Photometric redshift analysis in the Dark Energy Survey science verification data

• Autor(a) principal: Sánchez Alonso, Carles
• Data de Publicação: 2014
• Outros Autores: Carrasco Kind, Matías, Lin, H., Serra Ricart, Miquel, Abdalla, Filipe B., Amara, Adam, Banerji, M., Bonnet, Christopher Clive, Brunner, Robert J., Capozzi, Diego, Carnero Rosell, Aurelio, Castander Serentill, Francisco Javier, Costa, Luiz N. da, Cunha, Carlos Eduardo, Fausti Neto, Angelo, Gerdes, David W., Greisel, N., Gschwend, Julia de Figueiredo, Hartley, William, Jouvel, Stéphanie, Lahav, Ofer, Lima, Marcos Vinicius Borges Teixeira, Maia, Marcio Antonio Geimba, Martí, P., Ogando, Ricardo L.C., Ostrovski, F., Pellegrini, Paulo Sérgio de Souza, Rau, Markus Michael, Sadeh, Iftach, Seitz, Stella, Sevilla Noarbe, Ignacio, Sypniewski, Adam J., Vicente, J. de, Abbott, Timothy M. C., Allam, Sahar S., Atlee, David, Bernstein, Gary M., Bernstein, Joseph P., Buckley-Geer, Elizabeth, Burke, David Lyle, Childress, Michael, Davis, Tamara M., DePoy, Darren L., Dey, Arjun, Desai, S., Diehl, H. Thomas, Doel, Peter, Estrada, Juan, Evrard, August E., Fernandez, Enrique, Finley, David A., Flaugher, Brenna, Frieman, Joshua A., Gaztañaga, Enrique, Glazebrook, Karl, Honscheid, K., Kim, A. G., Kuehn, Kyler, Kuropatkin, Nikolay P., Lidman, Chris, Makler, Martín, Marshall, Jennifer L., Nichol, Robert C., Roodman, Aaron, Sanchez-Alvaro, Eusebio, Santiago, Basilio Xavier, Sako, Masao, Scalzo, Richard, Smith, Robert Christopher, Swanson, Molly E. C., Tarle, Gregory, Thomas, D., Tucker, Douglas L., Uddin, Syed, Valdes, Francisco, Walker, Alistair, Yuan, Fang, Zuntz, J.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UFRGS
• Texto Completo: http://hdl.handle.net/10183/115354
• topic: Mapeamentos astronômicos; Astronomical data bases: surveys; Galaxies: distances and redshifts; Galaxies: statistics; Large-scale structure of Universe

We present results from a study of the photometric redshift performance of the Dark Energy Survey (DES), using the early data from a Science Verification period of observations in late 2012 and early 2013 that provided science-quality images for almost 200 sq. deg. at the nominal depth of the survey.We assess the photometric redshift (photo-z) performance using about 15 000 galaxies with spectroscopic redshifts available from other surveys. These galaxies are used, in different configurations, as a calibration sample, and photo-z’s are obtained and studied using most of the existing photo-z codes. A weighting method in a multidimensional colour–magnitude space is applied to the spectroscopic sample in order to evaluate the photo-z performance with sets that mimic the full DES photometric sample, which is on average significantly deeper than the calibration sample due to the limited depth of spectroscopic surveys. Empirical photo-z methods using, for instance, artificial neural networks or random forests, yield the best performance in the tests, achieving core photo-z resolutions σ68 ∼ 0.08. Moreover, the results from most of the codes, including template-fitting methods, comfortably meet the DES requirements on photo-z performance, therefore, providing an excellent precedent for future DES data sets.