined from the
mapping. CS and C34S transitions J=7-6 were measured in about a half
dozen clouds. CO(1-0) was measured in most clouds in order to
determine the kinetic temperatures. The CS column densities were
calculated using the LTE approximation. All measurements were also
analyzed using a spherical LVG model. We present the observational
data and the results of this analysis.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2 120 33 The source list
table3 130 132 CS and C34S lines area and Gaussian line
parameters for the central positions of the
sources
table5 63 116 Results for the LTE analysis of the CS
observations
table6 43 28 The densities and cloud masses calculated in
LTE approximation from the lines C34S(2-1)
and CS(2-1)
table7 45 33 Results from the LVG analysis
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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/124/385 : Dense molecular cores. V. (Zinchenko+ 1997)
J/A+AS/133/337 : Dense molecular cores. VII. (Zinchenko+ 1998)
Byte-by-byte Description of file: table2
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Bytes Format Units Label Explanations
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2- 15 A14 --- Name Source name
17- 32 A16 --- names Other names
34- 35 I2 h RAh Right ascension 1950
37- 38 I2 min RAm Right ascension 1950
40- 43 F4.1 s RAs Right ascension 1950
45 A1 --- DE- Declination sign
46- 47 I2 deg DEd Declination 1950
49- 50 I2 arcmin DEm Declination 1950
52- 55 F4.1 arcsec DEs Declination 1950
57- 59 I3 km/s RV Radial velocity of the H2O maser
60 A1 --- n_RV [+] A '+' indicates velocity of an OH maser
62- 65 F4.2 kpc DistG ? Galacto-centric distance
68- 71 F4.2 kpc Dist1 ? Kinematic distance from CS data
72 A1 --- u_Dist1 [)] Uncertainty flag on Dist1
75- 79 F5.2 kpc Dist2 ? Kinematic distance from C34S data
80 A1 --- u_Dist2 [)] Uncertainty flag on Dist2
84- 86 I3 pc z1 ? Height above the galactic plane from CS data
87 A1 --- u_z1 [)] Uncertainty flag on z1
90- 93 I4 pc z2 ? Height above the galactic plane from
C34S data
94 A1 --- u_z2 [)] Uncertainty flag on z2
96- 99 F4.1 kpc DistRef ? Distance estimates from the literature
101 A1 --- r_DistRef Distance references (1)
103-112 A10 --- Ref Maser references (2)
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Note (1): Distance references:
1. Caswell J.L. & Haynes R.F. 1987, A&A, 171, 261 =1987A&A...171..261C 1987A&A...171..261C
2. Henning T. et al. 1990, A&A, 227, 542 =1990A&A...227..542H 1990A&A...227..542H
3. Lockman F. 1979,ApJ, 232, 761 =1979ApJ...232..761L 1979ApJ...232..761L
4. Moorwood A.F.M. et al. 1983, A&A, 125, 342 =1983A&A...125..342M 1983A&A...125..342M
5. Neckel T. et al. 1978, A&A, 69, 51 =1978A&A....69...51N 1978A&A....69...51N
6. Simpson J.P. et al. 1990, ApJ, 354, 165 =1990ApJ...354..165S 1990ApJ...354..165S
7. Testi L. et al. 1994, A&A, 288, 634 =1994A&A...288..634T 1994A&A...288..634T
8. Zavagno A. et al. 1992, A&A, 259, 241 =1992A&A...259..241Z 1992A&A...259..241Z
Note (2): Maser references:
a. Batchelor R.A. et al. 1980, Aust. J. Phys., 33, 139 =1980AuJPh..33..139B 1980AuJPh..33..139B
b. Braz M.A. & Scalise E. Jr. 1982, A&A, 107, 272 =1982A&A...107..272B 1982A&A...107..272B
c. Braz M.A. et al. 1989, A&AS, 77, 465 =1989A&AS...77..465B 1989A&AS...77..465B
d. Caswell J.L. et al. 1983, Aust. J. Phys., 36, 401 =1983AuJPh..36..361C 1983AuJPh..36..361C
e. Forster J.R. & Caswell J.L. 1989, A&A, 213, 339 =1989A&A...213..339F 1989A&A...213..339F
f. Guesten R. & Downes D. 1983, A&A, 117, 343 =1983A&A...117..343G 1983A&A...117..343G
g. Kaufmann P. et al. 1977, AJ, 82, 577 =1977AJ.....82..577K 1977AJ.....82..577K
h. Moran J.M. & Rodriguez L.F. 1980, ApJ, 236, L159 =1980ApJ...236L.159M 1980ApJ...236L.159M
i. Scalise E. Jr. & Braz M.A. 1980, A&A, 85, 149 =1980A&A....85..149S 1980A&A....85..149S
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Byte-by-byte Description of file: table3
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Bytes Format Units Label Explanations
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1- 12 A12 --- Name Source name
14- 22 A9 --- Pos Offsets of the observed position relative to
