Improved constraints on cosmological parameters from Type Ia supernova data
File(s)
Published version
Accepted version
Author(s)
March, MC
Trotta, R
Berkes, P
Starkman, GD
Vaudrevange, PM
Type
Journal Article
Abstract
We present a new method based on a Bayesian hierarchical model to extract constraints on cosmological parameters from Type Ia supernova (SNIa) data obtained with the SALT-II light-curve fitter. We demonstrate with simulated data sets that our method delivers tighter statistical constraints on the cosmological parameters over 90 per cent of the time, that it reduces statistical bias typically by a factor of ∼2–3 and that it has better coverage properties than the usual χ2 approach. As a further benefit, a full posterior probability distribution for the dispersion of the intrinsic magnitude of SNe is obtained. We apply this method to recent SNIa data, and by combining them with cosmic microwave background and baryonic acoustic oscillations data, we obtain Ωm= 0.28 ± 0.02, ΩΛ= 0.73 ± 0.01 (assuming w=−1) and Ωm= 0.28 ± 0.01, w=−0.90 ± 0.05 (assuming flatness; statistical uncertainties only). We constrain the intrinsic dispersion of the B-band magnitude of the SNIa population, obtaining σintμ= 0.13 ± 0.01 mag. Applications to systematic uncertainties will be discussed in a forthcoming paper.
Date Issued
2011-12-21
Date Acceptance
2011-08-04
Citation
Monthly Notices of the Royal Astronomical Society, 2011, 418 (4), pp.2308-2329
ISSN
1365-2966
Publisher
Oxford University Press (OUP)
Start Page
2308
End Page
2329
Journal / Book Title
Monthly Notices of the Royal Astronomical Society
Volume
418
Issue
4
Copyright Statement
© 2011 The Authors © 2011 RAS
Subjects
Science & Technology
Physical Sciences
Astronomy & Astrophysics
ASTRONOMY & ASTROPHYSICS
methods: statistical
supernovae: general
cosmological parameters
dark energy
HUBBLE-SPACE-TELESCOPE
LEGACY SURVEY
LIGHT CURVES
DARK ENERGY
BAYESIAN-INFERENCE
ASTRONOMICAL DATA
HIGH-REDSHIFT
DECLINE-RATE
OMEGA(LAMBDA)
OMEGA(M)
Publication Status
Published