2009/05/31 by David Wittman, D. Wittman · 5 citations
Mathematics · Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysics #Cosmology #Dark energy #Estimator #Galaxies: Formation, Evolution, Phenomena #Galaxy #Mathematics #Photometric redshift #Physics #Redshift #Redshift survey #Statistics #Stellar, planetary, and galactic studies #Weak gravitational lensing #astro-ph.CO
paper · pdf · doi:10.1088/0004-637x/700/2/l174
published as Astrophys.J.700:L174-L177,2009 · v2 accepted to ApJ Letters; includes minor clarifications and simulates an additional example filter set
arxiv created 2009/07/09 · openalex publication_date 2009/07/17 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We use simulations to demonstrate that photometric redshift "errors" can be greatly reduced by using the photometric redshift probability distribution p ( z ) rather than a one-point estimate such as the most likely redshift. In principle, this involves tracking a large array of numbers rather than a single number for each galaxy. We introduce a very simple estimator that requires tracking only a single number for each galaxy, while retaining the systematic-error-reducing properties of using the full p ( z ) and requiring only very minor modifications to existing photometric redshift codes. We find that using this redshift estimator (or using the full p ( z )) can substantially reduce systematics in dark energy parameter estimation from weak lensing, at no cost to the survey.