The correlation of SN 1998bw and GRB 980425 shows that some supernovae produce gamma-ray bursts. SN 1998bw resembled previous Type Ic supernovae in terms of its spectral evolution and finite polarization. A check of correlations between the Asiago supernova catalog and the BATSE catalog of gamma-ray bursts suggests that a correlation of gamma-ray bursts with Type Ic supernovae cannot be ruled out. The polarization of Type Ic and SN 1998bw suggests that the exploding configuration is substantially asymmetric and raises the issue of whether this asymmetry, linked to the nature of the core collapse process itself, is connected with the generation of the gamma-ray burst. Asymmetric models with axis ratio of 2 to 1 can account for the light curve and spectra of SN 1998bw without the need for the very large energy of spherically symmetric hypernova models.
19th Texas Symposium on Relativistic Astrophysics and Cosmology
- Pub Date:
- December 1998