Colloquia Schedule Fall 2015

No Colloquium scheduled.

"Convection in Cool Stars, as Revealed through Stellar Brightness Variations"

abstract

Fabienne Bastien

Pennsylvania State University

host: Adam Kraus or Bill Cochran

"Compact Objects in Globular Clusters"

abstract

Thomas Maccarone

Texas Tech

host: Karl Gebhardt

"Convection in Low-Mass Stellar Evolution, or 'What about magnetic fields?' "

abstract

Gregory Feiden

University of Uppsala, Sweden

host: Andrew Mann

"Tracing the Cosmic Shutdown of Star Formation in Massive Galaxies"

Over the last couple of decades, observational studies have progressed from the anthropology of nearby galaxies to a direct study of the early Universe, uncovering billions of years of cosmic growth and challenging galaxy formation models. The wealth of data from deep extragalactic surveys have revealed a picture where galaxies follow a relatively tight relation between star formation rate and stellar mass. This observed star formation sequence encapsulates information about feedback in galaxy formation and the evolution of gas density and gas accretion rates over cosmic time. All the while, there exists a growing population of massive "red and dead" (quiescent) galaxies that are no longer actively forming stars, falling far below the observed star formation sequence. The physical mechanisms responsible for quenching star formation and the buildup of the quiescent population remain poorly understood. Moreover, we do not have a cohesive evolutionary theory that ties together the observed structures and stellar populations of star-forming and quiescent galaxies. With a state-of-the-art compilation of space and ground-based imaging and spectroscopy, I will present a self-consistent empirical study of the sizes, stellar populations, and star formation rates of a complete sample of galaxies spanning the last eleven billion years. This novel data set combines deep, high-resolution rest-frame optical imaging with accurate distance measurements of both quiescent and star forming galaxies, making possible the first detailed studies of the early development stages of massive galaxies. These observations enable us to understand the physical mechanisms driving the growth of massive galaxies over 85% of the history of the universe, while also reconciling existing tensions with theoretical galaxy formation models.

close

Katherine Whitaker

Hubble Fellow, UMass Amherst

host: Steve Finkelstein

"The Assembly of Disk Galaxies"

abstract

Susan Kassin

Space Telescope Science Institute

host: Rachael Livermore

"Are we Correctly Measuring Star Formation Rates?"

abstract

Kristen McQuinn

University of Texas at Austin

host: Adam Kraus

No Colloquium Scheduled, to avoid conflict with:
Bashfest 2015: Frank N. Bash Symposium 2015, October 18-20, 2015

Speaker: Dr. Frank N. Bash and invited speakers

"New Horizons in Astronomy"

Tinsley Scholar: Interstellar Group (visiting: Oct 25-31)

"The Impact of Stellar Feedback on Molecular Clouds"

abstract

Stella Offner

Affiliation: University of Massachusetts, Amherst

host: Neal Evans

Tinsley Scholar: Theory Group (visiting: late Oct - early Nov)

"Disk Dynamos: Understanding the Origin of Galacic Magnetic Fields"

abstract

Ethan Vishniac

Johns Hopkins University

host: TBD

"From TripleSpec to NEWS: Exoplanet Discovery Science with Bread and Butter Infrared Spectroscopy"

abstract

Philip S. Muirhead

Boston University

host: Adam Kraus

"New Insights on Galaxy Formation from Comparisons of Simulated and Observed Galaxies"

abstract

Joel R. Primack

UC Santa Cruz

host: Paul Shapiro

No colloquium scheduled.

DeVaucouleurs Medalist

"Expansion of the Universe Seen by Hubble"

abstract

Adam Riess

Johns-Hopkins University, and Space Telescope Science Institute, and DeVaucouleurs Medalist

host: Shardha Jogee, Chair

"Supernovae and their Progenitor Systems (or lack thereof)"

abstract

Ori Fox

Space Telescope Science Institute

host: Jeff Silverman