The Sloan Digital Sky Survey-II Supernova Survey: Technical Summary

TL;DR

The SDSS-II Supernova Survey systematically discovers and measures light curves of intermediate-redshift supernovae, particularly Type Ia, over a large sky area, providing valuable data for cosmological studies.

Contribution

This paper presents the technical overview and initial results of the SDSS-II Supernova Survey, including its methodology and early supernova discoveries.

Findings

Discovered 327 spectroscopically confirmed SNe Ia

Measured light curves for 327 SNe Ia and identified additional probable cases

Collected host-galaxy spectra for 94 supernovae

Abstract

The Sloan Digital Sky Survey-II (SDSS-II) has embarked on a multi-year project to identify and measure light curves for intermediate-redshift (0.05 < z < 0.35) Type Ia supernovae (SNe Ia) using repeated five-band (ugriz) imaging over an area of 300 sq. deg. The survey region is a stripe 2.5 degrees wide centered on the celestial equator in the Southern Galactic Cap that has been imaged numerous times in earlier years, enabling construction of a deep reference image for discovery of new objects. Supernova imaging observations are being acquired between 1 September and 30 November of 2005-7. During the first two seasons, each region was imaged on average every five nights. Spectroscopic follow-up observations to determine supernova type and redshift are carried out on a large number of telescopes. In its first two three-month seasons, the survey has discovered and measured light curves for 327 spectroscopically confirmed SNe Ia, 30 probable SNe Ia, 14 confirmed SNe Ib/c, 32 confirmed SNe II, plus a large number of photometrically identified SNe Ia, 94 of which have host-galaxy spectra taken so far. This paper provides an overview of the project and briefly describes the observations completed during the first two seasons of operation.