Data Reduction Frequently Asked Questions

My data have spatially variable sky background - how can I subtract it properly?


There is no way to subtract such sky background properly within the X-shooter pipeline. All processing strategies rely on a spatially constant sky background. The best way is to process the data as STARE (see without sky subtraction and then use independent software tools to fit and subtract the sky from the rectified, wavelength calibrated 2-dimensional frame (MERGE2D).