Challenges for the new generation of wide-field photometric redshift surveys like J-PAS

Abstract

The Javalambre-Physics of the Accelerated Universe Astrophysical Survey (J-PAS) is a very wide-field Cosmological Survey aiming at providing the first radial BAO experiment to reach Stage IV and study galaxy evolution. To succeed in achieving the main scientific goals, the projects described through this proposal represent an initiative to face and overcome potential challenges. Clusters of galaxies play a direct and fundamental role in testing cosmological models. By virtue of their position at the high end of the cosmic mass power spectrum, provide a powerful way to constrain the frequency of high amplitude perturbations in the primordial density field. J-PAS will produce the most complete and mass-sensitive cluster cataloguesto date. However, retrieving univocal and precise photometric redshift estimations will represent a major effort. In this project, a sample of 25 massive galaxy clusters (from the CLASH-survey) will be used to develop a new methodology to assure J-PAS will succeed providing complete and reliable photometric redshift catalogues. In the era of precision cosmology, any source of systematic error may play a decisive role. An inefficient star/galaxy/qso separation will surely bias not only several tracers of dark matter halos (blurring the BAO estimations) but also analysis about the Milky Way or Galaxy evolution. In this project, it will be deeply investigated the best statistical classification method for J-PAS. Taking advantage that J-PAS will repeat its observation multiple times to fulfil a total photometric depth per filter, in this project the ALHAMBRA-survey observations will be used as a test-bench to develop a novel methodology to characterize the probability of every detection to be a variable source. Our analysis of JPAS will provide the deepest and most reliable analysis today of several hundred nearby galaxies and several thousand stars in the direction of the Galactic Halo. (AU)