Markarian 590: The AGN Awakens

TL;DR

This study documents the recent re-ignition of Markarian 590, a changing-look AGN, characterized by increased optical, UV, and X-ray emissions, formation of a warm corona, and a transition towards a Seyfert-1.2 state.

Contribution

First detailed multi-wavelength analysis of Mkn 590's re-ignition, linking increased accretion activity to corona formation and spectral state change.

Findings

Re-emergence of soft X-ray excess in October 2024.

Eddington fraction increased by a factor of ~20.

Mkn 590 is transitioning to a Seyfert-1.2 state.

Abstract

Changing-Look AGN (CLAGN) Mkn 590 recently underwent a sudden re-ignition, marked by substantial increases in optical/UV and X-ray continuum flux since last couple of years. Swift-XRT observations revealed the re-emergence of a soft X-ray excess (SXE) as the source transitioned from a low-flux state in July 2023 to a significantly higher flux state in October 2024. This evolution was in response to an order-of-magnitude increase in extreme-UV (EUV) continuum emission, detected by Swift-UVOT. Follow-up optical spectra from FLOYDS Faulkes confirmed the enhancement of dynamically broadened Balmer lines, He II emission, and Fe II complex. As the Eddington fraction increased by a factor of $\sim$ 20 over the last 20 months, we found clear evidence of formation of a warm corona, strongly linked to the cold accretion disc underneath. Based on our multi-wavelength study on recent data, we propose that Mkn 590 is currently becoming a Seyfert-1.2, similar to its state in 1990s.