Physics Department, Stockholm University, AlbaNova University Centre, 10691 Stockholm, Sweden
2 : UC Berkeley, Space Sciences Laboratory, 7 Gauss Way, Berkeley, CA, 94720-7450, USA e-mail: firstname.lastname@example.org
3 LPNHE, CNRS-IN2P3 and Universities of Paris 6 & 7, 75252 Paris, France
4 Univ. Paris-Sud, 91405 Orsay, France
5 Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge, CB3 0HA, UK
6 California Institute of Technology, Pasadena, CA 91125, USA
7 CENTRA-Centro M. de Astrofisica and Department of Physics, IST, Lisbon, Portugal
8 Astrophysics, Denys Wilkinson Building, Keble Road, OX1 3RH, Oxford, UK
9 Department of Astronomy, University of Barcelona, 08028 Barcelona, Spain
10 Isaac Newton Group of Telescopes, Apartado 321, 38700 Santa Cruz de La Palma, Spain
11 Laboratoire APC, University Paris 7, 10 rue Alice Domon et Léonie Duquet, 75205 Paris Cedex 13, France
12 LUTH, UMR 8102 CNRS, Observatore de Paris, Section de Meudon, 92195 Meudon Cedex, France
Accepted: 21 April 2008
Aims. We present multi-band light curves and distances for five type Ia supernovae at intermediate redshifts, .
Methods. Three telescopes on the Canary Island of La Palma, INT, NOT, and JKT, were used for discovery and follow-up of type Ia supernovae in the g' and r' filters. Supernova fluxes were measured by simultaneously fitting a supernova and host galaxy model to the data, and then calibrated using star catalogues from the Sloan Digital Sky Survey.
Results. The light curve shape and colour corrected peak luminosities are consistent with the expectations of a flat ΛCDM universe at the 1.5σ level. One supernova in the sample, SN1999dr, shows surprisingly large reddening, considering both that it is located at a significant distance from the core of its host (~4 times the fitted exponential radius) and that the galaxy can be spectroscopically classified as early-type with no signs of ongoing star formation.
Key words: cosmology: observations / cosmology: cosmological parameters / cosmology: distance scale / stars: supernovae: general
Based on joint observations made through the Isaac Newton Groups' Wide Field Camera Survey Programme with the Isaac Newton Telescope and the Jacobus Kapteyn Telescope operated on the island of La Palma by the Isaac Newton Group in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias. Part of the data presented here have also been taken using ALFOSC, which is owned by the Instituto de Astrofisica de Andalucia (IAA) and operated at the Nordic Optical Telescope under agreement between IAA and the NBIfAFG of the Astronomical Observatory of Copenhagen.
© ESO, 2008