COSMOS Observations: GALEX
Ultraviolet imaging - at wavelengths of 150 nanometer (Far-UV) and 225 nanometer (Near UV) - gives us insight into the activity of star formation in galaxies, because this emission is mostly due to massive young stars that have a very short lifespan.
GALEX has observed the entire COSMOS Field (minus some regions containing stars too bright for the instrument), as part of its Deep Imaging Survey in the Guaranteed Time (PI: D. Schiminovich). The field was observed for 100 hours and reaches a depth of 26 AB magnitudes.
More information about the GALEX mission can be found on the GALEX website.