Near-arcsecond resolution observations of the hot corino of the solar-type protostar IRAS 16293-2422

Complex organic molecules have previously been discovered in solar-type protostars, raising the questions of where and how they form in the envelope. Possible formation mechanisms include grain mantle evaporation, the interaction of the outflow with its surroundings, and/or the impact of UV/X-rays inside the cavities. In this Letter we present the first interferometric observations of two complex molecules, CH3CN and HCOOCH3, toward the solar-type protostar IRAS 16293 - 2422. The images show that the emission originates from two compact regions centered on the two components of the binary system. We discuss how these results favor the grain mantle evaporation scenario, and we investigate the implications of these observations for the chemical composition and physical and dynamical state of the two components.