A projected Nesterov-Kaczmarz approach to stellar population-kinematic distribution reconstruction in Extragalactic Archaeology

TL;DR

This paper introduces a projected Nesterov-Kaczmarz method for reconstructing stellar population-kinematic distributions in galaxies from optical measurements, improving efficiency and incorporating physical constraints.

Contribution

It presents a novel PNKR algorithm tailored for high-dimensional integral equations in galaxy analysis, integrating physical priors for enhanced reconstruction accuracy.

Findings

Successfully reconstructs distributions from simulated data

Outperforms pPXF in accuracy and efficiency

Incorporates physical constraints like smoothness and non-negativity

Abstract

In this paper, we consider the problem of reconstructing a galaxy's stellar population-kinematic distribution function from optical integral field unit measurements. These quantities are connected via a high-dimensional integral equation. To solve this problem, we propose a projected Nesterov-Kaczmarz reconstruction (PNKR) method, which efficiently leverages the problem structure and incorporates physical prior information such as smoothness and non-negativity constraints. To test the performance of our reconstruction approach, we apply it to a dataset simulated from a known ground truth density, and validate it by comparing our recoveries to those obtained by the widely used pPXF software.