Astrometry of OH/IR Stars Using 1612MHz Hydroxyl Masers. I. Annual Parallaxes of WX Psc and OH138.0+7.2 MEConference on Why Galaxies Care About AGB Stars III: A Closer Look in Space and Time, JUL 28-AUG
Journal article, 2017
We report on the measurement of the trigonometric parallaxes of 1612 MHz hydroxyl masers around two asymptotic giant branch stars, WX. Psc and OH. 138.0+7.2, using the NRAO Very Long Baseline Array with in-beam phase referencing calibration. We obtain a 3s upper limit of. <= 5.3 mas on the parallax of WX. Psc, corresponding to a lower limit distance estimate of. 190 pc. The obtained parallax of OH. 138.0+7.2 is 0.52 +/- 0.09 mas (+/- 18%), corresponding to a distance of 1.9(-0.3)(+0.4)kpc, making this the first hydroxyl maser parallax below one milliarcsecond. We also introduce a new method of error analysis for detecting systematic errors in the astrometry. Finally, we compare our trigonometric distances to published phase-lag distances toward these stars and find a good agreement between the two methods.
techniques:
Astronomy & Astrophysics
masers
agb stars
circumstellar oh masers
correlator
vera
proper motions
astrometry
pulsars
software
distance
OH 138.0+7.2)
stars: AGB and post-AGB
vlbi astrometry
h2o masers
stars: individual (WX Psc
Author
G. Orosz
Kagoshima University
H. Imai
Kagoshima University
R. Dodson
University of Western Australia
M. J. Rioja
Commonwealth Scientific and Industrial Research Organisation (CSIRO)
University of Western Australia
Spanish National Observatory (OAN)
S. Frey
Hungarian Academy of Sciences
R. A. Burns
Kagoshima University
Joint Institute for VLBI in Europe (JIVE)
S. Etoka
University of Hamburg
A. Nakagawa
Kagoshima University
H. Nakanishi
Kagoshima University
JAXA Institute of Space and Astronautical Science
SKA Organisation
Y. Asaki
Atacama Large Millimeter-submillimeter Array (ALMA)
National Institutes of Natural Sciences
S. R. Goldman
Keele University
Daniel Tafoya Martinez
Chalmers, Earth and Space Sciences, Onsala Space Observatory
Chalmers, Earth and Space Sciences, Radio Astronomy and Astrophysics
Astronomical Journal
0004-6256 (ISSN) 1538-3881 (eISSN)
Vol. 153 3 119- 119Subject Categories
Astronomy, Astrophysics and Cosmology
Roots
Basic sciences
Infrastructure
Onsala Space Observatory
DOI
10.3847/1538-3881/153/3/119