J-PLUS: Toward a homogeneous photometric calibration using Gaia BP/RP low-resolution spectra

Abstract

We present the photometric calibration of the 12 optical passbands for the Javalambre Photometric Local Universe Survey (J-PLUS) third data release (DR3) comprising $1\,642$ pointings of two square degrees each. We selected nearly $1.5$ million main sequence stars with a signal-to-noise ratio larger than ten in the 12 J-PLUS passbands and available low-resolution ($R = 20-80$) spectrum from the blue and red photometers (BP/RP) in Gaia DR3. We compared the synthetic photometry from BP/RP spectra with the J-PLUS instrumental magnitudes after correcting for the magnitude and color terms between both systems in order to obtain a homogeneous photometric solution for J-PLUS. To circumvent the current limitations in the absolute calibration of the BP/RP spectra, the absolute color scale was derived using the locus of $109$ white dwarfs closer than $100$ pc with a negligible interstellar extinction. Finally, the absolute flux scale was anchored to the Panoramic Survey Telescope and Rapid Response System (Pan-STARRS) photometry in the $r$ band. The precision of the J-PLUS photometric calibration estimated from duplicated objects observed in adjacent pointings and by comparison with the spectro-photometric standard star GD $153$ is $ 12$ mmag in $u$, $J0378$, and $J0395$, and it is $ 7$ mmag in $J0410$, $J0430$, $g$, $J0515$, $r$, $J0660$, $i$, $J0861$, and $z$. The estimated accuracy in the calibration along the surveyed area is better than $1$<!PCT!> for all the passbands. The Gaia BP/RP spectra provide a high-quality, homogeneous photometric reference in the optical range across the full sky in spite of their current limitations as an absolute reference. The calibration method for J-PLUS DR3 reaches an absolute precision and accuracy of $1$<!PCT!> in the 12 optical filters within an area of $3\,284$ square degrees.