On the association of gamma-ray bursts with supernovae

The recent discovery of a supernova (SN 1998bw) seemingly associated with G RB 980425 adds a new twist to the decades-old debate over the origin of gam ma-ray bursts. To investigate the possibility that some (or all) bursts are associated with supernovae, we performed a systematic search for temporal/ angular correlations using catalogs of BATSE and BATSE/Ulysses burst locati ons. We find no associations with any of the precise BATSE/Ulysses location s, which allows us to conclude that the fraction of high-fluence gamma-ray bursts from known supernovae is small (less than 0.2%). For the more numero us weaker bursts, the corresponding limiting fraction of 1.5% is less const raining due to the imprecise locations of these events. This limit (1.5% si milar or equal to 18 bursts) allows that a large fraction of the recent sup ernovae used as a comparison data set (18 supernovae similar or equal to 20 %) could have associated gamma-ray bursts. Thus, although we find no signif icant evidence to support a burst/supernova association, the possibility ca nnot be excluded for weak bursts.