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Past Colloquia

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…

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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…

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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…

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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…

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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…

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Galaxy Nuclei, Galaxy Outskirts

Cody Hall

Jenny Greene (Princeton)

May 04, 2012
14:00 - 15:00

I will talk about two different aspects of massive galaxy evolution.  First, I will discuss the possible importance of black hole feedback in shaping massive galaxies.  I will focus on our studies of the warm ionized gas in obscured quasars, in which we see tantalizing…

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Solar-eclipse science in the 21st century

Cody Hall

Jay M. Pasachoff (Williams College)

April 27, 2012
14:00 - 15:00

Just as ground-based nighttime astronomy has changed since Edwin Hubble took all-night 8-hour exposures of individual galaxies, contemporary solar-eclipse observations make use of the latest optical, electronic, and computer technologies to view our nearest star with capabilities that are not met out-of-eclipse on mountaintop observatories…

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Massive star forming galaxies at the peak of the galaxy formation epoch

Cody Hall

Reinhard Genzel (Max Planck Institute for Extraterrestrial Physics & UC Berkeley)

April 20, 2012
14:00 - 15:00

I will discuss the results of three major programs of studying star formation, cold gas, feedback and dynamics of massive ‘normal’ star forming galaxies near the peak of the epoch of galaxy formation (z~1-3). Our observations, carried out with the IRAM Plateau de Bure interferometer…

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Hot Jupiters: Problems and Opportunities

MP 134

John Johnson (Caltech)

April 11, 2012
15:00 - 16:00

Some of the best studied exoplanets are the hot Jupiters: Jovian planets with mercurial orbits (P < 10 days). These strange planets have played an outsized role in exoplanetary science. This is not because they are common—only 1% of stars have one—but because they are…

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Confronting Star-formation Models with Magnetic-field Observations

Cody Hall

Huabai Li (Max Planck Institute for Astronomy)

March 30, 2012
14:00 - 15:00

Self gravity, turbulence and magnetic fields (B-fields) certainly all play a role in the star-formation process, which transforms just a small fraction of the mass of molecular clouds into stars. How exactly these forces interact with each other to regulate star formation is, however, still…

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