Optical velocimetry has led to the detection of more than 500 planets to date and there is a strong effort to push m/s velocimetry to the near-infrared to access cooler and lighter stars. The presence of numerous telluric absorption lines in the nIR brings an important challenge. As the star's barycentric velocity varies through the year, the telluric absorption lines effectively varies in velocity relative to the star's spectrum by the same amount leading to important systematic RV offsets. We present a novel principal component analysis-based approach for telluric line subtraction and demonstrated its effectiveness with archival HARPS data for GJ436 and {\tau} Ceti, over parts of the R-band that contain strong telluric absorption lines. The main results are: 1) a better RV accuracy with excluding only a few percentage of the domain, 2) better use of the entire spectrum to measure RV and 3) a higher telescope time efficency by using A0V telluric standard from telescope archive.
@article{arxiv.1406.6927,
title = {Telluric-line subtraction in high-accuracy velocimetry: a PCA-based approach},
author = {Étienne Artigau and Nicola Astudillo-Defru and Xavier Delfosse and François Bouchy and Xavier Bonfils and Christophe Lovis and Francesco Pepe and Claire Moutou and Jean-François Donati and René Doyon and Lison Malo},
journal= {arXiv preprint arXiv:1406.6927},
year = {2015}
}
Comments
Presented at SPIE Astronomical Telescopes + Instrumentation 2014