LINER (low-ionization nuclear emission-line region) A type of gaseous region common in the centers of many kinds of galaxies. Some of these have been shown to be low-luminosity active galactic nuclei, perhaps an extension of Seyfert activity to the lowest levels, implying that the whole phenomenon of nuclear activity occurs in a significant fraction of bright galaxies. A LINER's spectrum is dominated by emission lines from low ionization states, such as OII, NII, and SII, with only weak lines from highly ionized states. Related category GALAXIES Also on this site: Encyclopedia of Alternative Energy & Sustainable Living Encyclopedia of History Transport Concepts & Designs (partner site) |