Résumé / Abstract Seminaire_IAP
« Relativistic Dynamics of Nuclear Star Clusters »

David Merritt
Rochester Inst.Technology (Rochester, New York, Etats-Unis d'Amérique)

Encounters between stars and stellar remnants at the centers of galaxies drive many important processes. The fact that these encounters take place near a supermassive black hole (SBH) alters the dynamics in a number of ways:

(1) The orbital motion is quasi-Keplerian so that correlations are maintained for much longer than in purely random encounters;

(2) relativity affects the motion, through mechanisms like precession of the periastron and frame dragging;

(3) the SBH spin is affected, directly by capture and indirectly by spin-orbit torques.

The interplay between these processes is just now beginning to be understood, but a key result is that relativity can be crucially important even at distances that are a substantial fraction of the SBH influence radius. I will discuss this work and its implications for stellar captures, for the evolution of SBH spins, and for the long-term evolution of galactic nuclei. .
vendredi 27 septembre 2013 - 11:00
Amphithéâtre Henri Mineur, Institut d'Astrophysique de Paris
Page web du séminaire / Seminar's webpage