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Institut d'Astrophysique et
de Géophysique (Bât. B5c)

Quartier Agora
Allée du 6 août, 19C
B-4000 Liège 1 (Sart-Tilman)

Tel.: 04.366.9774
Fax: 04.366.9729
Recul rapide Année précédente Séminaires : Archives 2018    
Jan Fév Mar Avr Mai Jun Jul Aoû Sep Oct Nov Déc
Mois précédent Mois suivant Février 2018
Séminaire suivant  1er séminaire : mercredi 21 février, 11h00
Cosmology with quasar time delays: a short history of Refsdal’s idea and of its implementation
Frédéric Courbin (EPFL Lausanne)

Time delays in gravitationally lensed quasars in principle allow to measure H0 independently of other cosmological parameters. I will review the field of quasar time delays from the very first measurements to the most recent ones and will show what are the main advantages and drawbacks of the method over others. Future prospects are given, especially in the context of Euclid, LSST, and monitoring with dedicated telescopes.
Séminaire précédant Séminaire suivant 2ème séminaire : lundi 26 février, 15h45
The curious case of scalar dark matter from exotic CP symmetry
Igor Ivanov (IST, Lisbon)
Séminaire précédant Séminaire suivant 3ème séminaire : mardi 27 février, 14h00
On critical thinking and cognitive pitfalls
Johan Braeckman (UGent)

In this lecture we investigate why people are so vulnerable to mental infections with totally irrational believes. Insights developed in social psychology, informal logic or neuroscience, make clear how quick human reasoning can go wrong, how easy one makes wrong connections, wrong statistical estimations and all to quick generalizations. Scientists doing research are often better armed against the danger of infection by irrational and pseudoscientific views. However, they are very good in rationalizing wrong views, picked up along the way, which often makes them stick to bad ideas much longer. Nobody is immune! Pseudoscientific theories will be discussed together with historical and current examples of apparent scientific and objective views that turned out to be infected by fallacies or wrong assumptions. The differences between science and pseudoscience and between rational and irrational thinking will be clarified. A pure rational way of thinking is most probably never to be reached, and may even be something we should not wish for, but we can get a better insight in how our brain processes information and creates false realities.
Mois précédent Mois suivant Mars 2018
Séminaire précédant Séminaire suivant 4ème séminaire : mercredi 14 mars, 15h45
Extrasolar planets meet star spots
Jürgen Schmitt (Universität Hamburg)

Transits of extrasolar planets offer not only the possibility to study the physical properties of planets, they also provide a new possibility to diagnose the surfaces of active stars, which allows the study of surface inhomogeneities with unprecedented angular resolution. I will discuss the modeling of extrasolar planet transit light curves, and in particular, how the analysis is affected by star spots and how the derived extrasolar planet parameters depend on the activity state of the spots. I will specifically discuss how the transit light curves change due to the presence of star spots and how this information can be used to construct surface maps of active stars and deduce stellar properties. I will discuss the potential of transit studies at shorter wavelengths and show how high-energy observations constrain the physical properties of extrasolar planets.
Séminaire précédant Séminaire suivant 5ème séminaire : vendredi 16 mars, 10h00
Digital Holographic Microscopy
Kent Wallace (Jet Propulsion Laboratory)
Séminaire précédant Séminaire suivant 6ème séminaire : jeudi 29 mars, 15h45
DOTIFS - a multi-deployable fiber-fed IFU Spectrograph
Sabyasachi Chattopadhyay (STAR)

Devasthal Optical Telescope Integral Field Spectrograph (DOTIFS) is a new multi-object integral field spectrograph being built by the Inter-University Centre for Astronomy and Astrophysics (IUCAA), Pune, India for the 3.6m Devasthal Optical Telescope, (DOT). The Devasthal Observatory has been constructed by the Aryabhatta Research Institute of Observational Sciences (ARIES), Nainital. DOTIFS is mainly designed to study the physics and kinematics of ionized gas, star formation, and H II regions in the nearby galaxies. DOTIFS is a novel instrument in terms of multi-IFUs, built in deployment system, and high throughput. A magnifier at the Cassegrain side port of the telescope feeds sixteen integral field units (IFUs). The IFUs can be deployed over an 8’ diameter focal plane by orthogonal actuators. An intelligent deployment algorithm has been developed to allow optimized reconfiguration and to avoid any collision between IFUs. The whole deployment system has a complex 3-dimensional structure to allow maximum positioning freedom to the IFUs. The IFUs are developed using the novel technique of photolithography which makes the instrument precise but cost-effective. Digital correlated double sampling is implemented as the detector readout to minimize the readout noise with a thorough analytical understanding of the noise components. The speaker will provide details of the instruments and the challenges. The instrument is in the phase of fabrication and is scheduled to be commissioned in late 2018.
Mois précédent Mois suivant Avril 2018
Séminaire précédant 7ème séminaire : jeudi 19 avril, 15h45 
Andrea Bonfanti (STAR)
Université de Liège > Faculté des Sciences > Département d'Astrophysique, Géophysique et Océanographie : CoWebAGO, Juin 2009.