These models are based on Paolo Coppi's hybrid thermal/non-thermal hot plasma emission model for X-ray binaries. The underlying physics and a detailed description of the code are included in the draft paper http://www.astro.yale.edu/coppi/eqpair/eqpap4.ps.
Do not use these models without reading and understanding this paper. Simplified models eqtherm and compth are provided for cases where non-thermal processes are not important and photon-photon pair production can be ignored. These should only be used if .
The temperature of the thermal component of the electron distribution and the total electron optical depth (for both ionization electrons and electron-positron pairs) are written out if the chatter level is set to 15. This information is important for checking self-consistency.
In versions 1.10 and above the Compton reflection is done by a call to the ireflect model code and the relativistic blurring by a call to rdblur. This does introduce some changes in the spectrum from earlier versions. For the case of a neutral reflector (i.e. the ionization parameter is zero) more accurate opacities are calculated. For the case of an ionized reflector the old version assumed that for the purposes of calculating opacities the input spectrum was a power-law (with index based on the 2-10 keV spectrum). The new version uses the actual input spectrum, which is usually not a power law, giving different opacities for a given ionization parameter and disk temperature. The Greens' function integration required for the Compton reflection calculation is performed to an accuracy of 0.01 (i.e. 1%). This can be changed using e.g. xset EQPAIR_PRECISION 0.05.
The parameters for all three models are:
|par1||lh/ls, ratio of the hard to soft compactnesses|
|par2||lbb, the soft photon compactness|
|par3||kTbb, if >0 then temperature of a blackbody; if <0 then abs(kTbb) is the Tmax parameter for the diskpn model|
|par4||lnt/lh, fraction of power supplied to energetic particles which goes into accelerating non-thermal particles|
|par5||tp, the Thomson scattering depth|
|par6||radius, the size of the scattering region (cm)|
|par7||gmin, minimum Lorentz factor of the pairs|
|par8||gmax, maximum Lorentz factor of the pairs|
|par9||Ginj, if <0 then non-thermal spectrum is assumed mono-energetic at gmax; if >0 then a power-law from gmin to gmax|
|par10||pairinj, if = 0 then accelerated particles are electrons from thermal pool; if = 1 then accelerated particles are electrons and positrons|
|par11||cosIncl, inclination of reflecting material wrt line-of-sight|
|par12||Refl, fraction of scattering region's emission intercepted by reflecting material|
|par13||Fe_abund, relative abundance of iron|
|par14||AbHe, relative abundance of other metals|
|par15||Tdisk, temperature of reflecting disk|
|par16||x, ionization parameter of reflector|
|par17||b, power-law index with radius of disk reflection emissivity|
|par18||Rin, inner radius of reflecting material (GM/c)|
|par19||Rout, outer radius of reflecting material (GM/c)|