Article

SUPERNOVA CONSTRAINTS AND SYSTEMATIC UNCERTAINTIES FROM THE FIRST THREE YEARS OF THE SUPERNOVA LEGACY SURVEY

A. ConleyDepartment of Astronomy and Astrophysics, University of Toronto, 50 St. George Street, Toronto, ON M5S 3H4, CanadaJ. GuyLPNHE, Université Pierre et Marie Curie Paris 6, Université Paris Diderot Paris 7, CNRS-IN2P3, 4 place Jussieu, 75252 Paris Cedex 05, FranceM. SullivanDepartment of Astrophysics, University of Oxford, Keble Road, Oxford OX1 3RH, UKN. RegnaultLPNHE, Université Pierre et Marie Curie Paris 6, Université Paris Diderot Paris 7, CNRS-IN2P3, 4 place Jussieu, 75252 Paris Cedex 05, FranceP. AstierLPNHE, Université Pierre et Marie Curie Paris 6, Université Paris Diderot Paris 7, CNRS-IN2P3, 4 place Jussieu, 75252 Paris Cedex 05, FranceC. BallandUniversité Paris 1, Orsay, F-91405, FranceS. BasaLAM, CNRS, BP8, Pôle de l'Étoile Site de Château-Gombert, 38, rue Frédéric Joliot-Curie, 13388 Marseille Cedex 13, FranceR. G. CarlbergDepartment of Astronomy and Astrophysics, University of Toronto, 50 St. George Street, Toronto, ON M5S 3H4, CanadaD. FouchezCPPM, CNRS-IN2P3 and Université Aix-Marseille II, Case 907, 13288 Marseille Cedex 9, FranceD. HardinUniversité Paris CitéI. HookINAF-Osservatorio Astronomico di Roma, via Frascati 33, 00040 Monteporzio (RM), ItalyD. A. HowellDepartment of Physics, University of California, Santa Barbra, Broida Hall, Mail Code 9530, Santa Barbara, CA 93106-9530, USAR. PainLPNHE, Université Pierre et Marie Curie Paris 6, Université Paris Diderot Paris 7, CNRS-IN2P3, 4 place Jussieu, 75252 Paris Cedex 05, FranceN. Palanque‐DelabrouilleCEA, Centre de Saclay, Irfu/SPP, F-91191 Gif-sur-Yvette, FranceK. PerrettNetwork Information Operations, DRDC Ottawa, 3701 Carling Avenue, Ottawa, ON, K1A 0Z4, CanadaC. J. PritchetDepartment of Physics and Astronomy, University of Victoria, P.O. Box 3055 STN CSC, Victoria BC, V8T 1M8, CanadaJ. RichCEA, Centre de Saclay, Irfu/SPP, F-91191 Gif-sur-Yvette, FranceV. Ruhlmann-KleiderCEA, Centre de Saclay, Irfu/SPP, F-91191 Gif-sur-Yvette, FranceD. D. BalamDepartment of Physics and Astronomy, University of Victoria, P.O. Box 3055 STN CSC, Victoria BC, V8T 1M8, CanadaS. BaumontLPSC, CNRS-IN2P3, 53 rue des Martyrs, 38026 Grenoble Cedex, FranceRichard S. EllisDepartment of Astrophysics, University of Oxford, Keble Road, Oxford OX1 3RH, UKS. FabbroDepartment of Physics and Astronomy, University of Victoria, P.O. Box 3055 STN CSC, Victoria BC, V8T 1M8, CanadaH. K. FakhouriLBNL, 1 Cyclotron Road, Berkeley, CA 91125, USAN. FourmanoitLPNHE, Université Pierre et Marie Curie Paris 6, Université Paris Diderot Paris 7, CNRS-IN2P3, 4 place Jussieu, 75252 Paris Cedex 05, FranceS. González–GaitánDepartment of Astronomy and Astrophysics, University of Toronto, 50 St. George Street, Toronto, ON M5S 3H4, CanadaM. L. GrahamDepartment of Physics and Astronomy, University of Victoria, P.O. Box 3055 STN CSC, Victoria BC, V8T 1M8, CanadaMichael J. HudsonDepartment of Physics and Astronomy, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1, CanadaE. Y. HsiaoLBNL, 1 Cyclotron Road, Berkeley, CA 91125, USAT. KronborgLPNHE, Université Pierre et Marie Curie Paris 6, Université Paris Diderot Paris 7, CNRS-IN2P3, 4 place Jussieu, 75252 Paris Cedex 05, FranceC. LidmanAustralian Astronomical Observatory, P.O. Box 296, Epping, NSW 1710, AustraliaA. MourãoCENTRA-Centro M. de Astrofisica and Department of Physics, IST, Lisbon, PortugalJames D. NeillCalifornia Institute of Technology, 1200 E. California Blvd., Pasadena, CA 91125, USAS. PerlmutterDepartment of Physics, University of California, Berkeley, 366 LeConte Hall MC 7300, Berkeley, CA 94720-7300, USAP. RipocheLPNHE, Université Pierre et Marie Curie Paris 6, Université Paris Diderot Paris 7, CNRS-IN2P3, 4 place Jussieu, 75252 Paris Cedex 05, FranceN. SuzukiLBNL, 1 Cyclotron Road, Berkeley, CA 91125, USAE. S. WalkerDepartment of Astrophysics, University of Oxford, Keble Road, Oxford OX1 3RH, UK

2010en

ABI

Abstract

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.

Identifiers

DOI: 10.1088/0067-0049/192/1/1

Citations and references

Cited by 30 references

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