Roadmap of GHOST@Gemini's Precision Radial Velocity Mode

TL;DR

This paper presents the development plan and expected performance of GHOST, a high-resolution spectrograph at Gemini South, focusing on its radial velocity measurement capabilities and future upgrades.

Contribution

It outlines the roadmap for GHOST's precision radial velocity mode, including potential upgrades and error analysis for achieving 1-10 m/s accuracy.

Findings

Estimated on-sky RV precision of 1-10 m/s

Potential upgrades to improve performance

Error sources affecting radial velocity measurements

Abstract

GHOST is a newly operational optical fiber-fed high-resolution spectrograph at the Gemini South 8.1m telescope. It currently offers the choice of two resolution modes captured by one (or two) input IFUs with a FOV of 1.2'' and a spectral resolving power of 56,000 and 76,000 for the unbinned CCDs. At the high-resolution mode, one can also instigate a simultaneous ThXe calibration lamp, which along with a simultaneous pseudo-slit profile constructed from reformatting the input IFU image will allow for precision radial velocity measurements. Here we talk about the proposed roadmap towards full queue operations, potential upgrades, and the error terms contributing to the final on-sky RV precision, which is estimated to be in the 1-10 m s$^{-1}$ range.