Overview of the Instrumentation for the Dark Energy Spectroscopic Instrument
Overview of the Instrumentation for the Dark Energy Spectroscopic Instrument
复制标题
DOI：
10.3847/1538-3881/ac882b
复制
发表时间：
2022-05
期刊：
影响因子：
--
通讯作者：
B. Abareshi;J. Aguilar;S. Ahlen;S. Alam;D. Alexander;R. Alfarsy;L. Allen;C. Prieto;O. Alves-O.
中科院分区：
文献类型：
--
作者：
B. Abareshi;J. Aguilar;S. Ahlen;S. Alam;D. Alexander;R. Alfarsy;L. Allen;C. Prieto;O. Alves-O.
暗能量光谱仪（DESI）于2021年5月开始了一项雄心勃勃的5年调查，通过对4000万个星系和类星体的光谱测量来探索暗能量的性质。DESI将确定精确的红移，并使用重子声振荡方法测量从附近宇宙到超过红移z > 3.5的距离，并使用红移空间扭曲来测量结构的增长和探测广义相对论的潜在修改。我们描述了显着的仪器，我们开发进行DESI调查。这包括：一个宽视场、直径为3.2 °的主焦点校正器;一个焦平面系统，在直径为0.812米的非球面焦面上有5020个光纤定位器; 10个连续的高效光纤电缆束，将焦平面连接到光谱仪;以及10个相同的光谱仪。每个光谱仪采用一对二向色镜将光分成三个通道，这三个通道一起记录360-980 nm的光，光谱分辨率范围为2000-5000。我们描述的科学要求，他们的技术要求，项目管理，子系统之间的接口连接。DESI安装在基特峰国家天文台的4米Mayall望远镜上，并实现了其所有性能目标。一些性能亮点包括均方根定位精度优于0.“1，以及z = 1.4-1.6的星系在8 × 10−17 erg s−1 cm−2/1000 s时[O ii]双峰的中值信噪比为7。最后，我们介绍了空中验证和调试的其他亮点、主要成功案例和经验教训。
The Dark Energy Spectroscopic Instrument (DESI) embarked on an ambitious 5 yr survey in 2021 May to explore the nature of dark energy with spectroscopic measurements of 40 million galaxies and quasars. DESI will determine precise redshifts and employ the baryon acoustic oscillation method to measure distances from the nearby universe to beyond redshift z > 3.5, and employ redshift space distortions to measure the growth of structure and probe potential modifications to general relativity. We describe the significant instrumentation we developed to conduct the DESI survey. This includes: a wide-field, 3.°2 diameter prime-focus corrector; a focal plane system with 5020 fiber positioners on the 0.812 m diameter, aspheric focal surface; 10 continuous, high-efficiency fiber cable bundles that connect the focal plane to the spectrographs; and 10 identical spectrographs. Each spectrograph employs a pair of dichroics to split the light into three channels that together record the light from 360–980 nm with a spectral resolution that ranges from 2000–5000. We describe the science requirements, their connection to the technical requirements, the management of the project, and interfaces between subsystems. DESI was installed at the 4 m Mayall Telescope at Kitt Peak National Observatory and has achieved all of its performance goals. Some performance highlights include an rms positioner accuracy of better than 0.″1 and a median signal-to-noise ratio of 7 of the [O ii] doublet at 8 × 10−17 erg s−1 cm−2 in 1000 s for galaxies at z = 1.4–1.6. We conclude with additional highlights from the on-sky validation and commissioning, key successes, and lessons learned.