High Precision Radial Velocity Measurements in the Infrared: A First Assessment of the RV Stability of CRIRES

Abstract

High precision radial velocity (RV) measurements in the near infrared are on high demand, especially in the context of exoplanet search campaigns shifting their interest to late type stars in order to detect planets with ever lower mass or targeting embedded pre-main-sequence objects. ESO is offering a new spectrograph at the VLT -- CRIRES -- designed for high resolution near-infrared spectroscopy with a comparably broad wavelength coverage and the possibility to use gas-cells to provide a stable RV zero-point. We investigate here the intrinsic short-term RV stability of CRIRES, both with gas-cell calibration data and on-sky measurements using the absorption lines of the Earth's atmosphere imprinted in the source spectrum as a local RV rest frame. Moreover, we also investigate for the first time the intrinsic stability of telluric lines at 4100 nm for features originating in the lower troposphere. Our analysis of nearly 5 hours of consecutive observations of MS Vel, a M2II bright giant centred at two SiO first overtone band-heads at 4100 nm, demonstrates that the intrinsic short-term stability of CRIRES is very high, showing only a slow and fully compensateable drift of up to 60 m/s after 4.5 hours. The radial velocity of the telluric lines is constant down to a level of approx. +/- 10 m/s (or 7/1000 of one pixel). Utilising the same telluriclines as a rest frame for our radial velocity measurements of the science target, we obtain a constant RV with a precision of approx. +/- 20 m/s for MS Vel as expected for a M-giant.

arXiv comment12 pages, 6 figures, accepted by A&A

References in corpus (2)

• A laser frequency comb that enables radial velocity measurements with a precision of 1 cm s${}^{-1}$
• Precise radial velocities of giant stars. IV. A correlation between surface gravity and radial velocity variation and a statistical investigation of companion properties

Cited by in corpus (18)

• The NIRSPEC Ultracool Dwarf Radial Velocity Survey
• The CRIRES Search for Planets Around the Lowest-Mass Stars. I. High-Precision Near-Infrared Radial Velocities with an Ammonia Gas Cell
• Precise Infrared Radial Velocities from Keck/NIRSPEC and the Search for Young Planets
• The effect of M dwarf starspot activity on low-mass planet detection thresholds
• Synthesising, using, and correcting for telluric features in high-resolution astronomical spectra
• Radial Velocities with CRIRES: Pushing precision down to 5-10 m/s
• On The Use of Absorption Cells as a Wavelength Reference for Precision Radial Velocity Measurements in the Near Infrared
• Intermediate Resolution Near-Infrared Spectroscopy of 36 late-M Dwarfs
• CRIRES-POP: A library of high resolution spectra in the near-infrared
• Measuring NIR Atmospheric Extinction Using a Global Positioning System Receiver
• Precise radial velocities of giant stars VIII. Testing for the presence of planets with CRIRES Infrared Radial Velocities
• Keck NIRSPEC Radial Velocity Observations of Late-M dwarfs
• A multi-method approach to radial-velocity measurement for single-object spectra
• Search for radial velocity variations in eight M-dwarfs with NIRSPEC/Keck II
• Detecting Planets around Very Cool Dwarfs at Near Infrared Wavelengths with the Radial Velocity Technique
• Retrieval of Precise Radial Velocities from Near-Infrared High Resolution Spectra of Low Mass Stars
• Infrared radial velocities of vB 10
• IGRINS RV: A Precision RV Pipeline for IGRINS Using Modified Forward Modeling in the Near-Infrared