DOE PAGES title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Consequences of CCD imperfections for cosmology determined by weak lensing surveys: from laboratory measurements to cosmological parameter bias

Abstract

Weak gravitational lensing causes subtle changes in the apparent shapes of galaxies due to the bending of light by the gravity of foreground masses. By measuring the shapes of large numbers of galaxies (millions in recent surveys, up to tens of billions in future surveys) we can infer the parameters that determine cosmology. Imperfections in the detectors used to record images of the sky can introduce changes in the apparent shape of galaxies, which in turn can bias the inferred cosmological parameters. Here in this paper we consider the effect of two widely discussed sensor imperfections: tree-rings, due to impurity gradients which cause transverse electric fields in the Charge-Coupled Devices (CCD), and pixel-size variation, due to periodic CCD fabrication errors. These imperfections can be observed when the detectors are subject to uniform illumination (flat field images). We develop methods to determine the spurious shear and convergence (due to the imperfections) from the flat-field images. We calculate how the spurious shear when added to the lensing shear will bias the determination of cosmological parameters. We apply our methods to candidate sensors of the Large Synoptic Survey Telescope (LSST) as a timely and important example, analyzing flat field images recorded with LSSTmore » prototype CCDs in the laboratory. In conclusion, we find that tree-rings and periodic pixel-size variation present in the LSST CCDs will introduce negligible bias to cosmological parameters determined from the lensing power spectrum, specifically w,Ωm and σ8.« less

Authors:
 [1];  [2];  [3];  [4];  [5]
  1. Nishina Center (RIKEN), Wako (Japan); Brookhaven National Lab. (BNL), Upton, NY (United States). RIKEN Research Center
  2. Columbia Univ., New York, NY (United States); Brookhaven National Lab. (BNL), Upton, NY (United States)
  3. Brookhaven National Lab. (BNL), Upton, NY (United States)
  4. Brookhaven National Lab. (BNL), Upton, NY (United States); California Inst. of Technology (CalTech), La Canada Flintridge, CA (United States). Jet Propulsion Lab.
  5. Nishina Center (RIKEN), Wako (Japan)
Publication Date:
Research Org.:
Brookhaven National Lab. (BNL), Upton, NY (United States)
Sponsoring Org.:
USDOE Office of Science (SC), High Energy Physics (HEP)
OSTI Identifier:
1260145
Alternate Identifier(s):
OSTI ID: 1295207
Report Number(s):
BNL-112138-2016-JA; BNL-112370-2016-JA
Journal ID: ISSN 1538-4357; KA2301020
Grant/Contract Number:  
SC0012704; AC02- 98CH10886; SC00112704
Resource Type:
Accepted Manuscript
Journal Name:
The Astrophysical Journal (Online)
Additional Journal Information:
Journal Name: The Astrophysical Journal (Online); Journal Volume: 825; Journal Issue: 1; Journal ID: ISSN 1538-4357
Publisher:
Institute of Physics (IOP)
Country of Publication:
United States
Language:
English
Subject:
79 ASTRONOMY AND ASTROPHYSICS; cosmological parameters; cosmology: miscellaneous; cosmology: observations; instrumentation:; instrumentation: detectors

