• DOI:10.1086/306308
• Corpus ID: 15762698

The High-Z Supernova Search: Measuring Cosmic Deceleration and Global Curvature of the Universe Using Type Ia Supernovae

@article{Schmidt1998TheHS,
  title={The High-Z Supernova Search: Measuring Cosmic Deceleration and Global Curvature of the Universe Using Type Ia Supernovae},
  author={Brian P. Schmidt and Nicholas B. Suntzeff and Mark M. Phillips and Robert A. Schommer and Alejandro Clocchiatti and Robert P. Kirshner and Peter M. Garnavich and Peter M. Challis and Bruno Leibundgut and Jason Spyromilio and Adam G. Riess and Alexei V. Filippenko and Mario Hamuy and R. C. Smith and Craig Hogan and Christopher W. Stubbs and Alan H. Diercks and David J. Reiss and Ronald L. Gilliland and John L. Tonry and Jose Manuel Campillos Maza and Alan Dressler and J. J. Walsh and Robin Ciardullo},
  journal={The Astrophysical Journal},
  year={1998},
  volume={507},
  pages={46 - 63}
}

• B. Schmidt, N. Suntzeff, +21 authors R. Ciardullo
• Published 15 May 1998
• Physics
• The Astrophysical Journal

The High-Z Supernova Search is an international collaboration to discover and monitor Type Ia supernovae (SNe Ia) at z > 0.2 with the aim of measuring cosmic deceleration and global curvature. Our collaboration has pursued a basic understanding of supernovae in the nearby universe, discovering and observing a large sample of objects and developing methods to measure accurate distances with SNe Ia. This paper describes the extension of this program to z ≥ 0.2, outlining our search techniques and follow-up program. We have devised high-throughput filters that provide accurate two-color rest frame B and V light curves of SNe Ia, enabling us to produce precise, extinction-corrected luminosity distances in the range 0.25 < z < 0.55. Sources of systematic error from K-corrections, extinction, selection effects, and evolution are investigated, and their effects estimated. We present photometric and spectral observations of SN 1995K, our program's first supernova (SN), and use the data to obtain a precise measurement of the luminosity distance to the z = 0.479 host galaxy. This object, when combined with a nearby sample of SNe, yields an estimate for the matter density of the universe of ΩM=-0.2−0.8+1.0 if ΩΛ = 0. For a spatially flat universe composed of normal matter and a cosmological constant, we find ΩM=0.4−0.4+0.5, Ω=0.6−0.5+0.4. We demonstrate that with a sample of ~30 objects, we should be able to determine relative luminosity distances over the range 0 < z < 0.5 with sufficient precision to measure ΩM with an uncertainty of ±0.2.