Projects

A Survey of z ≥ 5 Quasars with DESI

I am leading a survey of z ≥ 5 quasar using the Dark Energy Spectroscopic Instrument (DESI), which started on May 14, 2021. DESI will will obtain optical spectra for tens of millions of galaxies and quasars. The deep wide-field imaging from the DESI Legacy Imaging Surveys and the DESI multi-object spectroscopy allow a new wide-field survey of high-redshift quasars, extending through the entire DESI footprint (~ 14,000 square degrees). The wide spectral coverage (3600 -- 9800 A) of DESI covers the Ly-alpha emission of quasars up to z ~ 6.8. The first paper (Yang et al. 2023, Submitted) of this program will be coming soon to publish the first sample of 400 new quasars at 4.7 ≥ z ≥ 6.6 obtained from early DESI observations. A set of science projects will be carried out leveraging this program, including quasar luminosity function, quasar clustering, intergalactic medium, quasar spectral properties, intervening absorbers, and properties of early supermassive black holes. A first sample of more than 400 new quasars has been published in 2023, based on the first year observation. DESI z ≳ 5 Quasar Survey. I. A First Sample of 400 New Quasars at z 4.7-6.6