DES Science Portal: Computing Photometric Redshifts
Abstract
A significant challenge facing photometric surveys for cosmological purposes is the need to produce reliable redshift estimates. The estimation of photometric redshifts (photo-zs) has been consolidated as the standard strategy to bypass the high production costs and incompleteness of spectroscopic redshift samples. Training-based photo-z methods require the preparation of a high-quality list of spectroscopic redshifts, which needs to be constantly updated. The photo-z training, validation, and estimation must be performed in a consistent and reproducible way in order to accomplish the scientific requirements. To meet this purpose, we developed an integrated web-based data interface that not only provides the framework to carry out the above steps in a systematic way, enabling the ease testing and comparison of different algorithms, but also addresses the processing requirements by parallelizing the calculation in a transparent way for the user. This framework called the Science Portal (hereafter Portal) was developed in the context the Dark Energy Survey (DES) to facilitate scientific analysis. In this paper, we show how the Portal can provide a reliable environment to access vast data sets, provide validation algorithms and metrics, even in the case of multiple photo-zs methods. It is possible to maintain the provenance between the steps of a chain of workflows while ensuring reproducibility of the results. We illustrate how the Portal can be used to provide photo-z estimates using the DES first year (Y1A1) data. While the DES collaboration is still developing techniques to obtain more precise photo-zs, having a structured framework like the one presented here is critical for the systematic vetting of DES algorithmic improvements and the consistent production of photo-zs in the future DES releases.
Cite
@article{arxiv.1708.05643,
title = {DES Science Portal: Computing Photometric Redshifts},
author = {Julia Gschwend and Aurelio Carnero Rosell and Ricardo Ogando and Angelo Fausti Neto and Marcio Maia and Luiz da Costa and Marcos Lima and Paulo Pellegrini and Riccardo Campisano and Cristiano Singulani and Carlos Adean and Christophe Benoist and Michel Aguena and Matias Carrasco Kind and Tamara Davis and Juan de Vicente and Will Hartley and Ben Hoyle and Antonella Palmese and Iftach Sadeh and Tim Abbot and Filipe Abdalla and Sahar Allam and James Annis and Jacobo Asorey and David Brooks and Josh Calcino and Daniela Carollo and Francisco Castander and Chris D'Andrea and Shantanu Desai and August Evrard and Pablo Fosalba and Josh Frieman and Juan Garcia-Bellido and Karl Glazebrook and David Gerdes and Robert Gruendl and Gaston Gutierrez and Samuel Hinton and Devon Hollowood and Klaus Honscheid and Janie Hoormann and David James and Kyler Kuehn and Nikolay Kuropatkin and Ofer Lahav and Geraint Lewis and Chris Lidman and Huan Lin and Edward Macaulay and Jeniffer Marshall and Peter Melchior and Ramon Miquel and Anais Moller and Andrés Plazas and Eusebio Sanchez and Basilio Santiago and Vic Scarpine and Rafe Schindler and Ignacio Sevilla and Mathew Smith and Flavia Sobreira and Natalia Eiré Sommer and Eric Suchyta and Molly Swanson and Gregory Tarle and Brad Tucker and Douglas Tucker and Syed Uddin and Alistair Walker},
journal= {arXiv preprint arXiv:1708.05643},
year = {2019}
}
Comments
The first paper of the series about the DES Science Portal, submitted to the Astronomy & Computing journal. It shows the infrastructure of pipelines related to the production of photometric redshifts to feed science-ready catalogs