2022
Tuesday, May 17, 2022 Abstract booklet below! Download: Senior Project Poster session booklet S22-1.pdf |
Friday, May 6, 2022 Hegeman 107 12:00 pm – 1:00 pm EDT/GMT-4 Albert Einstein predicted gravitational waves in 1916, as a consequence of his general relativity theory. A century later, the Laser Interferometer Gravitational-Wave Observatory (LIGO) began observing these waves from merging systems of black holes and neutron stars. These observations cemented relativity theory and inaugurated an era of gravitational-wave multi-messenger astronomy. LIGO and its partners are just sensitive enough to measure the strongest gravitational waves. Cosmic Explorer (CE) is a next-generation ground-based gravitational-wave observatory envisioned to begin operations in the 2030s. With its spectacular sensitivity, CE will peer deeply into the universe’s dark side — observing gravitational waves from remnants of the first stars — and open a wide discovery aperture to the novel and unknown. |
Friday, April 29, 2022 Hegeman 107 12:00 pm – 1:00 pm EDT/GMT-4 Galaxy mergers and interactions are thought to play a key role in the evolution of galaxies. These collisions can affect many important galaxy properties, such as their physical structure, their star formation rates, and the growth of their central black holes. However, the details of this role, and how it has changed over the age of the Universe, is still a matter of much debate. Both theoretical models and some recent observations have suggested that mergers do not play a dominant role in the early Universe, but that instead much of the mass growth of galaxies and their black holes can be attributed to secular processes such as disk instabilities. I will present the results of a detailed, multiwavelength analysis of galaxy mergers and interactions and their impact on star formation and black hole growth via AGN. I will also discuss plans for future work using the James Webb Space Telescope. |
Friday, April 22, 2022
Beate G Liepert, EUS Program
Hegeman 107 12:00 pm – 1:00 pm EDT/GMT-4 Air pollution is well known as a public health problem, but not so such as a climate change driver. Only recently has the term “aerosols” entered public consciousness as a pathway with which the corona virus spreads. For atmospheric scientists however, aerosols (i.e., particulate matter) have been well known as one of the key uncertainties in climate change, due to their direct effect of reflecting solar energy back to space, and aerosol-cloud interactions. The presentation provides an overview of the role of aerosols in climate from an observational and a modelling point of view. The wickedness of the problem will become clear, when air pollution is reduced and as a consequence, global warming unmasked. |
Friday, April 15, 2022 Hegeman 107 12:00 pm – 1:00 pm EDT/GMT-4 Our ability to successfully forecast changes in climate relies on fundamental physical concepts – including radiative transfer, conservation laws, chemistry, and fluid dynamics – but much of the structural uncertainty in climate model projections relates to more empirical aspects of parameterizations of unresolved processes, such as cloud nucleation, ocean eddy mixing, and convection. There is an apparent tension between the confidence we have basic physics and the specifics of projected changes using these models. Other uncertainties relate to scenarios for important emissions (such as carbon dioxide, methane, and ozone and aerosol precursors), and the fundamentally chaotic nature of the weather (though not the climate). I will discuss the ways in which we can build confidence for the use of these models in assessing climate risk though the use of out-of-sample test case, hindcasts, multi-variate assessments and success in real forecasts. |
Friday, April 8, 2022 Hegeman 107 12:00 pm – 1:00 pm EDT/GMT-4 X-ray emission has long been observed from giant molecular clouds located in the galactic center region of our Milky Way. These molecular clouds are thought to be reprocessing past X-ray outbursts from supermassive black hole Sgr A*. By studying the clouds’ flux over time, we are able to reveal the past outburst activities of Sgr A* hundreds of years ago. I have been utilizing newly received NuSTAR and archival XMM-Newton observations of the “Bridge” molecular cloud in order to present a 20-year-long light curve of the cloud’s flux. This data reveals that the X-ray luminosity of the “Bridge” cloud has been monotonically increasing since ~2007, almost doubling in the last decade, and provides strong evidence of an outburst light front from Sgr A*. In this seminar, I will discuss aspects of the data analysis process, present results, and touch on my post-Bard experiences. |
