J-PLUS: The stellar mass function of quiescent and star-forming galaxies at 0.05 ≤ <i>z</i> ≤ 0.2

Aims. We derive the stellar mass function (SMF) of quiescent and star-forming galaxies at z ≤ 0.2 using 12-band (five broad plus seven narrow) photometry from the Javalambre Photometric Local Universe Survey (J-PLUS) third data release (DR3) over 3284 deg 2 , where the narrow bands improve photometric-redshift and stellar property precision relative to purely broadband surveys. Methods. We selected ∼890 000 galaxies with r ≤ 20 mag and photometric redshifts in the range 0.05 ≤ z ≤ 0.20 over an effective area of 2 881 deg 2 , corresponding to a comoving volume of V ≃ 1.6 × 10 8 Mpc 3 . Stellar masses and star formation rates were derived through spectral energy distribution (SED) fitting with the Code Investigating GALaxy Emission ( CIGALE ), and confronted with spectroscopic samples. Galaxies were classified as star-forming or quiescent based on their specific star formation rate (sSFR), adopting a threshold of log (sSFR [yr −1 ]) = −10.2. We computed SMFs for both populations using the 1/ V max method, applied completeness corrections, and fit a parametric single Schechter function. Results. The SMFs derived from J-PLUS DR3 are well described by Schechter functions and agree with previous photometric and spectroscopic studies. The characteristic mass for quiescent galaxies, log ( M ★ / M ⊙ ) = 10.80, is higher by 0.4 dex than that of star-forming galaxies. The faint-end slope is steeper for star-forming galaxies ( α = −1.2) than for quiescent ones ( α = −0.7). The quiescent fraction increases by 40% per dex in stellar mass, reaching f Q > 0.95 at log ( M ★ / M ⊙ ) > 11. Comparisons with the GAlaxy Evolution and Assembly (GAEA) semi-analytic model show an overabundance of simulated star-forming galaxies, particularly at intermediate masses. Conclusions. The SMFs and quiescent fraction from J-PLUS DR3 are consistent with the literature and provide valuable constraints for galaxy formation models. Quiescent galaxies represent 45% of the number density at log M ★ > 9 but contribute 75% of the stellar mass density. This work lays the groundwork for studies of environmental quenching using J-PLUS. The inclusion of seven narrowband filters improves redshift precision by 20%, enabling more accurate SED fitting and galaxy classification. These methods and findings can be extended with J-PAS, which will provide deeper and higher-resolution photometry over a wider spectral range.