The J-PLUS photometric system is well suited to study the properties of nearby galaxies (z < 0.015), where the 4000A break, and the Ha and [OII] prominent emission lines are covered by the filter set. At higher redshifts, both the lines and the break depart from the narrow-band filters and they are only observed with the standard broad-band filters. However, there are a few redshift windows beyond the nearby Universe that can be explored with J-PLUS. The most important ones are:
- Star-forming galaxies at z = 0.75. The [OII] line emission is observed through the F660 narrow-band filter at this redshift, and can be used to estimate the star formation rate 6.5 Gyr ago.
- Lyman Break Galaxies at z = 2 – 3.
- Star-forming galaxies at z = 4.5. The Lya line emission is observed through the F660 narrow-band filter at this redshift. We will obtain the largest sample of bright Lya emitter candidates ever, the perfect target list for spectroscopic follow-up.
Because of the depth and large area (~8500 deg²) of J-PLUS, the bright end of the targeted populations at each redshift will be studied with unprecedented detail.
Identifying and studying high redshift galaxies is crucial for our understanding of the early epochs of galaxy evolution. At the beginning of the nineties, the implementation of the so called dropout technique opened the era for detections of copious numbers of these early galaxies. They are identified based on their broadband colours.