Sn1998bw/grb980425 and Radio Supernovae
نویسندگان
چکیده
The unusual supernova SN1998bw, which is thought to be related to the γray burster GRB980425, is a possible link between the two classes of objects. Analyzing the extensive radio emission data avaliable for SN1998bw, we are able to describe its time evolution within the well established framework available for the analysis of radio emission from supernovae. This then allows description of a number of physical properties of the object. The radio emission can best be explained as interaction of a mildly relativistic (Γ ∼ 1.6) shock with a dense preexplosion stellar wind established circumstellar medium (CSM) which is highly structured both azimuthally, in clumps or filaments, and radially, with two observed density enhancements separated by ∼ 3 × 10 cm. With assumptions as to pre-explosion stellar wind conditions, it is possible to estimate that the progenitor to SN 1998bw had a mass loss rate of ∼ 3.5 × 10 M⊙ yr with Also Astrophysics Division, Space Science Department of ESA.
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