logpar is a power-law with an index which varies with energy as a log parabola. The zlogpar variant computes a redshifted spectrum. See for instance Massaro et al. (2004).
par1 | a, slope at the pivot energy |
par2 | b, curvature term |
par3 | pivotE, fixed pivot energy (best near low end of energy range). |
norm= K |
For zlogpar the formula and corresponding parameters are:
par1 | a, slope at the pivot energy |
par2 | b, curvature term |
par3 | pivotE, fixed pivot energy (best near low end of energy range). |
par4 | z, redshift |
norm= K |