The Quasar Catalogue for S-PLUS DR4 (QuCatS) and the estimation of photometric redshifts

Nakazono L.; Valenca R.R.; Soares G.; Izbicki R.; Ivezic Z.; Lima E.V.R.; Hirata N.S.T.; Sodre L.; Overzier R.; Almeida-Fernandes F.; Schwarz G.B.O.; Schoenell W.; Kanaan A.; Ribeiro T.; de Oliveira C.M.

The Quasar Catalogue for S-PLUS DR4 (QuCatS) and the estimation of photometric redshifts

Tipo

Artigo

Data de publicação

2024

Periódico

Monthly Notices of the Royal Astronomical Society

Citações (Scopus)

1

Autores

Nakazono L.
Valenca R.R.
Soares G.
Izbicki R.
Ivezic Z.
Lima E.V.R.
Hirata N.S.T.
Sodre L.
Overzier R.
Almeida-Fernandes F.
Schwarz G.B.O.
Schoenell W.
Kanaan A.
Ribeiro T.
de Oliveira C.M.

Resumo

© 2024 Oxford University Press. All rights reserved.The advent of massive broad-band photometric surveys enabled photometric redshift estimates for unprecedented numbers of galaxies and quasars. These estimates can be improved using better algorithms or by obtaining complementary data such as narrow-band photometry, and broad-band photometry over an extended wavelength range. We investigate the impact of both approaches on photometric redshifts for quasars using data from Southern Photometric Local Universe Survey (S-PLUS) DR4, Galaxy Evolution Explorer (GALEX) DR6/7, and the unWISE catalog for the Wide-field Infrared Survey Explorer (WISE) in three machine learning methods: Random Forest, Flexible Conditional Density Estimation (FlexCoDE), and Bayesian Mixture Density Network (BMDN). Including narrow-band photometry improves the root-mean-square error by 11 per cent in comparison to a model trained with only broad-band photometry. Narrow-band information only provided an improvement of 3.8 per cent when GALEX and WISE colours were included. Thus, narrow bands play a more important role for objects that do not have GALEX or WISE counterparts, which respectively makes 92 per cent and 25 per cent of S-PLUS data considered here. Nevertheless, the inclusion of narrow-band information provided better estimates of the probability density functions obtained with FlexCoDE and BMDN. We publicly release a value-added catalogue of photometrically selected quasars with the photo-z predictions from all methods studied here. The catalogue provided with this work covers the S-PLUS DR4 area (∼3000 square degrees), containing 645 980, 244 912, 144 991 sources with the probability of being a quasar higher than, 80 per cent, 90 per cent, 95 per cent up to r < 21.3 and good photometry quality in the detection image. More quasar candidates can be retrieved from the S-PLUS data base by considering less restrictive selection criteria.

Assuntos Scopus

Broad bands , Catalog , Conditional density , Galaxy evolution , Methods:statistical , Narrow bands , Photometrics , Quasars:general , Red shift , Wide-field