Low Redshift (z < 1) Supernova Studies

  • Wendy L. Freedman
Conference paper


The evidence for an accelerating universe, with its implication for the existence of a repulsive dark energy, is of profound significance for particle physics and cosmology. Yet the explanation for the dark energy remains a complete mystery. More precise observations are critical to characterize the nature of this acceleration. Type Ia supernovae offer a means of directly measuring luminosity distances and the change in the expansion rate with time. Moreover, potential effects due to evolution, chemical composition dependence, and changing dust properties (well-known astrophysical systematic issues), can be tested empirically. I describe briefly here several ongoing searches for supernovae at redshifts less than one: the LOTOSS, the Nearby Supernova Factory, ESSENCE, and Supernova Legacy Survey (SNLS) projects. I also provide an overview of the Carnegie Supernova Project (CSP), which differs from other projects to date in its goal of providing an I-band restframe Hubble diagram for type Ia supernovae (SNIa). The CSP is focused on testing for and reducing systematic uncertainties, obtaining a sample of multiwavelength observations of approximately 200 supernovae over the redshift range 0 < z < 0.6. The goal of these studies is to measure the evolution of the expansion rate, to characterize the acceleration of the Universe, and constrain the equation of state, w, to a precision and accuracy of 10%.


Dark Energy Light Curf Expansion Rate High Redshift Redshift Range 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


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Copyright information

© Springer-Verlag Berlin Heidelberg 2006

Authors and Affiliations

  • Wendy L. Freedman
    • 1
  1. 1.Carnegie ObservatoriesPasadenaUSA

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