# Star formation in far-IR AGN and non-AGN galaxies in the green valley. II. Morphological analysis

## TL;DR

This study analyzes the morphological features of green valley galaxies with and without FIR AGN activity, revealing higher interaction signs and star formation rates in AGN hosts, suggesting mergers and feedback mechanisms influence galaxy evolution.

## Contribution

It provides a detailed morphological comparison between FIR AGN and non-AGN green valley galaxies, highlighting the role of interactions and AGN feedback in star formation enhancement.

## Key findings

- Higher fraction of peculiar, interaction-signature galaxies among FIR AGN (38%) compared to non-AGN (19%).
- FIR AGN green valley galaxies exhibit higher star formation rates across all morphological types.
- Most green valley galaxies are on the main-sequence of star formation, regardless of morphology.

## Abstract

This paper studies morphological properties of 103 green valley FIR active and 2609 non-active galaxies presented in Mahoro et al. 2017. The photometric data from the COSMOS survey were used, and the morphological parameters, such as Abraham and Conselice-Bershady concentration indices, Gini, M20 moment of light, and asymmetry, were analysed taking into account public catalogues. Furthermore, a visual classification of galaxies was performed. We found that the fraction of peculiar galaxies with clear signs of interactions and mergers is significantly higher in AGN (38%) than non-AGN (19%) green valley galaxies, while non-AGN galaxies from our sample are predominantly spirals (46%). We found that the largest fraction of our green valley galaxies is located on the main-sequence (MS) of star formation, independently on morphology, which is in contrast with most of previous studies carried out in optical. We also found that FIR AGN green valley galaxies have significantly higher star formation rates in all analysed morphological types. Therefore, our results suggest that interactions and mergers obtained in the high fraction of FIR AGN contribute significantly to high star formation rates observed in the selected sample, but are not the only mechanism responsible for enhancing star formation, and others such as AGN positive feedback could contribute as well. In future we will study in more details the possibility of AGN positive feedback through the spectroscopic analysis of public and our SALT data.