Cited by 285Galaxies: Formation, Evolution, PhenomenaCosmology and Gravitation TheoriesAstronomy and Astrophysical Research

Calibrating Redshift Distributions beyond Spectroscopic Limits with Cross‐Correlations

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Newman, Jeffrey A.·2008·The Astrophysical Journal

Abstract

We describe a new method that can measure the true redshift distribution of any set of objects that are studied only photometrically. Measuring the angular cross-correlation between objects in the photometric sample with objects in some spectroscopic sample as a function of the spectroscopic z , along with other, standard correlation measurements, provides sufficient information to reconstruct the redshift distribution of the photometric sample. The spectroscopic sample need not resemble the photometric sample in galaxy properties, but must fall within its sky coverage. We test this hybrid, photometric-spectroscopic cross-correlation technique with Monte Carlo simulations based on realistic error estimates (including sample variance). The rms errors in recovering both the mean redshift and σ of the redshift distribution for a single photometric redshift bin with true distribution given by a Gaussian are 1.4 × 10 −3 (σ z /0.1)(Σ p /10) −0.3 (d N s / dz /25,000) −1/2 , where σ z is the true Gaussian σ , Σ p is the surface density of the photometric sample in galaxies arcmin −2 , and dN s / dz is the number of galaxies with a spectroscopic redshift per unit z . We test the impact of non-Gaussian redshift outliers and of systematic errors due to unaccounted-for bias evolution, errors in measuring autocorrelations, photometric zero-point variations, or mistaken cosmological assumptions, and find that none will dominate measurement uncertainties in reasonable scenarios. The true redshift distributions of even arbitrarily faint photometric samples may be determined to the precision required by proposed dark energy experiments (Δ⟨ z ⟩ ≲ 3 × 10 −3 at z ∼ 1) with this method.

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  • Photometric redshift calibration can be further improved by cross-correlating the photometric sample with redshift surveys of galaxies and quasars in the same fields.

    “It will be possible to further improve photometric redshift calibration by crosscorrelating the photometric sample with redshift surveys of galaxies and quasars in the same fi elds ( Newman 2008; Matthews & Newman 2010; Ménard et al. 2013; Davis et al. 2017 ) .”

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2 of the 54 references couldn’t be matched to a known paper.

Research works printed but not linked: 5

  1. Burke, D., et al. 2006, in Proc. SPIE, 6267, 38
  2. Glazebrook, K., et al. 2007, in ASP Conf. Ser. 379, Cosmic Frontiers, ed. N. Metcalfe & T. Shanks (San Francisco: ASP), 72
  3. Tyson, A. 2005, in ASP Conf. Ser. 339, Observing Dark Energy, ed. S. C. Wolff & T. R. Lauer (San Francisco: ASP), 95
  4. Tyson, A., & Angel, R. 2001, in ASP Conf. Ser. 232, The New Era of Wide Field Astronomy, ed. R. Clowes, A. Adamson, & G. Bromage (San Francisco: ASP), 347
  5. Tyson, J. A. 2006, in AIP Conf. Ser. 870, Intersections of Particle and Nuclear Physics, ed. T. M. Liss ( Melville, NY: AIP), 44

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Authors
Newman, J. A.
Affiliations
University of Pittsburgh (US)
Corresponding author
Newman, Jeffrey A.
Venue
The Astrophysical Journal
Published
2008-09
Volume
684
Issue
1
Pages
88-101
ISSN
  • 0004-637X (ISSN-L)
  • 1538-4357
OpenAlex
W2048401217
Cited by
285
References
54
Citations by year
2026: 12 · 2025: 15 · 2024: 14 · 2023: 20 · 2022: 18 · 2021: 27 · 2020: 28 · 2019: 21 · 2018: 20 · 2017: 15 · 2016: 25 · 2015: 14 · 2014: 13 · 2013: 8 · 2012: 11
FWCI
4.67
Type
journal article
Language
en
Open access
Locations
  • The Astrophysical Journal (publishedVersion)
  • arXiv (Cornell University) (submittedVersion)
  • arXiv (Cornell University)
Funders
  • National Aeronautics and Space Administration (NAS 526555)
  • Space Telescope Science Institute (NAS5- 26555, 26555)
  • Lawrence Berkeley National Laboratory
Topics
  • Physical Sciences › Physics and Astronomy › Astronomy and Astrophysics › Galaxies: Formation, Evolution, Phenomena
  • Physical Sciences › Physics and Astronomy › Astronomy and Astrophysics › Cosmology and Gravitation Theories
  • Physical Sciences › Physics and Astronomy › Instrumentation › Astronomy and Astrophysical Research
Keywords
photometric redshifts, angular cross-correlation, spectroscopic redshifts, sample variance, Dark Energy Survey, Monte Carlo simulation

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