Since 1997 the afterglow of \gamma -ray bursting sources ( GRBs ) has occasionally been detected in the radio , as well in other wavelengths bands .
In particular , the interesting and unusual \gamma -ray burst GRB980425 , thought to be related to the radio supernova SN1998bw , is a possible link between the two classes of objects .
Analyzing the extensive radio emission data available for SN1998bw , one can describe its time evolution within the well established framework available for the analysis of radio emission from supernovae .
This then allows relatively detailed description of a number of physical properties of the object .
The radio emission can best be explained as the interaction of a mildly relativistic ( \Gamma \sim 1.6 ) shock with a dense preexplosion stellar wind-established circumstellar medium ( CSM ) that is highly structured both azimuthally , in clumps or filaments , and radially , with observed density enhancements .
Because of its unusual characteristics for a Type Ib/c supernova , the relation of SN1998bw to GRB980425 is strengthened and suggests that at least some classes of GRBs originate in supernova ( SN ) massive star explosions .
Thus , employing the formalism for describing the radio emission from supernovae ( SNe ) and following the link through SN1998bw/GRB980425 , it is possible to model the gross properties of the radio and optical/infrared ( OIR ) emission from the half-dozen GRBs with extensive radio observations .
From this we conclude that at least some members of the “ slow-soft ” class of GRBs can be attributed to the explosion of a massive star in a dense , highly structured CSM that was presumably established by the preexplosion stellar system .