Introduction

We refer to the paper
"Photometric Redshifts based on standard SED fitting procedures" 
M. Bolzonella, J.-M. Miralles, R. Pelló, 2000, A&A 363, 476-492
for a complete discussion about the accuracy on simulated catalogues and on real data.
Here you can find a short description of the method and parameters involved, as well as a list of related papers.

From a photometric catalogue, hyperz finds the redshift of each object by means of a standard SED fitting procedure, i.e. comparing the observed magnitudes with the expected ones, computed from template Spectral Energy Distributions.

To compare the observed with the fiducial photometry, we need to handle the template spectra applying the absorption from the Lyman forest (following Madau prescriptions), the reddening (with different implemented laws) to the redshifted SEDs (either observed or synthetic). 
If required, the program compute on the real data the galactic dereddening, performed with a Seaton law and color excess EB-V selected from the user.

This is the flow chart representing how hyperz works in its standard configuration:





The principal outputs include: the photometric redshift zphot, satisfying the minimum chi2 criterion, the error bars at 3 confidence levels, the spectral type, age and extinction of the solution, the f(lambda) of the best fit SED, the probability associated to the minimum chi2 for each redshift step, the probability of lying at a given redshift (useful to look for galaxy cluster members), the absolute magnitude in a given filter and the secondary solutions.

The package also contains the program make_catalog, allowing to build simulated catalogues, very useful to test the accuracy for a given filter set.



 

Related papers

Photometric Redshifts based on standard SED fitting procedures
      M. Bolzonella, J.-M. Miralles, R. Pelló, 2000, A&A 363, 476-492

Photometric Redshifts in lensing clusters: Identification and Calibration of faint high-z galaxies 
       R. Pelló, J.-P. Kneib, M. Bolzonella, J.-M. Miralles, Conference Proceedings of the 
      "Photometric Redshifts and High Redshift Galaxies", April 28-30, 1999, Pasadena, 
   astro-ph/9907054

Two multiple-imaged z = 4.05 galaxies in the cluster-lens Abell 2390
        R. Pelló, J.-P. Kneib, J.-F. Le Borgne, J. Bézecourt, T.M. Ebbels, I. Tijera, 
        G. Bruzual, J.-M. Miralles, I. Smail, G. Soucail, T.J.Bridges, 
        1999,
A&A 346, 359-368

A comparative study of HDF-N and HDF-S using Photometric Redshifts
      M. Bolzonella, R. Pelló, Conference Proceedings of the 
     "Clustering at High Redshift" Conference, June 29 to July 2, 1999, Marseille (France)

Properties of high-z galaxies as seen through lensing clusters
      R. Pelló, J.-P. Kneib, J.-F. Le Borgne, B. Fort, Y. Mellier, M. Bolzonella, 
      L. Campusano , M. Dantel-Fort, J-M. Miralles, Conference Proceedings of the 
     "Clustering at High Redshift" Conference, June 29 to July 2, 1999, Marseille (France), 
     
astro-ph/9910467

Detection of Distant Clusters of Galaxies Using Photometric Redshift Techniques 
        R. Pelló,  J.-F. Le Borgne, J.-M. Miralles, G. Bruzual, Conference Proceedings of
       "Wide Field Surveys in Cosmology", 14th IAP meeting held May 26-30, 1998, Paris (France). 
        Publisher: Editions Frontieres, p. 410

Identification and study of distant galaxies through cluster lenses
       R. Pelló, J.-P. Kneib, G. Bruzual, 1998, 
     
Astrophysics and Space Science (A&SS) 263, Issue 1/4, p. 55-58

Détection et caracterisation de structures lointaines par la méthode des redshift photometriques
      J.-M. Miralles, PhD Thesis, 1998, Université Paul Sabatier, Toulouse (France)

Identification of a high redshift cluster in the field of Q2345+007 through deep BRIJK' photometry
       R. Pelló, J.-M. Miralles, J.-F. Le Borgne, J.-P. Picat, G. Soucail, G. Bruzual, 1996, 
      
A&A 314, 73


Last modified: December 8, 2000