Details

Autor(en) / Beteiligte

• Conley, A
• Guy, J
• Sullivan, M
• Regnault, N
• Astier, P
• Balland, C
• Basa, S
• Carlberg, R. G
• Fouchez, D
• Hardin, D
• Hook, I. M
• Howell, D. A
• Pain, R
• Palanque-Delabrouille, N
• Perrett, K. M
• Pritchet, C. J
• Rich, J
• Ruhlmann-Kleider, V
• Balam, D
• Baumont, S
• Ellis, R. S
• Fabbro, S
• Fakhouri, H. K
• Fourmanoit, N
• González-Gaitán, S
• Graham, M. L
• Hudson, M. J
• Hsiao, E
• Kronborg, T
• Lidman, C
• Mourao, A. M
• Neill, J. D
• Perlmutter, S
• Ripoche, P
• Suzuki, N
• Walker, E. S

Titel

Supernova Constraints and Systematic Uncertainties from the First Three Years of the Supernova Legacy Survey

Ist Teil von

• The Astrophysical journal. Supplement series, 2011-01, Vol.192 (1), p.1-jQuery1323920318051='48'

Ort / Verlag

United States: IOP Publishing

Erscheinungsjahr

2011

Quelle

EZB Electronic Journals Library

Beschreibungen/Notizen

• 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+0.16 --0.20(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 host-galaxy 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.