Andrew Cooper (Institute of Astronomy, National Tsing Hua University); DESI Collaboration
I will give an update on the status of the Dark Energy Spectroscopic Instrument, a revolutionary new wide-field 5000-fiber multi-object spectrograph on the Mayall 4m at Kitt Peak, funded by the US DoE and operated by an international collaboration led from Lawrence Berkeley National Lab. DESI will measure the effect of dark energy on the expansion of the Universe using 40 million galaxy redshifts, and probe the dark matter content and assembly history of the Milky Way with 8 million stellar spectra. DESI successfully completed its commissioning and survey validation (SV) program in the first half of 2021. It is now carrying out final preparations for 5 years of continuous main-survey observing scheduled to begin this summer. I will briefly review the motivation and strategy of the DESI Milky Way Survey, show some highlights from our SV observations (confirming that we can measure stellar radial velocities to an accuracy of < 5km/s and stellar parameters to < 0.1 dex at r=19), and summarize work by our group at NTHU on survey forecasts and the analysis of SV data.