5/11/09
Dear 162 students,
the following talk may be interesting to you. It's on the second floor of the SERF building in Room 280 on Wednesday at 4p
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4:00-5:00PM WEDNESDAY, 13 MAY 2009 280 SERF
ASTROPHYSICS SEMINAR
GREG ALDERING/LBNL
“Supernovae as Probes of Dark Energy”
ABSTRACT: The use of Type Ia supernovae as distance indicators led to the discovery of the accelerating expansion of the Universe more than a decade ago. Large 2nd generation surveys have significantly increased the size and quality of the high-redshift sample. The critical low-redshift reference sample useful for cosmology remains small however. The Nearby Supernova Factory (SNfactory) is using new nearby Type Ia supernovae to strengthen the measurement of the dark energy equation of state, with an emphasis on controlling systematic uncertainties and better understanding the underlying physics associated with Type Ia supernovae as distance indicators. To meet these goals the SNfactory has developed two new approaches to the problem -- an ultra-wide-field CCD survey at Palomar Observatory and replacement of filter-based supernova lightcurves with full spectral time series. In this talk I will discuss recent progress in measuring the dark energy equation of state with both high- and low-redshift supernovae, focusing on recent results from the Nearby Supernova Factory.