Seminars and Colloquia at ESO Garching and on the campus

Brown dwarfs have been extensively studied in nearby star-forming regions (d < 400 pc). However, theories suggest that high gas or stellar densities, as well as the presence of massive OB stars, may enhance brown dwarf formation relative to stars. To test this, it is crucial to study brown dwarf populations in massive young clusters, which provide dramatically different star-forming conditions. The nearest examples of such clusters are the supermassive star clusters (SSCs) Westerlund 1 and Westerlund 2, each exceeding 30000 Msun in total stellar mass.
As part of the EWOCS (Extended Westerlund 1 and 2 Open Clusters Survey) project, we have obtained deep JWST/NIRCam observations of these clusters. A key goal of this project is to derive their mass functions and assess whether extreme environments influence brown dwarf formation. By combining these results with studies of other massive young clusters led by members of the project, such as Trumpler 14 and RCW 38, we are placing the first robust constraints on the efficiency of brown dwarf formation in such environments.
In this talk, I will present the JWST/NIRCam data products of both clusters, the (sub)stellar initial mass function of Westerlund 1, and the detection and characterization of brown dwarfs in Westerlund 2, enabled by the rich multi-wavelength filter selection. I will also discuss the implications of these results for our understanding of star formation.

It is almost 100 years since the expansion of the universe was observationally discovered. Since then, astronomers argued on what the exact expansion rate is and how the universe will develop. Major refinements of the measurement of the Hubble constant have been introduced in the past decades. The latest developments led to an inconsistency of some of the measurements. The Hubble tension is the topic of active discussions, and the controversy is challenging the current cosmological model.

The rapid evolution of space technologies over the past decades, particularly in satellite positioning and communication systems, has revolutionized the way we perceive and experience the world. These technologies, now indispensable to countless aspects of our daily lives, are the result of decades of collaboration across disciplines and communities. As we continue to push the boundaries of innovation, research and development in science remain fundamentally dependent on developing environments that encourage collaboration and welcome diverse perspectives. This talk explores how strengthening teamwork and inclusivity within research teams can enhance innovation, ensuring that the future of space exploration is both groundbreaking and representative of the broader community it serves.