Past Events


Chalk Talk: Congyao Zhang (UChicago) & Francisco Javier Sanchez Lopez (Fermilab)

12:00–1:00 pm ERC 501

Congyao Zhang (UChicago) 
“Formation of Galaxy Clusters – from the Core to the Outskirts”

Francisco Javier Sanchez Lopez (Fermilab)
“Olber’s paradox revisited: effects of overlapping sources on cosmic shear estimation”

Feb 18

KICP seminar: Tien-Tien Yu (University of Oregon)

12:00–1:00 pm ERC 401

“A New Look at the Migdal Effect”

Feb 14
Feb 14

A&A Colloquium - Lorenzo Sironi (Columbia)

3:30–4:30 pm ERC 161

Fast and furious: magnetic reconnection in relativistic jets and black hole coronae

Relativistic jets of blazars and magnetized coronae of low-luminosity accretion flows, like Sgr A* at our Galactic Center, routinely display fast and bright flares of high-energy emission. Yet, the “engine” responsible for accelerating the emitting particles to ultra-relativistic energies is still unknown. With fully-kinetic particle-in-cell (PIC) simulations, we argue that magnetic reconnection — a process by which magnetic field lines of opposite polarity annihilate, releasing their energy to the particles — can satisfy all the basic conditions for the emission. In blazar jets, we show that reconnection can naturally explain the puzzling ultra-fast bright flares observed at GeV and TeV energies, whose duration can be even shorter than the light-travel time across the black hole that powers the jet. In low-luminosity accretion flows like Sgr A*, we show that reconnection — potentially seeded by turbulence — can power both thermal and non-thermal emission, and we produce physically-grounded synthetic images and spectra to be compared with infrared and X-ray observations and with the upcoming results of the Event Horizon Telescope.

Feb 12

Special A&A Colloquium: Benjamin Fulton (Caltech)

12:00–1:00 pm ERC 576

Is our Solar System Unique? A Holistic View of Exoplanet Demographics

The Kepler and K2 missions blessed the community with a plethora of planet transit detections which enabled studies of exoplanet size demographics. Much of the recent progress in this field is driven by improved characterization of the stellar hosts. Our group recently used precise radius measurements from the California-Kepler Survey (CKS) to detect a gap in the distribution of planet radii. The paucity of planets with sizes between 1.5 and 2.0 Earth radii supports the emerging picture that close-in planets smaller than Neptune are composed of small, rocky cores enveloped by varying amounts of low-density gas that determine their total sizes. This result demonstrated the value of precise and homogeneous stellar parameters. I will discuss implications of the radius distribution and our ongoing and complimentary work to measure the frequency of giant planets orbiting well beyond the snow line. The occurrence of close-in planets from Kepler combined with the latest results from long-baseline radial velocity surveys allow us to construct a comprehensive picture of planetary system architectures spanning three orders of magnitude in orbital separation and planet mass.

Feb 11

EFI Talk: Joaquin Vieira (UIUC)

3:30–4:30 pm MCP 201

“The Universe Seen In The Far-Infrared”

Feb 10

KICP seminar: Jessica M Turner (Fermilab)

12:00–1:00 pm ERC 401

“Heavy neutrinos and their role in the early Universe”

Feb 7

KICP colloquium: Abigail Crites (University of Toronto)

3:30–4:30 pm ERC 161

“Measuring the Epoch of Reionization with Line Intensity Mapping using TIME”

Feb 5

Special A&A Colloquium: Jaehan Bae (Carnegie Institution of Washington)

12:00–1:00 pm ERC 576

Toward a More Complete Picture of Planet Formation

Abstract: The studies of planet formation have long been dominated by theoretical work because observing planets in formation has been challenging. The situation is, however, gradually changing. Thanks to increasingly powerful observing facilities and techniques, we are now able to peer into the birthplaces of planets - protoplanetary disks, routinely finding signposts of ongoing planet formation. I will introduce state-of-the-art observations of protoplanetary disks, made available by the Atacama Large Millimeter/submillimeter Array and ground-based optical/IR telescopes equipped with adaptive optics. I will discuss how planet formation theories are being tested with and improved by observational data in conjunction with supercomputer simulations. I will conclude with a discussion of prospects for future directions, focusing on how we can connect studies of protoplanetary disks to those of solar and extrasolar planetary systems and develop a more complete picture of planet formation.

Feb 4

KICP seminar: Raymond T Co (University of Michigan)

12:00–1:00 pm ERC 401

“X-ray Search for Axions from Nearby Isolated Neutron Stars”

Jan 31