J-PLUS provides 12 photometric points for each observed pixel in the ~ 8500 deg² covered by the survey. With the broad-band filters tracing the global shape of the spectral energy distribution (SED), and the narrow-band filters covering several particular and important features of the SED at z < 0.015, such as the 4000A break and the nebular emission of Ha and [OII], J-PLUS has unique capabilities to study the spatially resolved properties of nearby galaxies.
The Local Group of galaxies is a group of relatively few galaxies that lacks very massive ones. It is an excellent laboratory for studies of galaxy evolution because it provides us with a wide range of different galaxy types in a variety of environments. J-PLUS not only will allow a homogeneous study of the Local Group galaxies but also it will be deep enough to probe regions well beyond where the surface brightness profiles of these galaxies are no longer described by a single exponential profile.
Globular clusters (GCs), easily observable in external galaxies, are among the oldest objects in the Universe. They provide powerful diagnostics in a wide range of astrophysical processes such as the nucleosynthetic processes governing chemical evolution or the star formation and assembly histories of galaxies. The study of GCs with J-PLUS will provide an estimate of the GC metallicity and age and will permit to study the correlations between the host galaxy and its GC system.
The J-PLUS filter system is well suited to study the star formation rate (SFR) in the local Universe, both globally and spatially resolved. The narrow-band filter J0660 covers the Hα and [NII] emission lines at z < 0.017, and it is our main source of information to derive the SFR.
Galaxies are not alone in the Universe and they gather together to form larger structures such as groups and clusters. The properties of the galaxies belonging to dense structures are different that those of isolated galaxies, highlighting the importance of environment and galaxy interactions in the evolution of galaxies. J-PLUS is an excellent survey to study the role of environment in galaxy evolution and, in particular, in the spatially resolved 2D properties of the nearby galaxies.
The light coming from galaxies is composed by the superposition of the fluxes emitted by their constituent stars or stellar populations. The determination of the type of stars that populate galaxies, along with the epoch when they were formed, provides valuable information about the process of galaxy formation and the assembly of their inner structures. The J-PLUS survey, with a photometric system properly designed to face local stellar population diagnostics and a wide area (~8500 deg2), will provide a huge sample of galaxies, including an unprecedented 2D spatially-resolved sub-sample in the nearby Universe.