J/A+A/606/A126 Orion Source I 3mm SiO maser emission (Issaoun+, 2017)
VLBA imaging of the 3mm SiO maser emission in the disk-wind from the massive
protostellar system Orion Source I.
Issaoun S., Goddi C., Matthews L.D., Greenhill L.J., Gray M.D.,
Humphreys E.M.L., Chandler C.J., Krumholz M., Falcke H.
<Astron. Astrophys. 606, A126 (2017)>
=2017A&A...606A.126I 2017A&A...606A.126I (SIMBAD/NED BibCode)
ADC_Keywords: Interstellar medium ; Masers
Keywords: ISM: individual objects: Orion BN/KL (except planetary nebulae) -
ISM: jets and outflows - radio lines: stars - stars: formation -
masers
Abstract:
High-mass star formation remains poorly understood due to
observational difficulties (e.g. high dust extinction and large
distances) hindering the resolution of disk-accretion and out
ow-launching regions.
Orion Source I is the closest known massive young stellar object (YSO)
and exceptionally powers vibrationally excited SiO masers at radii
within 100AU, providing a unique probe of gas dynamics and energetics.
We seek to observe and image these masers with Very Long Baseline
Interferometry (VLBI).
We present the first images of the 28SiO v=1, J=2-1 maser emission
around Orion Source I observed at (λ2mm) with the Very Long
Baseline Array (VLBA). These images have high spatial (∼0.3mas) and
spectral (∼0.054km/s) resolutions.
Description:
Reduced spectral cube of the SiO v=1, J=2-1 maser transition near
Orion Source I observed on Jan 24, 2011, in FITS format (with velocity
as primary axis). VLBA project code BG205.
Objects:
-------------------------------------------------------------
RA (2000) DE Designation(s)
-------------------------------------------------------------
05 35 14.16 -05 22 21.5 Orion BN/KL = NAME Orion BN/KL
05 35 14.5149 -05 22 30.582 Orion Source I
-------------------------------------------------------------
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
list.dat 171 1 Informations on fits file
fits/* . 1 Data cube (194G)
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Description of file: from AIPS header of issaoun.fit
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Image=BNKL-I (MA) Filename=CUBE .TRANS . 1
Telescope=VLBA Receiver=VLBA
Observer=BG205A User #= 100
Observ. date=24-JAN-2011 Map date=18-OCT-2016
Minimum=-5.60130215E+00 Maximum= 5.83315964E+01 JY/BEAM
----------------------------------------------------------------
Type Pixels Coord value at Pixel Coord incr Rotat
VELO-LSR 775 3.3254643E+04 -98.00 -5.4321068E+01 0.00
RA---SIN 8192 05 35 14.515 4096.00 -0.000050 0.00
DEC--SIN 8192 -05 22 30.582 6097.00 0.000050 0.00
STOKES 1 1.0000000E+00 1.00 1.0000000E+00 0.00
----------------------------------------------------------------
Coordinate equinox 2000.00
Map type=NORMAL Number of iterations= 9
Conv size= 0.00055 X 0.00019 Position angle= 0.00
Phase shifted in X 0.00000 in Y -0.10000
Rest freq 86243.423 Vel type: RADIO wrt LSR
Alt ref. value 8.62248E+10 wrt pixel 1.00
Maximum version number of extension files of type HI is 1
Maximum version number of extension files of type CC is 775
Maximum version number of extension files of type CG is 1
Maximum version number of extension files of type CG is 1
Maximum version number of extension files of type SL is 1
Maximum version number of extension files of type PL is 1
Keyword = 'WTNOISE ' value = 1.26000635D+00
Keyword = 'SUMWTIN ' value = 9.07234946D-03
Keyword = 'CCFLUX ' value = 0.000000E+00
Keyword = 'CCTOTAL ' value = 0.000000E+00
Keyword = 'OLDRFQ ' value = 8.61973300D+10
Keyword = 'CORRELAT' value = 'DIFX '
Keyword = 'SOURNAM1' value = ' '
Keyword = 'SOURNAM2' value = ' '
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Byte-by-byte Description of file: list.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 9 F9.5 deg RAdeg Right Ascension of center (J2000)
10- 18 F9.5 deg DEdeg Declination of center (J2000)
20- 22 I3 --- Nx Number of pixels along X-axis
24- 27 I4 --- Ny Number of pixels along Y-axis
29- 32 I4 --- Nz Number of pixels along Z-axis
34- 43 A10 "date" Obs.date Observation date
45- 52 F8.1 m/s bVELO-LSR Lower value of VELO-LSR interval
54- 60 F7.1 m/s BVELO-LSR Upper value of VELO-LSR interval
62- 68 F7.4 m/s dVELO-LSR VELO-LSR resolution
70- 78 I9 Kibyte size Size of FITS file
80- 90 A11 --- FileName Name of FITS file, in subdirectory fits
92-171 A80 --- Title Title of the FITS file
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Acknowledgements:
Sara Issaoun, sissaoun(at)science.ru.nl
(End) Sara Issaoun [Radboud University], Patricia Vannier [CDS] 31-Jul-2017