CONSTRAINING TYPE Ia SUPERNOVAE PROGENITORS FROM THREE YEARS OF SUPERNOVA LEGACY SURVEY DATA - Bianco, F; Howell, D; Sullivan, M; Conley, A; Kasen, D; Gonzalez-Gaitan, S; Guy, J; Astier, P; Balland, C; Carlberg, R; Fouchez, D; Fourmanoit, N; et al. (ASTROPHYSICAL JOURNAL, 2011)