Project description
New techniques to aid studies on exoplanet atmospheres
Since the first planet orbiting a distant star was detected more than two decades ago, over 4 000 exoplanets have been discovered. Now the focus is on investigating their composition, formation and habitability. These questions can be answered via the characterisation of their atmospheres. However, retrieving information about exoplanet atmosphere requires significant input on the spectral properties of the individual atoms and molecules that comprise it. Due to the unusual conditions found on most known exoplanets (elevated temperatures and high fluxes of stellar radiation), there is a lack of laboratory data that can be readily used, which severely limits exoplanetary models. The EU-funded ExoMolHD project will overcome this hurdle by merging quantum-based theoretical approaches with experimental data to acquire the spectra of exoplanets and their atmospheres.
Objective
It is just over two decades since the first extrasolar planet was discovered; we have learnt that such planets are ubiquitous with (nearly?) every star in our local neighbourhood supporting a planetary system. These newly-discovered planets are generally unlike those in our Solar System. Astronomers have taken the first steps in characterising exoplanetary atmospheres through spectroscopy. The advent of new space missions, such as Ariel and WFIRST, and high performance observatories from space and the ground, such JWST and ELTs, allied to new techniques, will begin to answer fundamental questions about the composition, formation and properties of exoplanets through detailed spectroscopic. A prerequisite for advances to be made is the availability of the fundamental atomic and molecular data necessary for interpreting new observations. The unusual conditions found on most known exoplanets, involving elevated temperatures and high fluxes of stellar radiation, means the required data are missing and not readily measurable in the laboratory. The ExoMolHD project will use advanced molecular quantum mechanics allied to novel empirical techniques based on available experimental data to respond to the modern challenges of exoplanetary models and retrievals by providing extensive ``higher definition'' data. ExoMolHD will (a) provide precise wavelengths for key molecules applicable for use in high resolution spectroscopic studies performed by telescopes such as the VLT and ELTs; (b) predict accurate spectroscopic data on key isotopically-substituted species; (c) provide temperature-dependent pressure shifts and pressure broadening parameters; (d) compute photodissociation cross sections and photolysis rates both in and outside thermodynamic equilibrium and (e) develop appropriate database structures, including detailed opacities, k-tables and precomputed atmospheric models. We will act to ensure the widest possible utilisation of the data.
Fields of science
Programme(s)
Topic(s)
Funding Scheme
ERC-ADG - Advanced GrantHost institution
WC1E 6BT London
United Kingdom