Measuring the Equation of State of the Universe

ESSENCE, "Equation of State: SupErNovae trace Cosmic Expansion " aka "the w project"


    2007/01/19 - Preliminary SN Ia joint list as compiled in Davis07 from Astier06, Riess07, Wood-Vasey07, Jha06, Hamuy96, Perlmutter99, Riess98, Tonry03, Knop03 and others.

    2007/01/03 - First Results from the ESSENCE Survey


We propose to find and follow ~200 Type Ia supernovae with the Mosaic Imager on the Blanco 4-m telescope over a five-year period.This search is designed to find supernovae distributed evenly over the redshift range [0.15, 0.75]. The survey will obtain VRI photometry which we will supplement with zJ photometry and spectra using Keck, MMT, Magellan, Gemini, and the VLT. We aim to answer a simple, but very important, question: is the dark energy of the universe consistent with a cosmological constant (w=-1)? If not, this means the dark energy must be a more general energy field such as "quintessence." This survey should determine w to +-0.1 (1 sigma). We propose to use the other half of the 30 half-nights per year already assigned to the SuperMacho Team. We will exploit the same data reduction pipelines already developed for SuperMacho to find SNe and to measure their light curves. By merging the two projects, we can use the same software, hardware, and people for two important investigations of matter and energy in the universe.

SNe discovered in 2007

SNe discovered in 2006

SNe discovered in 2005

SNe discovered in 2004

SNe discovered in 2003

SNe discovered in 2002

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Last updated: February 16, 2005 by C. Aguilera plus others