Speaker Series FA2019
Sept. 26th, Prof. Keith Riles
Title: From Attometers to Gigaparsecs - Gravitational Waves Define a New Astronomy
Oct. 10th, Dr. Camille Avestruz
Title: Computational Cosmology with Galaxy Clusters
Abstract: Galaxy clusters are the most massive collapsed structures in our universe. Their number count and mass evolution is sensitive to the accelerated expansion of our universe, which suppresses the growth of structures. Consequently, we can use observations of clusters to understand the contents and evolution of our universe. However, galaxy cluster observables are also sensitive to the complex astrophysical processes that make galaxy clusters excellent laboratories for extreme physics and galaxy formation. In this talk, I will discuss how we can use computational models to understand the interplay between physics, cosmology, and observational limitations.
Nov. 7th, Prof. Vanessa Sih
Title: Optical measurements of electron and nuclear spin polarization in semiconductors
Abstract: In this talk, I will share my personal path to becoming a Physics professor at Michigan and what I have learned along the way. I will also describe the research that my group is currently conducting, which includes using optical pump-probe techniques to generate and measure electron and nuclear spin polarization in materials. These measurements have revealed some unexpected effects, which has led to a better understanding of what goes on inside materials. From a practical point of view, the understanding of how to control and measure charge and magnetism has enabled the information age, and this area of research may enable improved devices in the future.
Dec. 5th: Student Talks
Virtual Skies: Using Simulations to Study Galaxy Clusters
Galaxy clusters are the most massive gravitationally-bound objects in our Universe. The history of their formation also contains key information about the early stages of the Universe, as well as its evolution since. The extraction of this information, however, is significantly hindered by our lack of knowledge of the astrophysics in these galaxy clusters. I will present work that aims to aid some of these issues using large-scale simulations.
Characterizing Supernovae Events by Galactic Location and Spectroscopic Features
In the age of survey astronomy, supernovae will be inadvertently discovered and may go unclassified for long periods of time, if not indefinitely. By looking at both HII regions (indicated by H-α emission) and the type of supernova as determined by spectra, it is of interest to relate the occurrences of core collapse supernovae (CCSN) to high star-forming regions in galaxies. Through imaging and spectral categorization, it is suggested that, despite working with a small sample, CCSN (Type II variants) tend to occur more often in areas of strong H𝝰 emissions (possibly indicating HII star-forming regions) than Type Ia supernovae. By creating an approximate connection between the types of supernovae that occur and their proximity to star-forming regions, supernovae can begin to be constrained based on their location within a galaxy.
Metrology for Thermal Noise Reduction in Gravitational Wave Interferometers
The astrophysical reach of gravitational wave laser interferometers is limited in the mid-frequency range by thermal noise, resulting from Brownian excitation of internal components. New optical coatings are being developed to mitigate the effects of thermal fluctuations in interferometer mirrors. These coatings will be employed in the next generations of Advanced Virgo and future gravitational wave detectors. Developments in the thermal metrology process will be presented.
The Search for a Neutrinoless Decay of a Muon to an Electron
Mu2e is an experiment that aims to measure the rate at which muons decay directly into electrons. This process is an example of charged flavor lepton violation, something that is not predicted by the standard model. Measuring the rate at which such a process happens could signal the existence of new physics and will constrain new models.