
Past Colloquia
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…
Unifying the Many Faces of Neutron Stars: The High Magnetic Field Connection
Cody Hall
Victoria Kaspi (McGill University)
March 16, 2012
14:00 - 15:00
Neutron stars show a bewildering array of observational properties which range from mild-mannered, faint pulsations to unpredictable blasts of X-rays and gamma-rays that can occasionally but briefly outshine the entire Galaxy in these bands. From the dramatic magnetars to the generally calmer radio pulsars, from…
Gravitational waves, promises and challenges to fulfill them
Cody Hall
Luis Lehner (Perimeter Institute for Theoretical Physics & University of Guelph)
March 09, 2012
14:00 - 15:00
Soon gravitational waves will provide a completely new way to understand our universe. To fully exploit this opportunity efforts –and expertise– beyond gravity are required. This talk has then two purposes: One, to review some few examples of what has been understood from the theoretical…
The nature of cosmic explosions: recent progress
Cody Hall
Avishay Gal-Yam (Weizmann Institute of Science)
February 17, 2012
14:00 - 15:00
Cosmic explosions mark the violent deaths of stars. While the emission from the explosion itself (manifesting, e.g., as a supernova) is often very bright and can be studied in detail, understanding the nature of the progenitor systems of these events is more difficult, as these…
Young Planets Caught at Formation
Cody Hall
Adam Kraus (U. Hawaii)
February 09, 2012
14:00 - 15:00
Young and directly-imaged exoplanets offer critical tests of planet-formation models that can’t be matched by RV and transit surveys of mature stars. However, these targets have been extremely elusive to date, with no exoplanets younger than ~10-20 Myr and only a handful of directly-imaged planets…
The Time Domain Renaissance: From Gamma-Ray Bursts to Advanced LIGO
Cody Hall
Brad Cenko (Berkeley)
February 06, 2012
14:00 - 15:00
With convergence of both science (i.e., community interests) and technology (the advent of new facilities enabled by Moore’s Law), time-domain exploration of the sky promises to be a frontier pursuit in the coming decade. In this talk I will review two recent results from our efforts to characterize variability…
The Accelerating Universe: Probing Inflation & Dark Energy with the Radio/Microwave Sky
Cody Hall
Keith Vanderlinde (McGill)
February 02, 2012
14:00 - 15:00
Two of the greatest mysteries in cosmology — and indeed all of modern physics — involve the exponential growth of space: the inflationary period of the early Universe, and the present-day Dark Energy-driven expansion. Recent technological advances are fuelling the exploration of these twin phenomena,…
Innovative Non-Dispersive Imaging Spectrometers: Technology Development and Upcoming Observational Opportunities
Cody Hall
Megan Eckart (Goddard SFC)
January 30, 2012
14:00 - 15:00
The development of a new detector technology often results in major advances in observational capabilities. Recently developed microcalorimeter detector arrays will revolutionize the study of the high-energy Universe by enabling non-dispersive spectrometers with high spectral resolution (R~1000-6000) in the soft X-ray band. These new instruments…
The Role of Dwarf Galaxy Interactions in Shaping the Magellanic System and Implications for Magellanic Irregulars and Dwarf Spheroidals
Cody Hall
Gurtina Besla (Columbia University)
January 27, 2012
14:00 - 15:00
I will present a new numerical model of the evolution of the Milky Way’s largest satellite galaxies, the Large and Small Magellanic Clouds (LMC/SMC), in which their current internal structure and kinematics and large-scale gas morphology are dictated by their mutual tidal interactions, rather than…
Small Stars with Small Planets and Big Consequences
Cody Hall
Phil Muirhead (Caltech)
January 25, 2012
15:00 - 16:00
The field of extrasolar planets is rapidly evolving. The quest to discover ever-more and ever-smaller exoplanets has pushed the field in two primary detections: (1) toward a comprehensive assessment of the frequency and statistics of various types of exoplanets–used as a guide for planet formation…