English

Improving Posterior Inference of Galaxy Properties with Image-Based Conditional Flow Matching

Instrumentation and Methods for Astrophysics 2025-12-05 v1 Astrophysics of Galaxies

Abstract

Estimating physical properties of galaxies from wide-field surveys remains a central challenge in astrophysics. While spectroscopy provides precise measurements, it is observationally expensive, and photometry discards morphological information that correlates with mass, star formation history, metallicity, and dust. We present a conditional flow matching (CFM) framework that leverages pixel-level imaging alongside photometry to improve posterior inference of galaxy properties. Using 105\sim10^5 SDSS galaxies, we compare models trained on photometry alone versus photometry plus images. The image+photometry model outperforms the photometry-only model in posterior inference and more reliably recovers known scaling relations. Morphological information also helps mitigate the dust--age degeneracy. Our results highlight the potential of integrating morphology into photometric SED fitting pipelines, opening a pathway towards more accurate and physically informed constraints on galaxy properties.

Keywords

Cite

@article{arxiv.2512.05078,
  title  = {Improving Posterior Inference of Galaxy Properties with Image-Based Conditional Flow Matching},
  author = {Mikaeel Yunus and John F. Wu and Benne W. Holwerda},
  journal= {arXiv preprint arXiv:2512.05078},
  year   = {2025}
}

Comments

Accepted at NeurIPS 2025 ML4PS workshop

R2 v1 2026-07-01T08:10:00.483Z