TY - JOUR
T1 - Supernova constraints and systematic uncertainties from the first three years of the Supernova Legacy Survey
AU - Conley, A.
AU - Guy, J.
AU - Sullivan, M.
AU - Regnault, N.
AU - Astier, P.
AU - Balland, C.
AU - Basa, S.
AU - Carlberg, R. G.
AU - Fouchez, D.
AU - Hardin, D.
AU - Hook, I. M.
AU - Howell, D. A.
AU - Pain, R.
AU - Palanque-Delabrouille, N.
AU - Perrett, K. M.
AU - Pritchet, C. J.
AU - Rich, J.
AU - Ruhlmann-Kleider, V.
AU - Balam, D.
AU - Baumont, S.
AU - Ellis, R. S.
AU - Fabbro, S.
AU - Fakhouri, H. K.
AU - Fourmanoit, N.
AU - González-Gaitán, S.
AU - Graham, M. L.
AU - Hudson, M. J.
AU - Hsiao, E.
AU - Kronborg, T.
AU - Lidman, C.
AU - Mourao, A. M.
AU - Neill, J. D.
AU - Perlmutter, S.
AU - Ripoche, P.
AU - Suzuki, N.
AU - Walker, E. S.
PY - 2011/1
Y1 - 2011/1
N2 - We combine high-redshift Type Ia supernovae from the first three years of the Supernova Legacy Survey (SNLS) with other supernova (SN) samples, primarily at lower redshifts, to form a high-quality joint sample of 472 SNe (123 low-z, 93 SDSS, 242 SNLS, and 14 Hubble Space Telescope). SN data alone require cosmic acceleration at >99.999% confidence, including systematic effects. For the dark energy equation of state parameter (assumed constant out to at least z = 1.4) in a flat universe, we find w = -0.91-0.20+0.16 (stat)+0.07-0.14 (sys) from SNe only, consistent with a cosmological constant. Our fits include a correction for the recently discovered relationship between hostgalaxy mass and SN absolute brightness. We pay particular attention to systematic uncertainties, characterizing them using a systematic covariance matrix that incorporates the redshift dependence of these effects, as well as the shape-luminosity and color-luminosity relationships. Unlike previous work, we include the effects of systematic terms on the empirical light-curve models. The total systematic uncertainty is dominated by calibration terms. We describe how the systematic uncertainties can be reduced with soon to be available improved nearby and intermediate-redshift samples, particularly those calibrated onto USNO/SDSS-like systems.
AB - We combine high-redshift Type Ia supernovae from the first three years of the Supernova Legacy Survey (SNLS) with other supernova (SN) samples, primarily at lower redshifts, to form a high-quality joint sample of 472 SNe (123 low-z, 93 SDSS, 242 SNLS, and 14 Hubble Space Telescope). SN data alone require cosmic acceleration at >99.999% confidence, including systematic effects. For the dark energy equation of state parameter (assumed constant out to at least z = 1.4) in a flat universe, we find w = -0.91-0.20+0.16 (stat)+0.07-0.14 (sys) from SNe only, consistent with a cosmological constant. Our fits include a correction for the recently discovered relationship between hostgalaxy mass and SN absolute brightness. We pay particular attention to systematic uncertainties, characterizing them using a systematic covariance matrix that incorporates the redshift dependence of these effects, as well as the shape-luminosity and color-luminosity relationships. Unlike previous work, we include the effects of systematic terms on the empirical light-curve models. The total systematic uncertainty is dominated by calibration terms. We describe how the systematic uncertainties can be reduced with soon to be available improved nearby and intermediate-redshift samples, particularly those calibrated onto USNO/SDSS-like systems.
KW - Cosmological parameters
KW - Cosmology: observations
KW - Supernovae: general
UR - http://www.scopus.com/inward/record.url?scp=78650988595&partnerID=8YFLogxK
U2 - 10.1088/0067-0049/192/1/1
DO - 10.1088/0067-0049/192/1/1
M3 - Review article
AN - SCOPUS:78650988595
SN - 0067-0049
VL - 192
JO - Astrophysical Journal, Supplement Series
JF - Astrophysical Journal, Supplement Series
IS - 1
ER -