Calibrating photometric redshifts of luminous red galaxies

Nikhil Padmanabhan, Tamás Budavári, David J. Schlegel, Terry Bridges, Jonathan Brinkmann, Russell Cannon, Andrew J. Connolly, Scott M. Croom, I. Csabai, Michael Drinkwater, Daniel J. Eisenstein, Paul C. Hewett, Jon Loveday, Robert C. Nichol, Kevin A. Pimbblet, Roberto De Propris, Donald P. Schneider, Ryan Scranton, Uroš Seljak, Tom Shanks & 3 others I. Szapudi, Alexander S. Szalay, David Wake

Research output: Contribution to journalArticle

84 Citations (Scopus)

Abstract

We discuss the construction of a photometric redshift catalogue of luminous red galaxies (LRGs) from the Sloan Digital Sky Survey (SDSS), emphasizing the principal steps necessary for constructing such a catalogue: (i) photometrically selecting the sample, (ii) measuring photometric redshifts and their error distributions, and (iii) estimating the true redshift distribution. We compare two photometric redshift algorithms for these data and find that they give comparable results. Calibrating against the SDSS and SDSS-2dF (Two Degree Field) spectroscopic surveys, we find that the photometric redshift accuracy is σ ∼ 0.03 for redshifts less than 0.55 and worsens at higher redshift (∼ 0.06 for z <0.7). These errors are caused by photometric scatter, as well as systematic errors in the templates, filter curves and photometric zero-points. We also parametrize the photometric redshift error distribution with a sum of Gaussians and use this model to deconvolve the errors from the measured photometric redshift distribution to estimate the true redshift distribution. We pay special attention to the stability of this deconvolution, regularizing the method with a prior on the smoothness of the true redshift distribution. The methods that we develop are applicable to general photometric redshift surveys.

Original languageEnglish
Pages (from-to)237-250
Number of pages14
JournalMonthly Notices of the Royal Astronomical Society
Volume359
Issue number1
DOIs
Publication statusPublished - May 1 2005

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calibrating
galaxies
catalogs
deconvolution
systematic errors
field survey
distribution
estimating
templates
filter
filters
curves
estimates

Keywords

  • Catalogues
  • Galaxies: fundamental parameters
  • Surveys

ASJC Scopus subject areas

  • Space and Planetary Science

Cite this

Padmanabhan, N., Budavári, T., Schlegel, D. J., Bridges, T., Brinkmann, J., Cannon, R., ... Wake, D. (2005). Calibrating photometric redshifts of luminous red galaxies. Monthly Notices of the Royal Astronomical Society, 359(1), 237-250. https://doi.org/10.1111/j.1365-2966.2005.08915.x

Calibrating photometric redshifts of luminous red galaxies. / Padmanabhan, Nikhil; Budavári, Tamás; Schlegel, David J.; Bridges, Terry; Brinkmann, Jonathan; Cannon, Russell; Connolly, Andrew J.; Croom, Scott M.; Csabai, I.; Drinkwater, Michael; Eisenstein, Daniel J.; Hewett, Paul C.; Loveday, Jon; Nichol, Robert C.; Pimbblet, Kevin A.; De Propris, Roberto; Schneider, Donald P.; Scranton, Ryan; Seljak, Uroš; Shanks, Tom; Szapudi, I.; Szalay, Alexander S.; Wake, David.

In: Monthly Notices of the Royal Astronomical Society, Vol. 359, No. 1, 01.05.2005, p. 237-250.

Research output: Contribution to journalArticle

Padmanabhan, N, Budavári, T, Schlegel, DJ, Bridges, T, Brinkmann, J, Cannon, R, Connolly, AJ, Croom, SM, Csabai, I, Drinkwater, M, Eisenstein, DJ, Hewett, PC, Loveday, J, Nichol, RC, Pimbblet, KA, De Propris, R, Schneider, DP, Scranton, R, Seljak, U, Shanks, T, Szapudi, I, Szalay, AS & Wake, D 2005, 'Calibrating photometric redshifts of luminous red galaxies', Monthly Notices of the Royal Astronomical Society, vol. 359, no. 1, pp. 237-250. https://doi.org/10.1111/j.1365-2966.2005.08915.x
Padmanabhan N, Budavári T, Schlegel DJ, Bridges T, Brinkmann J, Cannon R et al. Calibrating photometric redshifts of luminous red galaxies. Monthly Notices of the Royal Astronomical Society. 2005 May 1;359(1):237-250. https://doi.org/10.1111/j.1365-2966.2005.08915.x
Padmanabhan, Nikhil ; Budavári, Tamás ; Schlegel, David J. ; Bridges, Terry ; Brinkmann, Jonathan ; Cannon, Russell ; Connolly, Andrew J. ; Croom, Scott M. ; Csabai, I. ; Drinkwater, Michael ; Eisenstein, Daniel J. ; Hewett, Paul C. ; Loveday, Jon ; Nichol, Robert C. ; Pimbblet, Kevin A. ; De Propris, Roberto ; Schneider, Donald P. ; Scranton, Ryan ; Seljak, Uroš ; Shanks, Tom ; Szapudi, I. ; Szalay, Alexander S. ; Wake, David. / Calibrating photometric redshifts of luminous red galaxies. In: Monthly Notices of the Royal Astronomical Society. 2005 ; Vol. 359, No. 1. pp. 237-250.
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