Considerable interest is now focused on the detection of terrestrial mass planets around M dwarfs, and radial velocity surveys with high-resolution spectrographs in the near-infrared (NIR) are expected to be able to discover such planets. We explore the possibility of using commercially available molecular absorption gas cells as a wavelength reference standard for high-resolution fiber-fed spectrographs in the NIR. We consider the relative merits and disadvantages of using such cells compared with thorium-argon emission lamps and conclude that in the astronomical H band, they are a viable method of simultaneous calibration, yielding an acceptable wavelength calibration error for most applications. Four well-characterized and commercially available standard gas cells of H13C14N, 12C2H2, 12CO, and 13CO can together span over 120 nm of the H band, making them suitable for use in astronomical spectrographs. The use of isotopologues of these molecules can increase line densities and wavelength coverage, extending their application to different wavelength regions.
All Science Journal Classification (ASJC) codes
- Astronomy and Astrophysics
- Space and Planetary Science