J/ApJS/202/1 1mm spectral line survey toward GLIMPSE EGOs (He+, 2012)
A 1 mm spectral line survey toward GLIMPSE extended green objects (EGOs).
He J.H., Takahashi S., Chen X.
<Astrophys. J. Suppl. Ser., 202, 1 (2012)>
=2012ApJS..202....1H 2012ApJS..202....1H
ADC_Keywords: YSOs ; Interstellar medium ; Radio lines ; Infrared sources ;
Spectra, millimetric/submm
Keywords: ISM: clouds - ISM: jets and outflows - ISM: kinematics and dynamics -
radio lines: ISM - stars: formation - turbulence
Abstract:
A northern subsample of 89 Spitzer GLIMPSE extended green objects
(EGOs), the candidate massive young stellar objects, are surveyed for
molecular lines in two 1GHz ranges: 251.5-252.5 and 260.188-261.188GHz.
A comprehensive catalog of observed molecular line data and spectral
plots are presented. Eight molecular species are undoubtedly detected:
H13CO+, SiO, SO, CH3OH, CH3OCH3, CH3CH2CN, HCOOCH3,
and HN13C. The H13CO+ 3-2 line is detected in 70 EGOs, among
which 37 also show the SiO 6-5 line, demonstrating their association
with dense gas and supporting the outflow interpretation of the
extended 4.5um excess emission. Our major dense gas and outflow
tracers (H13CO+, SiO, SO, and CH3OH) are combined with our
previous survey of 13CO, 12CO, and C18O 1-0 toward the same
sample of EGOs for a multi-line, multi-cloud analysis of linewidth
and luminosity correlations.
Description:
We selected 89 EGOs with DEC>-38° from the over 300 EGOs in
Cyganowski et al. (2008, Cat. J/AJ/136/2391) as our working sample.
The infrared positions from the same paper are used.
The observations were conducted with the Arizona Radio Observatory 10m
Submillimeter Telescope (ARO SMT) over several nights during two
epochs: 2009 April 24 to May 11 and 2010 March 29 to April 27. The
observed frequency ranges were 251.5-252.5 GHz (USB; upper sidebands)
and 260.188-261.188 GHz (LSB; lower sidebands).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 98 89 Parameters of the EGOs: baseline RMS level at a
resolution of 1km/s, Vsys, and kinematic distances
table3.dat 94 598 Line parameters
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See also:
J/ApJS/196/9 : 95GHz methanol maser survey toward GLIMPSE EGOs (Chen+, 2011)
J/ApJ/710/150 : Molecular lines in EGOs (Chen+, 2010)
J/ApJ/702/1615 : CH3OH maser survey of EGOs (Cyganowski+, 2009)
J/ApJ/699/1153 : Distances to GRS molecular clouds (Roman-Duval+, 2009)
J/AJ/136/2391 : GLIMPSE Extended Green Objects catalog (Cyganowski+, 2008)
J/ApJ/582/756 : Velocities of HII regions (Kolpak+, 2003)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 11 A11 --- EGO Object name (GLL.ll+B.bb)
13- 14 I2 h RAh IR Hour of Right ascension (J2000)
16- 17 I2 min RAm IR Minute of Right ascension (J2000)
19- 22 F4.1 s RAs IR Second of Right ascension (J2000)
24 A1 --- DE- IR Sign of the Declination (J2000)
26- 27 I2 deg DEd IR Degree of Declination (J2000)
29- 30 I2 arcmin DEm IR Arcminute of Declination (J2000)
32- 33 I2 arcsec DEs IR Arcsecond of Declination (J2000)
35- 36 I2 mK rms1 RMS noise in baseline in lower sideband
38- 39 I2 mK rms2 RMS noise in baseline in upper sideband
41- 46 F6.2 km/s Vsys ? Systemic velocity (1)
48- 51 F4.2 km/s e_Vsys ? The 1σ error in Vsys
53- 60 A8 --- n_Vsys Notes upon systemic velocity (2)
62- 66 F5.2 kpc Dkin ? Kinematic distance or near kinematic distance
68- 71 F4.2 kpc E_Dkin ? Positive 1σ uncertainty in Dkin
73- 76 F4.2 kpc e_Dkin ? Negative 1σ uncertainty in Dkin
78- 82 F5.2 kpc Dfar ? Far kinematic distance
84- 87 F4.2 kpc E_Dfar ? Positive 1σ uncertainty in Dfar
89- 92 F4.2 kpc e_Dfar ? Negative 1σ uncertainty of Dfar
94- 98 A5 --- NoteD Notes upon kinematic distances (3)
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Note (1): Averaged over all strong lines.
