论文标题
仪器的概述黑暗能源光谱仪器
Overview of the Instrumentation for the Dark Energy Spectroscopic Instrument
论文作者
论文摘要
黑暗能源光谱仪器(DESI)进行了一项雄心勃勃的五年调查,探索了4000万个星系和类星体的光谱法探索暗能量的性质。 DESI将确定精确的红移,并采用Baryon声学振荡方法来测量从附近宇宙到Z> 3.5的距离,并测量结构和探针对一般相对性的潜在修改的增长。在本文中,我们描述了我们为DESI调查开发的重要仪器。新的仪器包括一个宽场,3.2度直径的原点校正器,将光聚焦到直径为0.812 m的5020机器人纤维定位器上。定位器及其纤维分为十个楔形的花瓣。每个花瓣都通过连续的高效,近50 m的光纤电缆束连接到十个光谱仪之一。这十个光谱仪都使用一对二色体将光线分为三个频道,共同记录了360-980 nm的光线,分辨率为2000 nm至2000年。我们描述了科学要求,仪器的技术要求以及项目的管理。 DESI安装在Kitt Peak的4-M Mayall望远镜上,我们还描述了为DESI准备的设施升级以及安装和功能验证过程。 DESI已实现了所有绩效目标,DESI调查始于2021年5月。一些性能重点包括Z> 2 Quasar的RMS定位器的精度优于0.1“,SNR/\sqrtå> 0.5,具有0.28e-17 erg/s/s/s/s/s/cm^2/a的Z> 2 Quasar,在4000 nm和Median SNM中,和MED-MED-MED-MED-7的8E-4 nm = 7。 ERG/s/cm^2在z = 1.4-1.6处的1000 s曝光中,我们从仪器上的验证和调试,关键的成功和经验教训中得出了亮点。
The Dark Energy Spectroscopic Instrument (DESI) has embarked on an ambitious five-year survey to explore the nature of dark energy with spectroscopy 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 z > 3.5, as well as measure the growth of structure and probe potential modifications to general relativity. In this paper we describe the significant instrumentation we developed for the DESI survey. The new instrumentation includes a wide-field, 3.2-deg diameter prime-focus corrector that focuses the light onto 5020 robotic fiber positioners on the 0.812 m diameter, aspheric focal surface. The positioners and their fibers are divided among ten wedge-shaped petals. Each petal is connected to one of ten spectrographs via a contiguous, high-efficiency, nearly 50 m fiber cable bundle. The ten spectrographs each use a pair of dichroics to split the light into three channels that together record the light from 360 - 980 nm with a resolution of 2000 to 5000. We describe the science requirements, technical requirements on the instrumentation, and management of the project. DESI was installed at the 4-m Mayall telescope at Kitt Peak, and we also describe the facility upgrades to prepare for DESI and the installation and functional verification process. DESI has achieved all of its performance goals, and the DESI survey began in May 2021. Some performance highlights include RMS positioner accuracy better than 0.1", SNR per \sqrtÅ > 0.5 for a z > 2 quasar with flux 0.28e-17 erg/s/cm^2/A at 380 nm in 4000s, and median SNR = 7 of the [OII] doublet at 8e-17 erg/s/cm^2 in a 1000s exposure for emission line galaxies at z = 1.4 - 1.6. We conclude with highlights from the on-sky validation and commissioning of the instrument, key successes, and lessons learned. (abridged)