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Kinematic signature of a rotating bar near a resonanceRecent work based on H I, star count and emission data suggests that the Milky Way has rotating bar-like features. In this paper, I show that such features cause distinctive stellar kinematic signatures near Outer Lindblad Resonance (OLR) and Inner Lindblad Resonance (ILR). The effect of these resonances may be observable far from the peak density of the pattern and relatively nearby the solar position. The details of the kinematic signatures depend on the evolutionary history of the 'bar' and therefore velocity data, both systematic and velocity dispersion, may be used to probe the evolutionary history as well as the present state of Galaxy. Kinematic models for a variety of sample scenarios are presented. Models with evolving pattern speeds show significantly stronger dispersion signatures than those with static pattern speeds, suggesting that useful observational constraints are possible. The models are applied to the proposed rotating spheroid and bar models; we find (1) none of these models chosen to represent the proposed large-scale rotating spheroid are consistent with the stellar kinematics and (2) a Galactic bar with semimajor axis of 3 kpc will cause a large increase in velocity dispersion in the vicinity of OLR (approximately 5 kpc) with little change in the net radial motion and such a signature is suggested by K-giant velocity data. Potential future observations and analyses are discussed.
Document ID
19950040030
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Weinberg, Martin D.
(Univ. of Massachusetts, Amherst, MA United States)
Date Acquired
August 16, 2013
Publication Date
January 10, 1994
Publication Information
Publication: The Astrophysical Journal, Part 1
Volume: 420
Issue: 2
ISSN: 0004-637X
Subject Category
Astrophysics
Accession Number
95A71629
Funding Number(s)
CONTRACT_GRANT: NAG5-1999
Distribution Limits
Public
Copyright
Other

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