2010A&A...515A.106F -
Astronomy and Astrophysics, volume 515, A106-106 (2010/6-1)
Evaluating the stability of atmospheric lines with HARPS.
FIGUEIRA P., PEPE F., LOVIS C. and MAYOR M.
Abstract (from CDS):
When searching for extrasolar systems using the radial velocity technique, the need for high-precision measurements implies that a precise wavelength calibration is required. The choice of the calibrator is a particularly important open question in the infra-red domain, where precision and achievements remain inferior to those in the optical. We investigate the long-term stability of atmospheric lines as a precise wavelength reference and analyze their sensitivity to different atmospheric and observing conditions.We use HARPS archival data for three bright stars, tau Ceti, µ Arae, and e Eri, which span 6 years and include high-cadence measurements performed over several nights. We cross-correlate this data with an O2 mask and evaluate both radial velocity and bisector variations to a photon noise level of 1m/s.We find that the telluric lines in the three data-sets are stable down to 10m/s (rms) over the 6 years. We also show that the radial velocity variations can be modeled by simple atmospheric models, yielding a final precision of 1-2m/s.The long-term stability of atmospheric lines was 10m/s over six years, in spite of atmospheric phenomena. Atmospheric lines can be used as a wavelength reference for short timescale programs, yielding a precision of 5m/s without any correction. A higher precision, of 2m/s, can be reached if the atmospheric phenomena are corrected for using the simple atmospheric model described, making it a very competitive method even on long timescales.
Abstract Copyright:
∼
Journal keyword(s):
atmospheric effects - instrumentation: spectrographs - methods: observational - techniques: radial velocities - planetary systems
Simbad objects:
7
Full paper
View the references in ADS
To bookmark this query, right click on this link: simbad:2010A&A...515A.106F and select 'bookmark this link' or equivalent in the popup menu