Ro-vibrational excitation of water in evolved stars, from calculations to experiment and observations & Water in the Universe conference agenda

Waterstars Ro-vibrational Excitation of water in evolved stars: From calculations to experiment and observations Starting date : 30 mars 2021 PRCI funding: 48 months Extended up to 31st of december 2025 Waterstars: Partners 1. Theory group, ISM, Ubx: T Stoecklin, P. Halvick, PhD: R Garcia-Vazquez (2021-2024) PES and Quantum Time independent close coupling approach 2. Comex Group, ISM, UBx Astrid Bergeat, S. Morales Crossed beam experiments 3. Femis Group , LAB, UBx F. Herpin, A. Baudry Observations and Astrophysical model calculations in non-local thermodynamic equilibrium 4. Spectre group, IPAG, UGA A. Faure, C. Rist PES, Non local radiative transfer, emolecule collisions PES Waterstars: Context •H2Othird abundant & widespread molecule in the circumstellar and interstellar media (after H2and CO) => central role in the chemistry of circumstellar and interstellar clouds. •H2O ro-vibrational transitions observed: stellar formation regions, extragalactic sources…,atmospheres and envelopes of O rich stars in our Galaxy •Atomium Alma LP covers energy levels from 40008300 K up to (011) and ( 030) •Evolved stars and the associated winds are the main producers of chemical species (gaz and dust) H2O detection:Atomium Alma project Baudry et al. A&A. 674: A125 (2023) - Detection of 10 very high energy transitions of water between 4000 to 9000 K (2700 to 6300 cm−1), well above the energy of transitions detected before (470 to 2400 K). The JKA KC = 65,2 –74,3 transition inside (1,2, 3) = (0,2,0) at 268.149 GHz seems to be widespread Equivalent state temperatures: 5261, 2294 and 5404 K Wavelengths: 2.73, 6.27 and 2.66 μm. Alma Atomium H2O detection 8 Inside the same vibrational level 6 Between two different vibrational levels Waterstars: Objectives 1. Compute ro-vibrational rate coefficients for H2O colliding with H, He, H2and e-beyond the RRA Provide extended data set using propensity rules(Bx - Grenoble) 2. Check new theoretical approaches against state resolved experiments: perform crossed beam experiments for vibrationally excited levels of H2O 3. Combine new observational data with elaborate radiative transfer code together with several vibrational states and the latest collisional rates Waterstars: State of the art * Theory: standard : Quantum Time independent close coupling approach: poor computational scaling => limited to small systems with no vibration( RR approximation), first work including NH3 umbrella mode * Experiment: crossed beam experiments also limited to non vibrating molecules (very few measurements) * Astrophysical modeling: Non local radiative transfer codes include H2O Excitation only inside the ground vibrational state using approximate collisional rates Major Results: Grenoble * Calculations of the RR rates of H218O, HDO and D2O with H2 for rotational levels < 300 cm-1 and T < 300K * Demonstration of weak maser effects for rotational lines of HDO and H218O detected with ALMA in the V883 Ori protoplanetary disk * List of lines extracted from the ExoMol database for all H2O ro-vibrational levels < 7542 cm-1 (~ 11,000 K), i.e. 2344 levels. * Extrapolation of collision rates of H2O with H2 for ro-vibration levels < 7542 cm-1 and temperatures < 5000 K from theoretical and experimental propensity rules Major Results: Grenoble Vibrational de/excitation of H2Oby collisions with e- Waterstars Water in the Universe Oléron island, 1-3 October 2025 Organising committee: Alain Baudry, Astrid Bergeat, Alexandre Faure, Fabrice Herpin, Claire Rist, Thierry Stoecklin Wednesday October 1 15h30-16h00: Introduction 16h00-16h30: Anita Richards, Observing water maser lines from the ground 16h30-17h00: Ricardo Garcia-Vazquez, New calculations for the vibrational relaxation of H2O and D2O 17h00-17h15: Coffee break 17h15-17h45: Jérôme Loreau, Vibrational excitation of ammonia and water induced by collisions 17h45-18h15: Viatcheslav Kokoouline, Water excitation by collisions with electrons 18h15-18h45: Jean-Hugues Fillion, Laboratory investigations on non-thermal solidgas exchanges in cold and illuminated regions of the interstellar medium 18h45-19h30 Welcome Aperitif 19H30-20H30 Dinner Thursday October 2 Morning 9h00-9h30: Jutta Toscano, Probing the individual reactivities of ortho and para water 9h30-10h00: Bas van de Meerakker, Inelastic collisions for astrophysics, observed in crossed-molecular beam experiments. 10h00-10h30 Coffee break 10h30-11h00: Jonathan Tennyson, Observation of water in exoplanets 11h00-11h30: Malcolm Gray, Mechanisms for the most powerful water maser flares 11h30-12h00: Lukasz Tychoniec, Water in protostars across infrared spectrum: from Herschel to JWST 12h00-12h30: Dmitri Babikov, Mixed quantum classical theory for rotational state-to-state transitions in H2O + H2, H2O + H2O and H2O + HCN collisions Thursday October 2 Afternoon 17h00-17h30 Coffee break 17h30-18h00 François Lique Collisional excitation of water precursors and astrophysical applications 18h00-18H30 Majdi Hochlaf Calculations of potential energy surfaces using neural networks 18h30-19h00 Otoniel Denis On the Development of potential energy surfaces for H₂O+Ng van der Waals complexes: From Reduced to Full-Dimensional Models 19h00-19h30 Clément Lauzin High-precision spectroscopic study of water and of water containing van der Waals complexes 19h30 Charente Aperitif 20H30-21H30 Conference Dinner Friday October 3 09h00-9h30: Stefan Willitsch, New methods for precision spectroscopy of the water ion using quantum logic 09h30-10h00: Alain Campargue, Empirical energy levels and line lists of nine stable water isotopologues from the analysis of far infrared absorption spectra at SOLEIL synchrotron 10h00-10h30 Coffee break 10h30-11h00: Dominique Bockelee-Morvan, Probing H2O photodissociation dynamics from JWST near-IR and mid-IR spectral surveys of OH prompt emission lines in a cometary atmosphere 11h00-11h30: Antonio Garcia-Munoz, H2O modelling in low mass exoplanets atmospheres. Chemistry, radiative transfer and energetics 11h30-12h00: Stefano Facchini, Imaging the distribution of water vapor in planet-forming disks with ALMA 12h00-12h15 Concluding remarks 12H15-13H15 Lunch 13H30 Bus departure to La Rochelle Railways station