A Comparative Analysis of the Outer Belt Primitive Families

Asteroid families are witnesses to the intense collisional evolution that occurred on the asteroid belt. The study of the physical properties of family members can reveal important information about the state of differentiation of the parent body and provide insights on how these objects were formed. Several of these asteroid families identified across the main-belt are dominated by low-albedo, primitive asteroids. These objects are important for the study of Solar System formation, since they were subject to weaker thermophysical processing and provide information of the early conditions of our planetary system. In particular, recent works suggested the presence of water-ice, hydrated and organic materials associated with members of the outer-belt families. We aim to study the diversity of physical properties among the Themis, Hygiea, Ursula, Veritas and Lixiaohua families. We present new spectroscopic data, combined with a comprehensive analysis using a variety of data available in the literature, such as albedo and rotational properties. Our results demonstrate a diverse scenario that can be correlated with dynamical mixing of asteroid populations and the level of differentiation of the parental body.