Past Colloquia
Astrometry and Adaptive Optics Enables Tests of Star Formation in Extreme Environments
Cody Hall
Jessica Lu (U of Hawaii)
February 13, 2013
14:00 - 15:00
Ground-based telescopes equipped with adaptive optics systems have overcome the blurring effects of the Earth’s atmosphere and now routinely provide diffraction-limited images at infrared wavelengths. This has led to a revolution in astrometry, and we can now measure stars’ relative positions with 150 micro-arcsecond precision,…
Detecting and Characterizing Exoplanets with a New Generation of Sky Surveys
Cody Hall
Nicholas Law (Dunlap)
February 06, 2013
14:00 - 15:00
Modern optical sky surveys like the Palomar Transient Factory and Pan-STARRs open new windows into a vast and dynamic sky, and their enormous datasets demand dramatic improvements in both data-mining algorithms and follow-up instrumentation. I will describe Robo-AO, a recently-commissioned robotic laser adaptive optics system,…
Galactic Dynamics and the Nature of Dark Matter
MP 102
Matthew Walker (Harvard)
February 04, 2013
15:00 - 16:00
I will explain how to use the motions of stars to learn about the nature of particles. More specifically, I will translate the stellar kinematics that I observe in the nearest, smallest and `darkest’ galaxies into a test of the standard hypothesis that dark matter…
The New Era of Exoplanet Direct Imaging
Cody Hall
Sasha Hinkley (Caltech)
January 31, 2013
15:00 - 16:00
Most of the hundreds of extrasolar planets identified in the past 15 years have been detected indirectly—through careful monitoring of the planets’ effect on their host star’s light. By overcoming the extremely large brightness contrast between the stars and their faint exoplanetary companions, we are…
What Shuts Down Star Formation in Galaxies?
Cody Hall
Alison Coil (UC San Diego)
January 25, 2013
14:00 - 15:00
The main question I will address in my talk is what shuts down star formation in galaxies. I will highlight recent observational work on outflowing galactic-scale winds and the potential impact of these winds on star formation in galaxies. I will present new work on which galaxies…
The highest redshift starburst galaxies revealed by the South Pole Telescope, ALMA, and gravitational lensing
Cody Hall
Scott Chapman (Dalhousie)
January 18, 2013
14:00 - 15:00
The South Pole Telescope has systematically identified large numbers of high-redshift strongly gravitationally lensed systems. These sources are selected by their extreme mm flux, which is largely independent of redshift and lensing configuration. I will report results from the first blind redshift survey undertaken with…
Las Cumbres Observatory: Building a global telescope network from the ground up
Cody Hall
Edward Gomez (LCOGT)
January 11, 2013
14:00 - 15:00
We are building a global network of telescopes which will be available to both professional scientists and the science curious public. Our telescope network will be a homogeneous group, evenly spaced in northern and southern hemispheres for maximum night sky coverage. As well as undertaking…
The Ecology of Galaxy Formation Within the “Cosmic Web”
Cody Hall
Chuck Steidel (Caltech)
December 07, 2012
14:00 - 15:00
I will discuss recent results from the “Keck Baryonic Structure Survey”, a unique survey of the high redshift universe optimized for sensitivity to both forming galaxies and the surrounding gas-phase circumgalactic and intergalactic baryons (and the exchange between the two) at 2 < z <…
The Formation of Massive Galaxies
Cody Hall
Pieter van Dokkum (Yale)
November 30, 2012
14:00 - 15:00
Owing to large surveys with the Hubble Space Telescope and ground-based telescopes we now have high resolution snapshots of the Universe dating back to only a few hundred million years after the Big Bang. The challenge now is to use this wealth of data to…
Hydrodynamics of nuclear combustion for stars from the early Universe
Cody Hall
Falk Herwig (U of Victoria)
November 23, 2012
14:00 - 15:00
Stellar evolution at very low and zero metallicity features convective mixing of proton-rich material into convective 12C-rich He-burning regions. During such events nuclear and convective mixing time scales are similar and substantial nuclear energy release into the hydrodynamic flow implies a combustion regime that can…