Globular Cluster Systems and the Missing Satellite Problem: Implications for Cold Dark Matter Models

Abstract

We analyze the metallicity distributions of globular clusters belonging to 28 early-type galaxies in the survey of Kundu & Whitmore. A Monte Carlo algorithm that simulates the chemical evolution of galaxies that grow hierarchically via dissipationless mergers is used to determine the most probable proto-galactic mass function for each galaxy. Contrary to the claims of Kundu & Whitmore, we Ðnd that the observed metallicity distributions are in close agreement with the predictions of such hierarchical formation models. The mass spectrum of protogalactic fragments for the galaxies in our sample has a power-law behavior, n(M) P Ma, with an index of a ^ [2. This spectrum is indistinguishable from the mass spectrum of dark matter halos predicted by cold dark matter models for structure formation. We argue that these protogalactic fragmentsÈthe likely sites of globular cluster formation in the early universeÈ are the disrupted remains of the "" missing ÏÏ satellite galaxies predicted by cold dark matter models. Our Ðndings suggest that the solution to the missing satellite problem is through the suppression of gas accretion in low-mass halos after reionization, or via self-interacting dark matter, and argue against models with suppressed small-scale power or warm dark matter.