Energetics of the explosion

This part is based mainly on hoeflich2003.

In a diagrammatic way, the quantity of produced energy is determined by the product of the explosion of dwarf white. It is presented in the form of kinetic energy (which disperse star) and in nuclear form (nickel). The quantity of nickel determines in its turn the luminosity and opacity; finally, opacity and produced total energy determine the shape of the lightcurve.

In a more quantitative way, the energy binding of dwarf white is of approximately $2.10^{51}\rm \, erg$, which corresponds to the difference between the binding energy of the oxygen and carbon cores + gravitational energy of dwarf white and the energy produced by fusion.

The energy lost in the form of neutrinos does not exceed 1%, which contrasts with the gravitational supernovæ for which the neutrinos account for 99% of energy.

All the energy produced during the explosion of dwarf white will contribute to the expansion of the layers of dwarf white and not to the lightcurve. As we saw, it is the decrease ${ }^{56}$Fe which nourishes the lightcurve. The energy produced by these reactions accounts for 3% of the total energy produced during the explosion if a production of ${ }^{56}$is considered.

The light output is independent of the details of the explosion and of the precise nature of the progenitor like figure 5.12 illustrates it . It is the produced quantity ${ }^{56}$of Ni which determines the luminosity of the supernova.

Appear: Comparison enters the lightcurve of a supernova of the Ia type and the double decrease ${ }^{56}$Co(issu of blanc2002).

Opacity controls the temporal evolution of the light output. A less significant quantity of produced nickel corresponds to a less luminosity, but also to a less significant temperature and thus a less opacity. This implies that the least brilliant supernovæ are those which have the narrowest lightcurves.

To be in agreement with the observation of the light elements in the spectrum, it is necessary that there is an pre-expansion of the layers of the supernova. As we saw previously, this is satisfied in the case with the models of deflagration and the models of delayed detonation. The production of nickel depends then on the density of transition between the phase from initial deflagration and the detonation in this second model.

The explosion causes a fast acceleration of the matter of the supernova. The photons $\gamma$ produced during the decrease of nickel are diffused to produce the lightcurve. The rise and fall times of the lightcurve are given by the lifespans of nickel, then of its decay product ${ }^{56}$the Co and the opacity of the layers expanding. The evolution of the spectra during time are an image of the evolution of photosphere.

Thus, less there is produced nickel, less the temperature of the layers is significant and the produced photons are emitted with a less significant energy in a spectral field where there is less of lines of Doppler diffusion. Opacity is thus less significant and one more quickly sees the layers deep of dwarf white. The production of luminosity is faster and the curve of narrower light.