J/ApJS/154/553 Inner galaxy massive star formation regions (Sewilo+, 2004)
Resolution of distance ambiguities of inner galaxy massive star formation
regions. II.
Sewilo M., Watson C., Araya E., Churchwell E., Hofner P., Kurtz S.
<Astrophys. J. Suppl. Ser., 154, 553-578 (2004)>
=2004ApJS..154..553S 2004ApJS..154..553S
ADC_Keywords: H II regions ; Interstellar medium ; Radio lines
Keywords: Galaxy: disk - H II regions - ISM: molecules - radio lines: ISM -
stars: formation
Abstract:
We report simultaneous H110α and H2CO line observations with
the NRAO Green Bank Telescope toward 72HII regions in the Spitzer
Space Telescope GLIMPSE survey area (|l|=10°-65° and
|b|≤1°). We used the H110α line to establish the velocity
of the HII regions and H2CO absorption lines to distinguish between
near and far distances. Accurate distances are crucial for the
determination of physical properties of massive star formation
regions.
Description:
The observations were made on 2002 November 1-3, 8-9, and 14 with the
Green Bank Telescope (GBT). Seventy-two sources were selected from the
IRAS Point Source Catalog.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 74 72 Observed Sources
table2.dat 36 72 Velocity Resolutions of the Spectra
table3.dat 61 54 H110α Line Parameters of Sources with a
Single Velocity Component
table4.dat 59 38 H110α Line Parameters of Sources with
Multiple H110α Velocity Components
table5.dat 71 308 H2CO Line Parameters
table7.dat 80 197 Kinematic Parameters
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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 --- Name Source name
17- 18 I2 h RAh Hour of right ascension (B1950)
20- 21 I2 min RAm Minute of right ascension (B1950)
23- 26 F4.1 s RAs Second of right ascension (B1950)
33 A1 --- --- Sign of declination (B1950)
34- 35 I2 deg DEd Degree of declination (B1950)
37- 38 I2 arcmin DEm Arcminute of declination (B1950)
40- 41 I2 arcsec DEs Arcsecond of declination (B1950)
49- 58 A10 --- OName IRAS name
64- 68 F5.2 kJy S100um Flux density at 100µm
73- 74 I2 min Tint Integration time (1)
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Note (1): The sum of the ON-source and OFF-source integration times.
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 12 A12 --- Name Source name
17- 20 F4.2 km/s DV(H2CO) Velocity resolution of H2CO (1)
25- 28 F4.2 km/s DV(H110a) Velocity resolution of H110α (1)
33- 36 F4.2 --- Comm Panel of the figure 1 of the paper
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Note (1): The intrinsic velocity resolution of the spectra is 0.188km/s.
One, two, and three Hanning smoothings reduce it to 0.38, 0.76, and
1.50km/s, respectively.
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 12 A12 --- Name Source name
14- 19 F6.1 mJy SH110a ? The H110α flux density at 4874.1570MHz
21- 24 F4.1 mJy e_SH110a ? The 1σ error in SH110a
26- 30 F5.1 km/s VLSR ? Local Standard of Rest Velocity
32- 34 F3.1 km/s e_VLSR ? The 1σ error in VLSR
36- 39 F4.1 km/s FWHM ? Full-Width at Half-Maximum
41- 44 F4.1 km/s e_FWHM ? The 1σ error in FWHM
46- 50 F5.2 Jy.km/s IntS ? Integrated flux density
52- 55 F4.2 Jy.km/s e_IntS ? The 1σ error in IntS
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 12 A12 --- Name Source name
13- 14 A2 --- Line Line identification
16 A1 --- f_Line [a] Flag on Line (1)
18- 22 F5.1 mJy SH110a ? The H110α flux density at 4874.1570MHz
24- 26 F3.1 mJy e_SH110a ? The 1σ error in SH110a
28- 32 F5.1 km/s VLSR Local Standard of Rest Velocity
34- 36 F3.1 km/s e_VLSR The 1σ error in VLSR
38- 41 F4.1 km/s FWHM ? Full-Width at Half-Maximum
43- 45 F3.1 km/s e_FWHM ? The 1σ error in FWHM
47- 50 F4.2 Jy.km/s IntS ? Integrated flux density
52- 55 F4.2 Jy.km/s e_IntS ? The 1σ error in IntS
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Note (1): "a" means that the intensity of the line is less than 3σ;
only its position is given.
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Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
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1- 12 A12 --- Name Source name (1)
15- 19 A5 --- Dir Source direction (G1)
20- 26 F7.1 mJy SH2CO ? The H2CO flux density at 4829.6594MHz
28- 32 F5.1 mJy e_SH2CO ? The 1σ error in SH2CO
34- 38 F5.1 km/s VLSR ? Local Standard of Rest Velocity
40 A1 --- leVLSR Limit flag on e_VLSR
42- 44 F3.1 km/s e_VLSR ? The 1σ error in VLSR
46- 50 F5.2 km/s FWHM ? Full-Width at Half-Maximum
52 A1 --- leFWHM Limit flag on e_FWHM
54- 56 F3.1 km/s e_FWHM ? The 1σ error in FWHM
58- 64 F7.3 Jy.km/s IntS ? Integrated flux density
66- 70 F5.3 Jy.km/s e_IntS ? The 1σ error in IntS
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Note (1): In the original table:
G18.46-0.00 MC 1a was noted G18.461-0.004 MC 1, and
G18.46-0.00 MC 1b was noted G18.461-0.004 MC 1
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Byte-by-byte Description of file: table7.dat
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Bytes Format Units Label Explanations
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1- 12 A12 --- Name Source name
14- 18 A5 --- Dir Source direction (G1)
20- 25 F6.2 km/s VLSR Local Standard of Rest Velocity
27- 30 F4.2 km/s e_VLSR The 1σ error in VLSR
32- 34 F3.1 kpc Dnear ? Near source distance
36- 39 F4.1 kpc Dfar ? Far source distance
41- 46 F6.1 km/s VTP Tangent point velocity
48- 50 F3.1 kpc DTP Tangent point distance
52- 55 F4.1 kpc DLSR ? Adopted kinematic source distance
57- 59 F3.1 kpc E_DLSR ? Upper limit in DLSR
61- 63 F3.1 kpc e_DLSR ? Lower limit in DLSR
65- 70 F6.1 pc Z ? Galactic plane distance
72- 75 F4.2 kpc RGC Galactic center distance
77- 79 A3 --- Code The Near/Far code (1)
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Note (1): The Near/Far code is defined as follows:
N = a source at the near kinematic distance;
F = a source at the far distance;
NS = a molecular cloud associated with an UC HII region (i.e., VH2CO_
within 10km/s of VHII at the near distance;
FS = a molecular cloud associated with an UC HII region (i.e., VH2CO_
within 10km/s of VHII at the far distance;
a = No classification or distance is given for this source, because we
cannot unambiguously distinguish between the near and far position of
the source in this velocity range;
b = This source is located at the tangent point, but the position should be
taken with caution since the rotation model does not predict a position
for these velocities.
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Global Notes:
Note (G1): Dir indicates the direction of the H2CO cloud, but we do
not imply an association between the H2CO cloud and the background
HII region.
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History:
From electronic version of the journal
References:
Araya et al., 2002ApJS..138...63A 2002ApJS..138...63A
Watson et al., Paper I 2003ApJ...587..714W 2003ApJ...587..714W
(End) Greg Schwarz [AAS], Marianne Brouty [CDS] 07-Apr-2005