Seminars and Colloquia at ESO Garching and on the campus

The surface brightness fluctuations (SBF) method offers a powerful, independent route to measuring extragalactic distances and plays a key role in calibrating the cosmic distance scale. In this talk, I will provide a brief overview of the SBF technique and its place within the broader landscape of distance indicators. I will then highlight recent scientific results based on SBF measurements, focusing in particular on the TRGB-SBF project with JWST and its implications for the ongoing "Hubble tension." I will also present early results from SBF studies using Euclid and LSST-precursor data. Finally, future prospects for the method with upcoming facilities, including Roman and the ELT will be presented.

One of the key goals of the ECOGAL project has been to derive realistic constraints on the initial conditions of disks in

different galactic environments. In this talk I will discuss why this is an important, necessary , and difficult problem to tackle,

the approach that we have been following and the results so far. I will highlight the need to develop and test realistic numerical

simulations, our progress in this area, and why the simple observational estimates of disk bulk properties that are commonly

published may result in profound mistakes (e.g. if used in planet population synthesis models).

Compact object binaries are a class of binary systems with periods below a few hours and physical separations

between components as small as the Earth-Moon distance consisting of compact objects such as white dwarfs,

compact helium stars and in rare cases even neutron stars. The study of these short period systems and their

subsequent mergers are important to our understanding of a wide range of areas including supernova Ia progenitors,

binary evolution and they are predicted to be the strongest Galactic gravitational wave sources in the LISA band. Compact binaries

are believed to form in interacting binaries through various phases of mass-transfer, which requires poorly understood

physical processes. As such the evolution of these systems is still uncertain. In this talk I will show how the development

of large-scale sky surveys, such as Gaia, the Zwicky Transient Facility, BlackGEM as well as SDSS-V help us to shape our

understanding of the final stages of compact binary evolution. I will also present a few highlights, including the discovery of

a candidate supernova Ia progenitor, and a new class of mass transferring compact helium stars.