Note (2): Note upon systemic velocity as follows:
new = new velocity not presented in Chen et al. (2010, Cat. J/ApJ/710/150);
chen10 = velocity from Chen et al. (2010, Cat. J/ApJ/710/150), non-detection
of H13CO+,3-2 in this work;
weak = the detection level of H13CO+,3-2 is lower than 5-sigma in terms
of integrated line area in our observations. Thus the velocity
should be used with caution.
Note (3): Note upon kinematic distances as follows:
Tan = No near/far kinematic distance ambiguity at the tangential point;
Outer = No near/far kinematic distance ambiguity outside of the solar circle;
IRDC = Near kinematic distance determined by the association to IRDCs;
Z1/2 = Near distance is preferred if the perpendicular distance is smaller
than the scale hight of 60 pc of the Galaxy but larger than or
nearly equal to two times of the scale hight;
HISA = H I self absorption method (Roman-Duval et al. 2009,
Cat. J/ApJ/699/1153);
21cm = The 21cm continuum absorption line method (Roman-Duval et al. 2009,
Cat. J/ApJ/699/1153);
HII = HI absorption line method for HII regions (Kolpak et al., 2003,
Cat. J/ApJ/582/756);
Aver = Average of near and far kinematic distances, with the near/far
difference included in uncertainty;
N/F = Both the near/far kinematic distances are given.
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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- 11 A11 --- EGO Object name (GLL.ll+B.bb)
13- 40 A28 --- Trans Detected molecular line transition (1)
42- 50 F9.2 MHz Freq Line frequency (2)
52- 55 F4.2 MHz e_Freq ? The 1σ error in Freq (2)
57- 61 F5.2 km/s FWHM FWHM line width (3)
63- 67 F5.2 km/s e_FWHM ? The 1σ error in FWHM (3)
69- 72 I4 mK Tmb Mainbeam line temperature
74- 75 I2 mK e_Tmb The 1σ error in Tmb
77- 81 F5.3 K.km/s Iint ? Line area (4)
83- 87 F5.3 K.km/s e_Iint ? The 1σ error in Iint (4)
89- 92 F4.1 --- SNR ? Signal to noise ratio of line area (5)
94 A1 --- Note Notes about line blending and line fitting (6)
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Note (1): The string '(E+A)' after the transition CH3OCH3,10(2,9)-9(1,8) means
it is a blending of four transitions: EA, AE, EE, and AA.
Note (2): If the value of e_Freq is missing, it means the line is either fit
with fixed catalogue frequency or fit with fix line frequency
increment in a multi-Gaussian profile fitting.
Note (3): If the value of e_FWHM is missing, it means the line is fit with the
same line width as other lines in a multi-Gaussian profile fitting.
Note (4): If the values of Iint, e_Iint and SNR are missing, it means the line
is the second component of a double Gaussian fit to the wide line w
ing of a broad line feature.
Note (5): Iint/e_Iint.
Note (6): Note as follows:
p = partially blended with neigbouring lines of which blended lines are fit
together by a multi-Gaussian profile with fixed catalogue frequencies
and identical line width;
b = totally blended lines of which member lines are fit independently with
a single Gaussian profile, so that the contribution from other blended
lines are not separated yet.
s = the second Gaussian component of the double-Gaussian fit to a line with
broad line wings.
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 09-Oct-2012