Eighty-Four New Low Redshift SN Ia Lightcurves From the SDSS-II SN Survey

As standardizable candles, type Ia supernovae are an important probe of the expansion history of the universe. The utility of these objects depends on the quality and breadth of the data set used to calibrate them. In this work, we will present 84 u, g, r, i lightcurves, taken by the SDSS II Supernova survey during the 2005-2007 seasons. With redshifts between 0.013 and 0.15, these lightcurves will make up a significant part of the new low-z training set, and have the advantage of all being taken with a single, very well-calibrated, telescope. As one of the first large training sets to be observed in ugriz, we have explored SDSS filter alternatives to the Lira relation commonly used to make SN Ia host-galaxy extinction corrections. Preliminary results from this work will also be presented.

Funding for the SDSS and SDSS-II has been provided by the Alfred P. Sloan Foundation, the Participating Institutions, the National Science Foundation, the U.S. Department of Energy, the National Aeronautics and Space Administration, the Japanese Monbukagakusho, the Max Planck Society, and the Higher Education Funding Concil for England. The SDSS web site is http://www.sdss.org.