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Title: Accounting for Chromatic Atmospheric Effects on Barycentric Corrections

Abstract

Atmospheric effects on stellar radial velocity measurements for exoplanet discovery and characterization have not yet been fully investigated for extreme precision levels. We carry out calculations to determine the wavelength dependence of barycentric corrections across optical wavelengths, due to the ubiquitous variations in air mass during observations. We demonstrate that radial velocity errors of at least several cm s{sup −1} can be incurred if the wavelength dependence is not included in the photon-weighted barycentric corrections. A minimum of four wavelength channels across optical spectra (380–680 nm) are required to account for this effect at the 10 cm s{sup −1} level, with polynomial fits of the barycentric corrections applied to cover all wavelengths. Additional channels may be required in poor observing conditions or to avoid strong telluric absorption features. Furthermore, consistent flux sampling on the order of seconds throughout the observation is necessary to ensure that accurate photon weights are obtained. Finally, we describe how a multiple-channel exposure meter will be implemented in the EXtreme PREcision Spectrograph (EXPRES).

Authors:
; ; ;  [1]
  1. Department of Astronomy, Yale University, 52 Hillhouse Avenue, New Haven, CT 06511 (United States)
Publication Date:
OSTI Identifier:
22661339
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 837; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ABSORPTION; ACCOUNTING; ACCURACY; COMPUTERIZED SIMULATION; CORRECTIONS; ERRORS; FREQUENCY DEPENDENCE; MASS; PHOTONS; POLYNOMIALS; RADIAL VELOCITY; SPECTRA; STARS; WAVELENGTHS

Citation Formats

Blackman, Ryan T., Szymkowiak, Andrew E., Fischer, Debra A., and Jurgenson, Colby A., E-mail: ryan.blackman@yale.edu. Accounting for Chromatic Atmospheric Effects on Barycentric Corrections. United States: N. p., 2017. Web. doi:10.3847/1538-4357/AA5EAD.
Blackman, Ryan T., Szymkowiak, Andrew E., Fischer, Debra A., & Jurgenson, Colby A., E-mail: ryan.blackman@yale.edu. Accounting for Chromatic Atmospheric Effects on Barycentric Corrections. United States. doi:10.3847/1538-4357/AA5EAD.
Blackman, Ryan T., Szymkowiak, Andrew E., Fischer, Debra A., and Jurgenson, Colby A., E-mail: ryan.blackman@yale.edu. Wed . "Accounting for Chromatic Atmospheric Effects on Barycentric Corrections". United States. doi:10.3847/1538-4357/AA5EAD.
@article{osti_22661339,
title = {Accounting for Chromatic Atmospheric Effects on Barycentric Corrections},
author = {Blackman, Ryan T. and Szymkowiak, Andrew E. and Fischer, Debra A. and Jurgenson, Colby A., E-mail: ryan.blackman@yale.edu},
abstractNote = {Atmospheric effects on stellar radial velocity measurements for exoplanet discovery and characterization have not yet been fully investigated for extreme precision levels. We carry out calculations to determine the wavelength dependence of barycentric corrections across optical wavelengths, due to the ubiquitous variations in air mass during observations. We demonstrate that radial velocity errors of at least several cm s{sup −1} can be incurred if the wavelength dependence is not included in the photon-weighted barycentric corrections. A minimum of four wavelength channels across optical spectra (380–680 nm) are required to account for this effect at the 10 cm s{sup −1} level, with polynomial fits of the barycentric corrections applied to cover all wavelengths. Additional channels may be required in poor observing conditions or to avoid strong telluric absorption features. Furthermore, consistent flux sampling on the order of seconds throughout the observation is necessary to ensure that accurate photon weights are obtained. Finally, we describe how a multiple-channel exposure meter will be implemented in the EXtreme PREcision Spectrograph (EXPRES).},
doi = {10.3847/1538-4357/AA5EAD},
journal = {Astrophysical Journal},
number = 1,
volume = 837,
place = {United States},
year = {Wed Mar 01 00:00:00 EST 2017},
month = {Wed Mar 01 00:00:00 EST 2017}
}