TY - JOUR
T1 - Performance Verification of the EXtreme PREcision Spectrograph
AU - Blackman, Ryan T.
AU - Fischer, Debra A.
AU - Jurgenson, Colby A.
AU - Sawyer, David
AU - McCracken, Tyler M.
AU - Szymkowiak, Andrew E.
AU - Petersburg, Ryan R.
AU - Joel Ong, J. M.
AU - Brewer, John M.
AU - Zhao, Lily L.
AU - Leet, Christopher
AU - Buchhave, Lars A.
AU - Tronsgaard, René
AU - Llama, Joe
AU - Sawyer, Travis
AU - Davis, Allen B.
AU - Cabot, Samuel H.C.
AU - Shao, Michael
AU - Trahan, Russell
AU - Nemati, Bijan
AU - Genoni, Matteo
AU - Pariani, Giorgio
AU - Riva, Marco
AU - Fournier, Paul
AU - Pawluczyk, Rafal
N1 - Publisher Copyright:
© 2020. The American Astronomical Society. All rights reserved.
PY - 2020/5
Y1 - 2020/5
N2 - The EXtreme PREcision Spectrograph (EXPRES) is a new Doppler spectrograph designed to reach a radial-velocity measurement precision sufficient to detect Earth-like exoplanets orbiting nearby, bright stars. We report on extensive laboratory testing and on-sky observations to quantitatively assess the instrumental radial-velocity measurement precision of EXPRES, with a focused discussion of individual terms in the instrument error budget. We find that EXPRES can reach a single-measurement instrument calibration precision better than 10 cm s-1, not including photon noise from stellar observations. We also report on the performance of the various environmental, mechanical, and optical subsystems of EXPRES, assessing any contributions to radial-velocity error. For atmospheric and telescope related effects, this includes the fast tip-tilt guiding system, atmospheric dispersion compensation, and the chromatic exposure meter. For instrument calibration, this includes the laser fRequency comb (LFC), flat-field light source, CCD detector, and effects in the optical fibers. Modal noise is mitigated to a negligible level via a chaotic fiber agitator, which is especially important for wavelength calibration with the LFC. Regarding detector effects, we empirically assess the impact on the radial-velocity precision due to pixel-position nonuniformities and charge transfer inefficiency (CTI). EXPRES has begun its science survey to discover exoplanets orbiting G-dwarf and K-dwarf stars, in addition to transit spectroscopy and measurements of the Rossiter-McLaughlin effect.
AB - The EXtreme PREcision Spectrograph (EXPRES) is a new Doppler spectrograph designed to reach a radial-velocity measurement precision sufficient to detect Earth-like exoplanets orbiting nearby, bright stars. We report on extensive laboratory testing and on-sky observations to quantitatively assess the instrumental radial-velocity measurement precision of EXPRES, with a focused discussion of individual terms in the instrument error budget. We find that EXPRES can reach a single-measurement instrument calibration precision better than 10 cm s-1, not including photon noise from stellar observations. We also report on the performance of the various environmental, mechanical, and optical subsystems of EXPRES, assessing any contributions to radial-velocity error. For atmospheric and telescope related effects, this includes the fast tip-tilt guiding system, atmospheric dispersion compensation, and the chromatic exposure meter. For instrument calibration, this includes the laser fRequency comb (LFC), flat-field light source, CCD detector, and effects in the optical fibers. Modal noise is mitigated to a negligible level via a chaotic fiber agitator, which is especially important for wavelength calibration with the LFC. Regarding detector effects, we empirically assess the impact on the radial-velocity precision due to pixel-position nonuniformities and charge transfer inefficiency (CTI). EXPRES has begun its science survey to discover exoplanets orbiting G-dwarf and K-dwarf stars, in addition to transit spectroscopy and measurements of the Rossiter-McLaughlin effect.
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U2 - 10.3847/1538-3881/ab811d
DO - 10.3847/1538-3881/ab811d
M3 - Article
AN - SCOPUS:85106817706
SN - 0004-6256
VL - 159
JO - Astronomical Journal
JF - Astronomical Journal
IS - 5
M1 - 236
ER -