A Pathfinder Instrument for Precision Radial Velocities in the Near-Infrared

TL;DR

This paper presents a new near-infrared spectrograph designed for high-precision radial velocity measurements, demonstrating promising results that could rival optical wavelength precision.

Contribution

The paper introduces a novel in-plane echelle spectrograph optimized for near-infrared radial velocity measurements with a resolution of R=50,000 and reports initial high-precision results.

Findings

Achieved ~10 m/s RMS radial velocity precision over hours.

Recent configuration reached 7 m/s RMS precision.

Infrared radial velocity precision may approach optical levels.

Abstract

We have designed and tested an in-plane echelle spectrograph configured to investigate precision radial velocities from ground-based near-infrared observations. The spectrograph operates across the spectral range of 0.9-1.7 mm at a spectral resolution of R = 50,000, and uses a liquid nitrogen-cooled HAWAII 1K detector. Repeated measurements of the Earth's rotation via integrated Sunlight with two different instrument arrangements in the near infrared Y band have produced radial velocities with ~10 m/s RMS over a period of several hours. The most recent instrument configuration has achieved an unbinned RMS of 7 m/s and suggests that infrared radial velocity precisions may be able to approach those achieved at optical wavelengths.