A New Gas Cell for High-Precision Doppler Measurements in the Near-Infrared

TL;DR

This paper introduces a novel near-infrared gas cell with a specific gas mixture designed to improve high-precision Doppler measurements for exoplanet detection around low-mass stars, covering key spectral bands.

Contribution

Development of a compact gas cell with a tailored gas mixture that spans the near-infrared spectrum for enhanced wavelength calibration in astronomical spectroscopy.

Findings

The gas cell covers most of the H and K-bands.

It demonstrates small, usable absorption lines in the J-band.

Compared favorably with existing near-infrared gas cells.

Abstract

High-resolution spectroscopy in the near-infrared could become the leading method for discovering extra-solar planets around very low-mass stars and brown dwarfs. To help to achieve an accuracy of ~m/s, we are developing a gas cell which consists of a mixture of gases whose absorption spectral lines span all over the near-infrared region. We present the most promising mixture, made of acetylene, nitrous oxide, ammonia, chloromethans and hydrocarbons. The mixture is contained in a small size 13 cm long gas cell and covers most of the H and K-bands. It also shows small absorptions in the J-band but they are few and not sharp enough for near infrared wavelength calibration. We describe the working method and experiments and compare our results with the state of the art for near infrared gas cells.