Colloquia Schedule Fall 2015

Colloquia are on Tuesdays (unless otherwise indicated) at 3:30 pm in RLM 15.216B


Sep. 1	No Colloquium scheduled.
Sep. 8	"Convection in Cool Stars, as Revealed through Stellar Brightness Variations" abstract Fabienne Bastien Pennsylvania State University host: Adam Kraus or Bill Cochran
Sep. 15	"Compact Objects in Globular Clusters" abstract Thomas Maccarone Texas Tech host: Karl Gebhardt
Sep. 22	"Convection in Low-Mass Stellar Evolution, or 'What about magnetic fields?' " abstract Gregory Feiden University of Uppsala, Sweden host: Andrew Mann
Sep. 29	"Tracing the Cosmic Shutdown of Star Formation in Massive Galaxies" abstract Katherine Whitaker Hubble Fellow, UMass Amherst host: Steve Finkelstein
Oct. 6	"The Assembly of Disk Galaxies" abstract Susan Kassin Space Telescope Science Institute host: Rachael Livermore
Oct. 13	*"Are we Correctly Measuring Star Formation Rates?"* abstract Kristen McQuinn University of Texas at Austin host: Adam Kraus
Oct. 20	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"
Oct. 27	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
Nov. 3	Tinsley Scholar: Theory Group (visiting: late Oct - early Nov) "Disk Dynamos: Understanding the Origin of Galacic Magnetic Fields" The emergence of large scale magnetic fields in galaxies is poorly understood, and frequently claimed as evidence for new fundamental physics. Standard mean field dynamo theory predicts exponential, but very slow, growth of such fields. Combining this with reasonable seed field mechanisms has given rise to the expectation that high redshift galaxies will be very weakly magnetized and that the first generation of star formation will take place in a largely unmagnetized interstellar medium. The latter prediction is convenient, but unverified, and the former is not consistent with observational evidence. I will discuss a fundamental revision of dynamo theory, supported by simple physical arguments and computer simulations, which predicts a faster-than-exponential growth of the disk magnetic field. A consequence of this model is that detecting a disk galaxy without a large scale magnetic field will be quite difficult, and that early star formation took place in a magnetized environment. close Ethan Vishniac Johns Hopkins University host: TBD
Nov. 10	"From TripleSpec to NEWS: Exoplanet Discovery Science with Bread and Butter Infrared Spectroscopy" abstract Philip S. Muirhead Boston University host: Adam Kraus
Nov. 17	"New Insights on Galaxy Formation from Comparisons of Simulated and Observed Galaxies" abstract Joel R. Primack UC Santa Cruz host: Paul Shapiro
Nov. 24	No colloquium scheduled.
Dec. 1	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
Dec. 8	"Supernovae and their Progenitor Systems (or lack thereof)" abstract Ori Fox Space Telescope Science Institute host: Jeff Silverman