J/A+A/314/615 Maps of the 36 GHz methanol emission (Liechti+, 1996)
Maps of the 36 GHz methanol emission
Liechti S., Wilson T.L.
<Astron. Astrophys. 314, 615 (1996)>
=1996A&A...314..615L 1996A&A...314..615L (SIMBAD/NED BibCode)
ADC_Keywords: Masers
Keywords: ISM: molecules - ISM: clouds - ISM: HII regions - radio lines: ISM
Abstract:
We have used the Effelsberg 100-meter telescope to map the 36GHz
4-1->30E methanol transition in galactic star forming regions
where methanol masers were previously detected. In most sources, the
emission consists in one or several narrow (maser) features
superimposed on a broader, presumably quasi-thermal component. The
line shapes and positions of the narrow features are often similar to
those observed in the other ClassI methanol maser transitions (at 25,
44, 84 and 95GHz), but with some exceptions. Our observations confirm
that, unlike the strong ClassII methanol masers (at 12.2, and 6.6GHz),
the ClassI methanol masers are offset from the compact HII regions,
infrared sources and OH/H2O masers. In outflow sources, these are
located at the edge of the molecular lobes.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1 115 116 Line parameters for detected sources
table1.tex 88 423 LaTeX version of table1
table2 42 7 Non detected sources
table3 33 29 Main detected features in Sgr B2
table4 33 18 Main detected features in Sgr A-A
figure1.ps 130 1581 Postscript file of figure 1 (with caption)
figure3.ps 130 1821 Postscript file of figure 3 (with caption)
figure5.ps 130 729 Postscript file of figure 5 (with caption)
figure7.ps 130 983 Postscript file of figure 7 (with caption)
figure8.ps 131 1078 Postscript file of figure 8 (with caption)
figure9.ps 130 1306 Postscript file of figure 9 (with caption)
figure10.ps 130 937 Postscript file of figure 10 (with caption)
figure11.ps 130 1399 Postscript file of figure 11 (with caption)
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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- 14 A14 --- Name Source name (1)
16- 17 I2 h RAh Right ascension 1950 (hours) (1)
19- 20 I2 min RAm Right ascension 1950 (minutes) (1)
22- 25 F4.1 s RAs Right ascension 1950 (seconds) (1)
27 A1 --- DE- Declination sign
28- 29 I2 deg DEd Declination 1950 (degrees) (1)
31- 32 I2 arcmin DEm Declination 1950 (arcminutes) (1)
34- 35 I2 arcsec DEs Declination 1950 (arcseconds) (1)
37- 41 F5.1 Jy.km/s S ? Integrated flux density of the feature (2)
43- 46 F4.1 Jy.km/s e_S ? 1 sigma uncertainty on integrated flux
49- 54 F6.2 km/s V ? Center velocity of the feature (3)
56- 59 F4.2 km/s e_V ? 1 sigma uncertainty on center velocity
61- 65 F5.2 km/s W ? Width of the feature (3)
67- 70 F4.2 km/s e_W ? 1 sigma uncertainty on width
72- 74 I3 arcsec dRA ? R.A. position offset of the feature (4)
76 I1 arcsec e_dRA ? 1 sigma uncertainty on R.A. position offset
79- 81 I3 arcsec dDE ? Dec. position offset of the feature (4)
83 I1 arcsec e_dDE ? 1 sigma uncertainty on dec. position offset
87- 88 I2 arcsec theta ? Angular size of the feature (5)
90 I1 arcsec e_theta ? 1 sigma uncertainty on angular size
93-103 A11 --- Rem Remarks (6)
105-115 A11 --- F-name Other name for the position of the feature
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Note (1): The source name and coordinates are repeated for each detected
feature. The sources are ordered in increasing right ascension.
Note (2): The integrated flux density (determined from spectral gaussian fit
of the feature) is the one at the peak position (see note (3)). If no
peak position was determined, it is the maximum integrated area of
the different observed positions.
Note (3): The velocity (with respect to the l.s.r.) and width is the mean over
the all the observed positions and the 1 sigma uncertainty is the
statistical error of this mean.
Note (4): The offset is with respect to the R.A. and Dec. position of the
source.The position of the emission peak of the feature has been
determined by a spatial 2-dimension gaussian fit on the integrated
area of the line. The error is the error of the fit and does not
include pointing errors. When no fit was performed (line too weak,
extended or on the edge of the map), the position given is the
position where the maximum flux density has been detected.
Note (5): Theta is the mean size of the source assuming a gaussian shape,
calculated from the mean of the minor and major axis half power width
of the elliptical 2-dimensional gaussian fitted on the line area
contour map (assuming a 26" HPBW for the telescope beam). Theta is
not given when the peak of the detected emission is on the edge of
the map, or when the 2-dimension gaussian fit was not performed
(2 peaks, too extended, line too weak, ...).
Note (6): P: point-like source in our beam (i.e. < 10")
td: tentative detection
em: peak of the detected emission on the edge of the observed map
ex: extended emission
uncomp: map uncomplete
mf: many features, only the strongest are given
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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- 9 A9 --- Name Source name
11- 12 I2 h RAh Right ascension 1950
14- 15 I2 min RAm Right ascension 1950
17- 20 F4.1 s RAs Right ascension 1950
22 A1 --- DE- Declination sign
23- 24 I2 deg DEd Declination 1950
26- 27 I2 arcmin DEm Declination 1950
29- 30 I2 arcsec DEs Declination 1950
33- 37 F5.1 km/s Vcen Center velocity of observation
39- 41 f3.1 Jy rms 1 sigma upper limit (spectrum r.m.s. noise)
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Byte-by-byte Description of file: table3 table4
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Bytes Format Units Label Explanations
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1- 4 I4 Jy Fpeak Peak flux density of the feature
6- 10 F5.1 km/s Vcen Center velocity of the feature
12- 14 F3.1 km/s e_Vcen 1 sigma uncertainty on center velocity
17- 20 F4.1 km/s Width Width of the feature
22- 24 F3.1 km/s e_Width 1 sigma uncertainty on width
27- 29 I3 arcsec dRA Feature right ascension position offset (1)
31- 33 I3 arcsec dDE Feature declination position offset (1)
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Note (1): The offsets are with respect to the position given in Table 1 for
Sgr B2 (Table 3) and Sgr A-A (Table 4).
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Courtesy: Stella Liechti
(End) Patricia Bauer [CDS] 16-Apr-1996