J-PLUS: Systematic impact of metallicity on photometric calibration with the stellar locus

¹ Centro de Estudios de Física del Cosmos de Aragón (CEFCA), Unidad Asociada al CSIC, Plaza San Juan 1, 44001 Teruel, Spain
e-mail: clsj@cefca.es
² Department of Astronomy, Beijing Normal University, Beijing 100875, PR China
³ Centro de Estudios de Física del Cosmos de Aragón (CEFCA), Plaza San Juan 1, 44001 Teruel, Spain
⁴ Department of Physics, University of Warwick, Coventry CV4 7AL, UK
⁵ Instituto de Astronomia, Geofísica e Ciências Atmosféricas, Universidade de São Paulo, 05508-090 São Paulo, Brazil
⁶ Instituto de Astrofísica de Andalucía (IAA-CSIC), Glorieta de la astronomía s/n, 18008 Granada, Spain
⁷ IUFACyT, Universidad de Alicante, San Vicent del Raspeig, 03080 Alicante, Spain
⁸ Observatório Nacional, Rua General José Cristino, 77 - Bairro Imperial de São Cristóvão, 20921-400 Rio de Janeiro, Brazil
⁹ Instituto de Astrofísica de Canarias (IAC), 38205 La Laguna, Spain
¹⁰ Departamento de Astrofísica, Universidad de La Laguna (ULL), 38200 La Laguna, Spain
¹¹ Centro de Astrobiología (CSIC-INTA), ESAC Campus, Camino Bajo del Castillo s/n, 28692 Villanueva de la Cañada, Spain
¹² Spanish Virtual Observatory, 28692 Villanueva de la Cañada, Spain
¹³ Community Science and Data Center/NSF’s NOIRLab, 950 N. Cherry Ave., Tucson, AZ 85719, USA
¹⁴ Tartu Observatory, University of Tartu, Observatooriumi 1, 61602 Tõravere, Estonia
¹⁵ Donostia International Physics Centre (DIPC), Paseo Manuel de Lardizabal 4, 20018 Donostia-San Sebastián, Spain
¹⁶ IKERBASQUE, Basque Foundation for Science, 48013 Bilbao, Spain
¹⁷ University of Michigan, Department of Astronomy, 1085 South University Ave., Ann Arbor, MI 48109, USA
¹⁸ University of Alabama, Department of Physics and Astronomy, Gallalee Hall, Tuscaloosa, AL 35401, USA

Received: 29 January 2021
Accepted: 13 July 2021

Abstract

Aims. We present the photometric calibration of the twelve optical passbands for the Javalambre Photometric Local Universe Survey (J-PLUS) second data release (DR2), comprising 1088 pointings of two square degrees, and study the systematic impact of metallicity on the stellar locus technique.

Methods. The [Fe/H] metallicity from the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) for 146 184 high-quality calibration stars, defined with signal-to-noise ratio larger than ten in J-PLUS passbands and larger than three in Gaia parallax, was used to compute the metallicity-dependent stellar locus (ZSL). The initial homogenization of J-PLUS photometry, performed with a unique stellar locus, was refined by including the metallicity effect in colors via the ZSL.

Results. The variation of the average metallicity along the Milky Way produces a systematic offset in J-PLUS calibration. This effect is well above 1% for the bluer passbands and amounts 0.07, 0.07, 0.05, 0.03, and 0.02 mag in u, J0378, J0395, J0410, and J0430, respectively. We modeled this effect with the Milky Way location of the J-PLUS pointing, also providing an updated calibration for those observations without LAMOST information. The estimated accuracy in the calibration after including the metallicity effect is at 1% for the bluer J-PLUS passbands and below for the rest.

Conclusions. Photometric calibration with the stellar locus technique is prone to significant systematic bias in the Milky Way for passbands bluer than λ = 4500 Å. The calibration method for J-PLUS DR2 reaches 1–2% precision and 1% accuracy for 12 optical filters within an area of 2176 square degrees.