Archives Séminaires 2013-2014

Séminaire

Séminaire IPAG de Rim Fares (St Andrews), jeudi 22 mai 2014 à 11h00, IPAG seminar room

Extrasolar planets at small orbital distances (hot Jupiters) interact with their hosting star in several ways : irradiation, gravitation, flow of particles and magnetic fields. The planet, embedded in the large-scale stellar magnetic field throughout its orbit, can influence the star in the form of induced photospheric activity, or by influencing the stellar magnetic field via tidal interactions. Studying the stellar magnetic field can give us insights on the interactions in these systems. (...)

Séminaire

Séminaire IPAG de Conel Alexander (Department of Terrestrial Magnetism - Carnegie Institution of Washington DC), jeudi 29 mai 2014 à 11h00, IPAG seminar room

Two prominent models, the so-called Grand Tack and Nice models, were designed to explain the small mass of Mars and the current orbital configuration of the planets and planetesimals in the Solar System, respectively. Both invoke episodes of dramatic orbital migration of the giant planets. In the process, planetesimals from the outer Solar System are scattered into the terrestrial planet region. These presumably icy, or comet-like, bodies are potent potential sources of volatiles for the (...)

Séminaire

Séminaire IPAG de Guillaume Hurier (IAS), jeudi 5 juin 2014 à 11h00, IPAG seminar room

The Planck data covers a large frequency range from 30 GHz to 857 GHz. The sky emission in the micro-wave frequency domain is a mixture of several astrophysical sources, from our galaxy and extra-galactic objects. The 9 frequency channels observed by Planck allow us to performed astrophysical component separation. I present a new component separation method, MILCA, that allows to extract astrophysical components. For example, I present the reconstruction and the characterization of the CO (...)

Séminaire

Séminaire IPAG de Daryl Haggard (CIERA Fellow, Northwestern University ), jeudi 26 juin 2014 à 11h00, IPAG seminar room

The enigmatic object G2 (is it a gas cloud or a star ?) has passed pericenter in its encounter with Sgr A*. G2’s highly eccentric orbit brought it within 150 AU of Sgr A*, and IR monitoring has revealed signs of tidal disruption by the black hole. High-energy emission from the Sgr A*/G2 encounter was expected to rise toward pericenter (Spring 2014) and continue over several years as the material circularized, but no clear changes in Sgr A*’s X-ray or radio emission have yet been detected. (...)

Séminaire

Séminaire IPAG de Nick cowan (Northwestern University), jeudi 3 juillet 2014 à 11h00, IPAG seminar room

What started as a trickle in the mid 1990’s is now a torrent, with over one thousand extrasolar planets currently known, and thousands of candidates awaiting confirmation. The study of exoplanets has already revolutionized our view of planet formation, and will soon do the same to our understanding of planetary atmospheres and interiors. The diversity of exoplanets gives us the leverage to crack hard problems in planetary science : cloud formation, atmospheric circulation, plate tectonics, (...)