January 9, 2006 (Monday) Bob McElrath, UC Davis
January 23, 2006 (Monday) Hans Krimm, Goddard Space Center
February 20, 2006 (Monday) Steve Hsu, University of Oregon
March 6-10, 2006 (Monday-Friday) UltraMini Workshop on Electroweak Symmetry Breaking
March 30, 2006 Mandeep Gill, Caltech
4:00 pm, 472 Willamette Hall
Refreshments served at 3:45
The Swift gamma-ray burst explorer was launched on Nov. 20, 2004 from Cape Canaveral, Florida. The first instrument onboard became fully operational less than a month later. Since that time the Burst Alert Telescope (BAT) on Swift has detected more than eighty gamma-ray bursts (GRBs), most of which have also been observed within two minutes by the Swift narrow-field instruments: the X-Ray Telescope (XRT) and the Ultra-Violet and Optical Telescope (UVOT). Swift trigger notices are distributed worldwide within seconds of the trigger through the Gamma-ray burst Coordinates Network (GCN) and a substantial fraction of GRBs have been followed up by ground and space-based telescopes, ranging in wavelength from radio to TeV. Results have included the first rapid localization of a short GRB and further validation of the theory that short and long bursts have different origins; detailed observations of the short-term power-law decay of burst afterglows leading to an improved understanding of the fireball model; and detection of the most distant GRB ever found. Swift is also a sensitive X-ray observatory with capabilities to monitor galactic and extragalactic transients on a daily basis, carry out the first all-sky hard X-ray survey since HEAO-1, and study in detail the spectra of X-ray transients. In this talk I will provide a broad overview of the Swift mission and its most significant results, both in GRB science and in the search for and study of hard X-ray sources.
Refreshments served at 3:45
Recent observations of Type Ia supernovae, cosmic microwave background radiation and large scale structure indicate that the expansion rate of the universe is increasing. A number of models describing exotic forms of matter, generically referred to as dark energy (not to be confused with dark matter), have been proposed to explain this acceleration. For example, the dark energy may be due to Einstein's cosmological constant. In this talk I will give an introduction to big bang cosmology and dark energy, with emphasis on the dark energy equation of state and how it determines the future (large time evolution) of the universe.
4:00 pm, 472 Willamette Hall
Refreshments served at 3:45
In recent years, weak lensing has turned into a powerful tool to give estimates of cosmological parameters as well as to measure galactic cluster density profiles. In this seminar we will present another handle on weak lensing, going beyond the standard first order lensing normally extracted from data to discuss the second order moment, which measures the "arciness" of galaxies. We will then give some preliminary indications of how much this will be able to help us refine cluster mass profiles.
2:30 pm, 472 Willamette Hall
Refreshments served at 2:15