Volume 420, Number 1, June II 2004
|Page(s)||265 - 271|
|Section||Stellar structure and evolution|
|Published online||14 May 2004|
The kinematics of water masers in the stellar molecular outflow source, IRAS 19134+2131
Joint Institute for VLBI in Europe, Postbus 2, 7990 AA Dwingeloo, The Netherlands e-mail: email@example.com
2 Department of Physics and Astronomy, University of California, Los Angeles, CA 90095-1562, USA e-mail: firstname.lastname@example.org
3 Jet Propulsion Laboratory, 4800 Oak Grove Drive, Pasadena, CA 91109, USA e-mail: Raghvendra.Sahai@jpl.nasa.gov
4 Departamento de Astronomía, Universitat de Valéncia, 46100 Burjassot, Spain e-mail: email@example.com
5 Instituto de Astrofísica de Canarias, La Laguna, Tenerife 38200, Spain e-mail: firstname.lastname@example.org
Corresponding author: H. Imai, email@example.com
Accepted: 4 March 2004
Using the Very Large Array (VLA) and the Very Long Baseline Array (VLBA), we have observed water maser emission in the proto-planetary nebula candidate IRAS 19134+2131, in which the water maser spectrum has two groups of emission features separated in radial velocity by ~100 km s-1. The blue-shifted and red-shifted clusters of maser features are clearly separated spatially by ~150 mas, indicative of a fast collimated flow. However, not all of the maser features are aligned along the axis of the flow, as is seen in the similar high-velocity water maser source, W43A. Comparing the VLA and VLBA maps of the water maser source, we find 4 maser features that were active for 2 years. Using only VLBA data, we identified proper motions for 8 maser features. The full 3D outflow velocity is estimated to be ~130 km s-1, indicating that the dynamical age of the flow is only ~50 yr. On the basis of the relative positions with respect to the nearby extragalactic reference source, J1925+2106, we also obtain a secular motion of IRAS 19134+2131of mas yr-1 along the Galactic plane toward the Galactic centre. This indicates a “far distance" (≥16 kpc) for IRAS 19134+2131 if the Galactic rotation curve remains flat at 220 km s-1.
Key words: masers / stars: AGB and post-AGB / stars: distances / stars: kinematics / stars: winds, outflows / stars: individual: IRAS 19134+2131
© ESO, 2004
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.