A1 Refereed original research article in a scientific journal
The Double Tidal Disruption Event AT 2022dbl Implies that at Least Some “Standard” Optical Tidal Disruption Events Are Partial Disruptions
Authors: Makrygianni, Lydia; Arcavi, Iair; Newsome, Megan; Bandopadhyay, Ananya; Coughlin, Eric R.; Linial, Itai; Mockler, Brenna; Quataert, Eliot; Nixon, Chris; Godson, Benjamin; Pursiainen, Miika; Leloudas, Giorgos; French, K. Decker; Zitrin, Adi; Faris, Sara; Lam, Marco C.; Horesh, Assaf; Sfaradi, Itai; Fausnaugh, Michael; Nakar, Ehud; Ackley, Kendall; Andrews, Moira; Charalampopoulos, Panos; Davies, Benjamin D. R.; Dgany, Yael; Dyer, Martin J.; Farah, Joseph; Fender, Rob; Green, David A.; Howell, D. Andrew; Killestein, Thomas; Koivisto, Niilo; Lyman, Joseph; McCully, Curtis; Mitchell, Morgan A.; Padilla, Gonzalez Estefania; Rhodes, Lauren; Sahu, Anwesha; Terreran, Giacomo; Warwick, Ben
Publisher: American Astronomical Society
Publishing place: BRISTOL
Publication year: 2025
Journal: Astrophysical Journal Letters
Journal name in source: The Astrophysical Journal Letters
Journal acronym: ASTROPHYS J LETT
Article number: L20
Volume: 987
Issue: 1
Number of pages: 22
ISSN: 2041-8205
eISSN: 2041-8213
DOI: https://doi.org/10.3847/2041-8213/ade155
Web address : https://doi.org/10.3847/2041-8213/ade155
Self-archived copy’s web address: https://research.utu.fi/converis/portal/detail/Publication/499430723
Flares produced following the tidal disruption of stars by supermassive black holes can reveal the properties of the otherwise dormant majority of black holes and the physics of accretion. In the past decade, a class of optical-ultraviolet tidal disruption flares has been discovered whose emission properties do not match theoretical predictions. This has led to extensive efforts to model the dynamics and emission mechanisms of optical-ultraviolet tidal disruptions in order to establish them as probes of supermassive black holes. Here we present the optical-ultraviolet tidal disruption event AT 2022dbl, which showed a nearly identical repetition 700 days after the first flare. Ruling out gravitational lensing and two chance unrelated disruptions, we conclude that at least the first flare represents the partial disruption of a star, possibly captured through the Hills mechanism. Since both flares are typical of the optical-ultraviolet class of tidal disruptions in terms of their radiated energy, temperature, luminosity, and spectral features, it follows that either the entire class are partial rather than full stellar disruptions, contrary to the prevalent assumption, or some members of the class are partial disruptions, having nearly the same observational characteristics as full disruptions. Whichever option is true, these findings could require revised models for the emission mechanisms of optical-ultraviolet tidal disruption flares and a reassessment of their expected rates.
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This research was supported in part by grant NSF PHY-2309135 to the Kavli Institute for Theoretical Physics (KITP), where part of this work was done, during the “Toward a Physical Understanding of Tidal Disruption Events” program. We are grateful to Ashish Meena for helpful discussion and to the anonymous referee for useful comments.
L.M. acknowledges support through a UK Research and Innovation Future Leaders Fellowship (grant No. MR/T044136/1). Support for L.M. at Tel Aviv University was provided by the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation program (grant agreement No. 852097). I.A. acknowledges support from the ERC under the European Union’s Horizon 2020 research and innovation program (grant agreement No. 852097), from the Israel Science Foundation (ISF; grant No. 2752/19), from the United States–Israel Binational Science Foundation (BSF; grant No. 2018166), and from the Pazy foundation (grant No. 216312). M.N., M.A., J.F., D.A.H., C.M., E.P.G., and G.T. are supported by the United States National Science Foundation (NSF) grants AST-1911225 and AST-1911151. A.B. and E.R.C. acknowledge support from the National Aeronautics and Space Administration (NASA) through the Neil Gehrels Swift Guest Investigator Program (proposal number 1922148). Additional support for A.B. was provided by NASA through Chandra award number 25700383 issued by the Chandra X-ray Observatory Center, which is operated by the Smithsonian Astrophysical Observatory for and on behalf of NASA under contract NAS8-03060, and by NASA through the FINESST program, grant 80NSSC24K1548. E.R.C. acknowledges additional support from the NSF through grant AST-2006684 and from NASA through the Astrophysics Theory Program (grant No. 80NSSC24K0897). I.L. acknowledges support from a Rothschild Fellowship, the Gruber Foundation, and a Simons Investigator grant (No. 827103). A.H. is grateful for support by the BSF (grant No. 2020203), the ISF (grant No. 1679/23), and the Sir Zelman Cowen Universities Fund. C.J.N. acknowledges support from the Science and Technology Facilities Council (grant No. ST/Y000544/1) and the Leverhulme Trust (grant No. RPG-2021-380). K.D.F. acknowledges support from NSF grant AST–2206164. A.Z. acknowledges support by the BSF (grant No. 2020750), the NSF (grant No. 2109066), the Ministry of Science and Technology, Israel, and the ISF (grant No. 864/23). P.C. acknowledges support via the Research Council of Finland (grant No. 340613). M.J.D. is funded by the UK Science and Technology Facilities Council (STFC) as part of the Gravitational-wave Optical Transient Observer (GOTO) project (grant No. ST/V000853/1). J.L., M.P., and D.O. acknowledge support from a UK Research and Innovation Fellowship (MR/T020784/1).
This work makes use of data from the Las Cumbres Observatory global telescope network. This Letter includes data collected by the TESS mission, which are publicly available from the Mikulski Archive for Space Telescopes (MAST). Funding for the TESS mission is provided by NASA’s Science Mission directorate. We acknowledge the staff who operate and run the AMI-LA telescope at Lord’s Bridge, Cambridge, for the AMI-LA radio data. AMI is supported by the Universities of Cambridge and Oxford and by the European Research Council under grant ERC-2012-StG-307215 LODESTONE. We thank the National Radio Astronomy Observatory (NRAO) for carrying out the Karl G. Jansky Very Large Array (VLA) observations.
