Luminous galaxies are galaxies that emit a large amount of light, often due to high rates of star formation or the presence of an active galactic nucleus. These galaxies are typically observed at various wavelengths, from the ultraviolet to the infrared, in order to study their properties and evolution. Researchers study luminous galaxies to learn more about the processes that drive their high luminosities, such as gas accretion onto a supermassive black hole or intense bursts of star formation. Studying luminous galaxies can provide insights into the formation and evolution of galaxies in the universe.