Expert spectroscopic support for the ESA Ariel mission and the wider exoplanet community.
We coordinate the provision of spectroscopic data for the ESA Ariel mission, acting as an interface between the exoplanet modelling community and laboratory/theoretical spectroscopists.
The Ariel Spectroscopic Data and Databases Working Group (WG) brings together experts in molecular and atomic spectroscopy, laboratory astrophysics, and atmospheric modelling.
Our goals are to:
- Identify and provide spectroscopic data needed for the Ariel space mission and related exoplanet atmosphere studies.
- Serve as an expert contact point for questions on data availability, quality, and coverage.
- Coordinate with data producers (laboratory and theoretical groups) and users (retrieval and modelling teams) to close gaps in available data.
- Maintain a transparent, community-visible workflow via GitHub.
This GitHub organisation, Ariel-data, is the central hub for communication between data providers and data users.
The WG brings together experts in:
- Molecular and atomic spectroscopy
- Laboratory astrophysics
- Theoretical quantum chemistry and nuclear motion calculations
- Atmospheric modelling and retrievals
- Data curation and database development
A list of WG members, their affiliations, expertise, and contacts organised by their expert fields
- Katy Chubb, Bristol
- Severine Robert, BIRA-IASB
- Clara Sousa Silva, Bard
- Sergey Yurchenko, UCL
- Vincent Boudon, CNRS
- Aleksandra Foltynowicz Matyba, UMU
- Isabelle Kleiner, LISA CNRS
- Michaël Rey, Université de Reims Champagne-Ardenne
- Cyril Richard, CNRS
- Ibrahim Sadiek, Leibniz Institute for Plasma Science and Technology
- Stefania Stefani, IAPS-INAF
- Jonathan Tennyson, UCL
- Karan Molaverdikhani, Ludwig-Maximilians-Universität München
- Nicole F. Allard, Observatoire de Paris,
- Jeanna Buldyreva, Université Bourgogne Franche-Comté
- Andrei Sokolov, UCL
- Tijs Karman, Radboud University
- Olivia Venot, Université Paris Cité and Univ Paris Est Creteil
- Helgi Rafn Hrodmarsson, CNRS
- Iouli E. Gordon, HITRAN, CfA
- Robert J. Hargreaves, HITRAN, CfA
- Christian Hill, International Atomic Energy Agency
- Benjamin Bultel, Université Paris-Saclay
- Athena Coustenis, LESIA, Paris Observatory
- Christiane Helling, Space Research Institute
- Helena Lecoq-Molinos, TU Graz
- Alessandra Miglio, IAPS-INAF
- Joanna K. Barstow, The Open University
- Patrick Gerard Joseph Irwin, University of Oxford
- David A. Lewis, Space Research Institute
- Giovanna Rinaldi, IAPS-INAF
- Tim A. van Kempen, SRON Netherlands Institute for Space Research
We focus on data for molecules and atoms relevant to exoplanet atmospheres, particularly those targeted by Ariel and other current/future missions.
- Molecular and atomic line lists
- Opacities
- Temperature- and pressure-dependent cross sections
- Line broadening parameters
- Transition probabilities
- k-tables
- Oscillator strengths
- Collision-induced absorption (CIA), including temperature and pressure dependence
- Photodissociation cross sections
- Optical properties of particles (aerosols, condensates, hazes)
- Chemical reaction rate coefficients and related atmospheric chemistry data
We use GitHub Issues in category-specific repositories so that requests and discussions are:
- Traceable
- Publicly visible to the wider spectroscopic community
- Easy to follow up by WG members
- Go to the Ariel-data organisation.
- Choose the repository that best matches your request (see list below).
- Click the Issues tab.
- Click New issue and provide:
- Target molecule(s) or atom(s)
- Spectral range and resolution
- Temperature and pressure range
- Type of data (e.g. line list, CIA, broadening, photodissociation, aerosols, chemistry)
- Intended application (e.g. forward model, retrievals, specific mission/instrument)
- Submit the issue.
A WG member will pick it up, coordinate a response and, where needed, reach out to colleagues in the spectroscopic community.
The WG maintains several category-specific repositories. Each repository contains links, documentation, and notes on data availability, quality, and open issues.
-
broadening
Pressure broadening, line-shape parameters, and related line profile information. -
Databases
Overview of major spectroscopic databases, pointers to relevant entries for Ariel and exoplanet applications. -
aerosols
Optical properties (e.g. refractive indices, single-scattering properties) of particles, condensates, and hazes. -
linelists
Molecular and atomic line lists, transition probabilities, oscillator strengths, and related spectroscopic data. -
atmochemistry
Chemical networks, rate coefficients, and other reaction data relevant for exoplanet atmospheres. -
opacities
Opacity tables, temperature- and pressure-dependent cross sections, k-tables, and related pre-computed products. -
HITRAN
Information and guidance on using HITRAN and related compilations in the context of Ariel and exoplanet studies. -
CIA
Collision-induced absorption (CIA) data, including temperature and pressure dependent cross sections. -
UV-cross-sections
UV and photodissociation cross sections for molecules important in exoplanet atmospheres. -
General
Cross-cutting information, coordination notes, general documentation, and topics that do not fit in a single category.
We encourage data users and providers to follow or watch the relevant repositories and to contribute via issues and pull requests.
This WG operates within the ESA Ariel Consortium to ensure that the mission’s spectroscopic data needs are met and documented.
Many of the assessments and links collected here are based on our recent white paper:
Data availability and requirements relevant for the Ariel space mission and other exoplanet atmosphere applications
RASTI 3, 636–690 (2024)
DOI: 10.1093/rasti/rzae039
We aim to keep this GitHub space up to date and complementary to the white paper, reflecting new data, updates, and community input.
We acknowledge support from the ESA Ariel mission and the wider exoplanet spectroscopy community.
Please follow the citation and acknowledgement guidance in the relevant repositories and in the white paper when using data coordinated by this WG.
