Events at Physics
Events on Thursday, February 27th, 2020
- R. G. Herb Condensed Matter Seminar
- The Complex Mesoscale Dynamics of Condensed Matter Systems Unveiled by High-resolution Inelastic X-Ray Scattering
- Time: 10:00 am
- Place: 5310 Chamberlin Hall
- Speaker: Alessandro Cunsolo, Brookhaven National Laboratory
- Abstract: Since the end of the past millennium, high-resolution Inelastic X-Ray Scattering (IXS) has substantially improved our knowledge of the collective molecular dynamics of disordered systems. This technique enabled us to explore a host of phenomena occurring over distance and time windows respectively approaching nearest neighbor atomic separations and ‘in cage’ oscillation periods. It elucidated fundamental aspects of the high-frequency transport properties of fluids, such as the persistence of extended hydrodynamic excitations beyond the continuous limit, the microscopic mechanism driving relaxation phenomena, and the onset of quantum effects. In more recent years, an increasing number of IXS investigations have been focusing on more complex mesoscale structures promising new functionalities; the outcome of these studies could inspire new routes to manipulate the high-frequency acoustic propagation in materials. Finally, technical improvements of IXS and other synchrotron-based methods could soon enable a whole new class of investigations of transient phenomena in metastable states or undergoing a phase transition.
- Host: Gilbert
- Cosmology Journal Club
- Time: 12:00 pm
- Place: 5242 Chamberlin Hall
- Abstract: We discuss papers from arxiv.org related to cosmology each week. All are welcome and feel free to bring your lunch. If there is a paper you would like to present, or have questions or comments, please email Ross Cawthon (firstname.lastname@example.org) and Santanu Das (email@example.com).
- Astronomy Colloquium
- "The Life Cycle of galaxies in clusters over 10 Billion Years"
- Time: 3:30 pm
- Place: 4421 Sterling Hall, Coffee and cookies 3:30 PM, Talk begins 3:45 PM
- Speaker: Greg Rudnick, Director of Graduate Studies, University of Kansas, Department of Physics and Astronomy
- Abstract: Galaxies live in a range of environments, characterized by their volume density. For example, the densest regions of the Universe are in galaxy clusters, which contain hundreds to thousands of galaxies all in pseudo gravitational virial equilibrium. These dense environments can in turn alter the properties of the galaxies themselves in striking ways via a variety of gravitational and hydrodynamic processes. The result of these processes alter galaxy shapes, their internal dynamics, and shuts off the formation of new stars. I will present work I have been doing to characterize the evolution of galaxies in clusters over the past 10 billion years as a way of understanding how the environment can affect galaxies. I will describe how we have used extensive multi-wavelength data sets on distant clusters to form a picture in which infalling cluster galaxies likely have their gas supplies cut off, their morphologies transformed, and may even experience epochs of very frequent mergers. I will then describe new results from a large program called Gemini Observations of Galaxies in Rich Environments (GOGREEN) which is the premier spectroscopic survey of distant clusters. With the GOGREEN data, we are finding that the quenching of galaxies in dense environments at high redshift may proceed very differently from that at redshifts less than one, requiring a revision of our thoughts on how environment affects galaxy evolution at large lookback times.