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Title: Characterizing unknown systematics in large scale structure surveys

Photometric large scale structure (LSS) surveys probe the largest volumes in the Universe, but are inevitably limited by systematic uncertainties. Imperfect photometric calibration leads to biases in our measurements of the density fields of LSS tracers such as galaxies and quasars, and as a result in cosmological parameter estimation. Earlier studies have proposed using cross-correlations between different redshift slices or cross-correlations between different surveys to reduce the effects of such systematics. In this paper we develop a method to characterize unknown systematics. We demonstrate that while we do not have sufficient information to correct for unknown systematics in the data, we can obtain an estimate of their magnitude. We define a parameter to estimate contamination from unknown systematics using cross-correlations between different redshift slices and propose discarding bins in the angular power spectrum that lie outside a certain contamination tolerance level. We show that this method improves estimates of the bias using simulated data and further apply it to photometric luminous red galaxies in the Sloan Digital Sky Survey as a case study.
Authors:
;  [1] ;  [2] ;  [3] ;  [4] ;  [5] ;  [6] ;  [7] ;  [8] ; ;  [9] ;  [10] ;  [11] ;  [12] ;  [13] ;  [14]
  1. McWilliams Center for Cosmology, Department of Physics, Carnegie Mellon University, Pittsburgh, PA 15213 (United States)
  2. Department of Physics and Astronomy, University of Wyoming, Laramie, WY 82071 (United States)
  3. Berkeley Center for Cosmological Physics, LBL and Department of Physics, University of California, Berkeley, CA 94720 (United States)
  4. Institute of Cosmology and Gravitation, University of Portsmouth, Portsmouth, PO1 3FX (United Kingdom)
  5. Princeton University Observatory, Peyton Hall, Princeton, NJ 08544 (United States)
  6. Apache Point Observatory, P.O. Box 59, Sunspot, NM 88349 (United States)
  7. Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138 (United States)
  8. Department of Astronomy, Ohio State University, Columbus, OH 43210 (United States)
  9. CEA, Centre de Saclay, Irfu/SPP, F-91191 Gif-sur-Yvette (France)
  10. Departamento de Astronomía, Universidad de Chile, Casilla 36-D, Santiago (Chile)
  11. Université Paris 6 et CNRS, Institut d'Astrophysique de Paris, 98bis blvd. Arago, 75014 Paris (France)
  12. Department of Astronomy and Astrophysics, Pennsylvania State University, University Park, PA 16802 (United States)
  13. Instituto de Astrofisica de Canarias (IAC), E-38200 La Laguna, Tenerife (Spain)
  14. Center for Cosmology and Particle Physics, New York University, New York, NY 10003 (United States)
Publication Date:
OSTI Identifier:
22373669
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Cosmology and Astroparticle Physics; Journal Volume: 2014; Journal Issue: 04; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; CALIBRATION; CONTAMINATION; CORRELATIONS; DENSITY; GALAXIES; INFORMATION; QUASARS; RED SHIFT; SIMULATION; SKY; UNIVERSE