J/ApJ/640/982 43GHz SiO maser features around VX Sgr (Chen+, 2006)
Inward motions of the compact SiO masers around VX Sagittarii.
Chen X., Shen Z.-Q., Imai H., Kamohara R.
<Astrophys. J., 640, 982-994 (2006)>
=2006ApJ...640..982C 2006ApJ...640..982C
ADC_Keywords: Masers
Keywords: circumstellar matter - masers - stars: individual (VX Sagittarii) -
stars: kinematics
Abstract:
We report Very Long Baseline Array (VLBA) observations of 43GHz v=1,
J=1-0 SiO masers in the circumstellar envelope of the M-type
semiregular variable star VX Sgr at three epochs during 1999
April-May. These high-resolution VLBA images reveal a persistent
ringlike distribution of SiO masers with a projected radius of ∼3
stellar radii. The typical angular size of 0.5mas for individual maser
features was estimated from two-point correlation function analysis of
maser spots.
Description:
The 43GHz v=1, J=1-0 SiO maser emission toward VX Sgr was observed at
three epochs (1999 April 24, May 23, and May 31) using the Very Long
Baseline Array (VLBA) of the NRAO.
Objects:
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RA (2000) DE Designation(s)
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18 08 04.0 -22 13 27 VX Sagittarii = V* VX Sgr
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 86 110 43GHz SiO maser features around VX Sgr
observed by the VLBA on 1999 April 24 (Epoch 1)
table3.dat 86 110 43GHz SiO maser features around VX Sgr
observed by the VLBA on 1999 May 23 (Epoch 2)
table4.dat 86 105 43GHz SiO maser features around VX Sgr
observed by the VLBA on 1999 May 31 (Epoch 3)
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See also:
J/A+A/393/115 : 86GHz SiO maser survey of late-type stars (Messineo+, 2002)
J/A+A/418/103 : 86GHz SiO maser survey in the Inner Galaxy (Messineo+, 2004)
J/A+A/435/575 : 86GHz SiO maser survey of late-type stars III (Messineo+ 2005)
Byte-by-byte Description of file: table2.dat table3.dat table4.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- Seq Sequential number (1)
4 A1 --- n_Seq [ab] Note on Seq (2)
6- 10 F5.2 km/s VLSR Velocity in the Local Standard of Rest
at the peak of the velocity profile
12- 15 F4.2 km/s e_VLSR Error in VLSR
17- 20 F4.2 km/s Delu Velocity range across the feature (3)
22- 25 F4.2 km/s DelV FWHM velocity ΔV
27- 30 F4.2 km/s e_DelV Error on DelV
32- 38 F7.3 mas x Feature position in Right Ascension (4)
40- 44 F5.3 mas e_x Error on x (4)
46- 52 F7.3 mas y Feature position in Declination (4)
54- 58 F5.3 mas e_y Error on y (4)
60- 63 F4.2 mas L Angular size of the feature
65- 68 F4.1 Jy Sp Peak flux density (43GHz) of the feature
70- 74 F5.1 Jy.km/s Sint Integrated flux density of all spots
in the feature
76- 78 I3 --- ID1 ? Match ID at epoch 1
80- 82 I3 --- ID2 ? Match ID at epoch 2
84- 86 I3 --- ID3 ? Match ID at epoch 3
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Note (1): Seq corresponds to ID1 in table 2 ([CSI2006] 1 NNN in Simbad),
ID2 in table 3 ([CSI2006] 2 NNN in Simbad), and
ID3 in table 4 ([CSI2006] 3 NNN in Simbad).
Note (2): Note on Seq, defined as follows:
a = Feature that cannot be well represented by a Gaussian curve
b = Reference feature
Note (3): Δu is defined as the difference between the maximal and
minimal velocities of the spots in the feature.
Note (4): Feature positions (x, y) in Right Ascension and Declination were
determined from an intensity-weighted average over maser spots in
the feature. The uncertainty (σx, σy) of a feature
position was defined as the square root of the squared sum of the
mean spot distance from the defined feature position and the mean
measurement error of the spot positions. The weights proportional to
the intensity of the spot were applied in the uncertainty estimation.
The typical position uncertainties of the features are 0.01 and
0.02mas for Right Ascension and Declination, respectively. The
positions are measured with respect to the reference feature at (0,0).
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History:
From electronic version of the journal
(End) Marianne Brouty [CDS] 14-Aug-2007