Research
Galaxy formation and evolution

Galaxy formation and evolution

Jul 29, 2026 · 2 min read
research

A second major axis is galaxy formation and evolution across cosmic time. With collaborators at SISSA I have analysed the spectral properties of high-redshift galaxies using theoretical models of star formation and dust processes.

This led to GalaPy, a public code that simulates the panchromatic emission of galaxies from X-rays to radio, offering full SED modelling, Bayesian inference, and a computationally efficient implementation. It is the fastest SED-generation tool of its kind, with a peak performance of almost 1000 SEDs per second on a single core, thanks to a hybrid C++/Python architecture that generates models on the fly rather than relying on templates.

Since its release GalaPy has gained users across Europe, Asia and South America, and has been adopted for studies ranging from nearby resolved galaxies to JWST high-redshift candidates. In a recent paper I presented the computational design of the code in detail: its object-oriented architecture, a hybrid parallelisation strategy combining vectorised array programming, shared-memory concurrency and distributed-memory message passing, and the optimisations that keep it portable with minimal memory overhead. That work also introduced two new capabilities — parallel sampling for Bayesian inference, and a fully analytical panchromatic AGN component.

Currently: GalaPy is developing along two directions. I am co-supervising a Ph.D. student implementing panchromatic line emission in GalaPy SEDs, covering both the physics of emission lines and the sampling strategies needed for efficient inference. Meanwhile growing adoption for JWST and ALMA data is driving further computational optimisation and validated spectroscopic fitting beyond the current photometric mode.

Key papers: Ronconi et al. 2024 · Ronconi & Lapi 2026

Software: GalaPy

SED Modelling Bayesian Inference JWST ALMA
Tommaso Ronconi
Authors
Tommaso Ronconi (he/him)
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.