2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/9636We present an observational mass function ranging from galaxies to massive galaxy clusters, derived from direct dynamical mass estimates. Our mass function shows, in the low-mass range of galaxies and groups, a behaviour in agreement with that of standard CDM (n=-2), while in the high-mass range (clusters) our mass function is shallower (and thus contains more power) than standard CDM; it also results shallower than the recent mass function by Bahcall & Cen (1993, ApJ 407, L49).9 pages (2 figures not included, available upon request), LATEX, SISSA Ref. 132/93/AAstrophysicstext