A three-segment broken power law (ie with two break energies).
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E £ Ebreak,1 |
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Ebreak,1 ≤ E ≤ Ebreak,2 |
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Ebreak,2 ≤ E |
where :
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par1= |
power law photon index for E < Ebreak,1 |
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par2=Ebreak,1 |
first break point for the energy, keV |
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par3= |
power law photon index for Ebreak,1 < E < Ebreak,2 |
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par4=Ebreak,2 |
second break point for the energy, keV |
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par5= |
power law photon index for E > Ebreak,2 |
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Norm =K |
photons keV-1cm-2s-1 at 1 keV |
If POW_EMIN and POW_EMAX have been defined by the xset command then the norm becomes the flux in units of 10-12 ergs cm-2 s-1 over the energy range (POW_EMIN, POW_EMAX) keV unless POW_EMIN = POW_EMAX in which case the norm becomes the flux density in micro-Jansky at POW_EMIN keV. In these cases it is important that POW_EMIN and POW_EMAX lie within the energy range on which the model is being evaluated.
