Optical and cm follow-ups of the Changing-Look event in Mkn 590

TL;DR

This study reports multi-wavelength follow-up observations of the Changing-Look AGN Mkn 590, revealing correlated variability in optical, X-ray, and radio emissions, and providing insights into the connection between accretion processes and jet activity.

Contribution

It presents new optical spectra and radio measurements during a state change, highlighting the evolution of circumnuclear gas and accretion-jet links in Mkn 590.

Findings

Increase in broad hydrogen Balmer lines

Radio flux correlates with X-ray variability

Evidence of evolving circumnuclear gas

Abstract

The Changing-Look active galactic nucleus Mkn 590 is currently in a rejuvenated state, exhibiting a contemporaneous flux rise across X-rays, UV, optical and cm wavelengths. In this study, we present three new optical spectra obtained with the Nordic Optical Telescope, alongside three 1.4 GHz continuum measurements from the Giant Meterwave Radio Telescope, acquired since Nov. 2024. We identified a clear increase in the broad hydrogen Balmer line emission in the most recent observational epochs. Additionally, the core radio flux densities appear to track the overall X-ray variability, suggesting a possible connection between the accretion flow and jet activity. Based on these data, we aim to explore the evolution of the circumnuclear gas in this source and potential links between accretion and ejection activity.