Citation Formats

Okura, Yuki, Petri, Andrea, May, Morgan, Plazas, Andrés A., and Tamagawa, Toru. Consequences of CCD imperfections for cosmology determined by weak lensing surveys: from laboratory measurements to cosmological parameter bias. United States: N. p., 2016. Web. doi:10.3847/0004-637X/825/1/61.
Okura, Yuki, Petri, Andrea, May, Morgan, Plazas, Andrés A., & Tamagawa, Toru. Consequences of CCD imperfections for cosmology determined by weak lensing surveys: from laboratory measurements to cosmological parameter bias. United States. https://doi.org/10.3847/0004-637X/825/1/61
Okura, Yuki, Petri, Andrea, May, Morgan, Plazas, Andrés A., and Tamagawa, Toru. Mon . "Consequences of CCD imperfections for cosmology determined by weak lensing surveys: from laboratory measurements to cosmological parameter bias". United States. https://doi.org/10.3847/0004-637X/825/1/61. https://www.osti.gov/servlets/purl/1260145.
@article{osti_1260145,
title = {Consequences of CCD imperfections for cosmology determined by weak lensing surveys: from laboratory measurements to cosmological parameter bias},
author = {Okura, Yuki and Petri, Andrea and May, Morgan and Plazas, Andrés A. and Tamagawa, Toru},
abstractNote = {Weak gravitational lensing causes subtle changes in the apparent shapes of galaxies due to the bending of light by the gravity of foreground masses. By measuring the shapes of large numbers of galaxies (millions in recent surveys, up to tens of billions in future surveys) we can infer the parameters that determine cosmology. Imperfections in the detectors used to record images of the sky can introduce changes in the apparent shape of galaxies, which in turn can bias the inferred cosmological parameters. Here in this paper we consider the effect of two widely discussed sensor imperfections: tree-rings, due to impurity gradients which cause transverse electric fields in the Charge-Coupled Devices (CCD), and pixel-size variation, due to periodic CCD fabrication errors. These imperfections can be observed when the detectors are subject to uniform illumination (flat field images). We develop methods to determine the spurious shear and convergence (due to the imperfections) from the flat-field images. We calculate how the spurious shear when added to the lensing shear will bias the determination of cosmological parameters. We apply our methods to candidate sensors of the Large Synoptic Survey Telescope (LSST) as a timely and important example, analyzing flat field images recorded with LSST prototype CCDs in the laboratory. In conclusion, we find that tree-rings and periodic pixel-size variation present in the LSST CCDs will introduce negligible bias to cosmological parameters determined from the lensing power spectrum, specifically w,Ωm and σ8.},
doi = {10.3847/0004-637X/825/1/61},
journal = {The Astrophysical Journal (Online)},
number = 1,
volume = 825,
place = {United States},
year = {Mon Jun 27 00:00:00 EDT 2016},
month = {Mon Jun 27 00:00:00 EDT 2016}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record

Citation Metrics:
Cited by: 2 works
Citation information provided by
Web of Science

Save / Share:

Works referenced in this record:

Spurious shear in weak lensing with the Large Synoptic Survey Telescope
journal, November 2012

  • Chang, C.; Kahn, S. M.; Jernigan, J. G.
  • Monthly Notices of the Royal Astronomical Society, Vol. 428, Issue 3
  • DOI: 10.1093/mnras/sts223

Physics of fully depleted CCDs
journal, March 2014


Challenges for precision shape measurements
journal, March 2014


Mapping the dark matter with weak gravitational lensing
journal, February 1993

  • Kaiser, Nick; Squires, Gordon
  • The Astrophysical Journal, Vol. 404
  • DOI: 10.1086/172297

Dark-energy constraints and correlations with systematics from CFHTLS weak lensing, SNLS supernovae Ia and WMAP5
journal, March 2009


Consequences of thick CCDs on image processing
journal, April 2014


Bayesian galaxy shape measurement for weak lensing surveys - I. Methodology and a fast-fitting algorithm
journal, November 2007


Cosmology with weak lensing surveys
journal, June 2008


Impact of spurious shear on cosmological parameter estimates from weak lensing observables
journal, December 2014


Use of sensor characterization data to tune electrostatic model parameters for LSST sensors
journal, May 2015


Pixel area variation in CCDs and implications for precision photometry
conference, August 2008

  • Smith, Roger M.; Rahmer, Gustavo
  • SPIE Astronomical Telescopes + Instrumentation, SPIE Proceedings
  • DOI: 10.1117/12.789665

Precision astronomy with imperfect fully depleted CCDs — an introduction and a suggested lexicon
journal, March 2014


Detection of weak gravitational lensing distortions of distant galaxies by cosmic dark matter at large scales
journal, May 2000

  • Wittman, David M.; Tyson, J. Anthony; Kirkman, David
  • Nature, Vol. 405, Issue 6783
  • DOI: 10.1038/35012001

Works referencing / citing this record:

Quantifying systematics from the shear inversion on weak-lensing peak counts
journal, June 2018