With the launch of the Swift satellite in 2004, great strides have been
made toward understanding the once mysterious gamma-raybursts. By studying their X-ray, optical and radio afterglows, we have been
able to derive the energy of the explosion, the geometry of the
outflow, the density structure of the circumburst medium, and the
properties of their host galaxies. Although many questions remain
unanswered, a basic picture is beginning to emerge in which long-duration
gamma-ray bursts originate from the birth of a black hole. The subsequent
explosion, with a typical energy of 10^51 erg, drives a highly
collimated, ultra-relativistic shock in thecircumburst medium with a density of order 1 cm-3. We now know that most
long duration GRBs are also accompanied by a sub-relativisticquasi-spherical explosion which gives rise to a Type Ibc supernova. In
this talk, I will illustrate how radio observations of GRB afterglows have
enabled this progress to be achieved. In addition I will discuss how radio
observations of local Type Ibc supernovae can be used as a unique tool to
shed light on the GRB-SN connection. In particular, I will present the
radio derived constraints on the energy coupled to relativistic ejecta from
our survey of ~100 local SNe Ibc which impose severe constraints on the
\"hypernova\" model.
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