Photometric redshifts and k-corrections for the Sloan Digital Sky Survey Data Release 7

O'MILL, ANA LAURA; DUPLANCIC, FERNANDA; GARCIA LAMBAS, DIEGO; SODRÉ, LAERTE

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY

WILEY-BLACKWELL PUBLISHING, INC

Lugar: MNRAS, Wiley-Blackwell, John Wiley & Sons, 101 George Street, Edinburgh, EH2 3ES, UK; Año: 2011 vol. 413 p. 195 - 1408

0035-8711

We present a catalogue of galaxy photometric redshifts and k-corrections for the SloanDigital Sky Survey Seven Data Release (SDSS-DR7), available on the World Wide Web.The photometric redshifts were estimated with an artificial neural network using five ugrizbands, concentration indices and Petrosian radii in the g and r bands. We have exploredour redshift estimates with different training set concluding that the best choice to improveredshift accuracy comprises the Main Galaxies Sample (MGS), the Luminous Red Galaxies,and galaxies of active galactic nuclei covering the redshift range 0 < z 6 0.3. For the MGS,the photometric redshift estimates agree with the spectroscopic values within rms = 0.0227.The derived distribution of photometric redshifts in the range 0 < zphot 6 0.6 agrees wellwith the model predictions.k-corrections were derived by calibration of the k-correct v4.2 code results for theMGS with the reference frame (z = 0.1) (g − r) colours. We adopt a linear dependence of kcorrections on redshift and (g − r) colours that provide suitable distributions of luminosityand colours for galaxies up to redshift zphot = 0.6 comparable to the results in the literature.Thus, our k-correction estimate procedure is a powerful, low computational time algorithmcapable of reproducing suitable results that can be used for testing galaxy properties atintermediate redshifts using the large SDSS database.