Reference : UMR7583-GENTUA-039
Workplace : CRETEIL
Date of publication : Monday, September 12, 2022
Type of Contract : FTC Scientist
Contract Period : 24 months
Expected date of employment : 1 January 2023
Proportion of work : Full time
Remuneration : between 3321,55 and 4082,90 € gross per month (for professional experience from 2 to less than 6 years)
Desired level of education : PhD
Experience required : 1 to 4 years
To learn more about the fascinating new worlds of exoplanets, several space telescopes have been designed, such as the James Webb Space Telescope (JWST) and the Atmospheric Remote-sensing Infrared Exoplanet Large Survey (Ariel, launch in 2029). The broad wavelength coverage and high sensitivity of the instruments on these telescopes will allow us to extract much more information from their data than has been possible so far, leading to many breakthroughs. However, these breakthroughs will only be possible if the models used to interpret the high-resolution observations are robust and reliable. In particular, the infrared spectra of exoplanets are analysed using retrieval models to determine the characteristics of the exoplanet atmosphere, such as the thermal profile, and to constrain the abundances of the main molecules. Significant research has been carried out in recent years to reduce the biases associated with the interpretation of spectroscopic data and enormous progress has already been made to improve these models and to take into account different effects and processes influencing planetary spectra (clouds, geometry, chemical composition, etc.). In the framework of the ANR project "EXACT (EXoplanetary Atmospheric Chemistry at high Temperature)", we wish to continue the developments allowing to improve the representation of the chemical composition in the data inversion models, by taking into account the chemical disequilibrium. To this end, the candidate will participate in the coupling between a retrieval model (TauREx) and an atmospheric kinetics model (Venot+2020) in order to take into account the out-of-equilibrium chemical composition in the analysis of observations. This model will be used to analyse observations of exoplanets, in particular those of the JWST, but also to prepare future observations of the Ariel telescope. Depending on the candidate's interest in Artificial Intelligence, it will also be possible to explore the use of Machine Learning methods to improve the performance of the retrieval and chemical kinetics model(s).
The candidate will work closely with Dr. Olivia Venot and her national and international collaborators. The main tasks will be to
- Use/develop the retrieval model TauREx and the kinetic model
- Use the new CHON+PS chemical scheme in the retrieval model
- Analyse and interpret observations
- Participate in the development of new observation proposals.
- Write scientific papers and disseminate research results at conferences and seminars.
- Participate in meetings of the Ariel Scientific Consortium
-The candidate should hold a PhD in astrophysics, atmospheric physics or chemistry, or in a related field of research, with a strong interest in astrophysics, in particular exoplanets. The candidate is expected to have:
- A good knowledge of, or experience with, retrieval models (ideally TauREx).
- Knowledge of, or experience with, atmospheric chemical kinetics models.
- Knowledge of, or experience with, the proposal and processing of observations would be an advantage.
- Good programming skills, especially in Python, and possibly Fortran 90.
- Good knowledge of English to work in an international environment.
- Ability to work collaboratively, yet independently, within a team.
This work takes place in the framework of the ANR project "EXACT" led by Dr Olivia Venot. The candidate will join the Exobiology and Astrochemistry group, whose main objectives are the search for molecular structures and the study of the various physico-chemical processes governing the chemical evolution of various planetary objects (exoplanets, comets, Mars, Titan...). They are internationally recognised as world-class experts in the field of planetary atmospheres, both from a theoretical and experimental modelling point of view. They are heavily involved in the analysis of observational data from ground-based facilities and space missions. This team of about twenty people is composed of several permanent researchers, PhD candidates and post-docs. The work will also be carried out within a network of international collaborations, in particular with University College London (UCL) for the study of exoplanet atmospheres and the development of the Ariel mission.
The Laboratoire Interuniversitaire des Systèmes Atmosphériques (LISA) is a joint research unit of the CNRS, the Université Paris-Est Créteil and the Université de Paris. It is part of the Observatoire des Sciences de l'Univers EFLUVE and of the IPSL Research Federation. It is located in Créteil, an important student city in the Paris region. The research laboratory is a leader in atmospheric modelling at the international level. Its main mission is to contribute to improving our knowledge of the functioning of terrestrial and planetary atmospheres in order to understand their past and predict their future evolution.
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