Statistical study of extrasolar Kuiper belts with Herschel/DUNES

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Accretion of planetesimals to planets is known to be more efficient in inner parts of protoplanetary discs. In their outer parts, where the disc surface density is too low or gravity of planets formed closer-in dynamically heat the disc, accretion ceases at sub-planetary sizes and only yields ensembles of planetesimals and dwarf planets. These populations of small bodies on the periphery of the planetary systems are called “extrasolar Kuiper belts” or debris discs. While the planetesimals themselves cannot be directly detected around other stars, the dust that they produce in a continuous collisional cascade can be observed through its thermal emission. Valuable information about the formation and evolution of invisible planets and planetesimals is imprinted into the observational statistics of such dusty debris discs – and can be retrieved from it. These statistics reflect phases of unperturbed, collisional evolution of debris discs combined with perturbing events such as the outward migration of planets. Based on substantial preliminary work, we propose to quantify these links by means of specific models of debris disc evolution and the population synthesis method, making use of the new data coming from the Herschel Space Observatory. In this way, we aim at setting new constraints on formation and evolution scenarios of planetary systems.