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标题：An Extreme-precision Radial-velocity Pipeline: First Radial Velocities from EXPRES
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作者：Ryan R.Petersburg ; J.M.Joel Ong (王加冕) ; Lily L.Zhao 等
期刊名称：The Astronomical journal
印刷版ISSN：0004-6256
电子版ISSN：1538-3881
出版年度：2020
卷号：159
期号：5
页码：2604-2617
DOI：10.3847/1538-3881/ab7e31
语种：English
出版社：American Institute of Physics
摘要：The EXtreme-PREcision Spectrograph (EXPRES) is an environmentally stabilized, fiber-fed, R = 137,500, optical spectrograph.It was recently commissioned at the 4.3 m Lowell Discovery Telescope near Flagstaff, Arizona.The spectrograph was designed with a target radial-velocity (RV) precision of 30 cm s−1.In addition to instrumental innovations, the EXPRES pipeline, presented here, is the first on-sky, optical, fiber-fed spectrograph to employ many novel techniques—including an "extended flat" fiber used for wavelength-dependent quantum efficiency characterization of the CCD, a flat-relative optimal extraction algorithm, chromatic barycentric corrections, chromatic calibration offsets, and an ultra-precise laser frequency comb for wavelength calibration.We describe the reduction, calibration, and RV analysis pipeline used for EXPRES and present an example of our current sub-meter-per-second RV measurement precision, which reaches a formal, single-measurement error of 0.3 m s−1 for an observation with a per-pixel signal-to-noise ratio of 250.These velocities yield an orbital solution on the known exoplanet host 51 Peg that matches literature values with a residual rms of 0.895 m s−1.
关键词：High-resolution spectroscopy;Radial velocity;Astronomy data analysis;Observational astronomy