Measuring Stellar Radial Velocities with a Dispersed Fixed-Delay Interferometer

Abstract

We demonstrate the ability to measure precise stellar barycentric radial velocities with the dispersed fixed-delay interferometer technique using the Exoplanet Tracker (ET), an instrument primarily designed for precision differential Doppler velocity measurements using this technique. Our barycentric radial velocities, derived from observations taken at the KPNO 2.1 meter telescope, differ from those of Nidever et al. by 0.047 km/s (rms) when simultaneous iodine calibration is used, and by 0.120 km/s (rms) without simultaneous iodine calibration. Our results effectively show that a Michelson interferometer coupled to a spectrograph allows precise measurements of barycentric radial velocities even at a modest spectral resolution of R ~ 5100. A multi-object version of the ET instrument capable of observing ~500 stars per night is being used at the Sloan 2.5 m telescope at Apache Point Observatory for the Multi-object APO Radial Velocity Exoplanet Large-area Survey (MARVELS), a wide-field radial velocity survey for extrasolar planets around TYCHO-2 stars in the magnitude range 7.6<V<12. In addition to precise differential velocities, this survey will also yield precise barycentric radial velocities for many thousands of stars using the data analysis techniques reported here. Such a large kinematic survey at high velocity precision will be useful in identifying the signature of accretion events in the Milky Way and understanding local stellar kinematics in addition to discovering exoplanets, brown dwarfs and spectroscopic binaries.

9 pages, 4 figures. Accepted for publication in ApJ

References in corpus (12)

• The Geneva-Copenhagen survey of the Solar neighbourhood: Ages, metallicities, and kinematic properties of 14,000 F and G dwarfs
• Radial Velocities for 889 Late-type Stars
• A Low Latitude Halo Stream around the Milky Way
• The Lick Planet Search: Detectability and Mass Thresholds
• Detection of a NEPTUNE-mass planet in the ${\rho }^1$ Cancri system using the Hobby-Eberly Telescope
• Pieces of the puzzle: Ancient substructure in the Galactic disk
• The Discovery of Tidal Tails Around NGC 5466
• The fundamental definition of 'radial velocity'
• The First Extrasolar Planet Discovered with a New Generation High Throughput Doppler Instrument
• Fixed-delay Interferometry for Doppler Extra-solar Planet Detection
• The N2K Consortium VI: Doppler Shifts Without Templates and Three New Short-Period Planets
• First Planet Confirmation with a Dispersed Fixed-Delay Interferometer

Cited by in corpus (5)

• Theory of Dispersed Fixed-Delay Interferometry for Radial Velocity Exoplanet Searches
• An Inexpensive Field-Widened Monolithic Michelson Interferometer for Precision Radial Velocity Measurements
• Discovery of a Low-Mass Companion to a Metal-Rich F Star with the MARVELS Pilot Project
• Very Low-Mass Stellar and Substellar Companions to Solar-like Stars From MARVELS VI: A Giant Planet and a Brown Dwarf Candidate in a Close Binary System HD 87646
• Attaining Doppler Precision of 10 cm/s with a Lock-In Amplified Spectrometer