Anomalous extinction behaviour towards the Type Ia SN 2003cg
Abstract
We present optical and near-infrared photometry and spectroscopy of the Type Ia SN 2003cg, which exploded in the nearby galaxy NGC 3169. The observations cover a period between -8.5 and +414 days post-maximum. SN 2003cg is a normal but highly-reddened Type Ia event. Its B magnitude at maximum B_max = 15.94+/-0.04 and Delta m_15(B)_obs = 1.12+/-0.04 (Delta m_15(B)_intrinsic = 1.25+/-0.05). Allowing R_v to become a free parameter within the Cardelli et al. (1989) extinction law, simultaneous matches to a range of colour curves of normal SNe Ia yielded E(B-V) = 1.33+/-0.11, and R_v = 1.80+/-0.19. While the value obtained for R_v is small, such values have been invoked in the past, and may imply a grain size which is small compared with the average value for the local ISM.
Cite
@article{arxiv.astro-ph/0603316,
title = {Anomalous extinction behaviour towards the Type Ia SN 2003cg},
author = {N. Elias-Rosa and S. Benetti and E. Cappellaro and M. Turatto and P. A. Mazzali and F. Patat and W. P. S. Meikle and M. Stehle and A. Pastorello and G. Pignata and R. Kotak and A. Harutyunyan and G. Altavilla and H. Navasardyan and Y. Qiu and M. E. Salvo and W. Hillebrandt},
journal= {arXiv preprint arXiv:astro-ph/0603316},
year = {2009}
}
Comments
28 pages, 21 figures. Accepted for publication in MNRAS. Minor changes following the referee suggestions