AT 2018dyk: tidal disruption event or active galactic nucleus? Follow-up observations of an extreme coronal line emitter with the Dark Energy Spectroscopic Instrument

We present fresh insights into the nature of the tidal disruption event (TDE) candidate AT 2018dyk. AT 2018dyk has sparked a debate in the literature around its classification as either a bona-fide TDE or as an active galactic nucleus (AGN) turn-on state change. A new follow-up spectrum taken with t...

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Detalles Bibliográficos
Autores: Clark, Peter, Callow, Joseph|||0000-0002-0804-9533, Graur, Or, Greenwell, Claire|||0000-0002-7719-5809, Hu, Lei|||0000-0001-7201-1938, Aguilar, Jessica Nicole, Ahlen, Steven, Bianchi, Davide, Brooks, David, Pérez Ràfols, Ignasi|||0000-0001-6979-0125
Tipo de recurso: artículo
Fecha de publicación:2025
País:España
Institución:Universitat Politècnica de Catalunya (UPC)
Repositorio:UPCommons. Portal del coneixement obert de la UPC
Idioma:inglés
OAI Identifier:oai:upcommons.upc.edu:2117/442400
Acceso en línea:https://hdl.handle.net/2117/442400
https://dx.doi.org/10.1093/mnras/staf724
Access Level:acceso abierto
Palabra clave:Galaxies: active
Transients: tidal disruption events
Àrees temàtiques de la UPC::Física::Astronomia i astrofísica
Descripción
Sumario:We present fresh insights into the nature of the tidal disruption event (TDE) candidate AT 2018dyk. AT 2018dyk has sparked a debate in the literature around its classification as either a bona-fide TDE or as an active galactic nucleus (AGN) turn-on state change. A new follow-up spectrum taken with the Dark Energy Spectroscopic Instrument, in combination with host-galaxy analysis using archival SDSS–MaNGA data, supports the identification of AT 2018dyk as a TDE. Specifically, we classify this object as a TDE that occurred within a gas-rich environment, which was responsible for both its mid-infrared (MIR) outburst and development of Fe coronal emission lines. Comparison with the known sample of TDE-linked extreme coronal line emitters (TDE-ECLEs) and other TDEs displaying coronal emission lines (CrL-TDEs) reveals similar characteristics and shared properties. For example, the MIR properties of both groups appear to form a continuum with links to the content and density of the material in their local environments. This includes evidence for a MIR colour–luminosity relationship in TDEs occurring within such gas-rich environments, with those with larger MIR outbursts also exhibiting redder peaks.