Full text
| |
| Author(s): |
Carolina Queiroz de Abreu Silva
Total Authors: 1
|
| Document type: | Doctoral Thesis |
| Press: | São Paulo. |
| Institution: | Universidade de São Paulo (USP). Instituto de Física (IF/SBI) |
| Defense date: | 2021-01-21 |
| Examining board members: |
Luis Raul Weber Abramo;
Olivier Ilbert;
Marcos Vinicius Borges Teixeira Lima;
Martin Makler;
Rogério Riffel
|
| Advisor: | Luis Raul Weber Abramo |
| Abstract | |
Quasars are active galactic nuclei powered by the accretion of matter onto a supermassive black hole lying at their centers. They are not only the brightest and most highly biased tracers of large-scale structure, but they are also believed to co-evolve with their host galaxies, making them invaluable sources to both cosmology and galaxy evolution studies. Their UV-optical spectra are characterized by a non-thermal continuum and a series of broad emission lines, which can be well-resolved with narrow-band filters. In this thesis, we present a method for estimating precise photometric redshifts (photo-zs) for quasars detected with narrow-band surveys. Our method (dubbed QPz) finds a first-approximation best-fit model for the quasar photospectrum in terms of the so-called eigenspectra - the most relevant modes of variation of broad-line quasars, computed using as a basis a selection of SDSS spectra. At each redshift the photospectrum is modelled as a linear combination of four redshifted eigenspectra combined with an extinction power law. In this work, we utilized spectroscopically confirmed quasars detected with the miniJPAS primary catalog and the first data release of S-PLUS as test cases, and we also constructed and employed mock catalogues to demonstrate the potential that the future J-PAS will have to deliver precise photo-zs for quasars. We validate our method by comparing its performance with a new version (not publicly available yet) of the LePhare code, which is a standard template-fitting approach employed in the literature. (AU) | |
| FAPESP's process: | 15/11442-0 - Combining quasars and galaxies to trace large-scale structure |
| Grantee: | Carolina Queiroz de Abreu Silva |
| Support Opportunities: | Scholarships in Brazil - Doctorate |