pexriv: reflected powerlaw, ionized medium

Exponentially cut off power law spectrum reflected from ionized material (Magdziarz & Zdziarski 1995). Ionization and opacities of the reflecting medium is computed as in the absori model. The output spectrum is the sum of the cut-off power law and the reflection component. The reflection component alone can be obtained for $rel_{refl} < 0$. Then the actual reflection normalization is $\vert rel_{refl}\vert$. Note that you need to then change the limits of $rel_{refl}$ to exclude zero (as then the direct component appears). If $E_c$ = 0 there is no cutoff in the power law. The metal and iron abundance are variable with respect to those defined by the command abund.

The core of this model is a Greens' function integration with one numerical integral performed for each model energy. The numerical integration is done using an adaptive method which continues until a given estimated fractional precision is reached. The precision can be changed by setting PEXRIV_PRECISION eg xset PEXRIV_PRECISION 0.05. The default precision is 0.01 (ie 1%).

par1 $\Gamma$, first power law photon index, $N_E \propto
par2 $E_c$, cutoff energy (keV) (if $E_c$ = 0 there is no cutoff)
par3 $rel_{refl}$, reflection scaling factor (0 = no reflected component, <0 reflection component only)
par4 redshift, z
par5 abundance of elements heavier than He relative to the solar abundances
par6 iron abundance relative to that defined by abund
par7 cosine of inclination angle
par8 disk temperature in K
par9 disk ionization parameter, $\xi = 4\pi F_{ion} / n$, where $F_{ion}$ is the 5eV - 20keV irradiating flux, $n$ is the density of the reflector; see Done et al. (1992).
norm photon flux at 1 keV (photons/keV/cm$^2$/s) of the cutoff broken power-law only (no reflection) in the observed frame.

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Last modified: Tuesday, 28-May-2024 10:09:22 EDT