
Past Colloquia
A Thousand Earths: A Constellation of Very Large Space Telescopes for Large-Scale Biosignature Surveys
Daniel Apai, University of Arizona
March 20, 2024
2:00pm - 3:00pm
Abstract: Thorough, population-level understanding of habitable and inhabited planets requires systematic studies of large samples of planets. However, the very slow growth of the light-collecting area of space telescopes and their very high costs remain severely limiting factors for exoplanet and biosignature studies. I will…
Searching for Cosmic Dawn and Beyond with Radio Observations
Cynthia Chiang, McGill University
March 13, 2024
2:00pm - 3:00pm
Abstract: Observations of redshifted 21-cm emission of neutral hydrogen are a rapidly growing area of cosmology research. Measurements of the radio sky at ~200 MHz and below are a promising tool for exploring cosmic dawn, and at the lowest frequencies (tens of MHz), future observations…
DADDAA Faculty Search: “Quest for the Most Distant Universe – Today and Beyond”
MS 4171 (Medical Sciences Building)
Dr. Seiji Fujimoto
March 07, 2024
2:00pm - 3:00pm
Abstract: Finding and characterizing the earliest systems are crucial for answering fundamental cosmological questions such as the emergence of first galaxies and black holes (BHs), as well as the cosmic reionization process. The advent of JWST has advanced our capability to detect and analyze systems from…
Tracing Star Formation Across Scales: A Case Study in the Solar Neighborhood
Cody Hall
Catherine Zucker, Center for Astrophysics | Harvard & Smithsonian
March 06, 2024
2:00pm - 3:00pm
Abstract: The processes regulating star formation in galaxies act across many orders of magnitude in spatial scale. Thus, a key challenge in understanding star formation is bridging the small-scale physics within molecular clouds and the large-scale structure of spiral galaxies. Fully constraining the physics of star…
DADDAA Faculty Search: “Neutron Stars & Black Holes: Astrophysical Laboratories for Nuclear Physics and Nuclear Yardsticks for Astrophysical Phenomena”
MS 4171 (Medical Sciences Building)
Prof. Reed Essick
February 15, 2024
2:00pm - 3:00pm
Multimessenger observations of compact stellar remnants offer a unique opportunity to study the behavior of matter in the most extreme environments anywhere in the universe. I will review what recent gravitational-wave, x-ray, and radio observations of neutron stars, along with nonparametric hierarchical Bayesian inference, tell…
DADDAA Faculty Search: “Advancing Precision Spectroscopy and Detecting Earth Analogs”
MS 4171 (Medical Sciences Building)
Dr. Lily Zhao
February 08, 2024
2:00pm - 3:00pm
Abstract: Extreme precision radial velocity (EPRV) measurements, capable of capturing signals with an amplitude of just 10-30 cm/s, are needed to calculate low-mass planet compositions, inform planet dynamics, and enable interpretable atmosphere spectroscopy. Achieving this level of precision spectroscopy requires innovation at all levels, from…
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…