add ACH2 and BE refractive index data from Zubko
We have data tables of the BE and ACH2 refractive index of Zubko et al., mnras, 1996, 282, 1321-1329 These one extend from 0.054 to 1997 µm for BE and 0.04 to 912 µm for the ACH2.
The original measurement are those of Colangeli et al., 1995, A&A, 113, 56.
These files were contributed by Mathieu Compiègne (CITA).