LINER galaxy properties and the local environment

COLDWELL, GEORGINA V; MESA, VALERIA; DUPLANCIC, FERNANDA; ALONSO, SOL; COLDWELL, GEORGINA V; MESA, VALERIA; DUPLANCIC, FERNANDA; ALONSO, SOL

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY

WILEY-BLACKWELL PUBLISHING, INC

Año: 2018 vol. 476 p. 2457 - 2464

0035-8711

We analyse the properties of a sample of 5560 low-ionization nuclearemission-line region (LINER) galaxies selected from SDSS-DR12 at low redshift, for a complete range of local density environments. The hostLINER galaxies were studied and compared with a well-defined controlsample of 5553 non-LINER galaxies matched in red shift, luminosity,morphology and local density. By studying the distributions of galaxycolours and the stellar age population, we find that LINERs are redderand older than the control sample over a wide range of densities. Inaddition, LINERs are older than the control sample, at a given galaxycolour, indicating that some external process could have accelerated theevolution of the stellar population. The analysis of the host propertiesshows that the control sample exhibits a strong relation betweencolours, ages and the local density, while more than 90 per cent of theLINERs are redder and older than the mean values, independently of theneighbourhood density. Furthermore, a detailed study in three localdensity ranges shows that, while control sample galaxies are redder andolder as a function of stellar mass and density, LINER galaxies mismatchthe known morphology-density relation of galaxies without low-ionizationfeatures. The results support the contribution of hot and old stars tothe low-ionization emission although the contribution of nuclearactivity is not discarded.