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Subsections

Pile-Up Model Components

  
pileup

CCD pile-up model used for brightish point sources observed by Chandra. This is an implementation of the fast pile-up algorithm proposed by John Davis (see http://space.mit.edu/$\sim$davis/papers/pileup2001.pdf). The frame time and maximum number of photons to pile up should be fixed. The grade morphing is expressed through a single parameter, alpha, which should be left as a free parameter. Note that to calculate fluxes etc. for the model you must remove the pileup component.

par1     =  frame time (in seconds)
par2     =  maximum number of photons to pile up
par3     =  grade correction for single photon detection
par4     =  grade morphing parameter (good grade fraction is assumed proportional to par4(p-1) where p is the number of piled photons)
par5     =  PSF fraction. Only this fraction will be treated for pile-up
par6     =  Number of regions. The counts to be piled-up will be distributed among par6 regions, which will be piled-up independently.


next up [*] [*]
Next: Mixing Model Components Up: XSPEC V11.3 Models Previous: Convolution Model Components
Ben Dorman
2003-11-28