The Dark Energy Survey supernova program: cosmological biases from supernova photometric classification
Abstract
Cosmological analyses of samples of photometrically identified type Ia supernovae (SNe Ia) depend on understanding the effects of ‘contamination’ from core-collapse and peculiar SN Ia events. We employ a rigorous analysis using the photometric classifier SuperNNova on state-of-the-art simulations of SN samples to determine cosmological biases due to such ‘non-Ia’ contamination in the Dark Energy Survey (DES) 5-yr SN sample. Depending on the non-Ia SN models used in the SuperNNova training and testing samples, contamination ranges from 0.8 to 3.5 per cent, with a classification efficiency of 97.7–99.5 per cent. Using the Bayesian Estimation Applied to Multiple Species (BEAMS) framework and its extension BBC (‘BEAMS with Bias Correction’), we produce a redshift-binned Hubble diagram marginalized over contamination and corrected for selection effects, and use it to constrain the dark energy equation-of-state, w. Assuming a flat universe with Gaussian ΩM prior of 0.311 ± 0.010, we show that biases on w are <0.008 when using SuperNNova, with systematic uncertainties associated with contamination around 10 per cent of the statistical uncertainty on w for the DES-SN sample. An alternative approach of discarding contaminants using outlier rejection techniques (e.g. Chauvenet’s criterion) in place of SuperNNova leads to biases on w that are larger but still modest (0.015–0.03). Finally, we measure biases due to contamination on w0 and wa (assuming a flat universe), and find these to be <0.009 in w0 and <0.108 in wa, 5 to 10 times smaller than the statistical uncertainties for the DES-SN sample.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Jun 03, 2022
- Source ID
- 10.1093/mnras/stac1404
Entities
People
- (des Collaboration)
- A Carnero Rosell
- A Carr
- A Palmese
- A Pieres
- A Roodman
- Anais Möller
- Andrés A. Plazas Malagón
- B A Bassett
- B E Tucker
- B Flaugher
- B. Popovic
- C To
- Chris Lidman
- Christopher Frohmaier
- D Carollo
- D L Hollowood
- D W Gerdes
- D. Bacon
- D. J. James
- D. L. Burke
- D. Scolnic
- Daniel Gruen
- Daniel I. Brooks
- Dillon Brout
- E Bertin
- E. Kovacs
- E. R. Sánchez
- Eric Suchyta
- F J Castander
- F Paz-chinchón
- G Tarlé
- G. Gutierrez
- G. Taylor
- Geraint F. Lewis
- H T Diehl
- I Sevilla-noarbe
- Ismael Ferrero
- J Annis
- J Asorey
- J De Vicente
- J Frieman
- J. L. Marshall
- Jorge Carretero Palacios
- Juan García-Bellido
- Juliane Weller
- K Glazebrook
- K Honscheid
- K Kuehn
- K Reil
- L Kelsey
- L N Da Costa
- Lluís Galbany
- M A G Maia
- M E S Pereira
- M Schubnell
- M. Sako
- M. Vincenzi
- Manuela Lima
- Mark Sullivan
- Mathew Smith
- Matteo Costanzi
- Michel Aguena
- Nikolay Kuropatkin
- O Lahav
- Or Graur
- P Doel
- P Fosalba
- P. Armstrong
- Philip Wiseman
- R C Nichol
- R D Wilkinson
- R L C Ogando
- R Miquel
- R. Kessler
- Robert W. Morgan
- S R Hinton
- S Serrano
- S. Allam
- S. Everett
- Shruti Desai
- T N Varga
- T. S. Li
- Tamara M. Davis
- U Malik
Organizations
- African Institute for Mathematical Sciences
- American Museum of Natural History
- Arctic Sciences
- Argonne National Laboratory
- Australian National University
- Autonomous University of Madrid
- Barcelona Institute for Science and Technology
- Carnegie Institution for Science
- Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas
- Clermont Auvergne University
- Duke University
- European Research Council
- Fermilab
- Harvard–Smithsonian Center for Astrophysics
- Indian Institute of Technology Hyderabad
- Institute for Fundamental Physics of the Universe
- Institute of Space Studies of Catalonia
- Lowell Observatory
- Ludwig-Maximilians-Universität München
- Max Planck Institute for Extraterrestrial Physics
- Ministry of Science of Spain
- Ministry of Science, Innovation and Universities
- National Aeronautics and Space Administration
- National Center for Supercomputing Applications
- National Council for Scientific and Technological Development
- National Institute for Astrophysics
- National Science Foundation
- Oak Ridge National Laboratory
- Ohio State University
- Princeton University
- SLAC National Accelerator Laboratory
- Santa Cruz Institute for Particle Physics
- Science and Technology Facilities Council
- Sorbonne Universités
- South African Astronomical Observatory
- Spanish National Research Council
- Stanford University
- Swinburne University of Technology
- Texas A&M University
- United States Department of Energy
- University College London
- University of California
- University of Cambridge
- University of Cape Town
- University of Chicago
- University of Hamburg
- University of Michigan
- University of Oslo
- University of Pennsylvania
- University of Portsmouth
- University of Queensland
- University of Southampton
- University of Sussex
- University of Sydney
- University of São Paulo
- University of Trieste
- University of Wisconsin–Madison