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Full-Text Articles in Physical Sciences and Mathematics
Kinematic Signature Of A Rotating Bar Near A Resonance, Md Weinberg
Kinematic Signature Of A Rotating Bar Near A Resonance, Md Weinberg
Astronomy Department Faculty Publication Series
There have been several recent suggestions that the Milky Way has rotating bar-like features based on HI and star count data. In this paper, I show that such features cause distinctive stellar kinematic signatures near OLR and ILR. The effects 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 systemic and velocity dispersion, may be used to probe the evolutionary history as well as the present state of the Galaxy. …
Weakly Damped Modes In Star-Clusters And Galaxies, Md Weinberg
Weakly Damped Modes In Star-Clusters And Galaxies, Md Weinberg
Astronomy Department Faculty Publication Series
A perturber may excite a coherent mode in a star cluster or galaxy. If the stellar system is stable, it is commonly assumed that such a mode will be strongly damped and therefore of little practical consequence other than redistributing momentum and energy deposited by the perturber. This paper demonstrates that this assumption is false; weakly damped modes exist and may persist long enough to have observable consequences. To do this, a method for investigating the dispersion relation for spherical stellar systems and for locating weakly damped modes in particular is developed and applied to King models of varying concentration. …