How to choose the start and end level for the analysis. Intermediate levels.

Once you have specified startLevel and endLevel, all the steps listed in the GENERAL_levelList parameters between these two levels (both included) will be performed. For instance, in section 7.1 you used:

startLevel="COR" endLevel="IMA2" 
GENERAL_levelList="COR,GTI,DEAD,BIN_I,BKG_I,CAT_I,IMA,IMA2,BIN_S,SPE,LCR,COMP,CLEAN"

The levels from COR to IMA2 (included) listed in GENERAL_levelList were performed.

You can choose what to run according to what kind of output you need. Basically:

• If you are interested only in imaging results set

  startLevel="COR" endLevel="IMA2"
  

  with the complete list of GENERAL_levelList given above, as done in section 7.1.
• If you have already a catalog of sources for which to extract the spectra (e.g.specat.fits), do not have sources brighter than 600 mCrabs in the list (see warning at the end of this section), and you are not interested in the imaging results anymore you can skip all the imaging related levels and do:

  startLevel="COR" endLevel="SPE" GENERAL_levelList="COR,GTI,DEAD,BIN_S,SPE"
  

  Remember that if you do not do the imaging part then isgri_srcl_res.fits is not created! This file is the default one that is used for spectral extraction (7.2). Do not forget to specify the catalog you have built for this purpose setting the SCW2_cat_for_extract equal to specat.fits.
• Likewise, if you are interested only in lightcurve results and do not have sources brighter than 600 mCrabs in the list (see warning at the end of this section), you should create PIFs for all sources of interest with ii_pif program (see Section 9.11 for an example), and afterwards you may use:

  startLevel="COR" endLevel="LCR" GENERAL_levelList="COR,GTI,DEAD,BIN_S,LCR"
  

  again with SCW2_cat_for_extract equal to specat.fits.
• If you are familiar with the sources of your field (i.e. you have already run the imaging part, for instance) and you want to extract images, spectra and lighturves in one go, set SCW2_cat_for_extract equal to specat.fits and run your analysis with

  startLevel="COR" endLevel="LCR"
  

  and the complete list of levels in GENERAL_levelList.

Warning! If you skip the level BKG_I and do spectral extraction then the file with PIFs of strong sources is not done so no strong source subtraction is done in spectral extraction. If you really want to do step SPE or LCR without having done before the step BKG_I then you have two possibilities:

1. there is no strong source in the FOV. In this case everything is OK
2. you have to run at least BKG_I and BIN_I (for example with just one energy band to save time)