Release Notes

Version 1.0 (Public Release)

Release Date: [Date of release]

This is the initial public release of GalfitS.

New Features:

• Core Fitting Engine: * Simultaneous morphological and SED fitting of galaxy components. * Support for multiple imaging bands and optional spectroscopic data. * JAX-based backend for high-performance computing on CPUs and GPUs.

• Modeling Capabilities: * Library of 2D profiles: Sersic, Ferrer, Edge-on Disk, Gaussian Ring, and more. * Fourier modes for non-axisymmetric features (e.g., spiral arms). * Stellar Population Synthesis (SPS) models for galaxy components, supporting various Star Formation Histories (burst, continuous, binned). * AGN models including continuum (power-law, thin disk), emission lines, and torus dust emission. * Foreground star modeling.

• Optimization & Sampling: * Multiple fitting backends:

  • Gradient-based optimizer (jaxopt).

  • Nested sampling with dynesty for Bayesian inference and posterior estimation.

  • Evolutionary Strategies (evosax) for global optimization.

  • Flexible parameter constraint system via external files.

  • Support for astrophysical priors (e.g., Mass-Size relation, Mass-Metallicity relation).

• Data Handling: * Automated image cutout, sky subtraction, and mask generation utilities. * Empirical PSF construction tool. * Support for astropy FITS files and WCS.

• Usability: * Command-line interface for running fits. * Detailed configuration files (.lyric) for defining fitting runs. * Plotting utilities for visualizing results (image residuals, model SEDs, SFHs).

• Documentation: * Initial version of the documentation, including installation, quickstart, and configuration guides.

Known Issues:

• The documentation is still under development. Some sections may be incomplete.

• Error handling for invalid configuration file parameters could be more verbose.

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Future releases will focus on expanding the model library, improving performance, and enhancing the user interface and documentation.