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Past Colloquia

Early Reionization Science from 21 cm Experiments and the Path Towards a New Cosmological Probe

Cody Hall

Jonathan Pober (Brown University)

June 10, 2016
14:00 - 15:00

Abstract: 21 cm cosmology — the concept of using radio telescopes to observe the highly redshifted 21 cm line of neutral hydrogen on cosmological scales — is a field on the verge of a breakthrough.   The technique is faced with the significant challenge of recovering…

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The Impact of Stellar Feedback on Molecular Clouds

Cody Hall

Stella Offner (University of Massachusetts)

June 03, 2016
14:00 - 15:00

Low-mass stars influence their surroundings through a variety of feedback processes. However, because they are less energetic than high-mass stars, their contributions are often ignored. In this talk, I will discuss numerical simulations including protostellar outflows and winds from main sequence B-type stars. I will…

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The Cosmic Abundance of Molecular Gas – The CO Power Spectrum Survey

Cody Hall

Dan Marrone (Univeristy of Arizona)

May 27, 2016
14:00 - 15:00

The cool, molecular phase of the interstellar medium is the fuel that enables the formation of new stars. In the early universe, large gas reservoirs dominated the baryonic mass of galaxies and enabled a cosmic star formation density that peaked at 10 times the current…

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The Gravitational-Wave Universe seen with Pulsar Timing Arrays

Cody Hall

Chiara Mingarelli (CalTech)

May 20, 2016
14:00 - 15:00

Pulsar Timing Arrays (PTAs) are currently the only way to search for gravitational radiation in the nanohertz band. Sources of interest include gravitational wave (GW) backgrounds generated by supermassive black hole binaries (SMBHBs) and processes in the early universe such as relic GWs and cosmic…

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Quantitative Polarimetry: from Star Formation to Cosmological Studies

Cody Hall

Thiem Hoang, CITA

May 13, 2016
14:00 - 15:00

We are entering a golden age of multiwavelength polarimetry with numerous CMB experiments (e.g., SPIDER, BICEP/Keck, LiteBIRD) hunting for primordial gravitational waves through B-mode polarization, and a dozen of big instruments designed to elucidate the roles of magnetic fields in star formation (e.g., SOFIA, SMA,…

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Observations of Intra-Halo Matter at High Redshift, and Associated Instrumentation Research for Magellan and GMT

Cody Hall

Rob Simcoe (MIT)

May 06, 2016
14:00 - 15:00

I will describe recent results on the early metal enrichment of loosely-bound galactic halo gas, inferred from our group’s quasar absorption line observations at Magellan. These surveys utilize optical and infrared spectra of 100 sightlines with the FIRE infrared spectrograph, including 35 objects at z>5.7. …

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The Growth of the Most Massive Galaxies in the Highest Density Regions: Evidence for In-Situ Star Formation in SpARCS Brightest Cluster Galaxies

Cody Hall

Tracy Webb (McGill University)

April 29, 2016
14:00 - 15:00

The most massive galaxies in the local universe reside at the centres of galaxy clusters. Often called Brightest Cluster Galaxies (BCGs), they exhibit, as a class, highly uniform properties and are distinct from the general galaxy population. This suggests formation processes which are themselves distinct…

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How to identify a habitable planet? Thinking inside (and a bit outside) the box

Cody Hall

Lisa Kaltenegger (Cornell, Carl Sagan Institute)

April 22, 2016
14:00 - 15:00

Abstract: Among the thousand of exoplanets detected, several are within the so-called Habitable Zone and some of them are called “the most Earth-like”. But what is the data behind those claims? The talk will discuss several important topics in the search for other habitable worlds….

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Asteroseismology Reveals Strong Magnetic Fields in the Cores of Red Giant Stars

Cody Hall

Jim Fuller (Caltech)

April 15, 2016
14:00 - 15:00

Internal stellar magnetic fields are inaccessible to direct observations and little is known about their amplitude, geometry and evolution. I will discuss how strong magnetic fields in the cores of red giant stars can be identified with asteroseismology. The fields manifest themselves via depressed dipole…

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Dreams of Streams: Exploring the stellar outskirts of nearby galaxies

Cody Hall

Daniel Dale (University Wyoming)

April 08, 2016
14:00 - 15:00

I will review highlights from the Spitzer Extended Disk Galaxy Exploration Science (EDGES) survey, a Warm Mission program to obtain sensitive infrared imaging for 92 nearby galaxies.  Highlights will include the radial trends in their star formation histories as well as characterizations of their outermost…

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