Séminaires

Galaxy Evolution in the Fornax Cluster
Marc Sarzi (Armagh Observatory and Planetarium)

Salle de réunion AGO (local -1/14), Institut d'Astrophysique et de Géophysique
Bâtiment B5c, Quartier Agora, Allée du 6 Août, 19C, B-4000 Liège 1 (Sart-Tilman)

Galactic environment is thought to be one of the key factors in driving the cosmic quenching of star formation in galaxies. The Fornax cluster is a nearby intermediate-mass cluster that is more representative of the clusters found in the Universe compared to other nearby clusters such as Virgo and Coma. Fornax thus represents an ideal environment to understand the relative role of hydrodynamic and gravitational processes affecting galaxies in crowded environment.

In this context, I will discuss the results of the Fornax3D magnitude-limited survey of galaxies in the Fornax cluster with MUSE integral-field spectral. Additionally, I will present the results of ancillary studies based on deep optical and radio observations (with VST and MeerKAT) revealing objects currently on-going star-formation quenching. To further gain insight on the physical mechanisms behind such phenomena, we derive the star-formation history of Fornax galaxies with a spectrophotometric approach to both MUSE integral-field spectroscopic and S-PLUS imagining data. At the same time we also explore Fornax-like clusters in the TNG-50 simulations to derive the neutral-gas predicted distribution both across the whole cluster and around individual galaxies, following this also in time. This gives us a view of both on-going gravitational and hydrodynamical interactions in the Fornax cluster galaxies as well as a gauge on the past impact that these had in driving their star-formation histories, which we can compare to model predictions.

Orion’s Massive Stars: Delta and Epsilon Ori
Alžběta Oplištilová (STAR Institute Université de Liège)

Salle de réunion AGO (local -1/14), Institut d'Astrophysique et de Géophysique
Bâtiment B5c, Quartier Agora, Allée du 6 Août, 19C, B-4000 Liège 1 (Sart-Tilman)

Massive stars are cosmic engines. By exploding as supernovae, they power galaxies, shape the interstellar medium, and enrich it with heavy elements. Yet, their inner workings remain among the most challenging frontiers in stellar astrophysics. The evolution of massive stars is critically influenced by multiplicity; most have one or more companions, while a few remain single. This raises the question: could these single stars be the end products of multiple systems? Interferometry is one of the best methods for detecting and characterising stellar multiplicity. The Orion complex is the nearest massive-star-forming region with multiple OB stars, and thus the most suitable for detailed studies. It hosts a number of massive stars, particularly in the Orion Belt. I constructed two complex models: the triple star Delta Ori and the single star Epsilon Ori using interferometric data in synergy with astrometry, photometry, high-resolution spectroscopy, and spectral energy distribution. Delta Ori is currently in the pre-mass-transfer evolutionary stage, while Epsilon Ori is a significantly oblate supergiant due to its rapid rotation. As the only massive single star in the Orion Belt, Epsilon Ori likely follows a non-standard evolutionary path.

Genesis: the ESA mission to measure Earth down to the millimeter
Gilles Wautelet (LPAP, STAR Institute, ULiège)

Salle de réunion AGO (local -1/14), Institut d'Astrophysique et de Géophysique
Bâtiment B5c, Quartier Agora, Allée du 6 Août, 19C, B-4000 Liège 1 (Sart-Tilman)

TBD