The Effects of Telluric Contamination in Iodine-calibrated Precise Radial Velocities
AuthorWang, Sharon Xuesong
Wright, Jason T.
Howard, Andrew W.
Muirhead, Philip S.
AffiliationUniv Arizona, Steward Observ
MetadataShow full item record
PublisherIOP PUBLISHING LTD
CitationSharon Xuesong Wang et al 2019 AJ 158 216
RightsCopyright © 2019. The American Astronomical Society. All rights reserved.
Collection InformationThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at email@example.com.
AbstractWe characterized the effects of telluric absorption lines on the radial velocity (RV) precision of stellar spectra taken through an iodine cell. To isolate the effects induced by telluric contamination from other stellar, instrumental, or numerical systematic RV noise, we extracted RVs from simulated iodine-calibrated spectra of three RV standard stars regularly observed by Keck/HIRES. We add in water absorption lines according to measured precipitable water vapor (PWV) contents over a one-year period. We conclude that telluric contamination introduces additional RV noise and spurious periodic signals at the level of 10–20 cm s−1, consistent with similar previous studies. Our findings show that forward modeling the telluric lines effectively recovers the RV precision and accuracy, with no prior knowledge of the PWV needed. Such a recovery is less effective when the water absorption lines are relatively deep in the stellar template used in the forward modeling. Overall, telluric contamination plays an insignificant role in typical iodine-calibrated RV programs aiming at ~1–2 m s−1, but we recommend adding modeling of telluric lines and taking stellar template observations on nights with low humidity for programs aiming to achieve a precision of better than 1 m s–1.
VersionFinal published version
SponsorsNASA Earth and Space Science Graduate Fellowship (2014-2016); National Science Foundation (NSF) [AST-1211441]; Center for Exoplanets and Habitable Worlds - Pennsylvania State University; Eberly College of Science; Pennsylvania Space Grant Consortium; W.M. Keck Foundation