The emergence of Life relied on the presence of key molecules like water and prebiotic molecules. The primitive objects of our Solar System (comets, asteroids), which formed in the disk of dust and gas surrounding the young Sun, are thought to have delivered them to Earth during heavy bombardments. Observations show that the deeply embedded Class 0 protostars also harbour a very rich chemistry in their inner regions. What occurs to the chemical composition between this early stage of the star formation process and the formation of planets, comets, and asteroids is unknown. Do the molecules detected in these young protostars survive or are they destroyed and reformed at a later stage before being incorporated into planets, comets, and asteroids? This ERC project aims to reconstruct the physico-chemical evolution from the deeply embedded protostellar stage to the planet forming disk stage, through multi-source analyses of high angular resolution observations combined with chemical modeling studies. I will investigate the evolution of complex organic chemistry and isotopic fractionation during the star formation process using interferometric observations (ALMA, NOEMA) of solar-type protostars. In addition, I will carry out numerical simulations with a state-of-the-art gas-grain chemistry code in order to interpret the observations as well as to characterize the impact of the physical conditions and their evolution (environment, grain growth and dust settling, episodic accretion) on the chemistry. This ERC project will lead to a new understanding of the evolution of the chemical composition from the earliest protostellar stage to the formation of the disk that will give birth to the planets, comets, and asteroids, while identifying the processes affecting the final composition of the disk. The observational work will require the development of innovative tools of interest for the astrochemical community that I will release publicly.

As the final product of stellar evolution, neutron stars are exotic bjects both in terms of their internal structure than their electromagnetic activity. We will study the electrodynamics of their magnetosphere using a theoretical and numerical techniques for plasma simulations of highly magnetized relativistic electron/positron pairs bathed in an intense photon field. We will decipher their enigmatic properties by including general relativity effects and of quantum electrodynamics on the dynamics of particles and electromagnetic waves. We will deduce the signatures from it associated observational data in the form of multi-wavelength pulsed radiation from existing and future terrestrial and space telescopes accessible to the various partners of the project.

The objective of this interdisciplinary project is to quantitatively interpret the unexpected ALMA detection of ro-vibrationally excited water molecules in evolved stars from a theoretical, experimental and astrophysical point of view. To this end, the collisions of ro-vibrationally excited water molecules with H2, H, He and the electrons will be studied by taking for the first time into account, the coupling between the bending and rotation modes of water. In order to validate the calculations experimentally, the Bordeaux crossed-beam machine will be adapted to generate a supersonic jet of vibrationally excited water molecules. The third pillar of the project dedicated to the modeling of the ALMA data will integrate the new collision rates into an advanced radiative transfer code. The new experimental and theoretical results produced in the course of the project to model our star observations will also be applicable to the general interstellar medium.

Evolved cool stars are major cosmic engines, providing strong mechanical, chemical, and radiative feedback on their host environment. Through strong stellar winds, still poorly understood, they enrich their environment with chemical elements, which are the building blocks of planets and life. These objects are known to propel strong stellar winds that carry the mass and angular momentum of the stars' surfaces at speeds that vary with stellar brightness, evolution phase and chemical composition. A complete understanding of their evolution in the near and distant Universe can only be achieved with a detailed knowledge of wind physics across the life cycle of these stars as well as in relation to their circumstellar environment. Our project PEPPER aims at building a coherent and comprehensive description of the mass-loss mechanism. The main questions we endeavour to tackle are: How are the winds launched and which physical processes determine their properties? How does the mass-loss rate and other wind properties depend on fundamental stellar parameters? What is the origin of the detected magnetic field on the stellar surface? What chemical processes dominate in the winds? Where does the interaction between dynamics and chemical phenomena lay? The core of our approach is the synergy between theory and observation. During the ANR project, current and future developments of 3D simulations will be used to explore and interpret all the observations made with different techniques in order to obtain a global, coherent vision of the evolved cool stars, from the bottom of the atmosphere up to the circumstellar environment. In order to reliably and significantly achieve this significant milestone, we request funding to support PEPPER members and ensure the project is staffed adequately to yield high-impact scientific returns in the field of evolved stars. PEPPER consortium includes four nodes in France which represent all the poles where stellar physics and, in particular, evolved stars are actively studied simultaneously from an observational, theoretical, or instrumental point of view. To complement this team, we request for funding for two PhD students and three postdoctoral researchers who will be spread over the four French nodes of our project, along with funds to support and secure the visibility and active partnership of all French team members.

COLD-WORLDS aims to use gravitational microlensing to explore a unique niche, cold planets down to Earth mass orbiting around any kind of star, at any distance towards the Galactic center, rogue planets and moons orbiting exoplanets (exomoons). These are in very different environments from most known exoplanets, allowing key tests of planet formation theory. Indeed, the maximum sensitivity is for planets at the snow line, close their formation location. To date, 55 microlensing planets have been published and these results challenge theories of planet formation. The core accretion population synthesis predictions by Ida’s and Bern’s groups are quite similar and both under-predict the number of observed cold planets at a mass ratio of q =2E-4) by a factor of ~25. It might be due to the run-away gas accretion phase of planet formation, which is a basic feature of the core accretion theory. Alternatively, it could be that there is some host star mass dependence of this run-away gas accretion gap that smooths out this feature when plotted as a function of mass ratio. So, it is important to accurately determine the individual masses for the planets and host stars. Microlensing provides precise mass-ratio and projected separations in units of the Einstein ring radius. In order to obtain the physical parameters (mass, distance, orbital separation) of the system, it is necessary to combine the result of light curve modeling with lens mass-distance relations and/or perform a Bayesian analysis with a galactic model. Often, physical parameters are determined to 30-50 %, or even worse. However, we have shown that a tight constraint can be obtained on the lens mass-distance, thanks to detection or upper limits on its luminosity using high angular resolution observations with 8m class telescopes or HST. The pioneering work by our team shows that we can derive physical parameters on known systems to 10 % or better with Keck adaptive optics for instance. In the uncertainty budget, we would then be dominated by extinction correction, distance to the source, calibrating luminosity function of main sequence stars and our understanding of the galactic structure. COLD-WORLDS will use infrared wide field imagers (public surveys from VISTA, UKIRT, and dedicated observations) and operate adaptive optics on 10m class telescopes. We obtained data already on 30 systems (Keck, VLT, SUBARU, HST) and we have 10 nights approved as Key Strategic Mission Support to WFIRST with Keck for the years 2018-2019. By 2019, we will have observations of the host stars of ~100+ systems with cold planets. We will use Gaia DR2 to measure the source distances, revisit the galactic disk, bar, bulge. Combining Gaia with the multiband observations, we will revisit our model of extinction. It will also give the kinematics on the line of sights to the Bulge and will allow to revise our Bayesian modeling of microlensing plane. We will then perform demographics of the Disk and Bulge cold planet populations and address the following science objectives. 1/ What is the mass distribution of cold planets down to ~1 Earth mass at the snow line, where most planets are formed? 2/ What is the spatial distribution and abundance of cold planets towards the centre of our Galaxy? 3/ How to routinely achieve better than 10% accuracy in microlensing planet mass determinations with the next generation of satellites (Euclid and WFIRST)? 4/ Producing a near-infrared (JHK) photometric archive from ESO dedicated surveys of the Galactic bulge, a lasting resource for broad areas of stellar and galactic astronomy. Our highly dedicated team covers all the range of needed expertise. It is also using public data and has all the needed allocated telescope time. It is a risk free, high impact project, giving roots to the Euclid and WFIRST microlensing surveys, while providing important results and useful legacy products.