The Supernova Legacy Survey: measurement of ΩM, and w from the first year data set

A&A 447, 31-48 (2006)
DOI: 10.1051/0004-6361:20054185

The Supernova Legacy Survey: measurement of $\Omega_{\mathsf{M}}$ , $\Omega_\mathsf{\Lambda}$ and w from the first year data set

P. Astier¹, J. Guy¹, N. Regnault¹, R. Pain¹, E. Aubourg^{2, 3}, D. Balam⁴, S. Basa⁵, R. G. Carlberg⁶, S. Fabbro⁷, D. Fouchez⁸, I. M. Hook⁹, D. A. Howell⁶, H. Lafoux³, J. D. Neill⁴, N. Palanque-Delabrouille³, K. Perrett⁶, C. J. Pritchet⁴, J. Rich³, M. Sullivan⁶, R. Taillet^{1, 10}, G. Aldering¹¹, P. Antilogus¹, V. Arsenijevic⁷, C. Balland^{1, 2}, S. Baumont^{1, 12}, J. Bronder⁹, H. Courtois¹³, R. S. Ellis¹⁴, M. Filiol⁵, A. C. Gonçalves¹⁵, A. Goobar¹⁶, D. Guide¹, D. Hardin¹, V. Lusset³, C. Lidman¹², R. McMahon¹⁷, M. Mouchet^{15, 2}, A. Mourao⁷, S. Perlmutter^{11, 18}, P. Ripoche⁸, C. Tao⁸ and N. Walton¹⁷

¹ LPNHE, CNRS-IN2P3 and Universités Paris VI & VII, 4 place Jussieu, 75252 Paris Cedex 05, France;
e-mail: astier@in2p3.fr
² APC, Collège de France, 11 place Marcellin Berthelot, 75005 Paris, France
³ DSM/DAPNIA, CEA/Saclay, 91191 Gif-sur-Yvette Cedex, France
⁴ Department of Physics and Astronomy, University of Victoria, PO Box 3055, Victoria, BC VSW 3P6, Canada
⁵ LAM, CNRS, BP8, Traverse du Siphon, 13376 Marseille Cedex 12, France
⁶ Department of Astronomy and Astrophysics, University of Toronto, 60 St. George Street, Toronto, ON M5S 3H8, Canada
⁷ CENTRA-Centro M. de Astrofisica and Department of Physics, IST, Lisbon, Portugal
⁸ CPPM, CNRS-IN2P3 and Université Aix-Marseille II, Case 907, 13288 Marseille Cedex 9, France
⁹ University of Oxford Astrophysics, Denys Wilkinson Building, Keble Road, Oxford OX1 3RH, UK
¹⁰ Université de Savoie, 73000 Chambery, France
¹¹ LBNL, 1 Cyclotron Rd, Berkeley, CA 94720, USA
¹² ESO, Alonso de Cordova 3107, Vitacura, Casilla 19001, Santiago 19, Chile
¹³ CRAL, 9 avenue Charles André, 69561 Saint-Genis-Laval cedex, France
¹⁴ California Institute of Technology, Pasadena, California, USA
¹⁵ LUTH, UMR 8102, CNRS and Observatoire de Paris, 92195 Meudon, France
¹⁶ Department of Physics, Stockholm University, Sweden
¹⁷ IoA, University of Cambridge, Madingley Road, Cambridge CB3 0EZ, UK
¹⁸ Department of Physics, University of California Berkeley, Berkeley, CA 94720, USA

(Received 9 September 2005 / Accepted 11 October 2005 )

Abstract
We present distance measurements to 71 high redshift type Ia supernovae discovered during the first year of the 5-year Supernova Legacy Survey (SNLS). These events were detected and their multi-color light-curves measured using the MegaPrime/MegaCam instrument at the Canada-France-Hawaii Telescope (CFHT), by repeatedly imaging four one-square degree fields in four bands, as part of the CFHT Legacy Survey (CFHTLS). Follow-up spectroscopy was performed at the VLT, Gemini and Keck telescopes to confirm the nature of the supernovae and to measure their redshift. With this data set, we have built a Hubble diagram extending to z=1, with all distance measurements involving at least two bands. Systematic uncertainties are evaluated making use of the multi-band photometry obtained at CFHT. Cosmological fits to this first year SNLS Hubble diagram give the following results: $\Omega_{\rm M}= 0.263 \pm 0.042\;(stat) \pm 0.032\;(sys)$ for a flat $\Lambda$ CDM model; and $w = -1.023 \pm 0.090\;(stat) \pm 0.054\;(sys)$ for a flat cosmology with constant equation of state w when combined with the constraint from the recent Sloan Digital Sky Survey measurement of baryon acoustic oscillations.

Key words: supernovae: general -- cosmology: observations -- cosmological parameters

SIMBAD Objects

The Supernova Legacy Survey: measurement of , and w from the first year data set

The Supernova Legacy Survey: measurement of $\Omega_{\mathsf{M}}$ , $\Omega_\mathsf{\Lambda}$ and w from the first year data set