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Title: The effect of weak lensing on distance estimates from supernovae

Using a sample of 608 Type Ia supernovae from the SDSS-II and BOSS surveys, combined with a sample of foreground galaxies from SDSS-II, we estimate the weak lensing convergence for each supernova line of sight. We find that the correlation between this measurement and the Hubble residuals is consistent with the prediction from lensing (at a significance of 1.7σ). Strong correlations are also found between the residuals and supernova nuisance parameters after a linear correction is applied. When these other correlations are taken into account, the lensing signal is detected at 1.4σ. We show, for the first time, that distance estimates from supernovae can be improved when lensing is incorporated, by including a new parameter in the SALT2 methodology for determining distance moduli. The recovered value of the new parameter is consistent with the lensing prediction. Using cosmic microwave background data from WMAP7, H {sub 0} data from Hubble Space Telescope and Sloan Digital Sky Survey (SDSS) Baryon acoustic oscillations measurements, we find the best-fit value of the new lensing parameter and show that the central values and uncertainties on Ω {sub m} and w are unaffected. The lensing of supernovae, while only seen at marginal significance in this low-redshiftmore » sample, will be of vital importance for the next generation of surveys, such as DES and LSST, which will be systematics-dominated.« less
Authors:
;  [1] ; ; ; ;  [2] ;  [3] ;  [4] ;  [5] ; ;  [6] ;  [7] ;  [8] ;  [9] ;  [10] ;  [11] ;  [12]
  1. Department of Physics, University of the Western Cape, Cape Town 7535 (South Africa)
  2. Institute of Cosmology and Gravitation, University of Portsmouth, Portsmouth, PO1 3FX (United Kingdom)
  3. Astrophysics, Cosmology and Gravity Centre (ACGC), Department of Mathematics and Applied Mathematics, University of Cape Town, Rondebosch 7701 (South Africa)
  4. South African Astronomical Observatory, P.O. Box 9, Observatory 7935 (South Africa)
  5. Wayne State University, Department of Physics and Astronomy, Detroit, MI 48202 (United States)
  6. Center for Particle Astrophysics, Fermi National Accelerator Laboratory, P.O. Box 500, Batavia, IL 60510 (United States)
  7. CENTRA Centro Multidisciplinar de Astrofísica, Instituto Superior Técnico, Av. Rovisco Pais 1, 1049-001 Lisbon (Portugal)
  8. Department of Physics, University of Notre Dame, Notre Dame, IN 46556 (United States)
  9. Department of Physics and Astronomy, University of Utah, Salt Lake City, UT 84112 (United States)
  10. Department of Astronomy and Astrophysics, The Pennsylvania State University, University Park, PA 16802 (United States)
  11. Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, La Canada Flintridge, CA 91109 (United States)
  12. The Oskar Klein Centre, Department of Astronomy, AlbaNova, SE-106 91 Stockholm (Sweden)
Publication Date:
OSTI Identifier:
22348359
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 780; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; BARYONS; CONVERGENCE; CORRECTIONS; CORRELATIONS; COSMOLOGY; DISTANCE; FORECASTING; GALAXIES; GRAVITATIONAL LENSES; OSCILLATIONS; RED SHIFT; RELICT RADIATION; SPACE; SUPERNOVAE; TELESCOPES