Attenuation below Lyman limit
The attenuation modules attenuate the SED below the Lyman limit (for instance the dustatt_calzleit module use the Leitherer formula even if it is not defined below 912 Å). But this attenuation should be treated differently, like it's done in the nebular module with a parameter giving the fraction of Lyman continuum photos absorbed by dust.
First the attenuation modules should exclude the Lyman continuum from the attenuation. Then we should decide either between:
- We assume that no Lyman continuum photon is absorbed by dust. Users needing a more precise attenuation should use the nebular module.
- We take the “fraction of Lyman continuum photons absorbed by dust” out of the nebular module and add it to the attenuation modules.