Slicing through multicolor space: Galaxy redshifts from broadband photometry

A. J. Connolly, I. Csabai, A. S. Szalay, D. C. Koo, R. G. Kron, J. A. Munn

Research output: Contribution to journalArticle

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Abstract

As a means of better understanding the evolution of optically selected galaxies we consider the distribution of galaxies within the multicolor space U, BJ, RF, and IN. We find that they form an almost planar distribution out to βJ=22.5 and zJ, RF, and IN space these properties are highly correlated, we can define an optimal rotation of the photometric axes that makes much of this information orthogonal. Fitting the observed spectroscopic redshifts with a quadratic function of the four magnitudes we show that redshifts for galaxies can be estimated to an accuracy better than Δz=0.05. This dispersion is due to the photometric uncertainties within the photographic data. Assuming no galaxy evolution we derive a set of simulated galaxy fluxes in the U, J, F, and N passbands. Using these data we investigate how the redshift is encoded within the broadband magnitudes and the intrinsic dispersion of the photometric-redshift relation. We find that the signal that defines a galaxy's photometric redshift is not related to specific absorption or emission lines but comes from the break in the overall shape of the galaxy continuum at around 4000 Å. Using high signal-to-noise photometric data we estimate that it is possible to achieve an intrinsic dispersion of less than Δz=0.02.

Original languageEnglish
Pages (from-to)2655-2664
Number of pages10
JournalAstronomical Journal
Volume110
Issue number6
Publication statusPublished - Dec 1995

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slicing
photometry
galaxies
broadband
continuums
distribution
estimates

ASJC Scopus subject areas

  • Space and Planetary Science
  • Astronomy and Astrophysics

Cite this

Connolly, A. J., Csabai, I., Szalay, A. S., Koo, D. C., Kron, R. G., & Munn, J. A. (1995). Slicing through multicolor space: Galaxy redshifts from broadband photometry. Astronomical Journal, 110(6), 2655-2664.

Slicing through multicolor space : Galaxy redshifts from broadband photometry. / Connolly, A. J.; Csabai, I.; Szalay, A. S.; Koo, D. C.; Kron, R. G.; Munn, J. A.

In: Astronomical Journal, Vol. 110, No. 6, 12.1995, p. 2655-2664.

Research output: Contribution to journalArticle

Connolly, AJ, Csabai, I, Szalay, AS, Koo, DC, Kron, RG & Munn, JA 1995, 'Slicing through multicolor space: Galaxy redshifts from broadband photometry', Astronomical Journal, vol. 110, no. 6, pp. 2655-2664.
Connolly AJ, Csabai I, Szalay AS, Koo DC, Kron RG, Munn JA. Slicing through multicolor space: Galaxy redshifts from broadband photometry. Astronomical Journal. 1995 Dec;110(6):2655-2664.
Connolly, A. J. ; Csabai, I. ; Szalay, A. S. ; Koo, D. C. ; Kron, R. G. ; Munn, J. A. / Slicing through multicolor space : Galaxy redshifts from broadband photometry. In: Astronomical Journal. 1995 ; Vol. 110, No. 6. pp. 2655-2664.
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