Abstract: In 1916 Albert Einstein published a paper demonstrating that space and time can be warped in the shape of a wave. One hundred years later, scientists from the Laser Interferometer Gravitational-wave Observatory (LIGO) Scientific Collaboration and the Virgo Collaboration announced the first observation of a "ripple of space-time" from two colliding black holes. This scientific achievement marked the beginning of a new way of exploring the dark side of our Universe. After just a few years, we know that black holes are ubiquitous in the universe. They come in (almost) all sizes, rule galaxies from their centers, make gold and platinum, and power the most energetic known phenomena in the sky. They could even be the most mysterious and most coveted substance yet to be found, dark matter. Sit back, relax, and get ready for a journey to the wonders of black holes:
astrophysics final frontier.
When: Friday, October 16, 2020, 7:30 P.M. CDT.
Abstract: In 1916, Albert Einstein published a paper demonstrating that space and time can be warped in the shape of a wave. One hundred years later, scientists from the Laser Interferometer Gravitational-wave Observatory (LIGO) Scientific Collaboration and the Virgo Collaboration announced the first observation of a “ripple of space-time” from two colliding black holes. This scientific achievement marked the beginning of a new way the “dark side” of our universe. In this talk, Cavaglia will discuss how the new Institute for Multi-messenger Astrophysics and Cosmology (IMAC) at Missouri S&T contributes to this science.
When: Wednesday, October 14, 2020, 12:00 P.M. CDT.
Learn about upcoming talks in the series at global.edu/speakers-series
Abstract: An Optical TPC detector has been used in combination with quasi-monoenergetic gamma beams at the HIgS facility (Duke University) to study alpha clustering and key reactions in nuclear astrophysics. The 16O(ɣ,α) and the 12C(ɣ,3α) reactions were studied. The inverse of the former reaction is crucial for determining the carbon-to-oxygen ratio after helium burning, which plays a large part in dictating a star's evolution. Exploring the inverse reaction in conjunction with the TPC has a number of key advantages. The latter 12C(ɣ,3α) reaction was studied to provide insight into the structure of the Hoyle state. The reaction populated the 10 MeV 2+ state in 12C, which is proposed as a collective excitation of the Hoyle state. Its various decay modes into three alpha-particles were studied and an upper limit for the direct 3 alpha decay branching ratio was calculated. Theoretical calculations were then used to extrapolate and calculate the corresponding branching ratio for the Hoyle state, which was found to be lower than expected for certain alpha cluster configurations.
When: Thursday, September 24, 2020, 4:00 P.M. CDT.
Abstract: Information about the late-time Universe is imprinted on the small scale CMB as photons travel to us from the surface of last scattering. Several processes are at play and small scale fluctuations are very rich and non-Gaussian in nature. I will review some of the most important effects and I will focus on the Sunyaev-Zel’dovich (SZ) effect and gravitational lensing. I will discuss how a combination of measurements can probe velocity fields at cosmological distances, serving as one of the most sensitive probes of initial conditions, and inform us on cluster energetics. If time allows, I will also discuss how to detect and characterize the properties of patchy reionization using the CMB as a backlight.
When: Wednesday, September 22, 2020, 2:00 P.M. CDT.