Evidence Against an Association Between Gamma-Ray Bursts and Type I Supernovae
Abstract
We use a rigorous method, based on Bayesian inference, for calculating the odds favoring the hypothesis that any particular class of astronomical transients produce gamma-ray bursts over the hypothesis that they do not. We then apply this method to a sample of 83 Type Ia supernovae and a sample of 20 Type Ib-Ic supernovae. We find overwhelming odds against the hypothesis that all Type Ia supernovae produce gamma-ray bursts, whether at low redshift (
10
9
:1
) or high-redshift (
10
12
:1
), and very large odds (
6000:1
) against the hypothesis that all Type Ib, Ib/c, and Ic supernovae produce observable gamma-ray bursts. We find large odds (
34:1
) against the hypothesis that a fraction of Type Ia supernovae produce observable gamma-ray bursts, and moderate odds (
6:1
) against the hypothesis that a fraction of Type Ib-Ic supernovae produce observable bursts.