Calculate CCSN and Type Ia SN rates for star particles

[stephenmwilkins]

Note: this is possibly best implemented at the grid creation step.

It would be useful to be able to calculate the CCSN and Type Ia SN rates for star particles and parametric star formation histories.

Ideally this would be available on the stellar grid. However, most models (all except BPASS?) don't provide this.

As an alternative we could implement a simple model. For example, assuming that all stars >8 Msun undergo CCSN. This could simply be a method on the stars component where the sole argument is the IMF.

[WillJRoper]

We can add a method to the GridFile in the grid generation that can take an input from a model and otherwise derives it based on the present day mass function at each grid point?

Either that or do a totally empirical method on the component on that side. One worry would be that mixing one or the other could get confusing and messy.

[aswinpvijayan]

I think most SPS models have the rates written out. Just need to read them in.

[WillJRoper]

In that case, it makes sense to add these as an additional grid with a flag for whether to include them? I think I prefer that over methods on a component anyway (but not strongly).