The Brighter-Fatter and other Sensor Effects in CCD Simulations for Precision Astronomy

TL;DR

This paper discusses modeling sensor effects in CCDs, like the brighter-fatter effect, to improve the accuracy of weak lensing measurements in astronomical surveys, using a Monte Carlo simulation approach.

Contribution

It introduces a photon-by-photon Monte Carlo model of CCD sensor effects, aiming to validate it with laboratory data for better weak lensing analysis.

Findings

Development of a detailed CCD simulation model

Potential to reduce systematic errors in weak lensing measurements

Framework for validating sensor effects with laboratory data

Abstract

Upcoming and current large astronomical survey experiments often seek to constrain cosmological parameters via measurements of subtle effects such as weak lensing, which can only be measured statistically. In these cases, instrumental effects in the image plane CCDs need to be accounted and/or corrected for in measurement algorithms. Otherwise, the systematic errors induced in the measurements might overwhelm the size of the desired effects. Lateral electric fields in the bulk of the CCDs caused by field shaping potentials or space charge build up as the electrons in the image are acquired can cause lateral deflections of the electrons drifting in the CCD bulk. Here, I report on the LSST effort to model these effects on a photon-by-photon basis by the use of a Monte Carlo technique. The eventual goal of this work is to produce a CCD model validated by laboratory data which can then be used to evaluate its effects on weak lensing science.