Frontiers of Astronomy Lecture Series—“Galaxy Dynamics: A Tale of Light and Darkness”

Members of the Case Western Reserve University community are invited to the first installment of the 2018-19 Frontiers of Astronomy Lecture Series Thursday, Oct. 11, at 8 p.m. at the Cleveland Museum of Natural History. Benoit Famaey of the University of Strasbourg in France will present “Galaxy Dynamics: A Tale of Light and Darkness.”

Talk description

Galaxy dynamics are confronted with one of the deepest problems of modern physics: the dark matter problem. The motions of stars and gas observed exceed what can be explained by the mass visible in those same stars and gas. Either:

1. There is a vast amount of unseen mass in some novel form—dark matter;
2. The data indicate a breakdown of our understanding of dynamics on the relevant scales; or
3. Both.

Famaey will review the observational evidence for an intimate connection between the baryonic surface density and the total gravitational field in galaxies. This observational fact presents a fine-tuning problem for the particle dark matter interpretation of mass discrepancies in galaxies. On the other hand, this is naturally explained within the MOND (Modified Newtonian dynamics) paradigm, hypothesizing an effective breakdown of Newtonian dynamics in the extremely low acceleration regime. However, MOND predictions break down on scales larger than galaxies. Theories combining the MOND phenomenology in galaxies while preserving the predictions of the current standard cosmological model on the largest scales are perhaps a promising way to reconcile these conflicting observational facts.

About the speaker

Benoit Famaey is a senior research associate of the CNRS at the University of Strasbourg in France, a position he has held since 2009. He investigates the dynamics of stars in our own galaxy, the Milky Way, as well as external galaxies, and the implications for the dark matter problem. In recent years, Famaey was awarded the "Prix Espoir de l'Université de Strasbourg 2015" and the "Prix Sciences 2018 de l'Académie Rhénane." He received bachelor’s, master’s and PhD degrees from Brussels University in Belgium. Famaey then went to the Rudolf Peierls Centre for Theoretical Physics in Oxford in the United Kingdom as a postdoctoral scholar, before going back to Brussels for another postdoctoral position, and to the Argelander Institute for Astronomy in Bonn in Germany as a Humboldt Fellow.

Series details

In cooperation with the Cleveland Museum of Natural History and the Cleveland Astronomical Society, the Department of Astronomy—through the support of the Arthur S. Holden, Sr. Endowment—is sponsoring the 2018-19 Frontiers of Astronomy Lecture Series. During this series, renowned astronomers will give five free lectures throughout the year at the Cleveland Museum of Natural History. Learn more about the Frontiers of Astronomy Lecture Series.