On the trapping of starts by a newborn stellar supercluster

CARPINTERO, D. D.; MUZZIO, J. C.

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY

Royal Astronomical Society

Lugar: Oxford; Año: 2009 vol. 397 p. 1021 - 1026

0035-8711

Numerical experiments conducted by Fellhauer et al. (2006) suggest that a supercluster maycapture up to about 40 per cent of its mass from the galaxy where it belongs.Nevertheless, in those experiments the cluster was created making appear itsmass out of nothing, rather than from mass already present in the galaxy. Herewe use a thought experiment, plus a few simple computations, to show that thedifference between the dynamical effects of these two scenarios (i.e., masscreation vs. mass concentration) is actually very important. We also present theresults of new numerical experiments, simulating the formation of the clusterthrough mass concentration, that show that trapping depends critically on theprocess of cluster formation and that the amounts of gained mass aresubstantially smaller than those obtained from mass creation. Besides, thecriterion used by Felhauer et al. (2006) to decide the membership to the supercluster isnot adequate, and the use of a more sensible criterion, based on Jacobi´sintegral, renders a number of captures at least an order of magnitude smaller.All things considered, the captures cannot exceed, at most, a few percent of themass of the cluster.