Colloquium on Nov. 15, 2023

Weighing galaxies with strong gravitational lensing

Speaker: Alessandro Sonnenfeld (SJTU)

Venue: SWIFAR Building 2111

Time: 15:00 PM, Wednesday, Nov. 15, 2023

Abstract:

We are living in a golden age of extragalactic astronomy: observations over broad wavelength ranges, wide fields and unprecedented depth are allowing us to uncover important details on the formation and evolution of galaxies. Yet, key quantitative aspects on the properties of galaxies remain not well constrained. The most important such aspects are the stellar mass, the star formation efficiency (how much of the initial reservoir of gass is turned into stars), and the dark matter distribution of galaxies. Lack of precise knowledge on these quantities is limiting our progress in both galaxy evolution and cosmology. Gravitational lensing is one of the most reliable tools to measure galaxy masses at cosmological distances, and therefore offers a solution to this problem. Upcoming missions such as Euclid and the Chinese Space Station Telescope (CSST) will enable the discovery of tens of thousands of strong lenses, opening up the era of statistical strong lensing. I will discuss the opportunities that statistical strong lensing will bring for our understanding of galaxies, as well as the challenges associated with it.

Report PPT:  SWIFAR_Alessandro Sonnenfeld.pdf