GUIBRUSHR®
Graphic User Interface for Bayesian Retrieval Using Spectroscopy at High Resolution
GUIBRUSHR is the flagship pipeline I develop with the exoplanet group at INAF–OATo. Its scientific aim is to measure what exoplanet atmospheres are made of, and to connect that composition to how planets form and evolve. To get there it brings together, in one tool, analysis steps that are usually scattered across separate codes, and it is built to make a normally complex, error-prone process straightforward: an intuitive interface replaces long configuration files, and streamlined data management handles large astronomical datasets.
I led the rewrite of the original IDL codebase into Python, adding CPU parallelization that sharply cut execution times, and I'm now extending it with GPU parallelization of the radiative-transfer step. The software generates transmission and emission models for clear and cloudy atmospheres using radiative-transfer engines such as petitRADTRANS and PyratBay, and explores parameter space with differential-evolution MCMC retrievals and real-time visualization.
Key modules. GUIBRUSHR is organized into modules, each handling one step on the path from raw starlight to a planet's atmospheric composition, tied together by a local database that keeps every target, observing night and result reproducible.
Reading the spectra
- Data Reduction: turns raw high-resolution spectra into calibrated, wavelength-aligned data ready for analysis. Now also a standalone tool supporting GIANO-B, HARPS-N, CRIRES+ and ESPRESSO.
- Telluric Removal: Earth's atmosphere and the host star imprint strong lines that bury the planet's far weaker signal. This module removes them order by order with a PCA-based approach, while preserving the slightly Doppler-shifted planetary lines.
- Cross-Correlation: co-adds the thousands of faint molecular lines into a single, statistically significant detection, confirming which species are present from the planet's orbital motion.
Modelling the atmosphere
- Forward Model: builds physical transmission and emission spectra for the expected molecules, the temperature structure and clouds (with petitRADTRANS or PyratBay), used both as cross-correlation templates and as the models compared with the data.
- Bayesian Retrieval: a differential-evolution MCMC infers the atmosphere's molecular abundances, temperature structure, clouds and velocities, with proper uncertainties, running on high-resolution, low-resolution or both jointly.
- Synthetic data & database: generates realistic mock observations to validate the full chain, while a local SQLite3 database stores targets, observing nights and results for reproducible science.
GUIBRUSHR has already contributed to peer-reviewed work, including Basilicata et al. (2025).