J/A+A/325/255 5cm OH masers survey (Baudry+ 1997)
A survey of star-forming regions in the 5 cm lines of OH
Baudry A., Desmurs J.-F., Wilson T.L., Cohen R.J.
<Astron. Astrophys. 325, 255 (1997)>
=1997A&A...325..255B 1997A&A...325..255B (SIMBAD/NED BibCode)
ADC_Keywords: Masers ; Radio lines ; Polarization
Keywords: masers - stars: formation - interstellar medium: HII regions;
magnetic fields - radio lines: ISM
Description:
We have undertaken a comprehensive search for 5 cm OH masers in
regions visible from Effelsberg with the 100-m telescope (i.e., those
with declinations above -29o). Our sample is based on bright sources
taken from the IRAS Point Source Catalog and/or from previous 18cm
OH and H_ 2_O surveys. Among the 165 sources observed, 16 are new
(15 exhibit emission and one source shows both absorption and
emission). Two new absorption line sources have been tentatively
detected. The general properties of the 5cm OH sources are presented
and discussed. The 6035MHz line is more often detected than the
6031MHz line. Nevertheless, the latter line is frequently present, a
fact that is not explained by present OH excitation models. Simple
calculations tend to show that there are enough FIR photons to pump
the 6035 and 6031MHz masers, and we found that the statistics of the
ratio S_ radio/S IR_ at 18, 5 and 6cm suggest that the maser
pumping efficiency decreases with increasing OH excitation.
Variability on short (months) or long (years) time-scales is a common
feature in many 5 cm OH sources. We also present observations of the 6
GHz satellite lines and report, besides W3(OH), on two certain and
perhaps two newly detected weak sources. Some implications on the
excitation of OH are briefly discussed.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1 96 168 Observations of the 6031 and 6035 MHz
transitions of OH
table2 80 161 Line parameters of maser emission sources
observed in 1995 July
table3 102 41 Integrated flux densities of maser sources
table4 73 19 Observations of the 6017 and 6049 MHz
transitions of OH
table6 49 116 The sense and percentage of circular
polarization of maser features
table7 45 28 Identification of possible Zeeman patterns
tables.tex 80 1263 LaTeX version of the tables
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Byte-by-byte Description of file: table1
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Bytes Format Units Label Explanations
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1- 10 A10 --- IRAS IRAS source
12- 33 A22 --- Names Other names
35- 36 I2 h RAh Observed right ascension (1950)
38- 39 I2 min RAm Observed right ascension (1950)
41- 45 F5.2 s RAs Observed right ascension (1950)
47 A1 --- DE- Declination sign
48- 49 I2 deg DEd Observed declination (1950)
51- 52 I2 arcmin DEm Observed declination (1950)
54- 58 F5.2 arcsec DEs Observed declination (1950)
60- 63 I4 km/s Vlsrmin LSR Velocity range (lower value)
65- 68 I4 km/s Vlsrmax LSR Velocity range (upper value)
70 A1 --- l_Sen6031MHz(RCP) Limit flag on Sen6031MHz(RCP) (1)
71- 73 F3.2 Jy Sen6031MHz(RCP) ? Sensitivity at 6031MHz, RCP
74- 75 A2 --- n_Sen6031MHz(RCP) Note on Sen6031MHz(RCP) (2)
76 A1 --- l_Sen6031MHz(LCP) Limit flag on Sen6031MHz(LCP) (1)
77- 79 F3.2 Jy Sen6031MHz(LCP) ? Sensitivity at 6031MHz, LCP
80 A1 --- n_Sen6031MHz(LCP) Note on Sen6031MHz(LCP) (2)
82 A1 --- l_Sen6035MHz(RCP) Limit flag on Sen6035MHz(RCP) (1)
83- 85 F3.2 Jy Sen6035MHz(RCP) ? Sensitivity at 6035MHz, RCP
86- 88 A3 --- n_Sen6035MHz(RCP) Note on Sen6035MHz(RCP) (2)
90 A1 --- l_Sen6035MHz(LCP) Limit flag on Sen6035MHz(LCP) (1)
91- 93 F3.2 Jy Sen6035MHz(LCP) ? Sensitivity at 6035MHz, LCP
94- 96 A3 --- n_Sen6035MHz(LCP) Note on Sen6035MHz(LCP) (2)
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Note (1): The upper limits correspond to 3σ
Note (2): E = Emission (see details in Tables 2 and 3)
A = Absorption (see details in Table 5)
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Byte-by-byte Description of file: table2
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Bytes Format Units Label Explanations
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1- 10 A10 --- Source IRAS source name
12- 20 A9 --- Name Other name
22 A1 --- n_Line6031MHz [RL] R: Right, L: left
23- 24 I2 --- Line6031MHz ? Line identification number at 6031MHz
25 A1 --- nLine6031MHz [*] Note (1)
27- 32 F6.2 km/s V6031MHz ? Velocity at 6031MHz
33 A1 --- u_V6031MHz [?] Uncertainty flag on V6031MHz
34- 37 F4.1 Jy Sp6031MHz ? Peak flux density at 6031MHz
38 A1 --- u_Sp6031MHz [?] Uncertainty flag on Sp6031MHz
40- 43 F4.2 km/s LW6031MHz ? Linewidth at 6031MHz
44 A1 --- u_LW6031MHz [?] Uncertainty flag on LW6031MHz
46 A1 --- n_Line6035MHz [RL] R: Right, L: left
47- 48 I2 --- Line6035MHz ? Line identification number at 6035MHz
49 A1 --- nLine6035MHz [*] Note (1)
51- 56 F6.2 km/s V6035MHz ? Velocity at 6035MHz
58- 63 F6.2 Jy Sp6035MHz ? Peak flux density at 6035MHz
64 A1 --- u_Sp6035MHz [?] Uncertainty flag on Sp6035MHz
66- 69 F4.2 km/s LW6035MHz ? Linewidth at 6035MHz
70 A1 --- u_LW6035MHz [?] Uncertainty flag on LW6035MHz
