2022
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
2021
Open group seminar: Shivam Pandey (UPenn)
2:30–3:30 pm ERC 401
Shivam Pandey (UPenn) “Perturbation theory for non-linear galaxy biasing in photometric galaxy surveys”
KICP seminar: Maria Vincenzi (Duke)
12:00–1:00 pm ERC 401
Maria Vincenzi (Duke) “Present and future of SN Ia cosmology: from the Dark Energy Survey to the Vera Rubin Observatory”
Webinar: SH0ES team with new H0 results and Pantheon updates
11:00 am–12:00 pm ERC 401
SH0ES team Webinar with new H0 results and Pantheon updates
KICP Colloquium: Will Farr (Stony Brook University)
3:30–4:30 pm ERC 161
Will Farr (Stony Brook University) “Ringing Black Hole Bells and Other Exciting Recent Results in Gravitational Wave Astronomy”
Chicagoland Survey Science Cosmology Meeting
9:00 am–5:00 pm ERC 401
Open group seminar: Rohan Naidu (Harvard)
2:00–3:00 pm ERC 517
Rohan Naidu (Harvard) “Unraveling the Galactic Stellar Halo with the H3 Survey”
KICP seminar: Carles Sanchez (Penn)
12:00–1:00 pm ERC 401
Carles Sanchez (Penn) “Pushing the limits of the Dark Energy Survey: Selecting and characterizing high redshift galaxy samples for optimal CMB lensing cross-correlations”
A&A Colloquium: Anna-Christina Eilers (MIT)
3:30–4:30 pm ERC 161
The Growth of Supermassive Black Holes in the Early Universe
The existence of luminous quasars hosting supermassive black holes within the first billion years of cosmic history challenges our understanding of black hole growth. An important piece of the puzzle is the lifetime of quasars - the time that galaxies shine as active quasars and during which the bulk of the black hole growth occurs - but to date its value remains uncertain by several orders of magnitude. I will present a new method to obtain constraints on the lifetime of quasars based on the sizes of ionized regions around quasars known as proximity zones. These proximity zones act as a “quasar clock” and enable us to study the co-evolution of supermassive black holes and their host galaxies from a new perspective. Surprisingly, our results indicate that black holes might be able to grow several orders of magnitude faster than previously thought, which provides a potential solution to the long-standing puzzle of the rapid black hole assembly in the early universe. I will further show how future observations with the upcoming James Webb Space Telescope will enable new insights into galaxy-quasar co-evolution across cosmic time.