The diversity of Type Ia supernova ( SN Ia ) photometry is explored using a grid of 130 one-dimensional models .
It is shown that the observable properties of SNe Ia resulting from Chandrasekhar-mass explosions are chiefly determined by their final composition and some measure of “ mixing ” in the explosion .
A grid of final compositions is explored including essentially all combinations of ^ { 56 } Ni , stable “ iron ” , and intermediate mass elements that result in an unbound white dwarf .
Light curves ( and in some cases spectra ) are calculated for each model using two different approaches to the radiation transport problem .
Within the resulting templates are models that provide good photometric matches to essentially the entire range of observed SNe Ia .
On the whole , the grid of models spans a wide range in B -band peak magnitudes and decline rates , and does not obey a Phillips relation .
In particular , models with the same mass of ^ { 56 } Ni show large variations in their light curve decline rates .
We identify and quantify the additional physical parameters responsible for this dispersion , and consider physically motivated “ cuts ” of the models that agree better with the Phillips relation , discussing why nature may have preferred these solutions .
For example , models that produce a constant total mass of burned material of 1.1 \pm 0.1 \mathrm { M } _ { \odot } do give a crude Phillips relation , albeit with much scatter .
If one further restricts that set to models that make 0.1 to 0.3 \mathrm { M } _ { \odot } of stable iron and nickel isotopes , and then mix the ejecta strongly between the center and 0.8 \mathrm { M } _ { \odot } , reasonable agreement with the Phillips relation results , though still with considerable spread .
We conclude that the supernovae that occur most frequently in nature are highly constrained by the Phillips relation and that a large part of the currently observed scatter in the relation is likely a consequence of the intrinsic diversity of these objects .