The ISM attenuation due to neutral H, neutral He and once ionized He. This is a modified version of the Rumph et al. (1994) model, using the ismatten program by Pat Jelinsky, and allows the user to set the model redshift.
par1= | H column density ( atoms/cm) |
par2= | HeI column density ( atoms/cm) |
par3= | HeII column density ( atoms/cm) |
par4=z | redshift |