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| Paper: |
Physical Properties of Gaseous Features in Barred Galaxies: Effects of the Bar Strength |
| Volume: |
488, 8th International Conference of Numerical Modeling of Space Plasma Flows (ASTRONUM 2013) |
| Page: |
90 |
| Authors: |
Kim, W.-T.; Seo, W.-Y.; Kim, Y. |
| Abstract: |
Barred galaxies commonly possess gaseous substructures such as a pair of dust lanes, a nuclear ring, and nuclear spirals at their centers. We use hydrodynamic simulations to study the physical properties of the substructures and their relationships with the bar strength. We vary the bar mass fbar relative to the spheroidal component as well as its aspect ratio, and increase the bar strength over 0.2Gyr. We find expressions for the bar strength Qb and the radius where the maximum bar torque occurs. When compared with observations, these suggest that bars in real galaxies are most likely to have fbar∼0.3. While dust lanes are aligned parallel to the bar and tend to be more straight under a stronger and more elongated bar, nuclear rings are aligned perpendicular to the bar. The radius of a nuclear ring, in general smaller than the inner Lindblad resonance radius, is a decreasing function of Qb, consistent with observations. This demonstrates that the ring size is determined primarily by the bar strength rather than the resonance. Nuclear spirals located inside nuclear rings are transient such that they unwind and become stronger with time until turning into shocks, with an unwinding rate higher for larger Qb, consistent with observations. All of these results suggest that it is the bar strength that determines the physical properties of gaseous substructures in barred galaxies. |
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