17-21 March 2019
Sunstar Hotel, Grindelwald, Switzerland
Europe/Zurich timezone

Precise Near Infrared Radial Velocities With iSHELL

20 Mar 2019, 11:45
15m
Sunstar Hotel, Grindelwald, Switzerland

Sunstar Hotel, Grindelwald, Switzerland

Dorfstrasse 168, 3818 Grindelwald Switzerland
Oral Instruments in nIR NIR instruments

Speaker

Prof. Peter Plavchan (George Mason University)

Description

We present our radial-velocities (RVs) with the iSHELL spectrograph at the NASA Infrared Telescope facility. Replacing the 25 year old CSHELL instrument, iSHELL offers improvements in spectral grasp (~40x), resolution (70,000 versus 46,000), throughput, optics, and detector characteristics. Our primary goal with iSHELL is to characterize the precise radial-velocity performance of the methane isotopologue absorption gas cell in the calibration unit. Over the last two years, we've obtained 3-12 epochs of bright nearby RV standards as well as RV variables of our own. A new flexible telluric model allows for dynamic abundance ratios in Earth's atmosphere, and physically-motivated analytic fringing models account for internal reflections from the optics in the instrument. We've demonstrated 6 m/s precision on Barnard’s star over one year, sufficient to confirm Neptune-mass planets around M Dwarfs discovered by the NASA TESS mission. With further development on the the non-standard blaze and line spread functions present in iSHELL data, we aim to achieve 3-5 m/s long-term precision, sufficient to detect terrestrial mass planets in the habitable zone of nearby M Dwarfs.

Primary authors

Prof. Peter Plavchan (George Mason University) Cale Bryson (George Mason University)

Presentation Materials