Tracking the spectral properties of ESO 511-G030 across different epochs

Middei, R.; Petrucci, P.-O.; Bianchi, S.; Ursini, F.; Matzeu, G. A.; Vagnetti, F.; Tortosa, A.; Marinucci, A.; Matt, G.; Piconcelli, E.; De Rosa, A.; De Marco, B.; Reeves, J.; Perri, M.; Guainazzi, M.; Cappi, M.; Done, C.

Abstract

The Type 1 active galactic nucleus (AGN) ESO 511-G030, a formerly bright and soft excess dominated source, was observed in 2019 in the context of a multi-wavelength monitoring campaign. In the new exposures, the source was found to be in a flux state approximately ten times lower than archival exposures and without any trace of the soft excess. Interestingly, the X-ray weakening observed in the 2019 data corresponds to a comparable fading of the UV flux, suggesting a strong link between these two components. The UV-X-ray spectral energy distribution (SED) of ESO 511-G030 shows remarkable variability. We tested both phenomenological and physically motivated models on the data, finding that the overall emission spectrum of ESO 511-G030 in this extremely low flux state is due to the superposition of a power-law-like continuum (Γ ∼ 1.7) and two reflection components emerging from hot and cold matter. Both the primary X-ray continuum and relativistic reflection are produced in the inner regions close to the supermassive black hole. The prominent variability of ESO 511-G030 and the lack of a soft excess can be explained by the dramatic change in the observed accretion rate, which dropped from an L/LEdd of 2% in 2007 to one of 0.2% in 2019. The X-ray photon index also became harder during the low flux observations from 2019, perhaps as a result of a photon starved X-ray corona.

Citation

Middei, R., Petrucci, P., Bianchi, S., Ursini, F., Matzeu, G. A., Vagnetti, F., …Done, C. (2023). Tracking the spectral properties of ESO 511-G030 across different epochs. Astronomy & Astrophysics, 672, 1-17. https://doi.org/10.1051/0004-6361/202244022

• Journal Article Type: Article
• Acceptance Date: Feb 4, 2023
• Online Publication Date: Apr 5, 2023
• Publication Date: 2023-04
• Deposit Date: Nov 8, 2023
• Publicly Available Date: Nov 8, 2023
• Journal: Astronomy & Astrophysics
• Print ISSN: 0004-6361
• Electronic ISSN: 1432-0746
• Publisher: EDP Sciences
• Peer Reviewed: Peer Reviewed
• Volume: 672
• Article Number: A101
• Pages: 1-17
• DOI: https://doi.org/10.1051/0004-6361/202244022
• Keywords: Space and Planetary Science; Astronomy and Astrophysics
• Public URL: https://durham-repository.worktribe.com/output/1901679