X-shooter response function monitoring

"The VLT data flow operations of XSHOOTER covers the generation of flux calibrated science spectra. A new component to maintain and overview this process is the monitoring of the spectral response function. We describe the \nparameterisation of the XSHOOTER flat field spectrum and response function in terms of deviation from reference calibrations.\nWith the new scheme the stability of the response function and the impact of operational constraints like the frequent exchange of flat lamps is now monitored. This demonstrates the benefit for the quality assurance of the science spectra."