Daniel Eisenstein, Harvard University
April 2, 2020
DESI commissioning has raced forward this winter, and we have now demonstrated the key performance parameters of the instrument! Since installation, refinement of the performance of the 8 square degree corrector, high-precision (10 micron) positioning of the fibers under active feedback, accurate calibration of the spectrographs, and on-sky commissioning of the whole user interface have been demonstrated.
All of this progress culminated in the successful demonstration in March of spectroscopy with the full DESI system of many tens of thousands of survey targets. We have observed spectra of faint galaxies and quasars with redshift distributions and spectroscopic signal-to-noise that match well to what we expected.
Unfortunately, as it is with so many around the world, the COVID-19 outbreak is forcing us to adjust our plans. We’re taking a break from on-sky observing until it is easier for our collaboration members to travel safely to Arizona. But we’re fortunate that this winter’s commissioning produced so much data that we can work on it, in the meantime. DESI will be back, we hope soon, with continued momentum toward our next goal of validating the survey design.