Resolving star-forming clumps in a z $\sim$ 2 lensed galaxy: a pixelated Bayesian approach

TL;DR

This paper introduces a Bayesian pixelated source reconstruction method for analyzing gravitationally lensed galaxies, effectively resolving star-forming clumps down to 100 pc with improved signal-to-noise ratio.

Contribution

The novel Bayesian pixelated approach enhances resolution and SNR in reconstructing lensed galaxy images, surpassing traditional ray-tracing methods.

Findings

Resolves star-forming clumps down to 100 pc.

Improves SNR by nearly ten times.

Effective in analyzing a z~2 lensed galaxy.

Abstract

We present a pixelized source reconstruction method applied on Integral Field Spectroscopic (IFS) observations of gravitationally lensed galaxies. We demonstrate the effectiveness of this method in a case study on the clumpy morphology of a $z \sim 2$ lensed galaxy behind a group-scale lens. We use a Bayesian forward source modelling approach to reconstruct the surface brightness distribution of the source galaxy on a uniformly pixelized grid while accounting for the image point spread function (PSF). The pixelated approach is sensitive to clump sizes down to 100 pc and resolves smaller clump sizes with an improvement in the signal to noise ratio (SNR) by almost a factor of ten compared with more traditional ray-tracing approaches.