关于暗能量光谱巡天项目的概述：从巡天到科学
Overview of the Dark Energy Spectroscopic instrument (DESI): From survey to science
Aiming to explore the nature of dark energy, the Dark Energy Spectroscopic Instrument (DESI) is conducting a five-year massive survey to map the large structure of universe over one third of the sky and 11 billion years, with a powerful 5000-fiber multi-object optical spectrograph in Mayall 4-meter telescope at Kitt Peak National Observatory. This ambitious spectroscopic survey began in 2021 May and in total will acquire more than 40 million galaxies and quasars from local universe to beyond z > 3.5. After determining precise redshifts for these targets, DESI survey will employ the baryon acoustic oscillations, redshift-space distortions, and other methods to study dark energy, general relativity, and other cosmological quantities, such as neutrino mass and primordial non-Gaussianity. In the meantime, this survey will provide an extremely large spectroscopically confirmed sample of emission-line galaxies, luminous red galaxies, quasars, stars, and so on. In this talk, I will firstly give a brief introduction to DESI, including the instrument and big scientific picture, beginning from the DESI legacy imaging survey to the history, current status, and future expectations of DESI. In the second part, I will focus on the specific science cases, especially quasar related topics. Recent published works from other people and preliminary work or idea from my group would be involved. Finally, I will lead a discussion about the comparison and joint analysis between DESI and CSST. For example, multi-band images with high spatial resolution from CSST combined with high quality spectra from DESI could be very useful for quasar host galaxy decomposition.
