Arcus is a high-resolution soft X-ray and far-ultraviolet spectroscopy mission submitted to the National Aeronautics and Space Administration’s inaugural Astrophysics Probe solicitation. Arcus makes simultaneous observations in these two critical wavelength regimes to address a broad range of science questions highlighted by the 2020 Astronomy and Astrophysics Decadal Survey, from the temperature and composition of the missing baryons in the intergalactic medium to the evolution of stars and their influence on orbiting planets. We present the science motivation for and performance of the Arcus ultraviolet spectrograph (UVS). UVS comprises a 60-cm, off-axis Cassegrain telescope feeding an imaging spectrograph operating over the 970- to 1580-Å bandpass. The instrument employs two interchangeable diffraction gratings to provide medium-resolution spectroscopy (R>20,000 in two grating modes centered at ∼1110 and 1390 Å). The spectra are recorded on an open-face, photon-counting microchannel plate detector. The instrument design achieves an end-to-end sensitivity >10 times that of the Far-Ultraviolet Spectroscopic Explorer over the key 1020- to 1150-Å range and offers arcsecond-level angular resolution spectral imaging over a 6-arcminute-long slit for observations of extended sources. We describe the example science investigations for far-ultraviolet spectroscopy on Arcus, the resultant instrument design and predicted performance, and simulated data from potential General Observer programs with Arcus.

中文翻译：

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Arcus 紫外光谱仪：使用 Arcus X 射线探头实现远紫外光谱


Arcus 是一项高分辨率软 X 射线和远紫外光谱任务，已提交给美国国家航空航天局首届天体物理探测器征集活动。 Arcus 在这两个关键波长范围内同时进行观测，以解决 2020 年天文学和天体物理学十年调查所强调的广泛科学问题，从星际介质中缺失重子的温度和成分到恒星的演化及其对宇宙的影响绕轨道运行的行星。我们介绍了 Arcus 紫外光谱仪 (UVS) 的科学动机和性能。 UVS 包括一台 60 厘米离轴卡塞格伦望远镜，为在 970 至 1580 Å 带通范围内运行的成像光谱仪提供数据。该仪器采用两个可互换的衍射光栅来提供中等分辨率光谱（R>20,000，两种光栅模式，中心波长分别为 ∼1110 和 1390 Å）。光谱记录在开放式光子计数微通道板探测器上。该仪器设计在关键的 1020 至 1150 Å 范围内实现了远紫外光谱探测器的端到端灵敏度 >10 倍，并在 6 角分长的狭缝上提供角秒级角分辨率光谱成像，用于对扩展来源的观察。我们描述了 Arcus 上远紫外光谱学的示例科学调查、由此产生的仪器设计和预测性能，以及来自 Arcus 潜在通用观察者计划的模拟数据。