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- Slit tilt mapping: Fit of the slit tilts is a critical part of the sky subtraction and wavelength calibration process. Usually this happens in the background but it is sometimes useful to see the results, particularly if an error has occurred downstream in sky subtraction. Setting this tab from "Silent" to "Inspect Results" allows you to see which lines were used to define the slit tilt and how the fit performed. This mode is very slow since it displays rectified arc images for each of the 20 orders one by one for each exposure. In normal operation it should not be used, only to diagnose problems, or to familiarize yourself with the pipeline on first use. Debug mode includes additional stops in the code and is generally not useful for non-experts.
- Calibration file type: The default in FIREHOSE is to use the OH sky lines for slit-tilt mapping and wavelength calibration for exposures longer than 300 seconds. For those less than 300 sec, ThAr lamp exposures are used. Using this tab the user can force ThAr to be used for all exposures. In principle one could force OH for short exposures but in our expedience this has not worked well.
During extraction, you will see plots of the object profile appear to indicate data quality. The plots show a cross section of the object profile with errors, and the resultant fit. As the iterative model fit and local sky subtraction improve, you should see the residuals in this plot diminish, through each iteration on a given order.
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