  Low luminosity gamma-ray bursts (ll-GRBs) constitute a sub-class of gamma-ray
bursts (GRBs) that plays a central role in the GRB-supernova connection. While
ll-GRBs differ from typical long GRBs (LGRBs) in many aspects, they also share
some common features. Therefore, the question whether the gamma-ray emission of
ll-GRBs and LGRBs has a common origin is of great interest. Here we address
this question by testing whether ll-GRBs, like LGRBs according to the Collapsar
model, can be generated by relativistic jets that punch holes in the envelopes
of their progenitor stars. The collapsar model predicts that the durations of
most observed bursts will be comparable to, or longer than, the time it takes
the jets to breakout of the star. We calculate the jet breakout times of
ll-GRBs and compare them to the observed durations. We find that there is a
significant access of ll-GRBs with durations that are much shorter than the jet
breakout time and that these are inconsistent with the Collapsar model. We
conclude that the processes that dominate the gamma-ray emission of ll-GRBs and
of LGRBs are most likely fundamentally different.
