Séminaire/Seminar Galaxies |
| « Strong lensing: Illuminating galaxy clusters and the structures behind them » |
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Guillaume Malher |
| The strong gravitational lensing effect is a useful technique for studying both the deflector and the magnified sources behind it. In this talk, I will first review mass modelling approaches for galaxy clusters before presenting a cutting-edge lensing model that combines HST or JWST imaging with large spectroscopic coverage. Such a combination allows us to have a very refined mass distribution (dark matter and baryons) of a cluster of galaxies. An analysis of a larger sample of strong lensing clusters reveals that the lensing strength has a stronger correlation with the slope of the density profile rather than the total mass itself, indicating that the details of the mass distribution are more important than the total mass for future surveys. Most recent analyses revealed the lensing properties of even smaller substructures in clusters, wandering supermassive black holes (SMBH). The second part of the talk will focus on the lensed universe. Strong lensing offers unique opportunities that have no match in blank fields, from the highly magnified galaxies at z~2, resolved by lensing down to tens of pc scales, to the high-redshift lensed luminosity function that reaches fainter and smaller sources. Finally, I will discuss how the JWST and future facilities such as Rubin or Euclid combined with strong lensing will revolutionise our view of the universe in the near future. |
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jeudi 10 novembre 2022 - 11:30 Salle des séminaires Évry Schatzman Institut d'Astrophysique de Paris |
| Page web du séminaire / Seminar's webpage |