Impact of crosshatch patterns in H2RGs on high precision radial velocity measurements: Exploration of measurement and mitigation paths with HPF

TL;DR

This paper investigates how crosshatch patterns in H2RG detectors affect high-precision radial velocity measurements and explores measurement and correction methods using the Habitable-Zone Planet Finder's upgraded laser frequency comb.

Contribution

It provides measurements of sub-pixel QE variations in H2RG detectors and proposes a simple correction model to mitigate their impact on radial velocity data.

Findings

Sub-pixel QE variations cause measurable artifacts in spectra.

A first-order correction can reduce the impact of crosshatch patterns.

Upgraded laser frequency comb enables effective correction implementation.

Abstract

Teledyne's H2RG detector images suffer from cross-hatch like patterns which arises from sub-pixel quantum efficiency (QE) variation. In this paper we present our measurements of this sub-pixel QE variation in the Habitable-Zone Planet Finder's H2RG detector. We present a simple model to estimate the impact of sub-pixel QE variations on the radial velocity, and how a first order correction can be implemented to correct for the artifact in the spectrum. We also present how the HPF's future upgraded laser frequency comb will enable us to implement this correction.