The GRB/XRF-SN Association
  There is mounting evidence that long duration gamma ray bursts (GRBs) and X-ray flashes (XRFs) are produced by highly relativistic and narrowly collimated jets ejected in core collapse supernova (SN) explosions akin to SN 1998bw. We review the history of the GRB-SN association idea and its observational verification. We summarize the present evidence for a GRB/XRF-SN association. We comment on the possibility that most, perhaps all, SN explosions produce GRBs, including SNe of Type Ia which may produce short GRBs/XRFs. We list the major open questions that follow from a GRB/XRF-SN association. Possible uses of the GRB-SN association in cosmology are pointed out. 
Arnon Dar