NAOC Colloquium No.23 2023
|Reevaluation of the Dynamical masses of
Local Group galaxies / 再评估本星系群星系的动力学质量
|Prof. Francois Hammer (Paris Observatory)
|Wednesday 2:30 PM, Oct. 25, 2023
|NAOC A601 & Live Streaming on NAOC WeChat Channel
|Prof. Gongbo Zhao / 赵公博 (NAOC)
|Click to view the details (later)
|Click to watch the video (later)
|He will review the recent progresses that their Sino-French team has made using Gaia DR3 data. It includes the detection of a significant (Keplerian) decrease for the rotation curve of our Galaxy, and the fact that most Milky Way dwarfs are newcomers in the halo (as we already know for the Magellanic Clouds). Both discoveries lead to a considerable, downwards revision of the dynamical masses of Local Group galaxies, which will be presented. Finally, he'll discuss consequences on cosmological models, as well as new observational hints that constrain the mass of dwarf irregular galaxies, such as WLM and the Large Magellanic Cloud.
|Prof. Francois Hammer is an astronomer at the Paris-Observatory, co-leading the Sino-French collaboration Tianguan in astronomy and astrophysics with Profs Xiang-Ping Wu and Bertrand Cordier. Francois Hammer studied at the Ecole centrale des arts et manufactures (1980-82), and obtained his PhD in astrophysics in 1986 at the Universite Paris-Diderot. He has made several discoveries in the fields of gravitational lensing, cosmology and galaxy formation and structure. He won prize Descartes-Huyghens from the French and Netherlands Academies of Sciences in 2012, and won the CNRS bronze medal in 1987. He was responsible of the Giraffe spectrograph implemented in 2002 at the Very Large Telescope (VLT), and was one of the four investigators of the X-shooter spectrograph, implemented in 2009 at the VLT. He was the founding Director of GEPI at Paris Observatory (2001-2010), and the founding Principal Investigator of MOSAIC (2014-2020), which is the multi-object spectrograph of the European ELT.