Making a Short Gamma-Ray Burst from a Long One: Implications for the Nature of GRB 060614

Abstract

The absence of a supernova accompanying the nearby long GRB 060614 poses a great puzzle about the progenitor of this event and challenges the current GRB classification scheme. This burst displays a short-hard emission episode followed by extended soft emission with strong spectral evolution. Noticing that this burst has an isotropic gamma-ray energy only ∼8 times that of GRB 050724, a good candidate of merger-type short GRBs, we generate a "pseudo"burst that is ∼8 times less energetic than GRB 060614 based on the spectral properties of GRB 060614 and the (Amati) relation. We find that this pseudoburst would have been detected by BATSE as a marginal 1/2