Le LAM organise des séminaires scientifiques pour les chercheurs le jeudi à 10h30, dans l’amphithéâtre. Les équipes scientifiques organisent leurs propres événements (séminaires, café-club, journal-club, etc.). Pour en savoir plus, consultez la page de chaque équipe.
La plupart des événements sont annoncés dans l’agenda. Veuillez noter que tous ces événements ne sont pas ouverts au grand public. Pour ceux-ci, veuillez consulter la page des événements publics.
Vous trouverez ci-dessous la liste des séminaires scientifiques pour chercheurs pour la saison en cours.
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Galactic dynamics in the Gaia era
The seminar will start at 11am.
I briefly present some basic tools of theoretical Galactic dynamics, both in terms of the construction of equilibrium models and of linear perturbation theory. Then, I show how we can construct a stellar phase-space distribution function in the joint presence of the Galactic bar and spiral arms, which matches the exquisite data from Gaia. This provides for the first time a purely dynamical map of the non-axisymmetric structure of our Galaxy.
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Laurent Lamy 4 Avril
The (spring) magnetosphere of Uranus probed by a decade of HST observations of its ultraviolet aurorae
The re-detection and long-term monitoring of the ultraviolet aurorae of Uranus with the Hubble Space Telescope during the past decade has provided a new, so far unique, mean to remotely investigate from Earth the asymmetric magnetosphere of Uranus since its discovery by Voyager 2, while waiting for a future orbital mission. Various spectro-imagers have been used to collect instantaneous images and spectra of the aurorae and of the underlying atmosphere in the Far UV range under variable solar and solar wind conditions. The observations were obtained through a series of programs executed between 2011 and 2023, aimed at sampling various timescales ranging from a fraction of a planetary rotation (~17.24h) up to seasons. This time interval provided the opportunity to sample radically different magnetosphere/solar wind configurations between equinox and solstice. In this presentation, we review the properties of the auroral and airglow emissions, in terms of spatial distribution, energy budget, dynamics and new constraints brought onto the internal rotation period. We highlight how these results will help to prepare the observations to be acquired in orbit from a Uranus orbiter.
Important : If enough time, the seminar will be followed by a 3D projection of movie of the terrestrial polar (borealis and australis) aurorae in the LAM amphitheater.