High-redshift supernova discoveries on demand: First results from a new tool for cosmology and bounds on q0

We have developed a new tool for measurement of the cosmological parameters: a systematic search-and-study technique for high-redshift supernovae. In the first years of this Supernova Cosmology Project, we have discovered over 27 supernovae. Using a “batch” search strategy, almost all were discovered before maximum light and were observed over the peak of their light curves. The spectra and light curves indicate that almost all were Type Ia supernovae at redshifts z = 0.35 – 0.65. These high-redshift supernovae can provide a distance indicator and “standard clock” to study the cosmological parameters q 0 , Λ, Ω 0 , and H 0 . This presentation and the following presentation of Goldhaber et al . (1996), will discuss observation strategies and rates, analysis and calibration issues, the sources of measurement uncertainty, and the cosmological implications, including bounds on q 0 , of the first 7 high-redshift supernovae from our ongoing search. This is one of the most direct approaches to cosmological measurements, and could become a standard method in the field.