SN 2003du: 480 days in the life of a normal type Ia supernova^*

¹ Physics Department, Stockholm University, AlbaNova University Center, 106 91 Stockholm, Sweden e-mail: vall@physto.se
² INAF, Osservatorio Astronomico di Padova, vicolo dell'Osservatorio 5, 35122 Padova, Italy
³ European Southern Observatory, Karl-Schwarzschild-Strasse 2, 85748 Garching, Germany
⁴ Astrophysics Research Centre, School of Mathematics and Physics, Queen's University, Belfast BT7 1NN, UK
⁵ Departamento de Astronomía y Astrofísica, Pontificia Universidad Católica de Chile, Campus San Joaquín, Vicuña Mackenna 4860, Casilla 306, Santiago 22, Chile
⁶ INAF Osservatorio Astronomico di Trieste, via Tiepolo 11, 34131 Trieste, Italy
⁷ Max-Planck-Institut für Astrophysik, PO Box 1317, 85741 Garching, Germany
⁸ National Astronomical Observatories, Chinese Academy of Sciences, 100012 Beijing, PR China
⁹ Universidad de La Laguna, Av. Astrofísico Fransisco Sánchez s/n, 38206 La Laguna, Tenerife, Spain
¹⁰ Department of Astronomy, University of Barcelona, Marti i Franques 1, 08028 Barcelona, Spain
¹¹ Isaac Newton Group of Telescopes, Apartado de correos 321, 38700 Santa Cruz de La Palma, Canary Islands, Spain
¹² Astrophysics Group, Blackett Laboratory, Imperial College London, Prince Consort Road, London SW7 2AZ, UK
¹³ Department of Physics and Astronomy, University of Aarhus, 8000 Aarhus C, Denmark
¹⁴ Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, 2100 Copenhagen Ø, Denmark
¹⁵ Tavrida State University, Simferopol, Ukraine
¹⁶ Department of Astronomy, Stockholm University, AlbaNova University Center, 106 91 Stockholm, Sweden
¹⁷ Crimean Astrophysical Observatory, Ukraine
¹⁸ Sternberg Astronomical Institute, Moscow State University, Universitetskii pr. 13, Moscow 119992, Russia

Received: 12 July 2006
Accepted: 5 April 2007

Abstract

Aims.We present a study of the optical and near-infrared (NIR) properties of the Type Ia Supernova (SN Ia) 2003du.

Methods. An extensive set of optical and NIR photometry and low-resolution long-slit spectra was obtained using a number of facilities. The observations started 13 days before B-band maximum light and continued for 480 days with exceptionally good time sampling. The optical photometry was calibrated through the S-correction technique.

Results. The light curves and the color indices of SN 2003du closely resemble those of normal SNe Ia. SN 2003du reached a B-band maximum of 13.49 ± 0.02 mag on JD2 452 766.38 ± 0.5. We derive a B-band stretch parameter of , which corresponds to , indicative of a SN Ia of standard luminosity. The reddening in the host galaxy was estimated by three methods, and was consistently found to be negligible. Using an updated calibration of the V and absolute magnitudes of SNe Ia, we find a distance modulus mag to the host galaxy, UGC 9391. We measure a peak bolometric luminosity of erg s^-1 and Arnett's rule implies that of was synthesized during the explosion. Modeling of the bolometric light curve also indicates in the range . The spectral evolution of SN 2003du at both optical and NIR wavelengths also closely resembles normal SNe Ia. In particular, the ratio at maximum () = and the time evolution of the blueshift velocities of the absorption line minima are typical. The pre-maximum spectra of SN 2003du showed conspicuous high-velocity features in the H&K doublet and infrared triplet, and possibly in λ6355, lines. We compare the time evolution of the profiles of these lines with other well-observed SNe Ia and we suggest that the peculiar pre-maximum evolution of λ6355 line in many SNe Ia is due to the presence of two blended absorption components.