Friday, April 1, 2022 Hegeman 107 12:00 pm – 1:00 pm EDT/GMT-4 Stellar explosions and colliding neutron stars are important sources of the chemical elements in nature. While some of the astrophysical processes responsible for element creation are well understood, others have remained elusive for decades. Processes creating elements often involve short lived radioactive isotopes that can be produced at accelerator facilities. Studies with these isotopes allow us to constrain the relevant nuclear reaction rates and nuclear properties so one can understand in the laboratory how elements are created. Recent progress in astronomical observations, such as the observation and verification that the merging of two neutron stars is as a source of heavy element production in the Universe, need to be accompanied with similar progress in understanding the relevant properties of rare isotopes through nuclear physics experiments. I will review the important role that rare isotopes play in understanding stellar explosions, show some examples of recent nuclear physics measurements and give a (very abbreviated) outlook of future nuclear astrophysics studies. |
Friday, March 11, 2022 Hegeman 107 12:00 pm – 1:00 pm EST/GMT-5 These days it seems like everyone has an interest in astronomy. Young kids are watching YouTube videos about black holes, adults are participating in astronomy-themed lifelong learning courses, and thousands of people across the globe watched James Webb launch on Christmas morning. It’s important for educators and professionals to nurture this passion for astronomy in our community, in hopes of encouraging more people to pursue a career in the sciences. In this talk, I’ll share some of my research efforts in the area of star and planet formation and discuss how my initial career in science communication inspired me to develop an observational astronomy research program at SUNY Oneonta. I will also talk about my current outreach efforts throughout New York state, and my upcoming series with The Great Courses that’s designed to teach amateur astronomers how to get involved in Citizen Science. By providing students, amateur astronomers, and the general public with the skills and cosmic knowledge they yearn to acquire, we can set them on a path towards tackling some of the big unanswered questions about our Universe. |
Friday, February 25, 2022
Ivy Li, Rice University
Hegeman 107 12:00 pm – 1:00 pm EST/GMT-5 The Universe contains vastly more dark matter than baryonic matter, and yet dark matter's particle nature remains elusive. The challenge of discovering dark matter's particle nature has spurred a technological race around the world. Scientists build experiments to hedge their bets on measuring dark matter, all while developing computational methods to face ongoing Big Data challenges. One such dark matter experiment is XENONnT, a xenon time projection chamber located underground at the Laboratori Nazionali del Gran Sasso in Italy. XENONnT has already collected petabytes of data and will continue to do so; in the upcoming years, storing, processing, and analyzing such data has become both a physics and a computational problem. In this talk, I will discuss our current understanding of dark matter, introduce the XENONnT experiment and its dark matter search, and explore two computational aspects of its setup: data processing on Open Science Grid and data compression for managing petabytes of data. Finally, I will highlight ongoing work from our interdisciplinary group at Rice, particularly machine-learning applications for astroparticle physics, and share a bit about my pathway into physics. |
Friday, February 11, 2022
Andrew Harder, Lehigh University
Hegeman 107 12:00 pm – 1:00 pm EST/GMT-5 An elliptic Lefschetz fibration is a smooth 4-manifold M (possibly with boundary) which admits a map to a surface S (possibly with boundary), and so that all but a finite number of fibers are diffeomorphic to a 2-torus, and the rest are homeomorphic to a “pinched” 2-torus. The classification of elliptic Lefschetz fibrations can be reduced to a (hard) problem in linear algebra whose solution is known in several cases — for instance, a theorem of Moishezon and Livné says that if S is just the 2-sphere then it is known that any elliptic Lefschetz fibration has 12n fibres which are pinched 2-tori for some integer n, and that the topology of M is completely determined by n. Surprisingly, the situation where S is a 2-dimensional disc, despite being well studied, is not completely understood. In this talk, I will discuss an answer to this problem under certain conditions on the boundary of M and on the number of fibres which are singular. We reduce this problem to a question about linear algebraic objects called pseudo-lattices and apply a theorem of Kuznetsov to give a concrete description of a class of elliptic Lefschetz fibrations. Finally I will discuss my motivation for considering this problem and how this classification theorem reflects the numerical classification of weak del Pezzo surfaces in algebraic geometry. This is based on joint work with Alan Thompson. |