the positions given in table2
23 I1 --- J J values for the upper level of each
transition
25- 29 F5.2 K.km/s IntTmb1 ? Integrated line temperature
(from C34S data)
31- 34 F4.2 K.km/s e_IntTmb1 ? rms uncertainty on IntTmb1
37- 40 F4.2 K Tmb1 ? Line temperature (from C34S data)
42- 45 F4.2 K e_Tmb1 ? rms uncertainty on Tmb1
48- 53 F6.2 km/s RV1 ? Radial velocity (from C34S data)
55- 58 F4.2 km/s e_RV1 ? rms uncertainty on RV1
61- 64 F4.2 km/s DV1 ? Observed line width (from C34S data)
66- 69 F4.2 km/s e_DV1 ? rms uncertainty on DV1
72 A1 --- wing1 [bra] Note on the spectra (1)
74- 79 F6.2 K.km/s IntTmb2 ? Integrated line temperature (from CS data)
81- 84 F4.2 K.km/s e_IntTmb2 ? rms uncertainty on IntTmb2
87- 91 F5.2 K Tmb2 ? Line temperature (from CS data)
93- 96 F4.2 K e_Tmb2 ? rms uncertainty on Tmb2
99-104 F6.2 km/s RV2 ? Radial velocity (from CS data)
106-109 F4.2 km/s e_RV2 ? rms uncertainty on RV2
112-116 F5.2 km/s DV2 ? Observed line width (from CS data)
118-121 F4.2 km/s e_DV2 ? rms uncertainty on DV2
124-125 A2 --- wing2 [bra ] Note on the spectra (1)
127-128 A2 --- wing3 [bra ] Note on the spectra (1)
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Note (1): b: blue wing, r: red wing, a: strong absorption
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Byte-by-byte Description of file: table5
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Bytes Format Units Label Explanations
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1- 11 A11 --- Name Source name
13 I1 --- J J values for the upper level of each transition
17- 20 F4.1 K Tex ? Excitation temperature
22- 24 F3.1 K e_Tex ? rms uncertainty on Tex
29- 32 F4.2 --- taup ? Optical depth from C34S data
(classical method) (1)
34- 37 F4.2 --- e_taup ? rms uncertainty on taup
42- 45 F4.2 --- taua ? Optical depth from C34S data
(second method) (2)
47- 50 F4.2 --- e_taua ? rms uncertainty on taua
53- 57 F5.2 [cm-2] log(N) ? Column density calculated from the line
integrals (C34S data)
59- 62 F4.2 [cm-2] e_log(N) ? rms uncertainty on log(N)
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Note (1): The optical depth taup was obtained in the usual manner
from the ratio of the peak main beam temperatures assuming
identical excitation temperatures and beam filling factors
for both isotopes.
Note (2): If one takes into account the line broadening due to the
optical depth (Phillips et al., =1979ApJ...231..720P 1979ApJ...231..720P),
the observed line width, DV, can be expressed in terms of
the line width of the optically thin line, DV0, as
DV=(DV0/sqrt(ln2)).sqr(ln(tau/ln[2/1+exp(-tau)])).
This expression can be used to derive the optical depth
from the ratio of the line area for the two isotopes.
This value of the optical depth is denoted taua.
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Byte-by-byte Description of file: table6
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Bytes Format Units Label Explanations
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1- 12 A12 --- Name Source name
15- 18 F4.1 kpc Dist Distance
20- 24 F5.2 arcsec Size Size
27- 29 F3.1 [cm-3] log(n) Density
32- 36 I5 solMass Mass Cloud mass
39- 43 I5 solMass Mvir Virial mass of the core
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Byte-by-byte Description of file: table7
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Bytes Format Units Label Explanations
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1- 11 A11 --- Name Source name
15- 16 I2 K Tkin ? Kinetic temperature
17 A1 --- u_Tkin [?] Uncertainty flag on Tkin
19 A1 --- l_log(n1) Limit flag on log(n1)
20- 22 F3.1 [cm-3] log(n1) ? Total gas density derived from CS data
24 I1 0.1[cm-3] e_log(n1) ? rms uncertainty on log(n1)
27- 30 F4.1 [cm-2] log(N1) ? 32CS column density (from CS data)
32- 34 F3.1 [cm-3] log(n2) ? Total gas density derived from C34S data
36 I1 0.1[cm-3] e_log(n2) ? rms uncertainty on log(n2)
39- 42 F4.1 [cm-2] log(N2) ? 32CS column density (from C34S data)
44 I1 0.1[cm-2] e_log(N2) ? rms uncertainty on log(N2)
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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] 04-Apr-1996