  The discovery of long-lasting (~100 s) X-ray flares following short gamma-ray
bursts initially called into question whether they were truly classical
short-hard bursts. Opinion over the last few years has coalesced around the
view that the short-hard bursts arise from the merger of pairs of neutron
stars, or a neutron star merging with a stellar-mass black hole. The natural
timescales associated with these processes, however, essentially preclude an
X-ray flare lasting ~100 s. Here we show that an interaction between the GRB
outflow and a non-compact stellar companion at a distance of ~a light-minute
provides a natural explanation for the flares. In the model, the burst is
triggered by the collapse of a neutron star after accreting matter from the
companion. This is reminiscent of type Ia supernovae, where there is a wide
distribution of delay times between formation and explosion, leading to an
association with both star-forming galaxies and old ellipticals.
