SED_gen and source_creation have been modified to scale star particle SSP luminosities by formed mass (= integral of SFH) rather than current mass.
Reason: FSPS SFHs are normalized such that 1 solar mass is formed over the entire history, resulting in SSP/CSP spectra that are in units of Lsun/Hz/Mformed, where Mformed is the integral of the SFH. For single age SSPs, this is equal to the initial formed mass, which for older populations is different than the current mass due to mass loss of evolved stars. To scale by the formed mass, SED_gen now returns an additional parameter 'mfrac' which is the surviving stellar mass fraction for each SSP (Mformed = current mass / mfrac). SSP luminosities are then scaled by current_mass/mfrac to correctly account for the FSPS units scaling.
SED_gen and source_creation have been modified to scale star particle SSP luminosities by formed mass (= integral of SFH) rather than current mass.
Reason: FSPS SFHs are normalized such that 1 solar mass is formed over the entire history, resulting in SSP/CSP spectra that are in units of Lsun/Hz/Mformed, where Mformed is the integral of the SFH. For single age SSPs, this is equal to the initial formed mass, which for older populations is different than the current mass due to mass loss of evolved stars. To scale by the formed mass, SED_gen now returns an additional parameter 'mfrac' which is the surviving stellar mass fraction for each SSP (Mformed = current mass / mfrac). SSP luminosities are then scaled by current_mass/mfrac to correctly account for the FSPS units scaling.