GASP XXXIII. The ability of spatially resolved data to distinguish among the different physical mechanisms affecting galaxies in low-density environments

TL;DR

This study uses spatially resolved data from VLT/MUSE to classify and analyze the physical mechanisms affecting galaxies in low-density environments, highlighting the effectiveness and limitations of optical morphology in identifying these processes.

Contribution

It provides a detailed classification of 27 galaxies in low-density environments based on IFU data, expanding understanding of galaxy evolution mechanisms outside clusters.

Findings

Different physical mechanisms identified, including interactions, mergers, and gas stripping.

Spatially resolved data improves classification accuracy of galaxy processes.

Limitations of optical morphology in fully determining the mechanisms.

Abstract

Galaxies inhabit a wide range of environments and therefore are affected by different physical mechanisms. Spatially resolved maps combined with the knowledge of the hosting environment are very powerful to classify galaxies by physical process. In the context of the GAs Stripping Phenomena in galaxies (GASP), we present a study of 27 non-cluster galaxies: 24 of them were selected for showing asymmetries and disturbances in the optical morphology, suggestive of gas stripping, three of them are passive galaxies and were included to characterize the final stages of galaxy evolution. We therefore provide a panorama of the different processes taking place in low-density environments. The analysis of VLT/MUSE data allows us to separate galaxies into the following categories: Galaxy-galaxy interactions (2 galaxies), mergers (6), ram pressure stripping (4), cosmic web stripping (2), cosmic web enhancement (5), gas accretion (3), starvation (3). In one galaxy we identify the combination of merger and ram pressure stripping. Only 6/27 of these galaxies have just a tentative classification. We then investigate where these galaxies are located on scaling relations determined for a sample of undisturbed galaxies. Our analysis shows the successes and limitations of a visual optical selection in identifying the processes that deplete galaxies of their gas content and probes the power of IFU data in pinning down the acting mechanism.