An Ultraluminous Infrared Galaxy (ULIRG) is a Galaxy emitting more than 1012 times solar Luminosity in the Far Infrared. It can be considered a type of Luminous Infrared Galaxy, i.e., having 1011 times solar luminosity in far infrared. A Hyperluminous Infrared Galaxy is a galaxy with 1013 times solar luminosity in far infrared.
Hyperluminous Infrared Galaxy (HLIRG)
Luminous Infrared Galaxy (LIRG)