Past Colloquia
Exploring the Dark Side of the Universe
Cody Hall
Chris Fassnacht (UC Davis)
September 14, 2012
14:00 - 15:00
In this talk I will show how the powerful combination of gravitational lensing and sensitive, high-resolution imaging can provide direct observational tests of galaxy formation scenarios under the cold dark matter paradigm as well as interesting constraints on cosmology. In particular, I will discuss the…
Beyond Bulge-Disk Decomposition: The True Nature of S0 Galaxies
Cody Hall
Michael Merrifield (University of Nottingham)
September 14, 2012
14:00 - 15:00
Perhaps the most basic defining feature of a galaxy is that its starlight is typically divided between disk and spheroidal components. From the earliest studies, the way the light was split between these components formed a key element of the way in which galaxies were…
Magnetized Atmospheres of Hot Exoplanets
Cody Hall
Kristen Menou (Columbia U)
September 04, 2012
15:00 - 16:00
Comparative planetology now encompasses a large set of extrasolar planets. Direct observational constraints on the atmospheres of several very hot exoplanets have become available. I will report on various efforts to interpret these observations in terms of atmospheric responses to unusual forcing conditions. In particular,…
The first steps of planet formation across the stellar mass range
Cody Hall
Gijs Mulders (University of Amsterdam)
June 18, 2012
14:00 - 15:00
Protoplanetary disks are thought to be the main sites of planet formation, and to understand how planets form we need to understand the physical processes in these disks. One of these physical processes is turbulent mixing, which is the main driver of disk accretion. It…
Characterizing super-Earths and mini-Neptunes
Cody Hall
Diana Valencia (MIT)
June 13, 2012
14:00 - 15:00
We have formally entered the era of super-Earths as masses and/or radii are being measured routinely for planets with a mass of less than ~10 earth-masses. The composition of these planets reflects their initial chemical inventory and early formation processes, such as giant impact collisions and…
The influence of tectonics and magnetic field on the early evolution of Earth and Venus
Cody Hall
Peter E. Driscoll (Yale University)
June 08, 2012
14:00 - 15:00
Over much of Earth history the geomagnetic field has provided a unique protective boundary by balancing the erosive solar wind well above the top of the atmosphere. On the contrary, the lack of evidence for a large scale magnetic field at Venus has been cited…
How Distant Binary Stars Reshape Their Planetary Systems
MP 134
Nathan Kaib (Queen's University)
June 06, 2012
11:00 - 12:00
Although ~1/3 of all known planet-hosting binary stars are very wide (average stellar separations beyond 1000 AU), there are very few dynamical studies that consider planetary systems within such binaries. Contrary to previous assumptions, we show that many of these distant binaries will have dramatic…
Explosion modelling for Type Ia supernovae
Cody Hall
Stuart Sim (Australian National University)
May 25, 2012
14:00 - 15:00
Aside from being spectacular displays in their own right, Type Ia supernova explosions have a key role in measuring the expansion history of the Universe and synthesizing the iron group elements. But what is their origin? That Type Ia supernovae arise from exploding white dwarfs…
Tales from the outer solar system
Cody Hall
Mike Brown (Caltech)
May 18, 2012
14:00 - 15:00
The past few years have seen an explosion in the discoveries of Pluto- and near Pluto-sized bodies in the outer solar system, giving rise to a new classification of “dwarf planets.” Like Pluto, each of these largest dwarf planets has a unique story to tell…
Are the properties of the Unified Model obscuring torus expected to be the same for all AGN?
Cody Hall
Almudena Alonso-Herrero (Instituto de Fisica de Cantabria, CSIC-UC)
May 11, 2012
14:00 - 15:00
The Unified Model for active galactic nuclei (AGN) proposes the ubiquitous presence of an obscuring torus around their nuclei, with type 1 and type 2 AGN being intrinsically similar. The central region of an AGN is obscured when viewed along directions close to the equatorial…