Real-time Analysis and Selection Biases in the Supernova Legacy Survey

Abstract

The Supernova Legacy Survey (SNLS) has produced a high-quality, homogeneous sample of Type Ia supernovae (SNe Ia) out to redshifts greater than z=1. In its first four years of full operation (to June 2007), the SNLS discovered more than 3000 transient candidates, 373 of which have been confirmed spectroscopically as SNe Ia. Use of these SNe Ia in precision cosmology critically depends on an analysis of the observational biases incurred in the SNLS survey due to the incomplete sampling of the underlying SN Ia population. This paper describes our real-time supernova detection and analysis procedures, and uses detailed Monte Carlo simulations to examine the effects of Malmquist bias and spectroscopic sampling. Such sampling effects are found to become apparent at z~0.6, with a significant shift in the average magnitude of the spectroscopically confirmed SN Ia sample towards brighter values for z>0.75. We describe our approach to correct for these selection biases in our three-year SNLS cosmological analysis (SNLS3), and present a breakdown of the systematic uncertainties involved.

Accepted for publication in AJ

References in corpus (14)

• New Hubble Space Telescope Discoveries of Type Ia Supernovae at z > 1: Narrowing Constraints on the Early Behavior of Dark Energy
• Observational Constraints on the Nature of the Dark Energy: First Cosmological Results from the ESSENCE Supernova Survey
• Improved Distances to Type Ia Supernovae with Multicolor Light Curve Shapes: MLCS2k2
• Rates and properties of type Ia supernovae as a function of mass and star-formation in their host galaxies
• The type Ia supernova SNLS-03D3bb from a super-Chandrasekhar-mass white dwarf star
• SiFTO: An Empirical Method for Fitting SNe Ia Light Curves
• The Sloan Digital Sky Survey-II Supernova Survey: Search Algorithm and Follow-up Observations
• Towards a Cosmological Hubble Diagram for Type II-P Supernovae
• Supernova Shock Breakout from a Red Supergiant
• The Type Ia Supernova Rate at z ~0.5 from the Supernova Legacy Survey
• The Rise Time of Type Ia Supernovae from the Supernova Legacy Survey
• The Kuiper Belt Luminosity Function from m(R)=21 to 26
• SNLS Spectroscopy: Testing for Evolution in Type Ia Supernovae
• Clustering of supernova Ia host galaxies

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