The Acceleration of the Universe: Measurements of Cosmological Parameters from Type Ia Supernovae

Authors

A. Goobar, Stockholms universitet
S. Perlmutter, Lawrence Berkeley National Laboratory
G. Aldering, Lawrence Berkeley National Laboratory
G. Goldhaber, Lawrence Berkeley National Laboratory
R. A. Knop, Lawrence Berkeley National Laboratory
P. Nugent, Lawrence Berkeley National Laboratory
P. G. Castro, Lawrence Berkeley National Laboratory
S. Deustua, Lawrence Berkeley National Laboratory
S. Fabbro, Lawrence Berkeley National Laboratory
D. E. Groom, Lawrence Berkeley National Laboratory
I. M. Hook, Lawrence Berkeley National Laboratory
A. G. Kim, Lawrence Berkeley National Laboratory
M. Y. Kim, Lawrence Berkeley National Laboratory
J. C. Lee, Lawrence Berkeley National Laboratory
N. J. Nunes, Lawrence Berkeley National Laboratory
R. Pain, Lawrence Berkeley National Laboratory
C. R. Pennypacker, Lawrence Berkeley National Laboratory
R. Quimby, Lawrence Berkeley National Laboratory
C. Lidman, European Southern Observatory Santiago
R. S. Ellis, Institute of Astronomy
M. Irwin, Institute of Astronomy
R. G. McMahon, Institute of Astronomy
P. Ruiz-Lapuente, Universitat de Barcelona
N. Walton, Isaac Newton Group
B. Schaefer, Yale University
B. J. Boyle, Anglo Australian Observatory
A. V. Filippenko, University of California, Berkeley
T. Matheson, University of California, Berkeley
A. S. Fruchter, Space Telescope Science Institute
N. Panagia, Space Telescope Science Institute
H. J.M. Newberg, Fermi National Accelerator Laboratory
W. J. Couch, UNSW Sydney

Document Type

Article

Publication Date

1-1-2000

Abstract

The fate of the Universe, infinite expansion or a "big crunch", can be determined by measuring the redshifts and brightness of very distant supernovae. These provide a record of changes in the expansion rate of the Universe over the past several billion years. The mass density, ΩM, and cosmological-constant energy density, ΩΛ, are measured from a data-set consisting of 42 high-redshift Type Ia supernovae discovered by the Supernova Cosmology Project. The magnitude-redshift data for these supernovae, at redshifts between 0.18 and 0.83, are fit jointly with a set of supernovae from the Calán/Tololo Supernova Survey, at redshifts below 0.1, to yield values for the cosmological parameters. We find ΩflatM = 0.28+0.09-0.08 (1σ statistical)+0.05-0.04 (identified systematics). The data are strongly inconsistent with a Λ = 0 flat cosmology, the simplest inflationary universe model. An open, Λ = 0 cosmology also does not fit the data well: the data indicate that the cosmological constant is non-zero and positive, with a confidence of P(Λ > 0) = 99%, including the identified systematic uncertainties. Thus, the Universe is found to be accelerating, i.e., q0 = ΩM/2 - ΩΛ < 0. The best-fit age of the universe relative to the Hubble time is tflat0 = 14.9+1.4-1.1 (0.63/h) Gyr for a flat cosmology.

Publication Source (Journal or Book title)

Physica Scripta T

First Page

47

Last Page

58

Recommended Citation

Goobar, A., Perlmutter, S., Aldering, G., Goldhaber, G., Knop, R., Nugent, P., Castro, P., Deustua, S., Fabbro, S., Groom, D., Hook, I., Kim, A., Kim, M., Lee, J., Nunes, N., Pain, R., Pennypacker, C., Quimby, R., Lidman, C., Ellis, R., Irwin, M., McMahon, R., Ruiz-Lapuente, P., Walton, N., Schaefer, B., Boyle, B., Filippenko, A., Matheson, T., Fruchter, A., Panagia, N., Newberg, H., & Couch, W. (2000). The Acceleration of the Universe: Measurements of Cosmological Parameters from Type Ia Supernovae. Physica Scripta T, 85, 47-58. Retrieved from https://repository.lsu.edu/physics_astronomy_pubs/4773