GalaPy

May 1, 2024 · 1 min read
software

Role: lead author & maintainer. Stack: C++ compute core exposed through a Python API; hybrid parallelisation (vectorised array programming, shared-memory concurrency, distributed-memory message passing).

GalaPy simulates the panchromatic emission of galaxies from X-rays to radio and performs Bayesian spectral-energy-distribution fitting. Models are generated on the fly rather than interpolated from a template library, which is what allows a peak throughput of almost 1000 SEDs per second on a single core — the fastest SED-generation tool of its kind.

The library is designed around an object-oriented architecture that keeps it portable with minimal memory overhead, and it scales from a laptop to an HPC allocation without changing the user-facing API. Recent additions include parallel sampling for Bayesian inference and a fully analytical, panchromatic AGN component.

Since release, GalaPy has been adopted by groups across Europe, Asia and South America, for work ranging from nearby resolved galaxies to JWST high-redshift candidates. Its role in my wider programme is described in my research on galaxy formation and evolution.

Presented in Astronomy & Astrophysics 685, A161 (2024) — see the library paper — with the computational design detailed in Astronomy and Computing 55, 101079 (2026): the implementation paper.

Tommaso Ronconi
Authors
Fixed-Term Researcher · HPC Expert
Ciao! I am a researcher in Astrophysics and Cosmology at INAF’s Institute of Radioastronomy in Bologna, where I work as HPC expert at the Italian ALMA Regional Center. My research spans galaxy formation and evolution and large-scale-structure cosmology for modern surveys and experiments (i.e. SKAO, Euclid, ET) — from panchromatic SED modelling and Bayesian inference to full-sky mock light-cones. I am the author and maintainer of several open-source scientific packages (GalaPy, SCAMPy, and contributions to T-RECS and CosmoBolognaLib), built on a C++/Python and high-performance-computing foundation. Currently, I am leading the science-platform prototyping work package for the ESO ALMA support-centre development plan. I have supervised three graduate students and held lectures from the bachelor to the Ph.D. level.