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Title: TIME-DEPENDENT COROTATION RESONANCE IN BARRED GALAXIES

Abstract

The effective potential neighboring the corotation resonance region in barred galaxies is shown to be strongly time-dependent in any rotating frame, due to the competition of nearby perturbations of similar strengths with differing rotation speeds. Contrary to the generally adopted assumption that in the bar rotating frame the corotation region should possess four stationary equilibrium points (Lagrange points), with high quality N -body simulations, we localize the instantaneous equilibrium points (EPs) and find that they circulate or oscillate broadly in azimuth with respect to the pattern speeds of the inner or outer perturbations. This implies that at the particle level the Jacobi integral is not well conserved around the corotation radius. That is, angular momentum exchanges decouple from energy exchanges, enhancing the chaotic diffusion of stars through the corotation region.

Authors:
;  [1];  [2]
  1. Institute of Astronomy and Astrophysics, Academia Sinica, Taipei 10617, Taiwan (China)
  2. Geneva Observatory, University of Geneva, CH-1290 Sauverny (Switzerland)
Publication Date:
OSTI Identifier:
22667317
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 830; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ANGULAR MOMENTUM; DIFFUSION; DISTURBANCES; ENERGY TRANSFER; EQUILIBRIUM; GALAXIES; PERTURBATION THEORY; RESONANCE; ROTATION; SIMULATION; SPACE DEPENDENCE; STARS; TIME DEPENDENCE; VELOCITY

Citation Formats

Wu, Yu-Ting, Taam, Ronald E., and Pfenniger, Daniel, E-mail: ytwu@asiaa.sinica.edu.tw, E-mail: daniel.pfenniger@unige.ch, E-mail: taam@asiaa.sinica.edu.tw. TIME-DEPENDENT COROTATION RESONANCE IN BARRED GALAXIES. United States: N. p., 2016. Web. doi:10.3847/0004-637X/830/2/111.
Wu, Yu-Ting, Taam, Ronald E., & Pfenniger, Daniel, E-mail: ytwu@asiaa.sinica.edu.tw, E-mail: daniel.pfenniger@unige.ch, E-mail: taam@asiaa.sinica.edu.tw. TIME-DEPENDENT COROTATION RESONANCE IN BARRED GALAXIES. United States. doi:10.3847/0004-637X/830/2/111.
Wu, Yu-Ting, Taam, Ronald E., and Pfenniger, Daniel, E-mail: ytwu@asiaa.sinica.edu.tw, E-mail: daniel.pfenniger@unige.ch, E-mail: taam@asiaa.sinica.edu.tw. Thu . "TIME-DEPENDENT COROTATION RESONANCE IN BARRED GALAXIES". United States. doi:10.3847/0004-637X/830/2/111.
@article{osti_22667317,
title = {TIME-DEPENDENT COROTATION RESONANCE IN BARRED GALAXIES},
author = {Wu, Yu-Ting and Taam, Ronald E. and Pfenniger, Daniel, E-mail: ytwu@asiaa.sinica.edu.tw, E-mail: daniel.pfenniger@unige.ch, E-mail: taam@asiaa.sinica.edu.tw},
abstractNote = {The effective potential neighboring the corotation resonance region in barred galaxies is shown to be strongly time-dependent in any rotating frame, due to the competition of nearby perturbations of similar strengths with differing rotation speeds. Contrary to the generally adopted assumption that in the bar rotating frame the corotation region should possess four stationary equilibrium points (Lagrange points), with high quality N -body simulations, we localize the instantaneous equilibrium points (EPs) and find that they circulate or oscillate broadly in azimuth with respect to the pattern speeds of the inner or outer perturbations. This implies that at the particle level the Jacobi integral is not well conserved around the corotation radius. That is, angular momentum exchanges decouple from energy exchanges, enhancing the chaotic diffusion of stars through the corotation region.},
doi = {10.3847/0004-637X/830/2/111},
journal = {Astrophysical Journal},
number = 2,
volume = 830,
place = {United States},
year = {Thu Oct 20 00:00:00 EDT 2016},
month = {Thu Oct 20 00:00:00 EDT 2016}
}