hyperluminous infrared galaxy

A hyperluminous infrared galaxy (HLIRG or HyLIRG) is a galaxy emitting more than 10¹³ times solar luminosity (L_Sun) in the far infrared. Similar galaxy categories:

• luminous infrared galaxy (LIRG) - with 10¹¹ times sun luminosity in far infrared.
• ultraluminous infrared galaxy (ULIRG) - with 10¹² times solar luminosity in far infrared.

By definition, a HLIRG fits these definitions as well. A LIRG is generally a starburst galaxy and/or has an active galactic nucleus (AGN) or quasar.

I've also seen these thresholds specified as for the galaxy's full bolometric luminosity, sometimes merely stipulating that most of its emission is within the infrared or far infrared; I presume that these varying specifications don't greatly change the sets of qualifying galaxies.