New supersymmetric AdS_3 solutions

We construct infinite new classes of supersymmetric solutions of D=11 supergravity that are warped products of AdS_3 with an eight-dimensional manifold M_8 and have non-vanishing four-form flux. In order to be compact, M_8 is constructed as an S^2 bundle over a six-dimensional manifold B_6 which is either K\"ahler-Einstein or a product of K\"ahler-Einstein spaces. In the special cases that B_6 contains a two-torus, we also obtain new AdS_3 solutions of type IIB supergravity, with constant dilaton and only five-form flux. Via the AdS-CFT correspondence the solutions with compact M_8 will be dual to two-dimensional conformal field theories with N=(0,2) supersymmetry. Our construction can also describe non-compact geometries and we briefly discuss examples in type IIB which are dual to four-dimensional N=1 superconformal theories coupled to string-like defects.