摘要：Recent studies have demonstrated the diversity in type Ia supernovae (SNe Ia) at early times and highlighted a need for a better understanding of the explosion physics as manifested by observations soon after explosion. To this end, we present a Monte Carlo code designed to model the light curves of radioactively driven, hydrogen-free transients from explosion to approximately maximum light. In this initial study, we have used a parametrised description of the ejecta in SNe Ia, and performed a parameter study of the effects of the56Ni distribution on the observed colours and light curves for a fixed56Ni mass of 0.6M⊙. For a given density profile, we find that models with56Ni extending throughout the entirety of the ejecta are typically brighter and bluer shortly after explosion. Additionally, the shape of the density profile itself also plays an important role in determining the shape, rise time, and colours of observed light curves. We find that the multi-band light curves of at least one SNe Ia (SN 2009ig) are inconsistent with less extended56Ni distributions, but show good agreement with models that incorporate56Ni throughout the entire ejecta. We further demonstrate that comparisons with fullUV OIRcolour light curves are powerful tools in discriminating various56Ni distributions, and hence explosion models.
