Abstract
A bar rotating in a pressure-supported halo generally loses angular momentum and slows down due to dynamical friction. Valenzuela & Klypin report a counter-example of a bar that rotates in a dense halo with little friction for several Gyr, and argue that their result invalidates the claim by Debattista & Sellwood that fast bars in real galaxies require a low halo density. We show that it is possible for friction to cease for a while should the pattern speed of the bar fluctuate upward. The reduced friction is due to an anomalous gradient in the phase-space density of particles at the principal resonance created by the earlier evolution. The result obtained by Valenzuela & Klypin is probably an artifact of their adaptive mesh refinement method, but anyway could not persist in a real galaxy. The conclusion by Debattista & Sellwood still stands.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Preview
Unable to display preview. Download preview PDF.
References
Binney, J. & Tremaine, S. 1987, Galactic Dynamics (Princeton: Princeton University Press)
Debattista, V. P. & Sellwood, J. A. 1998, Ap. J. Lett., 493, L5
Debattista, V. P. & Sellwood, J. A. 2000, Ap. J., 543, 704
Hernquist, L. 1990, Ap. J., 356, 359
Holley-Bockelmann, K., Weinberg, M. D. & Katz, N. 2003, astro-ph/0306374
Holley-Bockelmann, K. & Weinberg, M. D. 2005, DDA abstract 36.0512
Kalnajs, A. J. 1977, Ap. J., 212, 637
Kravtsov, A. V., Klypin, A. & Khokhlov, A. M. 1997, Ap. J. Suppl., 111, 73
Lin, D. N. C. & Tremaine, S. 1983, Ap. J., 264, 364
Lynden-Bell, D. 1979, MNRAS, 187, 101
Lynden-Bell, D. & Kalnajs, A. J. 1972, MNRAS, 157, 1
Sellwood, J. A. 2003, Ap. J., 587, 638
Sellwood, J. A. 2004, astro-ph/0407533
Tremaine, S. & Weinberg, M. D. 1984, MNRAS, 209, 729
Valenzuela, O. & Klypin, A. 2003, MNRAS, 345, 406
Weinberg, M. D. 2004, astro-ph/0404169
Weinberg, M. D. & Katz, N. 2002, Ap. J., 580, 627
Author information
Authors and Affiliations
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2007 Springer
About this paper
Cite this paper
Sellwood, J.A., Debattista, V. (2007). ANOMALOUSLY WEAK DYNAMICAL FRICTION IN HALOS. In: DE JONG, R. (eds) ISLAND UNIVERSES. Astrophysics and Space Science Proceedings. Springer, Dordrecht. https://doi.org/10.1007/978-1-4020-5573-7_31
Download citation
DOI: https://doi.org/10.1007/978-1-4020-5573-7_31
Publisher Name: Springer, Dordrecht
Print ISBN: 978-1-4020-5572-0
Online ISBN: 978-1-4020-5573-7
eBook Packages: Physics and AstronomyPhysics and Astronomy (R0)