Characterization and Commissioning of the iLocater Spectrograph

该项目将完成一个名为iLocater的新仪器的建设，该仪器将使用亚利桑那州的一个大型望远镜搜索系外行星。iLocater是一种被称为摄谱仪的仪器，它将来自恒星的入射光扩散开来，并搜索行星在其恒星轨道上运行时引起的微小颜色变化。该仪器补偿了地球湍流大气的扭曲效应，并且可以使用小光纤将望远镜发出的光带到光谱仪上。这一特性使科学家能够看到行星引起的颜色变化和恒星表面变化的影响，从而发现和研究目前可以探测到的更小的系外行星。iLocater的设计非常稳定，可以探测到由行星引起的难以置信的微小颜色变化。iLocater将对系外行星系统进行研究，以表征它们的特性，并评估它们支持生命的潜力。该项目将为研究生提供开发仪器的培训，并为本科生提供夏季研究机会。现代多普勒仪器的性能主要受恒星变异性的影响，这种影响将表面不均匀性和随机运动的特征印在恒星光谱上。这种天体物理抖动通过在恒星光谱的吸收线中产生时间变化的不对称性，施加了噪声底限。该项目将完成在大型望远镜上使用自适应光学（AO）和单模光纤（smf）实现高光谱分辨率（R=132,000-273,000）的多普勒精密径向速度仪的建造。该仪器名为iLocater，将安装在亚利桑那州的大型双目望远镜（LBT）上，并在近红外（NIR）波长（yj波段）的衍射极限下工作。近红外带通非常适合AO性能，预计不太容易受到恒星变化的影响，并提供了对晚型恒星的峰值辐射的访问，其中行星的多普勒振幅大大大于围绕g型恒星运行的恒星。高光谱分辨率和高空间分辨率（41 mas）的结合将促进新的研究方向，例如研究围绕近距离双星运行的行星。完成后，iLocater将可供许多在LBT社区的美国天文学家使用，每年30个晚上，并且iLocater的数据产品将向公众开放。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

This project will complete the construction of a new instrument named iLocater that will search for exoplanets using a large telescope in Arizona. iLocater is an instrument called a spectrograph that spreads out the incoming light from stars and searches for the tiny color changes caused by planets moving in orbit around their star. The instrument compensates for the distorting effect of Earth’s turbulent atmosphere and can use small optical fibers to bring light from the telescope to the spectrograph. This feature allows scientists to see both the color changes caused by planets and the effects of the changing surface of stars which enable discovery and study of even smaller exoplanets that can currently be detected. iLocater is designed to be extremely stable to allow the detection of the incredibly small color change caused by planets to be measured. iLocater will undertake studies of exoplanetary systems to characterize their properties and assess their potential to support life. The project will supply training for graduate students in developing instrumentation and also summer research opportunities for undergraduate studentsThe performance of modern Doppler instruments is dominated by the effects of stellar variability, an effect that imprints the signature of surface inhomogeneities and stochastic motions onto stellar spectra. Such astrophysical jitter imposes a noise floor by creating temporally changing asymmetries in the absorption lines of stellar spectra. This project will complete building a Doppler precision radial velocity instrument that uses adaptive optics (AO) and single-mode fibers (SMFs) on a large telescope to achieve high spectral resolution (R=132,000-273,000). The instrument, named iLocater, will be installed on the Large Binocular Telescope (LBT) in Arizona and operates at the diffraction limit at near-infrared (NIR) wavelengths (YJ-bands). The NIR bandpass is well suited to AO performance, is expected to be less susceptible to stellar variability, and provides access to the peak radiation of late-type stars where the Doppler amplitudes of planets are substantially larger than those orbiting G-type stars. The combination of high spectral resolution and high spatial resolution (41 mas) will facilitate novel research directions, such as studying planets orbiting close separation binaries. On completion iLocater will be available to many US astronomers who are within the LBT community for 30 nights/year and there will be public access to the iLocater data products.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.