zredden: redshifted version of redden

IR/optical/UV extinction from Cardelli et al. (1989, ApJ, 345, 245).  The transmission is set to unity shortward of 900 Angstroms. This is incorrect physically but does allow the model to be used in combination with an X-ray photoelectric absorption model such as phabs.

 

 par1   = E(B-V)

 par2   = redshift