Testing the lognormality of the galaxy and weak lensing convergence distributions from Dark Energy Survey maps

نویسندگان

  • L. Clerkin
  • D. Kirk
  • M. Manera
  • O. Lahav
  • F. Abdalla
  • A. Amara
  • D. Bacon
  • C. Chang
  • E. Gaztañaga
  • A. Hawken
  • B. Jain
  • B. Joachimi
  • V. Vikram
  • T. Abbott
  • S. Allam
  • R. Armstrong
  • A. Benoit-Lévy
  • G. M. Bernstein
  • R. A. Bernstein
  • E. Bertin
  • D. Brooks
  • D. L. Burke
  • A. Carnero Rosell
  • M. Carrasco Kind
  • M. Crocce
  • C. E. Cunha
  • C. B. D’Andrea
  • L. N. da Costa
  • S. Desai
  • H. T. Diehl
  • J. P. Dietrich
  • T. F. Eifler
  • A. E. Evrard
  • B. Flaugher
  • P. Fosalba
  • J. Frieman
  • D. W. Gerdes
  • D. Gruen
  • R. A. Gruendl
  • G. Gutierrez
  • K. Honscheid
  • D. J. James
  • S. Kent
  • K. Kuehn
  • N. Kuropatkin
  • M. Lima
  • P. Melchior
  • R. Miquel
  • B. Nord
  • A. A. Plazas
  • A. K. Romer
  • A. Roodman
  • E. Sanchez
  • M. Schubnell
  • I. Sevilla-Noarbe
  • R. C. Smith
  • M. Soares-Santos
  • F. Sobreira
  • E. Suchyta
  • M. E. C. Swanson
  • G. Tarle
  • A. R. Walker
چکیده

It is well known that the probability distribution function (PDF) of galaxy density contrast is approximately lognormal; whether the PDF of mass fluctuations derived from weak lensing convergence (κWL) is lognormal is less well established. We derive PDFs of the galaxy and projected matter density distributions via the Counts in Cells (CiC) method. We use maps of galaxies and weak lensing convergence produced from the Dark Energy Survey (DES) Science Verification data over 139 deg. We test whether the underlying density contrast is well described by a lognormal distribution for the galaxies, the convergence and their joint PDF. We confirm that the galaxy density contrast distribution is well modeled by a lognormal PDF convolved with Poisson noise at angular scales from 1040(corresponding to physical scales of 3–10 Mpc). We note that as κWL is a weighted sum of the mass fluctuations along the line of sight, its PDF is expected to be only approximately lognormal. We find that the κWL distribution is well modeled by a lognormal PDF convolved with Gaussian shape noise at scales between 10and 20, with a best-fit χ/DOF of 1.11 compared to 1.84 for a Gaussian model, corresponding to p-values 0.35 and 0.07 respectively, at a scale of 10. Above 20a simple Gaussian model is sufficient. The joint PDF is also reasonably fitted by a bivariate lognormal. As a consistency check we compare the variances derived from the lognormal modelling with those directly measured via CiC. Our methods are validated against maps from the MICE Grand Challenge N-body simulation.

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تاریخ انتشار 2016