Welcome to the ORION-B project
Molecular lines and line ratios are commonly used to infer properties of Galactic and extra-galactic star forming regions. The new generation of (sub-)millimeter receivers turns every observation nearly into a line survey. To fully exploit this technical advance in extra-galactic studies requires detailed bench-marking of available line diagnostics. We aim to develop the Orion B Giant Molecular Cloud as a local template for interpreting Galactic and extra-galactic molecular line observations.
The above animation (credit & copyright: L. Orazi for the optical image and J. Pety, the ORION-B Collaboration & IRAM for the radio image) shows the Orion B cloud, known to house the Horsehead and Flame nebulae in optical and radio. The optical image mostly shows regions that are illuminated by the intense ultraviolet radiation from the massive young stars nearby, while the radio image reveals the hidden turbulent nature of the molecular gas where future generations of stars will be born.
ANR project website 
2024
2024-10-22: Lucas Einig successfully defended his PhD thesis — Relationships between observables and astrophysical conditions: a statistical and learning approach to the Orion B giant molecular cloud. 
2024-09-24: Léontine Ségal's first paper is accepted by A&A — Toward a robust physical and chemical characterization of heterogeneous lines of sight: The case of the Horsehead nebula.
2024-09-19: Lucas Einig and Pierre Palud's paper is accepted by A&A — Quantifying the informativity of emission lines to infer physical conditions in giant molecular clouds. I. Application to model predictions.
2024-02-19: Antoine Roueff's paper is accepted by A&A — Bias versus variance when fitting multi-species molecular lines with a non-LTE radiative transfer model: Application to the estimation of the gas temperature and volume density.
2024-01-20: Ivana Bešlić's paper is accepted by A&A — The magnetic field in the Flame nebula.
2023
2023-12-07: Pierre Palud successfully defended his PhD thesis — Sampling methods for statistical inference of non-linear inverse problems: spatial distribution of physico-chemical properties of the interstellar medium.
2023-10-01: Helena Mazurek starts her PhD thesis — From small to large scales: structure and composition of molecular gas.
2023-09-29: Miriam Santa-Maria successfully defended her PhD thesis — Characterization of the extended warm molecular gas in high-mass star-forming regions.
2023-09-05: Miriam Santa-Maria's first paper is accepted by A&A — HCN emission from translucent gas and UV-illuminated cloud edges revealed by wide-field IRAM 30 m maps of the Orion B GMC.
2023-07-31: Pierre Palud and Lucas Einig's paper is accepted by A&A — Neural network-based emulation of interstellar medium models.
2023-07-18: Lucas Einig's first paper is accepted by A&A — Deep learning denoising by dimension reduction: Application to the ORION-B line cubes.
2023-06-23: Pierre Palud's first paper is published by IEEE Transactions on Signal Processing — Efficient Sampling of Non Log-Concave Posterior Distributions With Mixture of Noises.
2022
2022-11-15: Antoine Zakardjian starts his PhD thesis — Inferring physical conditions in extragalactic GMCs through joint analysis of ORION-B and PHANGS data.
2022-11-14: Mathilde Gaudel's first paper is accepted by A&A — Gas kinematics around filamentary structures in the Orion B cloud.
2022-09-22: Léontine Ségal starts her PhD thesis — Robustness of the Estimation of Physical and Chemical Characteristics of Giant Molecular Clouds without Ground Truth.
2021
2021-10-01: Lucas Einig starts his PhD thesis — Relationships between observables and astrophysical conditions: a statistical and learning approach to the Orion B giant molecular cloud.
2020
2020-11-19: Second ORION-B press release — Artificial intelligence, a game-changer for studying stellar nurseries.
2020-10-01: Pierre Palud starts his PhD thesis — Sampling methods for statistical inference of non-linear inverse problems: spatial distribution of physico-chemical properties of the interstellar medium.
2020-08-25: Pierre Gratier's paper is accepted by A&A — Quantitative inference of the H2 column densities from 3 mm molecular emission: A case study towards Orion B.
2020-07-02: Emeric Bron's paper is accepted by A&A — Tracers of the ionization fraction in dense and translucent gas: I. Automated exploitation of massive astrochemical model grids.
2020-04-28: Antoine Roueff's paper is accepted by A&A — C18O, 13CO, and 12CO abundances and excitation temperatures in the Orion B molecular cloud: An analysis of the precision achievable when modeling spectral line within the Local Thermodynamic Equilibrium approximation.
2019
2019-02-06: Jan H. Orkisz's paper is accepted by A&A — A dynamically young, gravitationally stable network of filaments in Orion B.
2018
2018-10-22: Jan H. Orkisz successfully defended his PhD thesis — Understanding the structure of molecular clouds: multi-line wide-field imaging of Orion B.
2017
2017-10-02: Emeric Bron's paper is accepted by A&A — Clustering the Orion B giant molecular cloud based on its molecular emission.
2017-05-24: The ORION-B project is noticed in Nature — Astrophysics: Multi-molecular views of a stellar nursery.
2017-03-07: First ORION-B press release to celebrate the publications of the first three papers in the same A&A issue — Beyond the appearances: The anatomy of the Orion Jedi revealed by radio-astronomy.
2017-01-13: Pierre Gratier's paper is accepted by A&A — Dissecting the molecular structure of the Orion B cloud: Insight from Principal Component Analysis.
2017-01-02: Jan H. Orkisz's first paper is accepted by A&A — Turbulence and star formation efficiency in molecular clouds: solenoidal versus compressive motions in Orion B.
2016
2016-11-08: The first ORION-B paper (Jérôme Pety's one) is accepted by A&A — The anatomy of the Orion B Giant Molecular Cloud: A local template for studies of nearby galaxies.
2016-10-12: The ORION-B project is now on ResearchGate — ORION-B: The Anatomy of a Giant Molecular Cloud.
2016-09-27: Chloé Daudon successfully defended her internship — Statistical analysis of hyperspectral data. New keys to understand the structure, composition and the dynamics of the interstellar medium.
2016-04-01: Chloé Daudon is starting a 6 months internship with us to finish her engineering education — ENSG Géomatique
2015
2015-09-01: Jan H. Orkisz starts his PhD thesis — Understanding the structure of molecular clouds: multi-line wide-field imaging of Orion B.