Green Bean galaxies and the fading echoes of AGN activity

TL;DR

Green Bean galaxies are a rare, short-lived phase of AGN evolution characterized by large ionised clouds, providing insights into AGN fading, feedback, and activity transitions, based on spectroscopic observations.

Contribution

This study presents the first spectroscopic analysis of Green Bean galaxies using advanced observational techniques to understand their ionisation conditions and AGN activity history.

Findings

Characterised ionisation conditions in the galaxy SDSSJ095100.54+051026.7

Demonstrated the utility of long-slit and Fabry-Perot spectroscopy for studying Green Bean galaxies

Provided constraints on AGN fading timescales and feedback mechanisms

Abstract

Green Bean is a rare type of galaxy which represents a short-lived phase in the life cycle of active galactic nuclei (AGN), characterised by large-scale, powerful ionised clouds in the circumgalactic medium. Recent studies demonstrate that these extended ionised structures may reflect fading signatures of past AGN activity, often manifested in the form of large-scale ionisation cones. The analysis of their observational properties provides unique constraints on AGN lifetimes, feedback mechanisms, and transitions between radiative and kinetic modes of activity. In this paper we announce the first results of the project dedicated to the long-slit spectroscopic and scanning Fabry-Perot interferometric observations of Green Bean galaxies at the Russian 6-m telescope with SCORPIO-2 multi-mode instrument. We describe the data reduction and spectral fitting procedures that allow one to characterise ionisation conditions in extended gaseous regions of the galaxy SDSSJ095100.54+051026.7.