Abstract
An improved nonlinear asymptotic theory of spiral density waves is developed. It extends the theory developed by Yuan & Kuo to a global theory, not just one limited to the vicinity of the resonance. It can then be applied to the recent high-resolution observations of CO and HST NICMOS of nearby spiral galaxies. As an example, we apply the theory to the nearby grand-design spiral galaxy NGC 5248, which has excellent CO observations in the central regions and exhibits a continuous optical spiral pattern from about 7 kpc to about 100 pc. Using the improved nonlinear asymptotic theory, we confirm the earlier results that the inner two-arm spiral structure of NGC 5248 is driven by a slowly rotating bar potential at the outer inner Lindblad resonance and is a continuation of the outer optical spiral arms. Using the new theory, we calculate the streamlines, surface density, and line-of-sight velocity contours of the bar-driven flow in the central gas disk, and these results are in good agreement with the observations.
Original language | English |
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Pages (from-to) | 180-187 |
Journal | The Astrophysical Journal |
Volume | 644 |
Issue number | 1 |
DOIs | |
Publication status | Published - 2006 |
Externally published | Yes |
Subject classification (UKÄ)
- Astronomy, Astrophysics and Cosmology
Free keywords
- Galaxies: Individual: NGC Number: NGC 5248 Galaxies: Kinematics and Dynamics Galaxies: Spiral Galaxies: Structure