This file summarizes several instrument-specific settings that are related to the GTC/OSIRIS spectrograph.

Common Items

Targets centered on chip 2

GTC/OSIRIS has two detectors with the object of interest always centered on chip 2. For many users this might meaning executing run_pypeit with the -d 2 option, or by setting:

    spectrograph = gtc_osiris
    detnum = 2

in your PypeIt Reduction File.

Standards taken with wide-slit

GTC/OSIRIS standards are not taken with the same setup as the science. The standards are taken with a 2.5” wide slit, so standards are exempted from the usual criteria for distinguishing unique setups and are simply included in the setup(s) with the same dispersion element.

MOS fails

MOS setups are prone to failures, particularly when slits are very close together (which can lead to overlaps that are identified as slits) or very short. For overlapping slitlets, one can set:

        minimum_slit_length = 2.

to avoid these overlapping regions from being identified as slits.

Similarly, short slits which cause problems for flat-fielding, sky-subtraction or object detection can be ignored by setting the same parameter to ~4.0