DESI will precisely constrain cosmic expansion and the growth of structure by collecting ∼35 million redshifts across ∼80% of cosmic history and one third of the sky to study Baryon Acoustic Oscillations (BAO) and Redshift Space Distortions (RSD). We present a preliminary target selection for an Emission Line Galaxy (ELG) sample, which will comprise about half of all DESI tracers. The selection consists of a g-band magnitude cut and a (g−r) versus (r−z) color box, which we validate using HSC/PDR2 photometric redshifts and DEEP2 spectroscopy. The ELG target density should be ∼2400 deg⁻², with ∼65% of ELG redshifts reliably within a redshift range of 0.6<z<1.6. ELG targeting for DESI will be finalized during a “Survey Validation” phase.

DESI 将通过在 80% 的宇宙历史和三分之一的天空中收集 3500 万个红移来研究重子声学振荡 (BAO) 和红移空间畸变 (RSD)，从而精确约束宇宙膨胀和结构的增长。我们提出了发射线星系 (ELG) 样本的初步目标选择，该样本将包含所有 DESI 示踪剂的大约一半。选择包括g波段幅度切割和 ( g - r ) 与 ( r - z ) 颜色框，我们使用 HSC/PDR2 光度红移和 DEEP2 光谱对其进行验证。ELG 目标密度应为 ∼2400 deg ^{-2 ，在 0.6<} z的红移范围内可靠地有 ∼65% 的 ELG 红移<1.6。DESI 的 ELG 目标将在“调查验证”阶段最终确定。