XMM-Newton Science Analysis System


pnback (pnback-0.19.3) [22.0.0-9173c7d25-20250127]

Algorithm

 Read parameters
 Open and read input spectrum and spectrum OOT file header
 Open and read QPB calibration file
 if (withplotfiles) open LUNs for ASCII QDP output
 if (withimg) open and read input template image file
 get PN submode from spectrum header
 Open and read RMF, get channel to energy conversion
 Create the background spectrum by scaling the spectrum both by 
 the ratio of the exposure and the ratio of the backscale value,
 as well as the OOT scale factor.
 Subtract the OOT spectrum
 Set channel ranges for some energy bands, total, soft, hard
 Set channel ranges for the interpolation bridge
 do i=1,4 (nQUADs)
  if (selected) then
   Read in FOV spec for QUADi (areafov(i) and expofov(i))
   Read in FOV OOT spec for QUADi (areafov(i) and expofov(i))
   Fill FOV by-quad spectrum
  endif
 enddo
 do i=1,4 (nQUADs)
  if (selected) then
   Read in FWC spec for QUADi (areafwc(i) and expofwc(i))
   Normalize specFWC(1:4096,i) and specFWCunc(1:4096,i)
  endif
 enddo
 Remove any chip's data that has less area than limiting area
 do i=1,4 Object corner data
  if (selected) then 
   Read in Obj Corner spec for QUADi (areacoro(i) and expocoro(i))
   Calculate hardness
   Calculate rate
   Normalize the count rate
   Set the search values for the augmentation spectrum
   Augment spectra
   Calculate augmented count rate
   Scale by count rate and then test the scaling of the background spectrum
   Write augmented spectra to output file
  endif
 enddo
 do i=1,4 FWC corner data
  if (selected) then
   Read in FWC Corner spec for QUADi (areafwcc(i) and expofwcc(i))
   Subtract the OOT events from the spectrum and normalize the result
  endif
 enddo
 Smooth the data
 Exclude data if they are in a bridge region
 Create the masks to remove strong instrumental lines
 Remove the Al line from all spectra
 if (withplotfiles) open and write output QDP file header
 if (withimg) Create final image (check for bright pixels, reset if necessary)
 Create output spectrum (mask if necessary)
 if (withplotfiles) fill QDP plot, close several QDP files
 Add in the OOT events for CSTAT background spectrum
 if (withimage) fill opened final image (and OOT image), close images
 if (withplotfiles) open bridgefit QDP file
 Bridge the Al and high-energy gaps                                           
 Set a number of line-free windows                                          
 Extract the data from those windows                                        
 Fit a simple polynomial to the log of the data                             
 Use the result to interpolate over the Al gap
 Finish the bridge
 Write bkg spectrum 
 if (withplotfiles) Write bkg spectrum QDP plot, close QDP file
 Close bkg spectrum