2022
KICP colloquium: Daniel Scolnic (Duke University)
3:30–4:30 pm Zoom
Daniel Scolnic (Duke University) “New Results from the Pantheon+ and SH0ES Teams on Measuring the Hubble Constant”
Astro Tuesday: Abigail Lee (UChicago) and David Zegeye (UChicago)
12:00–1:00 pm Zoom
Abigail Lee (UChicago) “Using Carbon Stars as Standard Candles: Establishing the Foundations for an Independent Measurement of the Hubble Constant” and David Zegeye (UChicago) “The Square Kilometer Array as a Cosmic Microwave Background experiment”
Open group seminar: David Zegeye (UChicago) and Tom Crawford (UChicago)
10:30–11:30 am Zoom
David Zegeye (UChicago) and Tom Crawford (UChicago) will discuss CMBS4+SKA in the context of detecting CMB spectral anisotropy
KICP seminar: Julian Muñoz (Harvard-Smithsonian Center for Astrophysics)
12:00–1:00 pm Zoom
Julian Muñoz (Harvard & Smithsonian) “Cosmic Dawn: The next frontier in cosmology”
A&A Colloquium: Damiano Caprioli (University of Chicago)
3:30–4:30 pm Zoom - Please contact Laticia at lrebeles@oddjob.uchicago.edu for info
The Non-thermal Universe
Non-thermal particles are ubiquitous in the Universe: we can detect them at Earth as cosmic rays, probe them in-situ with spacecraft in the heliosphere, and observe their emission from galactic and extra-galactic objects over a vast range of frequencies spanning from radio to gamma-rays. I present some paradigmatic examples of how ab-initio plasma simulations can be used to further our understanding of particle acceleration and transport, and eventually the non-thermal phenomenology of several astrophysical objects. Moreover, I illustrate how cosmic rays and magnetic fields can play a crucial role in the interstellar medium and hence in galactic dynamics and evolution.
Astro Tuesday: Ilaria Lonoce (UChicago) and Madison Brady (UChicago)
12:00–1:00 pm Zoom
Ilaria Lonoce (UChicago) “The stellar initial mass function and its challenging measurement” and Madison Brady (UChicago) “Assessing /TESS/‘s Yield Around Nearby M Dwarfs”
KICP colloquium: Mariangela Lisanti (Princeton University)
3:30–4:30 pm Zoom
Mariangela Lisanti (Princeton University) “Galactic Probes of Dark-Sector Physics”
Astro Tuesday: Kayla Owens (UChicago) and Siddhartha Gupta (UChicago)
12:00–1:00 pm Zoom
Talks: Kayla Owens (UChicago) “Current Challenges in Cepheid Distance Calibrations Using Gaia EDR3” and Siddhartha Gupta (UChicago) “Lepton-driven Non-resonant Streaming Instability” | Host: Vikram Dwarkadas
A&A Colloquium: Daniel Fabrycky (University of Chicago)
3:30–4:30 pm Zoom - Please contact Laticia at lrebeles@oddjob.uchicago.edu for info.
Resonant Chains versus More “Typical” Exoplanetary Systems
In the field of exoplanets, the most extreme systems often capture our attention, and they teach us interesting lessons. However, statistical modeling of survey data is important too, as it identifies what are the more common processes involved in planet formation.
For some systems, three or more planets are linked by mean-motion resonances, forming a “resonant chain.” The observable transit timing variations allow masses and orbital parameters to be measured to excellent precision. Their current orbits, including orbital phase information, teaches us about the interactions of planets with disks. The spreading of resonant chains from exact resonance implicates tidal dissipation in the planets.
Resonant configurations are rare in the transit survey data though, and we report methods for characterizing the more “typical” close-in exoplanetary systems. After we had gotten used to extreme orbits among exoplanetary gas giants, we found surprisingly small mutual inclinations and eccentricities of the very common close-in systems of super-earths and sub-neptunes. Despite being on sub-AU scales, these architectural properties are very similar to the Solar System. Confronting planet formation theories with all this fossil evidence is an ongoing project.
2022 Winter Quarter Begins
All day