@article{aa26313dd96c42f78b904a32b1595343,
title = "Photometric properties of intermediate-redshift type Ia supernovae observed by the Sloan Digital Sky Survey-II Supernova Survey",
abstract = "We have analysed multiband light curves of 328 intermediate-redshift (0.05 ≤ z < 0.24) Type Ia supernovae (SNe Ia) observed by the Sloan Digital Sky Survey-II Supernova Survey. The multiband light curves were parametrized by using the multiband stretch method, which can simply parametrize light-curve shapes and peak brightness without dust extinction models. We found that most of the SNe Ia that appeared in red host galaxies (u − r > 2.5) do not have a broad light-curve width and the SNe Ia that appeared in blue host galaxies (u − r < 2.0) have a variety of light-curve widths. The Kolmogorov-Smirnov test shows that the colour distribution of SNe Ia appearing in red/blue host galaxies is different (a significance level of 99.9 per cent). We also investigate the extinction law of host galaxy dust. As a result, we find that the value of Rv derived from SNe Ia with medium light-curve widths is consistent with the standard Galactic value, whereas the value of Rv derived from SNe Ia that appear in red host galaxies becomes significantly smaller. These results indicate that there may be two types of SNe Ia with different intrinsic colours, and that they are obscured by host galaxy dust with two different properties.",
author = "N. Takanashi and M. Doi and N. Yasuda and H. Kuncarayakti and K. Konishi and Schneider, {D. P.} and D. Cinabro and J. Marriner",
note = "Funding Information: Funding for the creation and distribution of the SDSS and SDSS-II has been provided by the Alfred P. Sloan Foundation, the Participating Institutions, the National Science Foundation, the US Department of Energy, the National Aeronautics and Space Administration, the Japanese Monbukagakusho, the Max Planck Society and the Higher Education Funding Council for England. The SDSS web site is http://www.sdss.org/. This work was also supported in part by a Japan Society for the Promotion of Science (JSPS) core-to-core programme, {\textquoteleft}International Research Network for Dark Energy{\textquoteright}, and by a JSPS research grant. We also acknowledge support by CONICYT through FONDECYT grant 3140563, and by Project IC120009 {\textquoteleft}Millennium Institute of Astrophysics (MAS){\textquoteright} of the Ini-ciativa Cient{\'i}fica Milenio del Ministerio de Econom{\'i}a, Fomento y Turismo de Chile. Funding Information: William Herschel Telescope is operated by the Isaac Newton Group on the island of La Palma in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias. The W. M. Keck Observatory is operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation.",
year = "2017",
month = feb,
day = "1",
doi = "10.1093/mnras/stw2730",
language = "English (US)",
volume = "465",
pages = "1274--1288",
journal = "Monthly Notices of the Royal Astronomical Society",
issn = "0035-8711",
publisher = "Oxford University Press",
number = "2",
}