Past Colloquia
The Wind in the Machine: Using Machine Learning to Probe Quasar Outflows
Cody Hall, AB 107
Sarah Gallagher (Western University)
November 15, 2017
14:00 - 15:00
Every massive galaxy hosts a supermassive black hole that grew as a luminous quasar through active accretion when the universe was a fraction of its present age. Quasar activity can therefore be described as an “adolescent” phase of galaxy evolution: inevitable, difficult, and (perhaps) transformative….
Cosmology with Supernovae… and Kilonovae!
Cody Hall, AB 107
Dan Scolnic (Kavli Institute)
October 25, 2017
14:00 - 15:00
In this talk, I will present new analyses of Type Ia Supernovae that mark the most precise measurement of dark energy to date. I will go over how this analysis ties together with the analysis of the local value Hubble constant, for which tension persists…
Resolving scattering disks with ground-space VLBI
Cody Hall, AB 107
Vladimir Soglasnov (Lebedev Physical Institute)
October 18, 2017
14:00 - 15:00
Ground-Space VLBI observations of pulsars with baselines up to ~20 Earth diameters show a surprising view of visibility (delay-fringe rate plot, or delay-Doppler in “secondary spectra”). At low & medium baselines, besides the main peak in the origin it contains a number of needle-like spikes…
Finding Fast Radio Bursts with interferometers
Cody Hall, AB 107
Stefan Osłowski (Swinburne Institute of Technology)
October 11, 2017
14:00 - 15:00
While majority of the enigmatic Fast Radio Bursts have been detected with the single-dish Parkes Observatory radio telescope, new instruments are entering the search.Much progress has been made with interferometric discoveries of FRBs, with the UTMOST project leading the way. On the other hand, the…
The All-Sky Automated Survey for Supernovae (ASAS-SN)
Cody Hall, AB 107
Christopher Kochanek (Ohio State University)
October 04, 2017
14:00 - 15:00
The goal of ASAS-SN is to monitor the entire visible sky on a nightly basis for bright transients. ASAS-SN will reach this goal by the end of 2017. In the interim, ASAS-SN already dominates the discovery of bright supernovae (
Life Beyond Earth: Are Any Habitable Worlds Actually Inhabited?
MP 137, 60 St. George Street
Jill Tarter (SETI Institute)
September 28, 2017
15:00 - 16:00
Are we alone? Humans have been asking this question throughout history. We want to know where we came from, how we fit into the cosmos, and where we are going. We want to know whether there is life beyond the Earth and whether any of…
Galactic Archeology: The story of our Milky Way
Cody Hall
Keith Hawkins (Columbia University)
September 20, 2017
14:00 - 15:00
One of the key objectives of modern astrophysics is to understand the formation and evolution galaxies. In this regard, the Milky Way is a fantastic testing ground for our theories of galaxy formation. However, dissecting the assembly history of the Galaxy, requires a detailed mapping…
The James Webb Space Telescope and the landscape of observational astronomy in the 2020s
Cody Hall
Sarah Kendrew (European Space Agency)
February 10, 2017
14:00 - 15:00
Abstract: Building on the groundbreaking successes of the Hubble Space Telescope, the James Webb Space Telescope will open new windows on the Universe at infrared wavelengths. I will present the latest status of the mission, the roadmap towards science operations, and some of the scientific…
The distribution of stellar mass in galaxy clusters over cosmic time
Cody Hall
Remco van der Burg (CEA Saclay)
January 20, 2017
14:00 - 15:00
Galaxy clusters are the most massive gravitationally collapsed structures in the universe, and they have important cosmological and astrophysical applications. Measurements of the radial distribution of galaxies in clusters show how galaxies trace the underlying dark matter distribution, and provide constraints on the physics related…
Towards observational constraints on mapping between cosmological redshift and cosmic scale factor
Cody Hall
Radek Wojtak (Stanford University)
January 13, 2017
14:00 - 15:00
The standard relation between the cosmological redshift and cosmic scale factor is arguably one of a few unverified theoretical inputs underlying the computation of cosmological observables and modern cosmological inference. However, the richness of cosmological observations allows to change its theoretical status and the relation…