Past Colloquia
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…
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…
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…
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…
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…
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…
Star Formation in the Multiphase Interstellar Medium of Galaxies
Cody Hall
Chris McKee (UC Berkeley)
March 29, 2012
15:00 - 16:00
Star formation is at the nexus of astrophysics: stars are believed to be responsible for the re-ionization of the universe, they created all the heavy elements, they control the formation and evolution of galaxies and the formation of stars naturally leads to the formation of planets….
The PTF Open Cluster Survey: Tracking the Evolution of Rotation and Activity on the Lower Main Sequence
Cody Hall
Marcel Agüeros (Columbia U)
March 23, 2012
14:00 - 15:00
A star’s age is one of its most fundamental parameters. It is also, for isolated field stars, notoriously difficult to measure. While we have known for 40 years of the existence of a relation between a star’s age, rotation, and magnetic activity, observational limitations have…