# Nonlinearity and pixel shifting effects in HXRG infrared detectors

## TL;DR

This paper investigates the nonlinearity and pixel boundary shifts in HXRG infrared detectors, crucial for precision astronomy, by presenting laboratory measurements and analyzing archival data to understand sensor effects affecting cosmological observations.

## Contribution

It provides the first detailed characterization of nonlinearity and pixel boundary shifts in HXRG detectors, proposing models and measurement strategies for future calibration.

## Key findings

- Laboratory measurements of nonlinearity in HXRG detectors
- Evidence of pixel boundary shifts similar to brighter-fatter effect
- Discussion of calibration requirements for space missions

## Abstract

We study the nonlinearity (NL) in the conversion from charge to voltage in infrared detectors (HXRG) for use in precision astronomy. We present laboratory measurements of the NL function of a H2RG detector and discuss the accuracy to which it would need to be calibrated in future space missions to perform cosmological measurements through the weak gravitational lensing technique. In addition, we present an analysis of archival data from the infrared H1RG detector of the Wide Field Camera 3 in the Hubble Space Telescope that provides evidence consistent with the existence of a sensor effect analogous to the brighter-fatter effect found in Charge-Coupled Devices. We propose a model in which this effect could be understood as shifts in the effective pixel boundaries, and discuss prospects of laboratory measurements to fully characterize this effect.