Past Colloquia
DADDAA: Faculty Search: Probing Planet Formation with the Most Extreme Cases
Zoom Group Viewing in AB88
Dr. Fei Dai, Caltech
March 21, 2023
4:00 pm - 5:30 pm
Thousands of exoplanets have been discovered in the past ~30 years. Kepler has shown us close-in sub-Neptune exoplanets (<1AU, <4R_earth) are extremely common in our Galaxy but somehow absent in our solar system. The James Webb Space Telescope is poised to characterize some of these…
Astro Colloquium: Fast flares and furious transients: exploring the deep, high-speed sky
Cody Hall
Nick Law
March 15, 2023
3:00pm - 4:00pm
Current sky-survey telescopes’ limited fields of view hinder the rapid detection of rare fast events, including superflares capable of rendering exoplanets uninhabitable, fast stellar dips from Oort-cloud occultations, and electromagnetic counterparts to gravitational waves. I will discuss the impacts of stellar superflares on planet habitability…
DADDAA Faculty Search: “From Blips to Bits: FRB cosmology, Radio Cameras, and Astroinformatics”
UC179
Dr. Liam Connor
March 09, 2023
2:00pm - 3:30pm
Modern radio telescopes have seen tremendous gains in sensitivity, field of view, and frequency bandwidth, thanks largely to advances in signal processing. This has allowed us to uncover entirely new source classes, such as fast radio bursts (FRBs). Beyond the mystery of their origin, FRBs…
Closing the Loop in Early Universe Cosmology?
Cody Hall
Prof. Chris Smeenk, UWO
March 01, 2023
3:00pm - 4:00pm
Contemporary cosmology pursues several ambitious aims, including uncovering new aspects of fundamental physics based on their role in the very early universe. In pursuing these aims, cosmologists have revisited basic questions about what constitutes an acceptable scientific theory, what explanatory demands a theory should meet,…
Astrophysical Lessons from LIGO-Virgo-KAGRA’s Black Holes
Cody Hall
Prof. Maya Fishbach
February 15, 2023
3:00pm - 4:00pm
The LIGO-Virgo-KAGRA Collaboration has observed over 70 gravitational-wave sources to date, including mergers between black holes, neutron stars, and mixed neutron star—black holes. Focusing on the black hole mergers, I will describe some recent lessons into how, when, and where black holes are made. These…
Milky Way Stellar Stream Heating
AB107, 50 St. George Street
Raymond Carlberg, University of Toronto
January 25, 2023
3:00pm - 4:00pm
A key prediction of LCDM is that galactic halos are filled with sub-halos orbiting within them, whereas warm dark matter models would have few. Studies of individual Milky Way star streams find evidence of a few sub-halos, but the sub-halo population properties are unclear. Current…
The Landscape of Relativistic Stellar Explosions
Cody Hall
Prof. Anna Ho, Cornell
January 18, 2023
3:00pm - 4:00pm
For the last half-century, relativistic outflows accompanying the final collapse of massive stars have predominantly been detected via high-energy emission, as long-duration gamma-ray bursts (GRBs). Yet, it has long been hypothesized that GRBs are the tip of the iceberg of relativistic stellar explosions, because the…
Direct Detection Searches for Low-Mass Dark Matter Particles
Cody Hall
Miriam Diamond
January 11, 2023
3:00pm - 4:00pm
The quest to unmask the fundamental nature of dark matter has inspired a vast worldwide program of complementary experiments, including direct-detection, indirect-detection, and collider searches.Direct-detection searches over the past few decades, using technologies such as large liquid noble chambers, have been largely focused on Weakly Interacting Massive Particles in…
Discovering the cold extrasolar planets with gravitational microlensing
Online Zoom
Prof. Shude Mao
December 07, 2022
11:00am - 12:00pm
Microlensing has become a powerful method to detect cold extrasolar planets beyond the snowline and free-floating planets. In this talk, I will first introduce the basic concepts of gravitational microlensing, review some of the recent discoveries with ongoing surveys, and then finish with a discussion…
The Far Ultraviolet diffuse background
AB 107, Codyhall
Shrinivas Kulkarni, Caltech
November 23, 2022
3:00pm - 4:00pm
Historically, the search for the inter-galactic medium(IGM) motivated the search for the Far Ultraviolet (FUV) backgroundwhich in turn led to a number of experiments and missions. Decadeslater the focus shifted to FUV as the primary heating and ionizingagent of the atomic phases (warm and cold…