PetroFit: A Python Package for Computing Petrosian Radii and Fitting Galaxy Light Profiles

TL;DR

PetroFit is an open-source Python package that streamlines the calculation of Petrosian radii and fitting of galaxy light profiles, enhancing photometric accuracy and morphological analysis in astronomical imaging.

Contribution

It introduces a comprehensive, open-source toolkit for galaxy photometry and profile fitting, integrating Petrosian metrics with flexible 2D modeling capabilities.

Findings

Provides accurate Petrosian radii for galaxy photometry

Enables detailed galaxy light profile modeling and fitting

Includes correction tools for morphology-related biases

Abstract

PetroFit is an open-source Python package, based on Astropy and Photutils, that can calculate Petrosian profiles and fit galaxy images. It offers end-to-end tools for making accurate photometric measurements, estimating morphological properties, and fitting 2D models to galaxy images. Petrosian metric radii can be used for model parameter estimation and aperture photometry to provide accurate total fluxes. Correction tools are provided for improving Petrosian radii estimates affected by galaxy morphology. PetroFit also provides tools for sampling Astropy-based models (including custom profiles and multi-component models) onto image grids and enables PSF convolution to account for the effects of seeing. These capabilities provide a robust means of modeling and fitting galaxy light profiles. We have made the PetroFit package publicly available on GitHub (PetroFit/petrofit) and PyPi (pip install petrofit).