THE FUNDAMENTAL STRAIGHT-LINE OF GALACTIC GLOBULAR-CLUSTERS

A detailed analysis of the Fundamental Plane properties of globular cl usters is performed. If a sample of ordinary King Model clusters is co nsidered, it is found that, in the space (S-space) defined by the para meters (logr(c), log sigma(0), mu(v)(0)), their configuration is simil ar to a straight line. It is shown that, with rather simple assumption s, a simultaneous explanation of all the observed correlations between S-space parameters can be provided. It is suggested that, at earlier times, globular clusters populated a line in the three-dimensional S-s pace, i.e their original dynamical structure was fully determined by a single physical parameter. (C) 1998 Elsevier Science B.V.