Astron. Astrophys. 363, 517-525 (2000)

7. Summary and conclusion

A new technique is developed for estimating the photometric redshifts to galaxies. The advantage of this over the previous methods is that it allows a self-cosistent treatment of both photometric and chemical evolution of the template SEDs for different types of galaxies, in agreement with observations. For this reason, the present technique is particularly useful for application to high-redshift galaxies. The template SEDs are constrained to simultaneously satisfy the following criteria: a) produce the observed colours of galaxies at ; b) incorporate the spectral evolution for galaxies of different types; c) allow a self-consistent treatment of the dust contribution and its evolution with redshift; d) include correction for inter-galactic absorption by Lyman continuum and Lyman forest. The model parameters are then constrained, using a calibrating sample of HDF galaxies. Using only four optical passbands (UVRI), the photometric redshifts to galaxies can be estimated with an rms accuracy of 0.11. Including near-IR data (UVRIJK), gives a similar rms scatter in the photometric redshifts from this method. The sensitivity of the results to different EPS model parameters are explored and the degeneracy of the photometric redshifts and spectral types for galaxies are examined using a simulated catalogue.

© European Southern Observatory (ESO) 2000

Online publication: December 11, 2000
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