Laura Hermosa Muñoz, Isabel Márquez, Sara Cazzoli, Josefa Masegosa, Beatriz Agís-González
Published 2022-01-13, 30 pages, 7 figures. Accepted for publication in A&A
Outflows play a major role in the evolution of galaxies. However, we do nothave yet a complete picture of their properties (extension, geometry,orientation and clumpiness). For low-luminosity Active Galactic Nuclei (AGNs),in particular, low-ionisation nuclear emission line regions (LINERs), the rateof outflows and their properties are largely unknown. The main goal of thiswork is to create the largest, up-to-date atlas of ionised gas outflowcandidates in a sample of 70 nearby LINERs. We use narrow-band, imaging data toanalyse the morphological properties of the ionised gas nuclear emission ofthese galaxies and to identify signatures of extended emission with distinctiveoutflow-like morphologies. We obtained new imaging data from ALFOSC/NOT for 32LINERs. We complemented it with HST archival data for 6 objects and withresults from the literature for other 32 targets. We additionally obtained softX-ray data from Chandra archive to compare with the ionised gas. Thedistribution of the ionised gas in these LINER shows that $\sim$32% havebubble-like emission, $\sim$28% show a 'Core-halo', unresolved emission, and$\sim$21% have a disky-like distribution. Dust lanes prevent a detailedclassification for $\sim$11% of the sample ('Dusty'). If we account for thekinematical information, available for 60 galaxies, we end up with 48% of theLINERs with detected outflows/inflows (50% considering only kinematicalinformation based on Integral Field Spectroscopy). Our results suggest that theincidence of outflows in LINERs may vary from 41% up to 56%, based on both theHalpha morphology and the kinematical information from the literature. Theionised gas is co-spatial with the soft X-ray emission for the majority ofcases ($\sim$60%), so that they may have a common origin. We discuss the use ofHalpha imaging for the pre-selection of candidates likely hosting ionised gasoutflows.