ARF structure

struct ARF {

  long NumberEnergyBins;                  /* Number of response energies */

  float* LowEnergy; /*NumberEnergyBins*/  /* Start energy of bin */
  float* HighEnergy; /*NumberEnergyBins*/ /* End energy of bin */

  float* EffArea;    /*NumberEnergyBins*/ /* Effective areas */

  char EnergyUnits[FLEN_KEYWORD];         /* Units for energies */
  char arfUnits[FLEN_KEYWORD];            /* Units for effective areas */

  char Telescope[FLEN_KEYWORD];                             
  char Instrument[FLEN_KEYWORD];
  char Detector[FLEN_KEYWORD];
  char Filter[FLEN_KEYWORD];
  char ARFExtensionName[FLEN_VALUE];      /* EXTNAME keyword in SPECRESP */

};