Deriving High-Precision Radial Velocities

TL;DR

This chapter reviews the key factors influencing the derivation of high-precision radial velocities in astrophysics, focusing on spectrograph design, calibration techniques, and recent advancements enabling exoplanet detection.

Contribution

It provides a comprehensive overview of spectrograph components, calibration methods, and recent instrument developments that enhance radial velocity measurement precision.

Findings

Discussion of spectrograph design impacts on precision

Comparison of wavelength calibration techniques

Examples of exoplanets detected via radial velocity

Abstract

This chapter describes briefly the key aspects behind the derivation of precise radial velocities. I start by defining radial velocity precision in the context of astrophysics in general and exoplanet searches in particular. Next I discuss the different basic elements that constitute a spectrograph, and how these elements and overall technical choices impact on the derived radial velocity precision. Then I go on to discuss the different wavelength calibration and radial velocity calculation techniques, and how these are intimately related to the spectrograph's properties. I conclude by presenting some interesting examples of planets detected through radial velocity, and some of the new-generation instruments that will push the precision limit further.