# The Supernova Legacy Survey: Measurement of $\Omega_M$, $\Omega_\Lambda$ and w from the First Year Data Set

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. 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_M = 0.263 +/- 0.042(stat) +/- 0.032(sys) for a flat LambdaCDM model; and w = -1.023 +/- 0.090(stat) +/- 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.
keyword :
Document type :
Journal articles
Domain :

http://hal.in2p3.fr/in2p3-00025162
Contributor : Simone Lantz Connect in order to contact the contributor
Submitted on : Saturday, June 9, 2007 - 3:58:30 PM
Last modification on : Wednesday, November 17, 2021 - 12:30:14 PM

### Citation

P. Astier, J. Guy, N. Regnault, R. Pain, E. Aubourg, et al.. The Supernova Legacy Survey: Measurement of $\Omega_M$, $\Omega_\Lambda$ and w from the First Year Data Set. Astronomy and Astrophysics - A&A, EDP Sciences, 2006, 447, pp.31-48. ⟨10.1051/0004-6361:20054185⟩. ⟨in2p3-00025162⟩

Record views