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Note (1): *: feature detected in 1994 May only
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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- 10 A10 --- Source Source name
12- 20 A9 --- Names Other name
22- 27 F6.2 deg GLON Galactic longitude
28- 33 F6.2 deg GLAT Galactic latitude
35- 39 F5.2 Jy.km/s IS6031MHzr ? Integrated flux density at 6031MHz,
right side
40 A1 --- u_IS6031MHzr [?] Uncertainty flag on IS6031MHzr
42- 46 F5.2 Jy.km/s IS6031MHzl ? Integrated flux density at 6031MHz,
left side
47 A1 --- u_IS6031MHzl [?] Uncertainty flag on IS6031MHzl
49- 53 F5.2 Jy.km/s IS6035MHzr ? Integrated flux density at 6035MHz,
right side
56- 60 F5.2 Jy.km/s IS6035MHzl ? Integrated flux density at 6035MHz,
left side
61 A1 --- n_IS6035MHzl [*] Note (1)
62- 65 F4.1 kpc Dist ? Distance
69- 73 F5.2 kpc Dist2 ? Second value of distance when
uncertainty (2)
74 A1 --- n_Dist2 [)] Note on Dist2 (3)
75- 79 F5.1 Jy.kpc2.km/s L6031MHz ? Luminosity at 6031MHz
82- 85 F4.1 Jy.kpc2.km/s L6031MHz2 ? Second value of luminosity at 6031MHz
when uncertainty (2)
87- 92 F6.2 Jy.kpc2.km/s L6035MHz ? Luminosity at 6035MHz
95- 99 F5.1 Jy.kpc2.km/s L6035MHz2 ? Second value of luminosity at 6035MHz
when uncertainty (2)
100 A1 --- n_L6035MHz2 [)] Note on L6035MHz2 (3)
102 A1 --- Per [JM] Period (4)
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Note (1): The left circular 6035MHz spectrum was strongly corrupted
Note (2): When there is an ambiguity in the computation of the kinematic
distance for the observed source, there is two values for the
distance, and then two values for each luminosity.
Note (3): ): for the value less probable
Note (4): J: spectra obtained in 1995 July
M: spectra obtained in 1994 May
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Byte-by-byte Description of file: table4
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Bytes Format Units Label Explanations
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1- 10 A10 --- IRAS IRAS source name
12- 29 A18 --- Names Other names
31- 33 I3 km/s Vlsrmin ? LSR velocity range (lower value)
35- 38 I4 km/s Vlsrmax ? LSR velocity range (upper value)
40 A1 --- l_S6017MHz Limit flag on S6017MHz
41- 44 F4.2 Jy S6017MHz ? 3 σ limit at 6017MHz
46- 47 A2 --- n_S6017MHz Note on S6017MHz (1)
49 A1 --- l_S6049MHz Limit flag on S6049MHz
50- 53 F4.2 Jy S6049MHz ? 3 σ limit at 6049MHz
54- 56 A3 --- n_S6049MHz Note on S6049MHz (1)
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Note (1): A: Absorption; E: emission
1: Source observed in 1990 August; position and line parameters
given in text
2: Line parameters given in text
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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- 10 A10 --- Source Source name
12 I1 --- Note ? Note (1)
14- 24 A11 --- Name Other name
26- 29 I4 MHz Line Line
31 A1 --- Side [RL] Side of the line
33- 38 F6.2 km/s Vlsr LSR velocity (2)
40- 42 A3 --- SensPol Sense of Polarization
44- 45 I2 % Pol Polarization
47- 48 I2 % e_Pol rms uncertainty on Pol
49 A1 --- n_Pol Note on Pol (3)
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Note (1): Polarization derived from the 1995 July spectra except for
18592+0901, 19111+1048 and 21413+5442 whose polarization is
derived from the 1994 May spectra
Note (2): The velocity corresponds to the features identified in Table 2
Note (3): An asterisk means that one of the two spectra at a given velocity is
negative or has been truncated; the corresponding 3σ flux
density is then used in the single polarization scale
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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- 10 A10 --- Source Source name
12- 15 I4 MHz Line Line
17 I1 --- Nline1 First associated line number (1995 July data) (1)
19- 20 I2 --- Nline2 Second associated line number (1995 July data) (1)
21 A1 --- n_Nline [*] Note on the pair (2)
23- 28 F6.2 km/s Vel95 Center velocity for 1995 July observations
30- 33 F4.1 mgauss Field95 Field for 1995 July observations
35- 40 F6.2 km/s Vel94 ? Center velocity for 1994 May observations
42- 45 F4.1 mgauss Field94 ? Field for 1994 May observations
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Note (1): Line identification numbers as listed in Table 2
Note (2): *: Another feature pairing although less likely is possible (see text)
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Table5: Line parameters of absorption sources
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Source Line LSR velocity Linewidth Peak flux density
km/s km/s Jy
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02219+6152 (W3A) 6035 -39.71 2.86 -0.38
02219+6152 (W3A) 6031 -39.45 3.49 -0.41
18222-1317 (RAFGL 2147) 6035 +58.37 (0.30) -0.40
18592+0108 (W48) 6035 42.44 2.54 -0.19
18592+0108 (W48) 6031 42.44 2.54 -0.19
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Note: For 18222-1317 and 18592+0108, see text for derivation of line parameters.
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Acknowledgements: Alain Baudry
(End) Patricia Bauer [CDS] 29-May-1997