Searching for differences inSwift’s intermediate GRBs

Context. Gamma-ray bursts are usually classified in terms their high-energy emission into either short-duration or long-duration bursts, which presumably reflect two different types of progenitors. However, it has been shown on statistical grounds that a third, intermediate population is needed in this classification scheme, although an extensive study of the properties of this class has so far not been performed. The large amount of follow-up studies generated during the Swift era allows us to have a sufficient sample to attempt a study of this third population through the properties of their prompt emission and their afterglows.