
Past Colloquia
Puzzles in Galaxy Scaling Relations
Cody Hall
Stephane Courteau (Queen’s University)
November 25, 2016
14:00 - 15:00
Galaxies like our Milky Way can be described in terms of their structure, dynamics, and stellar populations. Some very robust correlations between galaxy structural properties, such as total luminosity, maximum circular velocity, and size display rather small scatter, hinting at well-regulated galaxy formation processes. A…
The Thermal Odyssey of the ionized Intergalactic Medium
Cody Hall
Matt McQuinn (University of Washington)
November 18, 2016
14:00 - 15:00
I will summarize the history of IGM temperature measurements from the Lyman-alpha forest as well as the theory for the IGM temperature after reionization. I will show that the simplest theory for thermal evolution, which has little parametric freedom, works remarkably well at reproducing recent…
DESI and Beyond: Design Considerations for Massive Redshift Surveys
Cody Hall
David Schlegel (Lawrence Berkeley National Laboratory)
November 11, 2016
14:00 - 15:00
The Dark Energy Spectroscopic Instrument (DESI) is under construction to measure the expansion history of the Universe using the Baryon Acoustic Oscillation technique. The DESI instrument is designed to efficiently measure galaxy redshifts to z=1.6, quasars at all redshifts, and the 3-dimensional Lyman-alpha forest at…
White Dwarf Supernovae: Distances and Differences
Cody Hall
Saurabh W. Jha (Rutgers University)
November 04, 2016
14:00 - 15:00
Most exploding white dwarfs are normal type-Ia supernovae (SN Ia) that have proven so useful as standardizable candles to measure cosmic distances and discover the accelerating Universe. I will describe current cosmological applications of SN Ia and future prospects with upcoming flagship projects like LSST…
The Connection between Binarity and Large-Scale Magnetic Fields in Hot, Massive Stars
Cody Hall
Jason Grunhut (Dunlap Institute)
October 28, 2016
14:00 - 15:00
Ordered magnetic fields are found in a variety of astrophysical objects, ranging from planets to Galaxies and beyond. While the details are not fully understood, magnetic fields in most objects are the result of dynamo processes that convert bulk mechanical motion into magnetic energy. Unlike…
Science Prospects with the Current and Future Network of Gravitational Wave Detectors
Cody Hall
Frédérique Marion (Laboratoire d'Annecy-le-Vieux de physique des particules (LAPP), CNRS)
October 21, 2016
14:00 - 15:00
As the second generation of ground-based gravitational wave interferometric detectors has come live and observed the first signals from binary black hole mergers, future observing runs will keep collecting data at unprecedented sensitivities, with an expanding network of detectors. The talk will discuss the plans…
Peculiar Transients as Probes of Stellar Evolution and Mass Loss
Cody Hall
Maria Drout (The Carnegie Observatories/Dunlap Institute)
October 14, 2016
14:00 - 15:00
The recent advent of wide-field time-domain surveys has launched an upheaval in field of stellar evolution. These surveys are uncovering new types of astronomical transients that not only challenge existing models for supernova explosions but also our understanding of what physical processes can occur during…
Gravitational Wave Observations: Status and Future Planning
Cody Hall
Sheila Rowan (University of Glasgow)
October 07, 2016
14:00 - 15:00
In September 2015 the twin ‘Advanced LIGO’ observatories allowed the first direct detection of gravitational waves from astrophysical sources. The waves detected originated from the collision and merger of two black holes 1.3 billion light years from earth. This detection marked the start of new…
Exoplanets Hidden by Stellar Activity
Cody Hall
Elodie Hebrard (York University)
September 30, 2016
14:00 - 15:00
The detection extra-solar planets through radial-velocity searches is likely limited by the intrinsic magnetic activity of the host stars. The correlated « noise » that arises from their natural radial-velocity variability (jitter) can easily mimic and hide the orbital signals of super-Earth and Earth-mass exoplanets,…
Mapping Hot Gas in the Universe using the Sunyaev-Zeldovich effect
Cody Hall
Eiichiro Komatsu (Max-Planck-Institut für Astrophysik, Germany)
September 23, 2016
14:00 - 15:00
Hot, thermal electrons in galaxy clusters up-scatter the cosmic microwave background photons, making clusters visible in the microwave sky. This effect, known as the Sunyaev-Zeldovich effect, has been detected routinely toward individual galaxy clusters. Since the SZ effect is proportional to a projected thermal pressure…