PIRSA:12090064

Supermassive black holes in non-spherical galactic nuclei and enhanced rates of star capture events

Vasiliev, E. (2012). Supermassive black holes in non-spherical galactic nuclei and enhanced rates of star capture events. Perimeter Institute. https://pirsa.org/12090064

Vasiliev, Eugene. Supermassive black holes in non-spherical galactic nuclei and enhanced rates of star capture events. Perimeter Institute, Sep. 25, 2012, https://pirsa.org/12090064 

          @misc{ pirsa_PIRSA:12090064,
            doi = {10.48660/12090064},
            url = {https://pirsa.org/12090064},
            author = {Vasiliev, Eugene},
            keywords = {Cosmology},
            language = {en},
            title = {Supermassive black holes in non-spherical galactic nuclei and enhanced rates of star capture events},
            publisher = {Perimeter Institute},
            year = {2012},
            month = {sep},
            note = {PIRSA:12090064 see, \url{https://pirsa.org}}
          }

Eugene Vasiliev Rochester Institute of Technology

Talk numberPIRSA:12090064
DOI10.48660/12090064
Collection
Talk Type Scientific Series
Subject

Abstract

We consider the stellar-dynamical processes which lead to the capture or tidal disruption of stars by a supermassive black hole, review the standard theory of two-body relaxation and loss-cone repopulation in spherical galactic nuclei, and extend it to the axisymmetric and triaxial nuclear star clusters. In the absense of symmetry which conserves angular momentum, the orbits of stars experience regular or chaotic changes of angular momentum even in the smooth potential of star cluster, which creates a substantial population of "centrophilic" orbits. We discuss the loss cone draining rates, i.e. rates of capture of stars from these orbits. Next we consider the relaxation phenomena in non-spherical nuclei, focusing on the differences between spherical, axisymmetric and triaxial cases. It turns out that the rates of repopulation of the loss cone are moderately higher in non-spherical systems, but in the triaxial case an additional, often substantial, increase of capture rates comes from draining of the centrophilic orbit population.