J-PLUS: The star formation main sequence and rate density at d < 75 Mpc

TL;DR

This study uses the J-PLUS survey to accurately measure the star formation main sequence and rate density in the local universe within 75 Mpc, providing new insights and a local benchmark for cosmic star formation history.

Contribution

It presents the first estimation of the SFMS and SFRD at z <= 0.017 using J-PLUS data, including a detailed analysis of Halpha emission and galaxy classification.

Findings

The SFMS is well defined for blue galaxies with a specific relation.

The Halpha luminosity function follows a Schechter function with specific parameters.

The local SFRD is measured as log rho_SFR = -2.10, lower than previous estimates.

Abstract

Our goal is to estimate the star formation main sequence (SFMS) and the star formation rate density (SFRD) at z <= 0.017 (d < 75 Mpc) using the Javalambre Photometric Local Universe Survey (J-PLUS) first data release, that probes 897.4 deg2 with twelve optical bands. We extract the Halpha emission flux of 805 local galaxies from the J-PLUS filter J0660, being the continuum level estimated with the other eleven J-PLUS bands, and the dust attenuation and nitrogen contamination corrected with empirical relations. Stellar masses (M), Halpha luminosities (L), and star formation rates (SFRs) were estimated by accounting for parameters covariances. Our sample comprises 689 blue galaxies and 67 red galaxies, classified in the (u-g) vs (g-z) color-color diagram, plus 49 AGN. The SFMS is explored at log M > 8 and it is clearly defined by the blue galaxies, with the red galaxies located below them. The SFMS is described as log SFR = 0.83 log M - 8.44. We find a good agreement with previous estimations of the SFMS, especially those based on integral field spectroscopy. The Halpha luminosity function of the AGN-free sample is well described by a Schechter function with log L* = 41.34, log phi* = -2.43, and alpha = -1.25. Our measurements provide a lower characteristic luminosity than several previous studies in the literature. The derived star formation rate density at d < 75 Mpc is log rho_SFR = -2.10 +- 0.11, with red galaxies accounting for 15% of the SFRD. Our value is lower than previous estimations at similar redshift, and provides a local reference for evolutionary studies regarding the star formation history of the Universe.