Astronomy and Astrophysics – Astronomy
Scientific paper
Aug 2005
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2005pasj...57..595h&link_type=abstract
Publications of the Astronomical Society of Japan, Vol.57, No.4, pp. 595-603
Astronomy and Astrophysics
Astronomy
7
Galaxy: Kinematics And Dynamics, Ism: H Ii Regions, Ism: Individual (Oh 43.8-0.1), Masers (H2O)
Scientific paper
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 ˜ 8 km s-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 W75N VLA2. The distance to OH 43.8-0.1 was also estimated based on the statistical parallax, yielding D = 2.8 ± 0.5 kpc. This distance is consistent with a near kinematic distance, and rules out a far kinematic distance (˜ 9kpc). 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.
Bushimata Takeshi
Choi Yoon Kyung
Fujii Takahiro
Hirota Tomoya
Honma Mareki
No associations
LandOfFree
Multi-Epoch VERA Observations of H2 Masters in OH 43.8-0.1 does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Multi-Epoch VERA Observations of H2 Masters in OH 43.8-0.1, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Multi-Epoch VERA Observations of H2 Masters in OH 43.8-0.1 will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-798052