The recognition that the metallicity of Type Ia supernova ( SNIa ) progenitors might bias their use for cosmological applications has led to an increasing interest in its role on the shaping of SNIa light curves .
We explore the sensitivity of the synthesized mass of ^ { 56 } Ni , M ( ^ { 56 } \mathrm { Ni } ) , to the progenitor metallicity starting from Pre-Main Sequence models with masses M _ { 0 } = 2 - 7 M _ { \odot } and metallicities Z = 10 ^ { -5 } -0.10 .
The interplay between convective mixing and carbon burning during the simmering phase eventually rises the neutron excess , \eta , and leads to a smaller ^ { 56 } Ni yield , but does not change substantially the dependence of M ( ^ { 56 } \mathrm { Ni } ) on Z .
Uncertain attributes of the WD , like the central density , have a minor effect on M ( ^ { 56 } \mathrm { Ni } ) .
Our main results are : 1 ) a sizeable amount of ^ { 56 } Ni is synthesized during incomplete Si-burning , which leads to a stronger dependence of M ( ^ { 56 } \mathrm { Ni } ) on Z than obtained by assuming that ^ { 56 } Ni is produced in material that burns fully to nuclear statistical equilibrium ( NSE ) ; 2 ) in one-dimensional delayed detonation simulations a composition dependence of the deflagration-to-detonation transition ( DDT ) density gives a non-linear relationship between M ( ^ { 56 } \mathrm { Ni } ) and Z , and predicts a luminosity larger than previously thought at low metallicities ( however , the progenitor metallicity alone can not explain the whole observational scatter of SNIa luminosities ) , and 3 ) an accurate measurement of the slope of the Hubble residuals vs metallicity for a large enough data set of SNIa might give clues to the physics of deflagration-to-detonation transition in thermonuclear explosions .