The Sloan Digital Sky Survey-II: Photometry and Supernova Ia Light Curves from the 2005 data

TL;DR

This paper presents a new photometric technique called scene modelling for accurately measuring supernova brightnesses from SDSS-II data, enabling precise light curves for 146 Type Ia supernovae.

Contribution

Introduction of scene modelling, a novel photometric method that extracts supernova brightness without resampling or convolution, improving accuracy and uncertainty estimates.

Findings

Accurate light curves for 146 SNe Ia from SDSS-II data.

Demonstration of scene modelling's effectiveness through various tests.

Calibrated magnitudes and fluxes for all spectroscopic SNe Ia from 2005.

Abstract

We present ugriz light curves for 146 spectroscopically confirmed or spectroscopically probable Type Ia supernovae from the 2005 season of the SDSS-II Supernova survey. The light curves have been constructed using a photometric technique that we call scene modelling, which is described in detail here; the major feature is that supernova brightnesses are extracted from a stack of images without spatial resampling or convolution of the image data. This procedure produces accurate photometry along with accurate estimates of the statistical uncertainty, and can be used to derive photometry taken with multiple telescopes. We discuss various tests of this technique that demonstrate its capabilities. We also describe the methodology used for the calibration of the photometry, and present calibrated magnitudes and fluxes for all of the spectroscopic SNe Ia from the 2005 season.