Title
Multi-epoch VERA observations of H<inf>2</inf>O masers in OH 43.8-0.1
Date Issued
01 January 2005
Access level
open access
Resource Type
journal article
Author(s)
Honma M.
Bushimata T.
Choi Y.K.
Fujii T.
Hirota T.
Horiai K.
Imai H.
Inomata N.
Iwadate K.
Jike T.
Kameya O.
Kamohara R.
Kan-Ya Y.
Kawaguchi N.
Kijima M.
Kobayashi H.
Kuji S.
Kurayama T.
Manabe S.
Miyaji T.
Nakagawa A.
Nakashima K.
Oh C.S.
Omodaka T.
Oyama T.
Rioja M.
Sakai S.
Sato K.
Sasao T.
Shibata K.M.
Shimizu R.
Sora K.
Suda H.
Tamura Y.
Yamashita K.
VERA Observatory
Publisher(s)
Oxford University Press
Abstract
We report on multi-epoch observations of H2O maser emission in the star-forming region OH 43.8-0.1, carried out with VLBI Exploration of Radio Astrometry. The large-scale maser distributions obtained by single-beam VLBI mapping reveal new maser spots scattered over the area of 0.″7 ×1.″0, in addition to a 'shell-like' structure with a scale of 0.″3 ×0.″5, which was mapped previously. Proper motions were also obtained for 43 spots based on 5-epoch monitoring with a time span of 281 days. The distributions of the proper motions show a systematic outflow in the north-south direction with an expansion velocity of ∼ 8kms-1. The overall distributions of the maser spots as well as the proper motions are better represented by a bipolar flow plus a central maser cluster with a complex structure, rather than a shell with uniform expansion, such as those found in Cep A R5 and W 75N VLA2. The distance to OH 43.8-0.1 was also estimated based on the statistical parallax, yielding D = 2.8 ±0.5kpc. This distance is consistent with a near kinematic distance, and rules out a far kinematic distance (∼ 9 kpc). Also, the radial velocity of the OH 43.8-0.1 combined with the distance provides a constraint on the flatness of the galactic rotation curve, indicating that there is no systematic difference in the rotation speeds at the Sun and at the position of OH 43.8-0.1, which is located at a galacto-centric radius of ∼ 6.3 kpc. © 2005. Astronomical Society of Japan.
Start page
595
End page
603
Volume
57
Issue
4
Language
English
OCDE Knowledge area
Física y Astronomía
Scopus EID
2-s2.0-25144519732
Source
Publications of the Astronomical Society of Japan
ISSN of the container
00046264
Sources of information: Directorio de Producción Científica Scopus