A Luminous Infrared (IR) Galaxy (LIRG) is a Galaxy
emitting more than 1011 times solar Luminosity (L)
in the Far Infrared (FIR).
They are often a Starburst Galaxy and/or have an
Active Galactic Nucleus (AGN) or a Quasar (QSO).
Hyperluminous Infrared Galaxy (HLIRG)
Ultraluminous Infrared Galaxy (ULIRG)