Archives Séminaires 2017-2018

Séminaire

Séminaire IPAG de Marta Alves (Radboud University Nijmegen), jeudi 22 mars 2018 à 11h00, salle Manuel Forestini IPAG

Magnetism is a fundamental force of nature. Since interstellar magnetic fields were discovered in our Galaxy in 1949, it has been established that magnetism is pervasive in the Universe. Planets, stars, and galaxies all show the presence of magnetic fields, which span a large range in strength and change considerably in structure. Throughout the years we have inferred the properties of galactic magnetic fields from a variety of observational methods. Not only from observations but also from (...)

Séminaire

Séminaire IPAG de Tristan Guillot (Lagrange, Observatoire de la Côte d’Azur), jeudi 29 mars 2018 à 11h00, salle Manuel Forestini IPAG

Juno has been in orbit around Jupiter since July 2016. Its goal is to probe the interior structure of the planet to understand its composition, dynamics, magnetic field and provide crucial constraints to understand the formation of the Solar System. The results obtained thus far are already a striking improvement for our knowledge of Jupiter. The deep atmosphere is found to be much more complex than anticipated. Its magnetic field shows strong variations related to anomalies yet to be (...)

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Séminaire IPAG de Anne-Lise Maire (MPIA Heidelberg), jeudi 5 avril 2018 à 11h00, salle Manuel Forestini IPAG

Astrometric monitoring of directly imaged exoplanets and brown dwarfs allows the study of their orbital parameters and system architectures. Because of the long orbital periods and/or faintness of these objects, accurate astrometry is challenging when based on data acquired on timescales of a few years. The new high-contrast imaging instrument VLT/SPHERE provides exquisite contrasts and astrometric accuracies down to about 1 mas thanks to its dedicated design and the use of optimized (...)

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Séminaire IPAG de Christian Bracco (Université de Nice-Sophia Antipolis & Observatoire de Paris), jeudi 26 avril 2018 à 11h00, salle Manuel Forestini IPAG

La période 1895-1901 est importante pour comprendre la formation et l’évolution des questionnements scientifiques du jeune Albert Einstein (1879-1955). Parallèlement à ses études en Suisse et à l’ETH de Zurich en particulier, il passe alors un temps significatif à Pavie et à Milan avec sa famille, qui y possède une entreprise électrotechnique. Nous décrirons son environnement scientifique à Pavie, qui lui permet, en 1895, dès l’âge de seize ans, sans avoir l’âge requis ni le diplôme nécessaire, de tenter (...)

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Séminaire IPAG de Mickaël Bonnefoy (IPAG), jeudi 3 mai 2018 à 11h00, salle Manuel Forestini IPAG

The SHINE survey conducted on the SPHERE high contrast imager at VLT is targeting 400-500 nearby stars to characterize the giant planet population beyond 5 AU. Once a companion is resolved, the collection of sub-instrument of SPHERE can uniquely provide its spectrum, photometry, and astrometry from 0.5 to 2.5 µm. Those informations are used to better understand the orbital, physical, and chemical properties of the objects, and in turn to access the formation modes and dynamical evolution of (...)

Séminaire spécial

Séminaire IPAG de Jeffrey J. Plaut (Jet Propulsion Laboratory & Caltech), mercredi 16 mai 2018 à 11h00, salle Manuel Forestini IPAG

For over 12 years radar sounding from Mars orbit has been used to probe the interior of the Red Planet’s ice sheets and glaciers. These observations have provided new perspectives on the history of Martian water and climate. This talk will present an overview of the discoveries made by radar and an update on the most recent research.

Séminaire

Séminaire IPAG de Andrea Mignone (University of Torino), jeudi 17 mai 2018 à 11h00, salle Manuel Forestini IPAG

This talk aims at reviewing the current state of the art in the computational modelling of high-energy astrophysical phenomena such as, for example, relativistic jet propagation and pulsar wind nebulae. A comprehensive modelling of such systems is a challenging task because physical mechanisms operate over an enormous range of spatial and temporal scales.
Although MHD simulations have been successfully applied to investigate the large-scale dynamics of these environments, important kinetic (...)

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Séminaire IPAG de Frédéric Gueth (IRAM), jeudi 24 mai 2018 à 11h00, salle Manuel Forestini IPAG

NOEMA is a 12-antennas millimeter interferometer located on the Plateau de Bure (Alps). It provides very versatile observation possibilities, with science topics covering the study of the solar system (planetary atmospheres, comets), stars and protoplanetary disk formation, late star evolution phases, chemical and physical properties of the interstellar medium, nearby galaxies, as well as galaxy formation at high redshift and the related cosmological studies. NOEMA is now approaching (...)

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Séminaire IPAG de Marcelo Guimaraes (IPAG), jeudi 31 mai 2018 à 11h00, salle Manuel Forestini IPAG

In recent years we have seen an increase in the quantity and quality of astronomical data and it is common now to speak of Big Data, especially in the GAIA Era. However, in some areas, the theoretical and computational tools necessary to analyse these huge amounts of data did not increase in the same velocity and amount, neither did the workpower availability. Radiative transfer models focused on the early stages of stellar evolution have been challenged to evolve in order to cope with high (...)

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Séminaire IPAG de Miho Janvier (IAS), jeudi 7 juin 2018 à 11h00, salle Manuel Forestini IPAG

Coronal Mass Ejections (CMEs) are large disturbances emanating from the Sun and are associated with flaring activity at our star, also called solar flares. They transport solar plasma and magnetic field in the interplanetary medium and can impact the space environment of the planets and small bodies of the solar system. Remote-sensing instruments on board spacecraft can monitor the evolution of the regions they originate from, their structures, as well as their evolution and their ejection (...)