The Spectroscopic Data Processing Pipeline for the Dark Energy Spectroscopic Instrument

Abstract We describe the spectroscopic data processing pipeline of Dark Energy Spectroscopic Instrument (DESI), which is conducting a redshift survey about 40 million galaxies and quasars using purpose-built instrument on 4 m Mayall Telescope at Kitt Peak National Observatory. The main goal DESI to measure with unprecedented precision expansion history universe baryon acoustic oscillation technique growth rate structure space distortions. Ten spectrographs three cameras each disperse light from 5000 fibers onto 30 CCDs, covering near-UV near-infrared (3600–9800 Å) spectral resolution ranging 2000 5000. generates wavelength- flux-calibrated spectra all targets, along classifications measurements. Fully processed night are typically available collaboration following morning. give details pipeline’s algorithms, provide performance results stability optics, quality sky background subtraction, accuracy instrumental calibration. This has been used process Survey Validation set, exceeded project’s requirements for performance, high efficiency purity greater than 99% target classes.