Low-ionization nuclear emission-line region

A low-ionization nuclear emission-line region (LINER) is a type of galactic nucleus that is defined by its spectral line emission.

Some astronomers have proposed that active galactic nuclei (AGN) with supermassive black holes are responsible for the LINER spectral emission.

[5][7][8] These debates are complicated by the fact that LINERs are found in a wide variety of objects with different brightnesses and morphologies.

Recent observations with the Spitzer Space Telescope show a clear connection between LINER emission in luminous infrared galaxies (LIRGs) and star formation activity.

A few near-infrared spectroscopic surveys have identified some LINERs in normal galaxies that may be powered by star formation.

[9] These results demonstrate that most LINER in nearby normal galaxies may not be powered by star formation, although a few exceptions clearly exist.

The Sombrero Galaxy (M104) as observed by the Hubble Space Telescope (HST). The Sombrero Galaxy is an example of a LINER galaxy . [ 1 ] Credit: HST/ NASA / ESA .