1. Measurements of Ω and Λ from 42 High-Redshift Supernovae
- Author
-
Perlmutter, S, Aldering, G, Goldhaber, G, Knop, RA, Nugent, P, Castro, PG, Deustua, S, Fabbro, S, Goobar, A, Groom, DE, Hook, IM, Kim, AG, Kim, MY, Lee, JC, Nunes, NJ, Pain, R, Pennypacker, CR, Quimby, R, Lidman, C, Ellis, RS, Irwin, M, McMahon, RG, Ruiz-Lapuente, P, Walton, N, Schaefer, B, Boyle, BJ, Filippenko, AV, Matheson, T, Fruchter, AS, Panagia, N, Newberg, HJM, Couch, WJ, and Project, The Supernova Cosmology
- Subjects
Particle and High Energy Physics ,Physical Sciences ,cosmology : observations ,distance scale ,supernovae : general ,astro-ph ,hep-ex ,hep-ph ,Astronomical and Space Sciences ,Atomic ,Molecular ,Nuclear ,Particle and Plasma Physics ,Physical Chemistry (incl. Structural) ,Astronomy & Astrophysics ,Astronomical sciences ,Particle and high energy physics ,Space sciences - Abstract
We report measurements of the mass density, Omega_M, andcosmological-constant energy density, Omega_Lambda, of the universe based onthe analysis of 42 Type Ia supernovae discovered by the Supernova CosmologyProject. The magnitude-redshift data for these SNe, at redshifts between 0.18and 0.83, are fit jointly with a set of SNe from the Calan/Tololo SupernovaSurvey, at redshifts below 0.1, to yield values for the cosmologicalparameters. All SN peak magnitudes are standardized using a SN Ia lightcurvewidth-luminosity relation. The measurement yields a joint probabilitydistribution of the cosmological parameters that is approximated by therelation 0.8 Omega_M - 0.6 Omega_Lambda ~= -0.2 +/- 0.1 in the region ofinterest (Omega_M 0) = 99%, including the identified systematic uncertainties. The best-fit ageof the universe relative to the Hubble time is t_0 = 14.9{+1.4,-1.1} (0.63/h)Gyr for a flat cosmology. The size of our sample allows us to perform a varietyof statistical tests to check for possible systematic errors and biases. Wefind no significant differences in either the host reddening distribution orMalmquist bias between the low-redshift Calan/Tololo sample and ourhigh-redshift sample. The conclusions are robust whether or not awidth-luminosity relation is used to standardize the SN peak magnitudes.
- Published
- 1999