Cosmology with quasars and AGNs

• Grant number: 12/25503-2
• Support Opportunities: Scholarships in Brazil - Master
• Start date: May 01, 2013
• End date: August 19, 2015
• Field of knowledge: Physical Sciences and Mathematics - Astronomy - Extragalactic Astrophysics
• Principal Investigator: Luis Raul Weber Abramo
• Grantee: Carolina Queiroz de Abreu Silva
• Host Institution: Instituto de Física (IF). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 12/00800-4 - The 3-D universe: astrophysics with large galaxy surveys, AP.TEM
• Associated scholarship(s): 14/21148-9 - Star/quasar separation and photo-z's of quasars in narrow-band filter surveys: the role of Bayesian priors, BE.EP.MS

Abstract

Quasars and AGNs are believed to inhabit the centers of very massive halos. Their bias is strongly redshift-dependent, and can reach bq~10 at z~5. This means that they have great potencial to map large-scale estructure. The main challenges are: i) how to overcome the near-degeneracy of quasars with stars in color-color and color-magnitude diagrams, and how to obtain good photometric redshifts (photo-z's); ii) how to take into account systematics inherited through shot noise; and iii) how to properly model bias, and whether or not there is a strong scale-dependence of quasar bias (especially at high redshifts). With this project, we will work mostly with problem (i), in the context of the planned narrow-band filter survey J-PAS. As a first step, we will include quasars and AGNs in one of the widely used photo-z codes, BPZ. We will test the code with the SDSS and zCOSMOS catalogs, and characterize purity, completeness and the quality of the photo-z's at several redshift slices. Another goal of this project will be to study points (ii) and (iii) - time permitting. (AU)

Academic Publications

(References retrieved automatically from State of São Paulo Research Institutions)

SILVA, Carolina Queiroz de Abreu. Identification and photometric redshifts for type-I quasars with medium- and narrow-band filter surveys. 2015. Master's Dissertation - Universidade de São Paulo (USP). Instituto de Física (IF/SBI) São Paulo.