Past Colloquia
Detecting Gravitational Waves With Pulsar Timing: Updates from NANOGrav and the IPTA
Cody Hall
Thankful Cromartie, Cornell University
January 17, 2024
2:00pm - 3:00pm
The North American Nanohertz Observatory for Gravitational Waves (NANOGrav) collaboration recently published its 15-Year Data Set, providing substantial evidence for a nHz background of gravitational waves and marking an exciting milestone for pulsar timing arrays. Since the publication of our 12.5-Year Data Set, which strongly…
Title: The Superpressure Balloon-borne Imaging Telescope
Cody Hall
Prof. Barth Netterfield
January 10, 2024
2:00pm - 3:00pm
Abstract: SuperBIT is a 0.5m diffraction-limited wide field imaging telescope operating in the visible and near-UV, which made its 39 day science flight in the spring of 2023. SuperBIT has a resolution of around 0.3 arc seconds and a field of view of 340 square arcminutes (compared with the ACS…
Solving Two 30-year Mysteries in the Formation and Dynamical Evolution of Binary Stars
Cody Hall
Prof. Max Moe, University of Wyoming
December 06, 2023
2:00pm - 3:00pm
Most stars are born in binary and multiple systems. Nearly all very close binaries with orbital periods P < 5 days are in triples, initially suggesting that the tertiary companion played a role in the dynamical hardening of the inner binary. However, several properties of…
A Flood of Exotic Globular Cluster Pulsar Discoveries
Cody Hall
Scott Ransom
November 29, 2023
2:00pm - 3:00pm
In the past five years, the number of known globular clusterpulsars, most of them of the millisecond variety, has nearly doubled, to atotal of over 300. The main reasons were the commissioning of theextremely sensitive FAST and MeerKAT radio telescopes, and increasedcomputing power applied to…
Exploring the Changing Sky: The Vera Rubin Observatory and the LSST Discovery Alliance
Michael Wood-Vasey University of Pittsburgh Board Chair, LSST Discovery Alliance
November 22, 2023
2:00pm - 3:00pm
The Vera C. Rubin Observatory is an 8.4-m telescope with a 10 square degree field of view camera that will observe the visible southern sky every 3 days as part of the Legacy Survey of Space and Time (LSST). The LSST movie of the sky…
Our Lonely Sun: How Multiple Star Systems Form (or don’t)
Cody Hall
Stella Offner, University of Texas at Austin
November 15, 2023
2:00pm - 3:00pm
Abstract: Most stars are born with one or more stellar companions. Observational advances over the last decade have enabled high-resolution, interferometric studies of forming multiple systems and statistical surveys of multiplicity in star-forming regions. These have yielded new insights into how such systems form and how multiplicity…
Accreting massive black holes and QUVIK a Czech UV space telescope
Cody Hall
Norbert Werner,
November 08, 2023
2:00pm - 3:00pm
Most galaxies comparable to or larger than the mass of the Milky Way host hot, X-ray emitting atmospheres and accreting supermassive black holes. I will present results based on radio and X-ray observations, which indicate that in massive early-type galaxies, the central radio sources are…
Sub-clusters and Gas and Binaries, oh my: Star Cluster Formation is Messy
Cody Hall
Alison Sills, McMaster University
November 01, 2023
2:00pm - 3:00pm
Stars are primarily formed in clustered environments in giant molecular clouds. Stars are also primarily found in binary or higher order multiple systems. This hierarchy of binaries inside clusters, particularly at early times, means that binary systems interact with other stars from the first moments…
Reconstructing the physics of transients using machine learning
Cody Hall
Wolfgang Kerzendorf, Michigan State University
October 25, 2023
2:00pm - 3:00pm
Supernova explosions are some of the most energetic and luminous events in the universe, andunderstanding them is crucial for many areas of astrophysics. One way to gain insight into the physicalprocesses involved in these explosions is through supernova tomography, which involves reconstructinga spatially resolved explosion…
How Black Holes Shine
Cody Hall
Prof. Bart Ripperda, CITA, University of Toronto
October 18, 2023
2pm - 3pm
Astrophysical black holes are surrounded by accretion disks, jets, and coronae consisting of magnetized relativistic plasma. They produce observable high-energy radiation from nearby the event horizon and it is currently unclear how this emission is exactly produced. The radiation typically has a non-thermal component, implying…