| Issue |
A&A
Volume 654, October 2021
|
|
|---|---|---|
| Article Number | A101 | |
| Number of page(s) | 24 | |
| Section | Numerical methods and codes | |
| DOI | https://doi.org/10.1051/0004-6361/202141236 | |
| Published online | 19 October 2021 | |
The miniJPAS survey: Photometric redshift catalogue
1
Centro de Estudios de Física del Cosmos de Aragón (CEFCA), Plaza San Juan, 1, 44001 Teruel, Spain
e-mail: ahernan@cefca.es
2
Centro de Estudios de Física del Cosmos de Aragón (CEFCA), Unidad Asociada al CSIC, Plaza San Juan, 1, 44001 Teruel, Spain
3
Donostia International Physics Centre, Paseo Manuel de Lardizabal 4, 20018 Donostia-San Sebastian, Spain
4
Instituto de Astrofísica de Andalucía (CSIC), PO Box 3004 18080 Granada, Spain
5
Tartu Observatory, University of Tartu, Observatooriumi 1, 61602 Tõravere, Estonia
6
Departamento de Astrofísica, Universidad de La Laguna, 38206 La Laguna, Tenerife, Spain
7
Instituto de Astrofísica de Canarias, 38200 La Laguna, Tenerife, Spain
8
Instituto de Física, Universidade de São Paulo, Rua do Matão 1371, 05508-090 São Paulo, Brazil
9
Departamento de Astronomia, Instituto de Física, Universidade Federal do Rio Grande do Sul (UFRGS), Av. Bento Gonçalves 9500, Porto Alegre, R.S, Brazil
10
Department of Physics, Lancaster University, Lancaster LA1 4YB, UK
11
Observatório Nacional, Ministério da Ciência, Tecnologia, Inovação e Comunicações, Rua General José Cristino, 77, São Cristóvão, 20921-400 Rio de Janeiro, Brazil
12
Ikerbasque, Basque Foundation for Science, 48013 Bilbao, Spain
13
Instituto de Física, Universidade Federal da Bahia, 40210-340 Salvador, BA, Brazil
14
Department of Astronomy, University of Michigan, 311 West Hall, 1085 South University Ave., Ann Arbor, USA
15
Department of Physics and Astronomy, University of Alabama, Box 870324, Tuscaloosa, AL, USA
16
Departamento de Astronomia, Instituto de Astronomia, Geofísica e Ciências Atmosféricas da USP, Cidade Universitária, 05508-900 São Paulo, SP, Brazil
17
Instruments4, Tampa, USA
Received:
2
May
2021
Accepted:
6
August
2021
MiniJPAS is a ∼1 deg2 imaging survey of the AEGIS field in 60 bands, performed to demonstrate the scientific potential of the upcoming Javalambre-Physics of the Accelerating Universe Astrophysical Survey (J-PAS). Full coverage of the 3800–9100 Å range with 54 narrow-band filters, in combination with 6 optical broad-band filters, allows for extremely accurate photometric redshifts (photo-z), which, applied over areas of thousands of square degrees, will enable new applications of the photo-z technique, such as measurement of baryonic acoustic oscillations. In this paper we describe the method we used to obtain the photo-z that is included in the publicly available miniJPAS catalogue, and characterise the photo-z performance. We built photo-spectra with 100 Å resolution based on forced-aperture photometry corrected for point spread function. Systematic offsets in the photometry were corrected by applying magnitude shifts obtained through iterative fitting with stellar population synthesis models. We computed photo-z with a customised version of LEPHARE, using a set of templates that is optimised for the J-PAS filter-set. We analysed the accuracy of miniJPAS photo-z and their dependence on multiple quantities using a subsample of 5266 galaxies with spectroscopic redshifts from SDSS and DEEP, which we find to be representative of the whole r < 23 miniJPAS sample. Formal 1σ uncertainties for the photo-z that are calculated with the Δχ2 method underestimate the actual redshift errors. The odds parameter has a stronger correlation with |Δz| and accurately reproduces the probability of a redshift outlier (|Δz| > 0.03), regardless of the magnitude, redshift, or spectral type of the sources. We show that the two main summary statistics characterising the photo-z accuracy for a population of galaxies (σNMAD and η) can be predicted by the distribution of odds in this population, and we use this to estimate the statistics for the whole miniJPAS sample. At r < 23, there are ∼17 500 galaxies per deg2 with valid photo-z estimates, ∼4200 of which are expected to have |Δz| < 0.003. The typical error is σNMAD = 0.013 with an outlier rate η = 0.39. The target photo-z accuracy σNMAD = 0.003 is achieved for odds > 0.82 with η = 0.05, at the cost of decreasing the density of selected galaxies to n ∼ 5200 deg−2 (∼2600 of which have |Δz| < 0.003).
Key words: methods: data analysis / catalogs / galaxies: photometry / galaxies: distances and redshifts
© ESO 2021
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