Colloquia
Colloquia: Astronomy & Astrophysics colloquia and KICP colloquia - Usually Wednesdays, 3:30 PM, ERC 161, unless otherwise specified. Reception starts at 4:30 PM in Hubble Lounge (Astronomy & Astrophysics colloquia) and ERC 401 (KICP colloquia). Persons with a disability who believe they may need assistance, please call the departmental secretary in advance at 773-702-8203 or email deptsecoddjob.uchicago.edu.

Current & Future Colloquia
DateTalk TitleSpeaker
January 22, 2020
KICP Colloquium
Scintillating Bubble ChambersEric Dahl, Northwestern University
January 29, 2020
Astronomy Colloquium
TBAAlexander Ji, Carnegie Observatories
March 11, 2020
Astronomy Colloquium
TBABrant Robertson, UC Santa Cruz
March 18, 2020
Astronomy Colloquium
TBAPeng Oh, UC Santa Barbara
April 22, 2020
Astronomy Colloquium
TBAMariska Kriek, UC Berkeley
May 20, 2020
Astronomy Colloquium
TBAPriyamvada Natarajan, Yale

Past Colloquia
DateTalk TitleSpeaker
January 15, 2020
Astronomy Colloquium
Bridging Galaxy Evolution Across Cosmic Time: Tracing the Interplay between Massive Stars and the Interstellar Medium with SpectroscopyDanielle Berg, Ohio State University
January 8, 2020
Astronomy Colloquium
From Large to Small: Symmetries and the Origins of Structure in the UniverseAustin Joyce, Columbia University

From Large to Small: Symmetries and the Origins of Structure in the Universe
January 8, 2020 | ERC 161 | 3:30 PM | Astronomy Colloquium
Austin Joyce, Columbia University

What was the universe like in its first moments? Remarkably, we can gain insight into the infancy of universe by looking at the largest scales today, using subtle correlations imprinted at very early times. This striking connection between the very large the very small is an opportunity to use cosmological observations to probe high energies, and also to bring modern theoretical tools to bear on the deep questions that cosmology presents us with. I will discuss recent progress in both directions, highlighting the power of effective field theory and symmetries as guiding principles. As an example, I will explain how the symmetry-oriented viewpoint can help unravel the origins of structure in the universe by enabling us to derive powerful model-independent tests of the simplest inflationary paradigm. Violations of these relations can signal the presence of new heavy particles, allowing us to use the primordial universe as the highest-energy particle accelerator. I will also describe recent theoretical advances in understanding the signatures of these heavy particles, and will explain how these advances could help shed light on fundamental questions, like the emergence of time in cosmology.

Bridging Galaxy Evolution Across Cosmic Time: Tracing the Interplay between Massive Stars and the Interstellar Medium with Spectroscopy
January 15, 2020 | ERC 161 | 3:30 PM | Astronomy Colloquium
Danielle Berg, Ohio State University

The first stars and galaxies initiated the epoch of reionization (EoR) and provided the seeds from which all galaxy evolution grew. Knowledge of the properties of these galaxies are needed to understand ionizing photon production and escape, andwill provide the crucial missing link needed to weave a coherent picture of galaxy evolution.I will present several programs that are establishing the needed framework to interpret the spectra of galaxies from z~0‒10, bridging the present-day and early universe. These programs use multi-wavelength spectroscopy to disentangle the spectral signatures that characterize the interplay between massive stars and their surroundings, and allow us to interpret how radiative processes shape galaxies. I will show how precise measures of the stellar and nebular properties of both nearby and distant lensed galaxies directly link the ionizing stellar populations with the baryon+metal feedback cycle and the conditions of ionizing photon production and escape. My studies provide a detailed foundation of the diversity of local star-forming galaxies with which to interpret cosmic evolution, as well as unique laboratories of nearly pristine gas in which to test conditions analogous to the first galaxies. In preparation for the coming UV window onto the early universe with the advent of the James Webb Space Telescope and the Giant Magellan Telescope, I will introduce the COS Legacy Archival Spectroscopic SurveY (CLASSY) - an upcoming large HST program that will produce the first high-resolution UV spectral atlas of star-forming galaxies. CLASSY will calibrate new tools that will allow us to completely describe the stars and interstellar medium in galaxies across redshift, setting the stage to study cosmic origins, ionizing production, and the evolution of galaxies in a unified framework.

Scintillating Bubble Chambers
January 22, 2020 | ERC 161 | 3:30 PM | KICP Colloquium
Eric Dahl, Northwestern University

Moderately superheated bubble chambers have proven to be an excellent method for WIMP hunting thanks to their world-leading electron-recoil discrimination, easy scalability, and diversity of potential WIMP targets. While the PICO Collaboration continues to increase the size and sensitivity of these devices, the successes of the past decade have also enabled a new bubble chamber variant where the superheated target is also a liquid scintillator. In these Scintillating Bubble Chambers, the nuclear recoil from a WIMP interaction simultaneously nucleates a bubble and creates a flash of scintillation light. On paper, this technique combines the electron recoil discrimination of a bubble chamber with the event-by-event energy reconstruction of a scintillator. In practice, these two signals conspire to allow scintillating bubble chambers to run at much lower thresholds than can be achieved in a standard PICO chamber. Superheated noble liquids, in particular, may be completely insensitive to electron recoils even when running at thresholds as low as 100 eV. I will describe our current understanding of why scintillating bubble chambers can reach these low thresholds, review the unique dark matter and neutrino physics open to a detector capable of electron/nuclear recoil discrimination at sub-keV energies, and update our progress on the first physics-scale scintillating bubble chamber, a 10-kg argon detector now under construction at Fermilab.

Reception at 4:30 PM in the ERC 401.

TBA
January 29, 2020 | ERC 161 | 3:30 PM | Astronomy Colloquium
Alexander Ji, Carnegie Observatories

Refreshments served at 4:30 PM, Hubble Lounge

TBA
March 11, 2020 | ERC 161 | 3:30 PM | Astronomy Colloquium
Brant Robertson, UC Santa Cruz

Refreshments served at 4:30 PM, Hubble Lounge

TBA
March 18, 2020 | ERC 161 | 3:30 PM | Astronomy Colloquium
Peng Oh, UC Santa Barbara

Refreshments served at 4:30 PM, Hubble Lounge

TBA
April 22, 2020 | ERC 161 | 3:30 PM | Astronomy Colloquium
Mariska Kriek, UC Berkeley

Refreshments served at 4:30 PM, Hubble Lounge

TBA
May 20, 2020 | ERC 161 | 3:30 PM | Astronomy Colloquium
Priyamvada Natarajan, Yale

Refreshments served at 4:30 PM, Hubble Lounge