This convolution model redshifts an additive model. It takes the calculated model and shifts energies by 1/(1+z) then applies an additional 1/(1+z) factor to the model values.
The energies command must be to used to extend the maximum energy over which the model is being calculated to (1+z) times the maximum energy in the response.
The parameter is:
An example model use is:
XSPEC> model phabs * zashift * (pow + ga)
which redshifts the power-law and gaussian then multiplies by local absorption.