Séminaires

Reading physics from stellar spectra
Maria Bergemann (New Horizons Solvay Lectures)

Salle A3, Petits Amphithéâtres - Galerie des Arts
Bâtiment B7b, Quartier Agora, Allée du 6 Août, 15, B-4000 Liège 1 (Sart-Tilman)

Observational stellar astrophysics is being revolutionised by large-scale stellar surveys and novel diagnostic techniques. I will focus on the frontiers in stellar spectroscopy.
First, I will describe the 3D non-equilibrium models that are poised to become workhorses of astronomy in the next decade.
Second, I will show how we overcome the challenge of combining of new models and complex noisy data. In particular, I will address the problem of the solar metallicity, and show new results for the solar Oxygen abundance obtained by our group.
Third, I will demonstrate how new data and new models drive progress in the areas that rely on stellar parameters and chemical composition of stars, focussing on precision tests of stellar structure and stellar evolution.

E-TEST: A prototype of large cryogenic mirror isolated from low-frequency seismic noise
Christophe Collette (Precision mechatronics laboratory, ULiège & BEAMS department, ULB)

Salle A3, Petits Amphithéâtres - Galerie des Arts
Bâtiment B7b, Quartier Agora, Allée du 6 Août, 15, B-4000 Liège 1 (Sart-Tilman)

The objective of the E-TEST instrumentation program is to develop a prototype for validating the Einstein-telescope-low-frequency (ET-LF) technology, i.e. a ‘large’ silicon mirror, an excellent suspension system for isolating the mirror from seismic motion, and a cooling strategy that is compatible with the isolation system. An active isolation system will be used and combined with a quasi-radiative cooling system at 10 K. A new patterned heat exchanger working radiatively have to be designed and implemented. The prototype will be installed in the existing facilities at the Space Centre of Liège (CSL) to take advantages of the knowledge in cryogenic qualification of Space Instruments.

Extreme astrophysics
Roger Blandford (KIPAC, Standford et titulaire de la chaire Jacques Solvay de Physique 2020)

Exèdre Dick Annegarn, Maison des Etudiants et Exèdre Dick Annegarn
Bâtiment B8, Quartier Agora, L'Agora 1, B-4000 Liège 1 (Sart-Tilman)

The electromagnetic spectrum has been opened up from meter radio waves to ~ PeV photons and augmented with 10 - 300 Hz gravitational wave, MeV - PeV neutrinos and MeV - ZeV (160 J) cosmic ray messages. Consequently, there is a high rate of discovery and understanding of phenomena whose explanation invokes accepted physics - classical (including general relativity), atomic, nuclear and particle (including QED) processes - in extreme environments. The richness of the discovery space can be epitomized by describing some new observations and ideas pertaining to relativistic outflows formed by spinning black holes and neutron stars, Ultra High Energy Cosmic Rays accelerated by strong shock waves surrounding rich clusters of galaxies and Fast Radio Bursts, generated by neutron stars with 100 GT magnetic fields.

TBA
Valentin Christiaens (STAR)

Le lieu où se tiendra cet évènement n'est pas encore déterminé...

TBA
Djordje Savic (STAR)

Le lieu où se tiendra cet évènement n'est pas encore déterminé...