Zhong, SY (reprint author), Chinese Acad Sci, Natl Astron Observ China, 20A Datun Rd, Beijing 100012, Peoples R China.
The tidal disruption (TD) of stars by supermassive central black holes from dense rotating star clusters is modeled by high-accuracy direct N-body simulations. As in a previous paper on spherical star clusters, we study the time evolution of the stellar tidal disruption rate and the origin of tidally disrupted stars, which are now accorded to several classes of orbits that only occur in axisymmetric systems (short-axis tube and saucer orbits). Compared with that in spherical systems, we found a higher TD rate in axisymmetric systems. The enhancement can be explained by an enlarged loss cone in phase space that stems from the fact that the total angular momentum J is not conserved. As in the case of spherical systems, the distribution of the last apocenter distance of tidally accreted stars peaks at the classical critical radius. However, the angular distribution of the origin of the accreted stars reveals interesting features. Inside the influence radius of the supermassive black hole the angular distribution of disrupted stars has a conspicuous bimodal structure with a local minimum near the equatorial plane. Outside of the influence radius this dependence is weak. We show that the bimodal structure of orbital parameters can be explained by the presence of two families of regular orbits, namely short-axis tube and saucer orbits. Also, we present the consequences of our results for the loss cone in axisymmetric galactic nuclei.
Astronomy & Astrophysics
; SPACE-TELESCOPE CENSUS
; FINAL-PARSEC PROBLEM
; EQUAL-MASS SYSTEM
; DYNAMICAL EVOLUTION
; SPIRAL GALAXIES
; EFFICIENT MERGER
Chinese Academy of Sciences through the Silk Road Project at NAOC
; Chinese Academy of Sciences through the Chinese Academy of Sciences Visiting Professorship [2009S1-5]
; Chinese Academy of Sciences through the "Qianren" special foreign experts program of China
; Ministry of Finance of People's Republic of China [ZDY Z2008-2]