Residual properties of fibered and hyperbolic 3-manifolds

We study the residual properties of geometric 3-manifold groups. In particular, we study conditions under which geometric 3-manifold groups are virtually residually p for a prime p, and conditions under which they are residually torsion-free nilpotent. We show that for every prime p, every geometric 3-manifold group is virtually residually p. We show that geometric 3-manifold groups are virtually residually torsion-free nilpotent precisely when they do not arise from Sol geometry.