TY - JOUR
T1 - TIME-DEPENDENT COROTATION RESONANCE in BARRED GALAXIES
AU - Wu, Yu Ting
AU - Pfenniger, Daniel
AU - Taam, Ronald E.
N1 - Publisher Copyright:
� 2016. The American Astronomical Society. All rights reserved.
PY - 2016/10/20
Y1 - 2016/10/20
N2 - 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.
AB - 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.
KW - galaxies: kinematics and dynamics
KW - methods: numerical
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U2 - 10.3847/0004-637X/830/2/111
DO - 10.3847/0004-637X/830/2/111
M3 - Article
AN - SCOPUS:84992692405
SN - 0004-637X
VL - 830
JO - Astrophysical Journal
JF - Astrophysical Journal
IS - 2
M1 - 111
ER -