An HST study of the supernovae accompanying GRB 040924 and GRB 041006

We present the results from a Hubble Space Telescope ACS study of the supernovae (SNe) associated with gamma-ray bursts (GRBs) 040924 (z = 0.86) and 041006 (z = 0.71). We find evidence that both GRBs were associated with an SN 1998bw -like supernova dimmed by similar to 1.5 and similar to 0.3 mag, respectively, making GRB 040924 the faintest GRB-associated SN ever detected. We study the luminosity dispersion in GRB/XRF-associated SNe and compare to local Type Ibc SNe from the literature. We find significant overlap between the two samples, suggesting that GRB/XRF-associated SNe are not necessarily more luminous and do not necessarily produce more Ni-56 than local SNe. Based on the current (limited) data sets, we find that the two samples may share a similar Ni-56 production mechanism.