# Spotting the differences between active and non-active twin galaxies on kpc-scales. A pilot study

## TL;DR

This pilot study compares active and non-active twin galaxies on kpc scales, revealing differences in disk lopsidedness, angular momentum, and stellar populations that may relate to nuclear activity activation mechanisms.

## Contribution

It introduces a comparative analysis of isolated twin galaxies, highlighting potential links between galaxy properties and nuclear activity activation.

## Key findings

- Active galaxies show lopsided disks and higher stellar angular momentum.
- Active galaxies have older stellar populations in their centers.
- Gas inflow mechanisms may trigger nuclear activity.

## Abstract

We present a pilot study aimed to identify large-scale galaxy properties that could play a role in activating a quiescent nucleus. To do so, we compare the properties of two isolated nearby active galaxies and their non-active twins selected from the Calar Alto Legacy Integral Field Area (CALIFA) survey. This pilot sample includes two barred and two unbarred galaxies. We characterise the stellar and ionised gas kinematics and also their stellar content. We obtain simple kinematic models by fitting the full stellar and ionised gas velocity fields and just the approaching/receding sides. We find that the analysed active galaxies present lopsided disks and higher values of the global stellar angular momentum ($\lambda_{R}$) than their non-active twins. This could be indicating that the stellar disks of the AGN gained angular momentum from the inflowing gas that triggered the nuclear activity. The inflow of gas could have been produced by a twisted disk instability in the case of the unbarred AGN, and by the bar in the case of the barred AGN. In addition, we find that the central regions of the studied active galaxies show older stellar populations than their non-active twins. The next step is to statistically explore these galaxy properties in a larger sample of twin galaxies.