The dynamics of the encounter of two globular clusters made up of 105 stars each in the bulge of an elliptical galaxy has been followed up to 15 orbital periods (1.7*107 years) by mean of a direct summation code. Aim of these simulations is to understand whether the merging of a group of globular clusters in a unique stellar system is possible in the central regions of galaxies before the strong coupled bulge-nucleus tidal actions destroy them. As a matter of fact three dynamical mechanisms act in competition during the merging of two globular clusters. The galactic tidal action tends on one side to break up clusters before they form a unique self-gravitating system; on the other side the same tidal force has also the effect to convert translational kinetic energy into internal random motion thus leading slowly clusters to inner galactic regions. Additionally the dynamical friction caused by the stellar field decelerates significantly the cluster orbital decay. Due to the non-linearity of the interactions among these mechanisms reliable results can be achieved just via detailed numerical simulations as those we present here.
Globular cluster merging in the inner galactic region / CAPUZZO DOLCETTA, Roberto Angelo; DI MATTEO, Paola; S., Paolini. - STAMPA. - 13:(2005), pp. 381-382. (Intervento presentato al convegno XXVth General Assembly of the IAU - 2003 tenutosi a Sydney (Australia) nel 13 - 26 July 2003).
Globular cluster merging in the inner galactic region
CAPUZZO DOLCETTA, Roberto Angelo;DI MATTEO, PAOLA;
2005
Abstract
The dynamics of the encounter of two globular clusters made up of 105 stars each in the bulge of an elliptical galaxy has been followed up to 15 orbital periods (1.7*107 years) by mean of a direct summation code. Aim of these simulations is to understand whether the merging of a group of globular clusters in a unique stellar system is possible in the central regions of galaxies before the strong coupled bulge-nucleus tidal actions destroy them. As a matter of fact three dynamical mechanisms act in competition during the merging of two globular clusters. The galactic tidal action tends on one side to break up clusters before they form a unique self-gravitating system; on the other side the same tidal force has also the effect to convert translational kinetic energy into internal random motion thus leading slowly clusters to inner galactic regions. Additionally the dynamical friction caused by the stellar field decelerates significantly the cluster orbital decay. Due to the non-linearity of the interactions among these mechanisms reliable results can be achieved just via detailed numerical simulations as those we present here.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
