DYNAMICAL AND OBSERVABLE CONSTRAINTS ON RAMBOS - ROBUST ASSOCIATIONS OF MASSIVE BARYONIC OBJECTS

If the halo dark matter consists of faint baryonic stars, then these o bjects probably formed at an early epoch within large associations wit h similar dynamical properties to globular or open clusters. We use th e luminosity function of globular clusters as a function of galactocen tric distance to provide a strong constraint on the properties of robu st associations of massive baryonic objects (RAMBOs). We show that at the solar radius, dynamical constraints confine such clusters to a bou nded and narrow parameter space with effective radii between 1 and 15 pc, corresponding to masses between similar to 10-10(4) M. and similar to 10(4)-10(5) M., respectively. RAMBOs cannot provide an explanation for the observed velocity dispersion of disk stars. Gravitational mic rolensing is the only method capable of constraining the abundance of dark matter in the form of RAMBOs, although recovering their internal properties will be very difficult due to their large covering factor a nd low internal velocity dispersion.