pro responsematrixchange

; this IDL code creates new internal bkg files for any response matrix for a 1 arcmin2 extraction area and for Rextraction=5 arcsec (point sources)
; the core REQUIRES IDL Astrolib to compile properly

  path = '/home/simone/Scrivania/XIFUbkgfiles/2020/'; insert your path to where the response matrix is located
  rmffile = 'XIFU_CC_BASELINECONF_2018_10_10'; insert your response matrix name (WITHOUT .rmf)
  extension = '.rmf'
  file=path+rmffile+extension
  
  ;read energy bounds from response matrix file
  FXBOPEN, UNIT,file, 'EBOUNDS' ;
  FXBREAD,UNIT, channels, 'CHANNEL' & FXBREAD,UNIT, Emin, 'E_MIN' & FXBREAD,UNIT, Emax, 'E_MAX';
  FXBCLOSE, UNIT;
  
  dE= Emax-Emin
  
  bkg=0.005; your expected NXB background level in cts/cm2/s/keV
  bkg2=bkg/8.2; cts/arcmin2/s/keV
  bkg3=bkg2*dE; cts/arcmin2/s/bin
  bkg4=bkg3*0.0218; cts/s/bin with Rextraction=5arcsec (point sources)
  
  a=mrdfits(path+'int1arcmin2.pha', 1, hdr, /fscale) ; this should be just a mock copy of your diffuse bkg file to be used as a template to write the internal one
  a.rate=bkg3
  mwrfits,a,path+'internal_1arcmin2_'+rmffile+'.pha',hdr,/create
  a.rate=bkg4
  mwrfits,a,path+'internal_pointsources_'+rmffile+'.pha',hdr,/create

  

  end